ENERGY FROM BIOMASS 3rd E. C. Conference Proceedings of the International Conference on Biomass held in Venice, Italy, ...
127 downloads
2125 Views
13MB Size
Report
This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!
Report copyright / DMCA form
ENERGY FROM BIOMASS 3rd E. C. Conference Proceedings of the International Conference on Biomass held in Venice, Italy, 25–29 March 1985
ENERGY FROM BIOMASS 3rd E. C. Conference Edited by
W.PALZ Commission of the European Communities, Brussels, Belgium J.COOMBS Bio-Services, London, UK and D.O.HALL King’s College, University of London, UK
ELSEVIER APPLIED SCIENCE PUBLISHERS LONDON and NEW YORK
This edition published in the Taylor & Francis e-Library, 2006. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to http://www.ebookstore.tandf.co.uk/.” ELSEVIER APPLIED SCIENCE PUBLISHERS LTD Crown House, Linton Road, Barking, Essex IG11 8JU, England Sole Distributor in the USA and Canada ELSEVIER SCIENCE PUBLISHING CO., INC. 52 Vanderbilt Avenue, New York, NY 10017, USA British Library Cataloguing in Publication Data International Conference on Biomass (1985: Venice) Energy from biomass: 3rd E. C. Conference. 1. Biomass energy I. Title II. Palz, W. III. Coombs, J. IV. Hall, D.O. 662′.6 TP360 Library of Congress Cataloging-in-Publication Data International Conference on Biomass (3rd: 1985: Venice, Italy) Energy from biomass. “Proceedings of The International Conference on Biomass held in Venice, Italy, 25–29 March 1985”—P. Organization of the conference by Commission of the European Communities, Directorate-General Science, Research and Development, and others. English, French and German. Bibliography: p. Includes indexes. 1. Biomass energy—Congresses. I. Palz, W. (Wolfgang), 1937- II. Coombs, J. III. Hall, D.O. (David Oakley) IV. Commission of the European Communities. Directorate-General Science, Research and Development. V.Title. TP360.I56 1985 333.79 85–16096 ISBN 0-203-97803-X Master e-book ISBN
ISBN 0-85334-396-9 (Print Edition) WITH 293 TABLES AND 471 ILLUSTRATIONS © ECSC, EEC, EAEC, Brussels and Luxembourg, 1985 Organization of the conference by: Commission of the European Communities, Directorate General Science, Research and Development, Brussels, in co-operation with Unesco, Ministero per la Ricerca Scientifica, Regione Veneto, Commune di Venezia, ENEA, Camera di Commercio, Azienda Regionale delle Foreste Emilia Romagna Published for the Commission of the European Communities, Directorate-General Information Market and Innovation, Luxembourg EUR 10024 LEGAL NOTICE Neither the Commission of the European Communities nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.
PREFACE The success of the previous Conferences on Energy from Biomass, held in Brighton 1980 and Berlin 1982, and the continued interest among European countries, encouraged the Commission of the European Communities to organise the third conference on this area of energy production. It brought together about 500 experts from many countries thus presenting an international forum for discussion of the most recent advances in research and development, manufacture and industrial applications. In the development of energy production from indigenous resources the importance of biomass is steadily increasing. This is now notable in temperate regions where it is associated with aspects of conservation, waste treatment and materials recycling as well as the use of crops, trees and residues from agriculture and forestry. Large government and industrial sponsored programmes in many countries of the world give ample evidence of this fact. This is particularly relevant at present in Europe where the problem of agricultural surpluses in the European Community is being discussed in terms of ethanol and short rotation forestry schemes. The conference was organised on the basis of a number of common themes representing the resources upon which biomass energy in Europe is based. These are the sun, trees, wastes, agriculture, aquaculture and natural communities. These common themes were explored from a different viewpoint during each day of the conference. The opening sessions were used to introduce the Energy from Biomass programme of the European Communities, followed by presentation of some of the key areas in terms of problems, resources and technical progress which are influencing the rate at which biomass energy systems are being adopted within Europe. On the third day the technical sessions were concerned with biomass production and handling, and on the fourth day with conversion of biomass to fuel. The last day was devoted to implementation and analysis of the current status of biomass schemes within Europe as well as systems around the world. As an integral part of the programme there were very well presented Poster sessions (over 200 papers) and Round Table discussions on topical themes such as resources, land use for food or fuel, and environmental impacts; also Workshops where specific technical aspects were discussed in depth were successfully inaugurated. The participation of technical, industrial and scientific people along with politicians and planners made for a lively meeting. Biomass for energy is maturing fast as an established component of the energy scene. These Conferences play a very useful role in enabling people of such diverse interests to interact to great advantage Professor D.O.Hall Dr W.Palz Conference Chairmen.
Chairmen PALZ W
CEC Belgium
HALL D O
UK
Conference Secretariat COOMBS J
UK
GRASSI G
CEC Belgium
General Organization MAGNABOSCO G
Belgium
Local Organization BONALBERTI F
Italy
Publications NICOLAY D
CEC Luxembourg
Members ALFANI F
Italy
BALDELLI C
Italy
BANKS P
Zimbabwe
BENEVOLO G
Italy
BERESOVSKI T
Unesco France
BERNINI C
Italy
BURLEY J
UK
CESCON P
Italy
CHARTIER P
France
CROATTO U
Italy
de MONTALEMBERT M
FAO Italy
DOSIK A
World Bank USA
FARINELLI H
Italy
FERRERO G L
CEC Belgium
FITTIPALDI V
Italy
FOSTER K
USA
HAKKILA P
Finland
HAVE H
Denmark
KINSELLA E
Ireland
LEQUEUX P
CEC Belgium
LIPINSKY E S
USA
LJUNGBLOM I
Sweden
MARGARIS N
Greece
MEINHOLD K
Germany
MIYACHI S
Japan
MOLLE J F
France
MONACO L
Brazil
MORSELLI G
Italy
NAVEAU H
Belgium
OVEREND R
Canada
PERNKOPF J
Austria
PIAVAUX M
CEC Belgium
PRICE R
UK
PSYLLAKIS D
Crete
RABSON R
USA
REDDY A
India
REED T
US
RIEDACKER A
France
SAVOIA G
Italy
SIREN G
Sweden
STEWART G A
Australia
STREHLER A
Germany
STRUB A
CEC Belgium
TAGANAS T
Philippines
TANTICHAROEN M
Thailand
TIWARI T
India
van SWAAIJ W
Netherlands
van UDEN N
Portugal
VALERI MANERA M
Italy
VELLUTI S
Italy
VILLET R
France
WEISSIMANN A
Germany
WELLINGER A
Switzerland
WU WEN
China
VIANELLO V
Italy
CONTENTS Preface
iv
OPENING SESSION The energy from biomass programme of the Commission of the European Communities A S STRUB La biomasse dans la competition energetique: A GIRAUD Biomass fuels in a European context: R M SELIGMAN The Italian biomass scene: G AMMASSARI Avenir de l’agriculture europeenne et valorisation de la biomasse: L PERRIN The common agricultural policy and biomass energy: J J SCULLY Kurzfristige verfugbarkeit von forstlicher biomasse in der Bundesrepublik Deutschland: A F WEISMANN La biomasse, source de substituts au pétrole dans le secteur des transports: P LEPRINCE and J P ARLIE
3
6 14 21 29 32 36
44
SESSION I: THE EUROPEAN SCENE Trees and wood as an energy source in the Nordic countries: G WILHELMSEN Biomass availability and use in the industrial regions A STREHLER Ressources en biomasses utilisables a des fins energetiques en milieu agricole—cas de l’europe des 10 C GOSSE Biomass for heating and fuels in Austria: a case study for Europe? A F J WOHLMEYER
56 62 71
80
A F J WOHLMEYER SESSION II: TECHNICAL SESSIONS Zur agrarpolitischen bedeutung der ethanolproduktion in der Bundesrepublik Deutschland: K MEINHOLD and H KOGL The use of forests as a source of biomass energy: F C HUMMELL The availability of wastes and residues as a source of energy: G PELLIZZI The potential of natural vegetation as a source of biomass energy: T V CALLAGHAN, G J LAWSON and R SCOTT Photobiology—the scientific basis of biological energy conversion: M C W EVANS The biomass to synthesis gas pilot plant programme of the CEC; a first evaluaton of its results: A A C M BEENACKERS and W P M VAN SWAAIJ Biomethanation, the paradox of a mature technology: E-J NYNS, M DEMUYNCK and H NAVEAU Novel methods and new feedstocks for alcohol from biomass: U RINGBLOM Use of algal systems as a source of fuel and chemicals: E BONALBERTI and U CROATTO
92
101 110 121 130 134
160 166 173
SESSION III: IMPLEMENTATION L E B E N—Large European bioenergy project: G GRASSI, U MIRANDA, C BALDELLI and F GHERI The production and use of fuel alcohol in Zimbabwe C M WENMAN Canada’s energy from the forest programme: R P OVEREND Integrated food-energy production systems: E L LA ROVERE The use of wastes as a source of energy in the UK: R PRICE The Southern US biomass energy programs with emphasis on Florida: W H SMITH Biomass energy utilisaton and its technologies in China rural areas: W WU Summaries of ROUND TABLES
182
Summaries of WORKSHOPS
255
189 194 217 224 233 240 248
CONTRIBUTED PAPERS
279
Biomass from short rotation coppice willow in Northern Ireland: G H McELROY and W M DAWSON Biomass gains in coppicing trees for energy crops: W A GEYER, G G NAUGHTON and M W MELICHER Short rotation coppice forest biomass production—the work of the IUFRO S1.05–10 working party: D AUCLAIR Short rotation forestry for energy production: M NEENAN Une plante energetique a cycle courte: le genet Cytisus scoparius: P TABARD Energy and biomass of piedmont hardwoods: M A MEGALOS, L HORTON, D J FREDERICK, A CLARK and D R PHILLIPS Coppiced trees as energy crops: M L PEARCE FAO’s activities on industrial wood-based energy: M A TROSSERO Energy forestry research in Britain: C P MITCHELL Forest biomass: INRA’s programme: E TESSIER-DU-CROS Euphorbia project: renewable energy production through the cultivation and processing of semi-arid land biomass in Kenya: M DECLERCK, Ph SMETS, J SMETS and J ROMAN Potentialites de production d’un couvert vegetal: M CHARTIER, J M ALLIRAND and G GOSSE Productivite de roseau phragmites: J M ALLIRAND, M CHARTIER and G GOSSE
281 286 291
295 300 306 311 314 318 323 331
337 344
Comparative biomass yields of energy crops: W H SMITH and J R FRANK Onopordum nervosum Boiss as a potential energy crop: J FERNANDEZ, P MANZANARES and J MANERO Straw as a biomass resource and its acquisition in the United Kingdom: J M CLEGG, S B C LARKIN, D H NOBLE and R W RADLEY Studies about the potential of sweet sorghum and Jerusalem artichoke for ethanol production based on fermentable sugar: G KAHNT and L LEIBLE The potential for straw as a fuel in the UK: L P MARTINDALE Immediately available liquid fuel crops in the EEC: H STURMER, H THOMA and E ORTMAIER Energetic outlets of agriculture in the EEC: J J BECKER The development of wetland energy crops in Minnesota, USA—managing stands for continued productivity: D R DUBBE, E G GARVER and D C PRATT Energy from agriculture—some results of Swedish energy cropping experiments: U WUNSCHE Epuration des eaux et produits de haute valeur tires de la jacinthe d’eau: F SAUZE An integrated system: mass algae culture in polluted luke-warm water for production of methane, high value products and animal feed A LEGROS, H NAVEAU, E-J NYNS, E DUJARDIN, F COLLARD and C SIRONVAL Properties of algal biomass production and the parameters determining its fermentative degradation K KREUZBERG, G REZNICZEK and G KLOCK Potentialites de production de biomasse aquatique dans les lagunes d’epuration M VUILLOT and J BARBE Production of algal biomass in Venice lagoon: environmental and energetic aspects G MISSONI and M MAZZAGARDI Hydrogen production, ammonia production and nitrogen fixation by free and immobilised cyanobacteria M BROUERS and D O HALL Effect of different factors on the productivity of nitrogen fixing blue-green alga Anabaena variabilis under outdoor conditions A G FONTES, J MORENO, M A VARGAS, M G GUERRERO and M LOSADA
346 354 359 364
369 374 376 380
385
390 395
401
409
415
418
425
An energy budget for algal culture on animal slurry in temperate climatic conditions H J FALLOWFIELD and M K GARRETT Photosynthetic basis of biomass production by water hyacinth grown under high CO2 level A LARIGAUDERIE, J ROY and A BERGER Eichhornia crassipes: production in repeated harvest systems on waste water in the Languedoc Region (France) M-L CHASSANY DE CASABIANCA The effect of nutrient application on plant and soil nutrient content in relation to biomass harvesting T V CALLAGHAN, G J LAWSON, A M MAINWARING and R SCOTT uptake through the roots in willow and sunflower and effect of uptake of willow cuttings P PELKONEN, E M VAPAAVUORI and H VUORINEN Controlled environment growth of Euphorbia lathyris in relation with temperature and water stress P T VENTAS, J L TENORIO, E FUNES and L AYERBE Micropropagation of willows (Salix spp) T TORMALA and E SAARIKKO The use of photointerpretation for biomass evaluation and possible biomass recovery in an area of the Lombardy region P BONFANTI and C SEMENZA Photosynthetic solar energy capturing in a cropping system with extensive exploitation of biomass for fuel production J ZUBR Micropropagation of some forest tree species G SAVOIA and S BIONDI Anaerobic digestion in the food processing industry: a feasibility study D J COX and D R NUTTALL Purification of biogas K EGGER, K SUTTER and A WELLINGER Contribution to comprehensive engineering conception of methanisation based on kinetic approach R BACHER, F YEBOUA AKA, M EL-HOUSSEINI and G GOMA Performance of anaerobic expanded bed reactors treating municipal sewage P GARCIA, L J REDONDO, I SANZ and F FDZ-POLANCO Anaerobic stabilisation of agricultural and foodbased industrial wastes J WINTER and F X WILDENAUER Anaerobic digestion and methane production of slaughterhouse wastes A STEINER, F X WILDENAUER and O KANDLER Fermentation mèthanique en discontinu des fumiers a la ferme: simulation du fonctionnement d’une installation en situation rèelle P A JAYET
431
436
441
448
454
461
466 470
475
483 492 497 503
510 515 521 526
The production of methane from biomass in the United States: economics, tradeoffs and prospects J R FRANK, T D HAYES and W H SMITH Anaerobic digestion of pig manure: results on farm scale and new process C AUBART and F BULLY An economic approach to biogas generation and use D J PICKEN Methane from biological anaerobic treatment of industrial organic wastes R CAMPAGNA, G DEL MEDICO and M PIERONI Experiences with anaerobic digestion of various cassava residues in Indonesia R WURSTER Biogas technology developed and evaluated by ENADIMSA A J GARCIA, S CUADROS and R FERNANDEZ Influence of hydrogen addition on the potential of methanogenic ecosystems R MOLETTA, J D FINK, G GOMA and G ALBAGNAC Butyrate production and volatile fatty acids interconversion during propionate degradation by anaerobic sludges R MOLETTA, H C DUBOURGUIER and G ALBAGNAC Large scale anaerobic digestion of animal wastes in The Netherlands F M L J OORTHUYS and H J W POSTMA The Anoxal process: anaerobic treatment of liquid industrial effluents J CUTAYAR and M MOULINEY Biogas production from solid pineapple cannery waste at elevated temperature M TANTICHARONE, S BHUMIRATANA T UTITHAM and N SUPAJUNYA Adhesion of anaerobic bacteria from methanogenic sludge onto inert solid surfaces D VERRIER and G ALBAGNAC Granular methanogenic sludge: microbial and structural analysis H C DUBOURGUIER, G PRENSIER, E SAMAIN and G ALBAGNAC Full-scale methanizatin of sugary waste waters in a downflow anaerobic filter D VERRIER, J P LESCURE, B DELANNOY and G ALBAGNAC Methane fermentation of distillery waste water of sugar cane alcohol on a fixed biomass pilot A BORIES, F BAZILE, J RAYNAL and E MICHELOT Fixed biomass on lignocellulose media for the methane fermentation of industrial waste water A BORIES, M DUVIGNAU and N CATHALA Two-phase digestion of distillery slops using a fixed bed reactor for biomethanation K WULFERT and P WEILAND
532
537 541 544 550 556 561 569
576 581 586
591
596 605 611
617
624
Biogas from green and silaged plants in a digester with internal liquid circuit W BAADER Anaerobic digestion of organic fraction of municipal solid waste— preliminary communication P CESCON, F CECCHI, F AVEZZU and P G TRAVERSO Improved technologies in biogas production from algae of the Venice lagoon and waste treatment U CROATTO Applicaton of gas from biomass: conditioning of gas or adaptation of gas fired equipment F A J RIETVELD Pilot plant biomethanation of cultivated marine algae Tetraselmis for energy production in southern Italy A LEGROS, M R TREDICI, G FLORENZANO, R MATERASSI, E-J NYNS and H NAVEAU Joint Belgium-Burundi biomethanation development project: main results after two years activity D COMPAGNION, D ROLOT, E-J NYNS, H P NAVEAU, V BARATAKANWA, D NDITABIRIYE, J NDAYISHIMIYE and P NIYIMBONA Industrial results of SGN fixed film anaerobic fermentation process M ARNOUX, J Y MOREL, G COMINETTA and C OGGIONNI The bio-gas projects in Emilia-Romagna (Italy): first results of five full scale plants L CORTELLINI, S PICCININI and A TILCHE Methane production from green and ensiled crops technological and microbial parameters E ZAUNER and U KÜNTZEL Feasibility and efficiency of thermophilic methane fermentation with pig manure and potato stillage as substrates U TEMPER, J WINTER, F WILDENAUER and O KANDLER Anaerobic digestion of macroalgae of the Lagoon of Venice: experiences with a 5 mc capacity pilot reactor S NICOLINI and A VIGLIA Bioenergy from tannery biomass: experimental work on anaerobic digestion from laboratory to real plant scale M BREGOLI, D FERRARI and A VIGLIA Utilisation of activated carbon and carbon molecular sieves in biogas purification and methane recovery E RICHTER, K-D HENNING, K KNOBLAUCH and H JUNTGEN Membrane Cleaning of Biogas for injection to pipelines F DE POLI, M MENDIA and N MIGLIACCIO Biomass and coenzyme F420 distribution in anaerobic filters N O’KELLY, P J REYNOLDS, A WILKIE and E COLLERAN
630 636
642
645
651
658
663 669
675
681
687
690
694
699 704
Kinetics of landfill leachate treatment by anaerobic digestion J M LEMA and E IBANEZ Biogas research in Austria J SPITZER, P SCHUTZ and W HIMMEL Mathematical model of a real scale digester R CHIUMENTI, A DE ANGELIS, F DE POLI and A TILCHE Anaerobic treatment of high load industrial waste water by means of a freecells fermentation process O ZUFFI, N MILANDE and B RAYMOND Cloning and analysis of genes involved in cellulose degradation by Clostridium thermocellum P BEGUIN, D PETRE, J MILLET, H GIRARD, R LONGIN, O RAYNAUD, M ROCANCOURT, O GREPINET and J-P AUBERT Nuclear magnetic resonance application in studying the biological production of ethanol from sugarcontaining media E TIEZZI, A LEPRI and S ULGIATI Basic trials to co-immobilize algae and yeast for the production of ethanol I MUCKE and W HARTMEIER Ethanol from unconventional substrates using yeast co-immobilized with non-yeast glycosidases W HARTMEIER, U FORSTER and C GIANI Ethanol from pentoses and pentosans by thermophilic and mesophilic microorganisms J WIEGEL and J PULS Rapid determination of yeast concentration in fermentation broths H NEIBELSCHUTZ and C BOELCKE Utilisation of bamboo for the production of ethanol J B DE MENEZES, C L M DOS SANTOS and A AZZINI Continuous conversion of lactose to ethanol using Zymomonas mobilis and immobilized B-galactosidase S TRAMM-WERNER and W HARTMEIER New continuous process for production of ethanol using immobilized cells reactor L LEULLIETTE, M HENRY and D GROS Acetone butanol fermentation of hydrolysates obtained by enzymatic hydrolysis of agricultural lignocellulosic residues R MARCHAL, M REBELLER, F FAYOLLE, J POURQUIE and J P VANDEĆASTEELE 692 Acid hydrolysis for the conversion of cellulosic biomass to ethanol J PAPADOPOULOS NMR analysis of fermentation products by Clostridium acetobutylicum C ROSSI, P VALENTI, N MARCHETTINI and N ORSI
710 715 721 724
727
732
737 743
749
754 758 764
770
773
778 786
Enzymatic hydrolysis and SCP production from solvent delignified Eucalyptus globus L. biomass M T A COLACO and H PEREIRA Enhanced butanol-tolerance in mutants of Clostridium acetobutylicum P VALENTI, P VISCA and N ORSI Influence de la nutrition azotee sur la croissance et la production d’hydrocarbures d l’algae unicellulaire Botryococcus braunii F BRENCKMANN, C LARGEAU, E CASADEVALL and C BERKALOFF Influence of light intensity on hydrocarbon and total biomass production of Botryococcus braunii—relationships with photosynthetic characteristics F BRENCKMANN, C LARGEAU, E CASADEVALL, B CORRE, and C BERKALOFF Screening of wild strains of the hydrocarbon-rich alga Botryococcus braunii—productivity and hydrocarbon nature P METZGER, E CASADEVALL, A COUTE and Y POUET Chromatographic studies of crude oils from wood D MEIER, R DORING and O FAIX Methyl esters of tallow as a diesel component D W RICHARDSON, R J JOYCE, T A LISTER and D F S NATUSCH Production of hydrocarbons from biomass W HELD, M PETERS, C BUHS, H H OELERT, G REIFENSTAHL and F WAGNER Renewable hydrocarbons and industrial chemicals from Kenyan plants A NG’ENY-MENGECH and S N KIHUMBA Corn drying, cereal straw combustion, harvest and energetic valorization of corn cobs X GAUTIER Woodstoves in the Netherlands, environmental and social impacts P A OKKEN Fluidised bed combustion of both light and wet biomass B WILTON and J F WASHBOURNE Development of a domestic firewood burner for cooking S G MUKHERJEE Joint enterprise and utilization of a briquetting plant for straw M BRENNDORFER Pelletization of straw C WILEN, K SIPILA, P STAHLBERG and J AHOKAS Charcoal as fuel: new technological approaches J F GOUPILLON Results from research work in heat generation from wood and straw A STREHLER Basics of the combustion of wood and straw M HELLWIG
791
797 804
810
818
823 827 836
842 848
852 859 862 867 873 879 884 891
Test results from pilot plants for firing wood and straw in the Federal Republic of Germany U KRAUS Biomass-fueled furnace coupled to greenhouse heating and crop drying systems R M SACHS, D ROBERTS, K M SACHS, B JENKINS, G FORISTER, J EBELING and D FUJINO Quality of densified biomass products J CARRE, J HERBERT, L LACROSSE and P LEQUEUX On the testing of woodburning cookstoves P BUSSMANN, K K PRASAD and F SULILATU Air pollution from biomass heated boilers compared with that from waste incineration and oil combustion C BENESTAD, M MOLLER, A OSVIK, T RAMDAHL and G TVETEN Kinetic of wood tar pyrolysis P MAGNE, A DONNOT and X DEGLISE An intermediate capital intensive pyrolysis system applicable to developing countries J W TATOM and K B BOTA Gasification of agricultural residues in a downdraft gasifier L LIINANKI, P-J SVENNINGSSON and G THESSEN Some kinetic aspects on the pyrolysis of biomass and biomass components C KOUFOPANOS, G MASCHIO, M PACI and A LUCCHESI Wood pyrolysis: a model including thermal effect of the reaction R CAPART, L FAGBEMI and M GELUS Platform tests of biomass combustion and gasification equipment M REYNIEIX Batch carbonisation of coconut shell and wood with the recovery of waste heat G R BREAG, A P HARKER and A E SMITH Fast pyrolysis of cellulose R G GRAHAM, B A FREEL, M A BERGOUGNOU, R P OVEREND and L K MOK Contribution to the exploitation of recovered wood through the development of carbonisation and activation processes G SAVOIA, G BARBIROLI, A GATTA, R OSTAN and G PASQUALI Results of tests with different gasifiers for farm use L BODRIA, M FIALA and G SALVI Environmental aspects of biomass gasification P S LAMMERS Modern equipment for the generation of producer gas out of block wood and granular wood waste K W JASTER
897
904
910 916 924
927 933
939 945 952 957 960
972
979
984 989 995
Gasification of biomasses by HTW-gasification process H TEGGERS, H J SCHARF and L SCHRADER Syngas production from wood by oxygen gasification under pressure G CHRYSOSTOME and J M LEMASLE Thermal degradation of firwood and firbark influence of size and gaseous atmospheres J R RICHARD and C VOVELLE Gasification of rice husk in a small downdraft moving bed R MANURUNG and A A C M BEENACKERS Fuel- and synthesis gas from biomass via gasification in the circulating fluid bed P MEHRLING and R REIMERT Methane from biomass-process optimisation A V BRIDGWATER and D H SMITH Sensitivity of theoretical gasifier performance to system parameters J M DOUBLE and A V BRIDGWATER Wood liquefaction: total mass and energy balances X DEGLISE, D MASSON, H KAFROUNI and A LADOUSSE Study of the direct liquefaction of wood in the presence of iron additives C BESTUE-LABAZUY, N SOYER, C BRUNEAU and A BRAULT Direct thermochemical liquefaction of plant biomass using hydrogenating conditions D MEIER, D R LARIMER and O FAIX Le prétraitment, l’hydrolyse, la pyrolyse et la liquefaction de la biomasse: vers une approche unifiee R P OVEREND and E CHORNET A techno-economic comparison of biomass thermochemical liquefaction processes Y SOLANTAUSTA and P J MCKEOUGH What future for the thermochemical liquefaction of biomass? C ESNOUF Improvement of the ethylene glycol water systems for the component separation of lignocelluloses D GAST and J PULS Hydrothermolysis of short rotation forestry plants G BONN, W SCHWALD, O BOBLETER and V I BENEA Synthesis of several alcohols from biomass gases with zeolite catalysts J C GOUDEAU, A BENGUEDACH and L JULIEN Investigations on methanol catalytic synthesis from biomass gases: optimization of the process on a new catalyst A BOURREAU, J C GOUDEAU, L JULIEN, A NEMICHE and F SOUIL The solid-liquid transfer process in a slightly hydrated heterogeneous medium: a way to synthesise organic chemicals from biomass M E BORREDON, L RIGAL, M DELMAS and A GASET
1000 1005 1011
1018 1025
1031 1037 1046 1052 1057
1063
1068
1074 1079
1084 1090 1095
1101
Bioconversion of organosolv lignins by different types of fungi A HAARS, A MAJCHERCZYK, J TROJANOWSKI and A HÜTTERMANN The fractionation of lignocellulosic substrates by steam explosion and the subsequent conversion of the various components to sugars, fuels and chemicals J N SADDLER, E K C YU, M MES-HARTREE, N LEVITIN and H H BROWNELL Chemicals from sugar industry waste products M G KEKRE and A TAHA New process for the fabrication of ethyl esters from crude vegetable oils and hydrated ethyl alcohol R STERN, G HILLIOIN, P GATEAU and J C GUIBET Biodegradation of native cellulose F ALFANI, L CANTERELLA, A GALLIFUOCO, L PEZZULLO and M CANTARELLA Study of enzymatic hydrolysis of alkali pretreated Onopordum nervosum C MARTIN, M J NEGRO, M ALFONSEL, F SAEZ, R SAEZ and J FERNANDEZ The role of microorganisms isolated from funguscomb-constructing African termites in the degradation of lignocellulose H ORSORE III. IMPLEMENTATION
1106
A biomass project (gasification and pyrolysis) for Lower Austria G SCHÖRNER New domestic renewable energy through high tehnology of biogases O KUUSINEN Prospective methodology adapted to global biomass project choices and integration (modelisation of a biomass valorization process) P MATARASSO and J P TABET An economic analysis of the energy valorisation of cereal straw in France V REQUILLART Integration and assessment of biomass research information by use of system analysis J W MISHOE Conversion of lignocellulosic material to ethanol influence of raw material yield and hemicellulose utilization on sales price of ethanol J FELBER, M SCHIEFERSTEINER and H STEINMULLER Bioenergy in regional energy systems—a case study from Hadeland in Norway A LUNNAN Possibilities of relieving the EC agricultural market through energy production for example rape and short-rotation forestry R APFELBECK
1136
1111
1116 1119
1123
1129
1134
1140 1145
1150 1156
1162
1167
1171
The economics of thermochemical routes from wood to liquids L A MICHAELIS Chemical investigations in the Swedish agrobioenergy project O THEANDER Energetic optimization of biomass in the farming systems of marginalised areas—labour and capital restrictions—economic analysis J P CHASSANY Biomass as an energy source in the French context, promises and constraints J C SOURIE Fuel ethanol in Brazil and the implications for control of lead additives in the EEC countries F ROSILLO-CALLE Residue briquetting in developing countries S JOSEPH and D HISLOP An economic process for the production of a diesel fuel substitute from edible oil fractions H P KREULEN, H C A VAN BEEK, E VAN DER DRIFT and G SPRUIJT Thermochemical processing of lignocellulosic residues: alternatives in Thailand D L PYLE and C A ZAROR Energy from biomass (programme & policies) O P VIMAL and N P SINGH Development of biomass in Malaysia K S ONG and C F LAU The biomass role in the Brazilian energy balance I GOCHNARG and G L GROSZMANN Small steam systems for the Third World D HISLOP and S JOSEPH Biomass energy and rural development in Coastal Ecuador M MCKENZIE HEDGER Dissemination of energy technologies: stove and forestry projects in Gujarat M M SKUTSCH Fuelwood scarcity in rural India: perceptions and policies S MATHRANI and D L PYLE Implementation of wood gasifiers and their use within the project “solar village Indonesia” G HOFFMANN, U OHRT and H PITZER 1.4 and 4.8 MW woodgas power plants in operation S SONNENBERG, W O ZERBIN and T KRISPIN The bamboo: raw material for paper industries or fermentation industries T TSHIAMALA, A MOTTET, L FRAIPONT, P THONART and M PAQUOT Issues related to introduction of energy-cane to Latin America P JAWETZ and G SAMUELS
1177 1183 1190
1196
1201
1208 1213
1218
1224 1229 1234 1239 1244 1251 1256 1262
1266 1271 1276
The potential for alcohol as a fuel for spark ignition engines in Tanzania J S CLANCY, G RICE and S KAWAMBWA IV INDUSTRIAL
1281
Biogas as fuel: the adaptation of a tractor diesel engine and a small spark ignition engine to biogas operation J FANKHAUSER, M RUDKOWSKI, E STADLER, K EGGER and A WELLINGER The use of gas from biomass in engines experiences E NOLTING and M LEUCHS Aquatic biomass production and piscicultural waste stabilization C LE FUR, C SIMEON, M SILHOL and Ph BLACHIER Understanding refuse decomposition processes to improve landfill gas energy potential D J V CAMPBELL, E R FIELDING and D B ARCHER Environment protection and energy recovery—decomposition gas from the Berlin-Wannsee municipal waste disposal site J SCHNEIDER Product development needs of weste management P VILPPUNEN Sewage sludge as energy source H P ZWIEFELHOFER Flame development in spark-ignition engines burning lean methanol mixtures R A JOHNS and A W E HENHAM Rubber seed oil for diesel engines in Sri Lanka P D DUNN and E D I H PERERA New direct injection diesel engine development for using vegetable oil as a fuel K ELSBETT, G ELSBETT and L ELSBETT Optimisation of the spark advance in biogas engines B LEDUC and P LADRIERE
1287
Author Index
1348
Subject Index
1359
List of Participants
1366
1293 1298 1304
1310
1315 1319 1323
1329 1337
1344
OPENING SESSION The Energy from Biomass Programme of the Commission of the European Communities— A.S.Strub La biomasse dans la compétition énergétique— A.Giraud Biomass Fuels in a European Context— R.M.Seligman The Italian Biomass Scene— G.Ammassari Avenir de l’agriculture européenne et valorisation de la biomasse— L.Perrin The Common Agricultural Policy and Biomass Energy— J.J.Scully Kurzfristige Verfügbarkeit von Forstlicher Biomasse in der Bundesrepublik Deutschland— A.F.Weismann La biomasse, source de substituts au pétrole dans le secteur des transports— P.Le Prince et J.P.Arlie
THE ENERGY FROM BIOMASS PROGRAMME OF THE COMMISSION OF THE EUROPEAN COMMUNITIES A.STRUB Commission of the European Communities Brussels Summary In the past decade, bioenergy has been the subject of considerable R&D in the E. C., in other industrialized countries and developing countries. At large scale, biomass cannot be used as a fuel without reference to the social and economic framework in which food and fibre are produced. The main objectives of “Energy from Biomass” R&D should therefore now be directed into the following key issues: energy security, environmental aspects, relieving the overproduction in some agricultural sectors, creation of jobs in rural areas. Biofuels may have an extra chance in the frame of the new European fuel blend policy. The most likely scheme foresees replacing lead by 3% of methanol and 2% of co-solvents. Co-solvents derived from biomass by fermentation could form the basis of such a strategy. Biomass utilization schemes would offer great promise for rural development. Energy plantations, collection of agricultural residues and coppice and their conversion into energy carriers of higher density could be part of a regional network. Many jobs could be created, large amounts of wastes could be recycled and unused forests could become accessible for new commercial exploitation. There is therefore a good reason for further developing this alternative, renewable energy resource. In the past decade, the production and use of biomass for energy purposes has been the subject of considerable R&D efforts in many industrialized and some developing countries. The technologies which drew the main attention were wood and straw-burning, biogas production from agricultural wastes and thermochemical conversion by processes such as pyrolysis and gasification. Since 1975 “Energy from Biomass” has been a major topic of the European Community’s First and Second Energy R&D Programmes. In 1980 these R&D programmes were completed by a granting scheme for energy demonstration projects, including biomass production and conversion. The results of the Community action are numerous and certainly contributed to the overall progress achieved and the confidence with regard to the energy potential at stake. This Conference and its two predecessors at Brighton (UK) and at Berlin (F.R.Germany), all organised by the Commission’s services
Energy from biomass
4
responsible for the Energy from Biomass R&D Programme, are including reports on the Commission’s activities. But the time has come to broaden the scope of our efforts. Since almost all of today’s biomass is generated in agriculture and forestry, it has to be recognized that the bioenergy concept must duly take into account the social and economic framework in which food and fibre are produced and used. The main objective of the Community’s future “Energy from Biomass” R&D will therefore not only be determined by energy relevance but include also key issues such as improvement of the environment, alternative use of agricultural overproduction and creation of jobs in rural areas. This is a very wide field. To cope with all the problems, a joint European effort is required. At present, the total bioenergy potential in the EC is estimated at about 5% of our energy consumption. This could be doubled by relatively small changes in agricultural and/or forestry production. Therefore, the possibility to reinforce or to re-orient the already powerful incentives for rural development in the EC should be carefully considered. Rural areas could seek technologies for deriving energy from indigenous biomass and thereby compensate for their inherent structural and energy supply handicaps. Environmental considerations are playing an increasing role when assessing the pro’s and con’s of energy production from biomass. (Methane production from animal waste is a positive example of effluent treatment.) Biofuels may get their chance in the framework of the new European fuel blend policy. A possible scheme foresees replacing lead by 3% of methanol and 2% of co-solvents. Co-solvents derived from biomass by fermentation could form the basis of such a scheme. But it is important to note that fuel blending will require a considerable amount of further R&D, before final conclusions can be drawn. But this should not prevent us from implementing what we already know. For the European Community, which currently produces agricultural products without a real market on more than 5 million hectares of its farmland, there is also a pressing need to assess the potential of energy plantations as a new possibility to alleviate the problem of excess food production. In summarising, we therefore can only underline that biomass utilization schemes would offer great promise for rural development. Energy plantations, collection of agricultural residues and coppice and their conversion into energy carriers of higher density could be part of a newly designed regional network. Many jobs could be created, large amounts of wastes could be recycled and unused forests could become accessible for new commercial exploitation. But this requires the undertaking of investigations with a very wide scope. Our studies have to address complete systems with all their aspects, many of which go beyond of what scientists and engineers might consider as relevant. It is certainly not enough to treat these questions from the technical and economical side. The scientist and the engineer can only investigate options and provide the technical possiblitiy for choices. We now need a clear political push in order to come to an early and efficient implementation of any choice.
The energy from biomass programme of the commission of the european communities
5
In conclusion we can say that there are many good reasons for further developing biomass as an alternative renewable energy resource. More and more additional, not energy related motivations for pursuing R&D in this field make me believe that this Conference is again very timely. It is so timely as it will allow the scientific community as well as the interested decision makers to assess or to re-assess their priorities in the light of the latest developments. Given the problems at stake, this is a necessity.
LA BIOMASSE DANS LA COMPETITION ENERGETIQUE A.GIRAUD Professeur à l’Université PARIS-DAUPHINE ancien Ministre de l’Industrie Les énergies fossiles, le pétrole, le gaz naturel et le charbon sont des produits de transformation de la biomasse. On sait que le charbon résulte de l’enfouissement et de la décomposition des grandes forêts de l’ère primaire. Le pétrole a pour origine le phyto et le zooplancton qui s’est formé puis déposé avec des sédiments dans les zones marines peu profondes et peu oxygénées. Quant au gaz naturel, son origine est moins bien connue, et peut-être plus diversifiée. Certains gisements paraissent associés à des zones carbonifères, et le grisou lui-même est d’ailleurs du méthane. Dans d’autres cas, le gaz paraît s’être formé au cours du même processus que celui qui a conduit au pétrole. Enfin des résultats récents attribuent la formation des grands gisements de gaz profonds à la transformation de l’ensemble des matières organiques gui se sont développées, puis déposées, dans des zones saumâtres de marais et de deltas analogues à celles que l’on trouve aujourd’hui dans certaines zones tropicales. La nature de la biomasse d’origine est peu connue. Ce que l’on sait le mieux se rapporte à la tourbe et au charbon. Il s’agissait de plantes lignocellulosiques; on a retrouvé des troncs d’arbres et de grandes fougères. Le pétrole, lui, paraît plutôt descendre de microalgues. Quant aux processus de transformation, on ne peut non plus les identifier avec certitude. La température, la pression créée par l’accumulation des sédiments ont sûrement joué un rôle, les micro-organismes et la catalyse enzymatique aussi. Ce qui nous reste de biomasse transformée est extraordinairement faible par rapport à la quantité qui s’est formée au cours des millénaires et il ne nous reste plus, en fait, que les produits les moins dégradables: les hydrocarbures saturés, les noyaux aromatiques ou naphténiques. Pas d’hydrocarbures oléfiniques ou acétyléniques, pas de produits oxygénés sauf le CO2 lui-même, présent dans les gaz. Le soufre que l’on rencontre dans la matière organique se retrouve en effet fréquemment en quantités notables dans le pétrole, le gaz ou le charbon. Ceci n’est pas le cas, par contre, de l’azote, constituant important des protéines, qui n’apparaît que dans certains gaz, ramené à l’état d’élément. Finalement, nous récupérons ces produits ultimes et rares de transformation de la biomasse enfouis dans les profondeurs du sol. La nature et les millénaires ont pris soin de sa fabrication. Il nous reste à supporter le coût de sa détection puis de son extraction des pièges, forcément relativement inviolables qui ont pu les retenir jusqu’ici: Si la fabrication ne nous a rien coûté, la découverte et l’extraction sont, elles, difficiles et dispendieuses.
La biomasse dans la competition energetique
7
La question qui se pose à nous, alors que nous consommons ces ressources qui ne sont pas illimitées et dont le coût va bon an, mal an, en croissant, est la suivante: la biomasse contemporaine peutelle concurrencer la biomasse fossile? Le premier point à établir est de savoir de quelle biomasse contemporaine il s’agit. Pas nécessairement, et méme probablement pas de celle qui a donné naissance aux combustibles fossiles: soit qu’ils ne soient plus répandus sur la terre dans les conditions actuelles comme les grandes fougères de l’époque carbonifère, soit que leur croissance soit trop lente ou leur concentration trop diluée comme le phytoplancton pétrollgène. Il ne s’agit pas davantage—et l’on doit insister sur ce point—des plantes cultivées actuelles qui ont été sélectionnées et développées par des générations d’agriculteurs, savants et moins savants, pour des objectifs tout autres qu’énergétiques: soit pour fournir de la nourriture comme la canne à sucre, la betterave, le blé, l’arachide, le colza ou la luzerne, soit pour fournir des matières premières industrielles comme le coton, l’hévéa ou le sapin du Nord. Des circonstances particulières ont cependant conduit les hommes à utiliser certaines de ces plantes existantes à des fins énergétiques, soit telles quelles comme le bois de feu, soit après transformation comme la canne à sucre ou le maïs. La connaissance de ces procédés de transformation a suggéré à son tour, le recours à d’autres plantes sur lesquelles certaines connaissances, plus ou moins avancées, ont été acquises. C’est ainsi qu’il est devenu possible de dresser un état provisoire et simplifié du domaine de la biomasse énergétique. Celui-ci est caractérisé par une liste d’espèces végétales assurant une transformation relativement efficace de l’énergie solaire reçue en composants (figure 1) dont la conversion en produits énergétiques est connue, aboutissant à une gamme acceptable de coûts.
Figure 1
A titre d’exemple, quelques-uns sont cités dans le tableau 1. Il convient d’insister sur le fait que cette liste n’est pas complète. Elle omet volontairement des produits certes très utilisables, comme certains résidus, mais dont la quantité restera fatalement très faible par rapport aux tonnages de pétrole ou de charbon. Elle ne cite pas non plus des produits qui sont peut-être l’avenir comme certaines microalgues trop peu connues pour qu’un raisonnement économique quelconque ait un sens.
Energy from biomass
8
Tableau 1 Culture
Rendetaent hamidité Composition de la matiere seche (en %) (en %) Lignine Cellulose Hemicellulose Lipides Glucides Proleines Cendres Europe PVD laillis à courte 12 à 16 t 20 à 25 t 50 20 à 30 40 à 45 25 à 30 1à3 rotation M.S./ha H.S./ha Canne de 18 à 22 t 50 21 42 32 3à4 Provence M.S./ha Luzerne 8 à 12 t 78 15 32 10 5 15 16 8 M.S./ha Graminées 8 à 13 t 50 à 80 12 32 28 3 10 10 5 Fourragères M.S./ha 2,5 78 13 à 14 2 Blé (grain) 5à7 15 3% t/ha Haïs (grain) 5 à 8 10 à 12 15 1,5 5 82 10 1,5 t/ha t/ha 1 72 7 6 Betterave 40 à 60 77 13 sucrière t/ha 75 8 6 lopinambour 40 à 50 80 11 t/ha Canne à sucre 50 à 120 70 10 23 15 1 42 5 6 t/ha Hanioc 20 à 50 65 3 8 90 3 3 t/ha Hapter 30 à 50 t 80 22 40 31 2 4à5 M.S./ha
Pour que l’on puisse parler de biomasse énergétique, il faut que le produit, s’il ne l’est déjà, soit mis sous une forme qui lui permette soit d’alimenter un foyer de combustion, soit de faire fonctionner un moteur. Il n’est pas nécessaire pour cela de fabriquer des sosies des produits pétroliers. Encore faut-il, en pratique, respecter certaines conditions essentielles, et celles-ci sont parfois surprenantes. Ainsi la gazéification directe du bois at-elle bien du mal à alimenter les moteurs qu’elle encrasse; dans presque tous les cas, le passage par le charbon de bois finit par être moins coûteux. Les ménagères africaines éprouvent beaucoup de réticence à remplacer le bois sec traditionnel par des agglomérés de pulpe de café ou autres qui refusent de s’allumer commodément. Dans l’état actuel de la question, la liste des produits que l’on peut réellement considérer comme capables de figurer de façon importante dans le bilan énergétique est très limitée. Elle comprend (figure 2) le bois lui-même, le charbon de bois (ou le bois torréfié), le méthanol et l’éthanol qui sont des produits de base; le mélange acétonobutylique, sensiblement plus coûteux pour l’instant, peut être nécessaire comme solvant de l’alcool dans l’essence. Nous ne retenons pas, pour l’instant, les huiles végétales qui devraient, cependant, être réintroduites s’il apparaissait la possibilité de trouver un substitut standard et économique au gas oil: n’oublions pas aussi que le moteur à essence peut être substitué au moteur diesel: en outre, dans beaucoup de pays elles doivent être réservées à l’alimentation. Nous n’évoquons pas non plus les résidus divers dont nous savons, bien sûr, qu’ils peuvent conduire à des utilisations locales économiques mais qui ne représentent pas de forts tonnages. Enfin, nous ne comptons pas pour l’instant la méthanisation directe des plantes car nous n’en voyons pas encore à l’horizon la viabilité industrielle à grande échelle sauf pour la dépollution.
La biomasse dans la competition energetique
9
Figure 2
Sur le plan technique, il est aujourd’hui démontré que le méthanol et l’éthanol, quitte à leur ajouter un tiers solvant comme le mélange acétonobutylique, peuvent remplacer l’essence dans les moteurs avec équivalence en volume pour les faibles pourcentages et en pouvoir calorifique au-dessus de quelques %. Pour ce faire, les voitures doivent connaïtre quelques transformations mineures, qui deviendront la règle sur des modèles de série, et un simple règlage d’ailleurs inutile pour les faibles pourcentages. Le kérosène, important dans les PVD, peut aussi être remplacé par les mêmes produits. Quant au gas oil et aux fuels, Selon les types d’usages, on peut les remplacer soit par le méthanol ou l’éthanol, soit par le bois et le charbon de bois, éventuellement gazéifiés. Il n’y a donc plus d’usage fondamental de la biomasse fossile qui ne puisse être pénétré par notre gamme de produits sauf peut-être le transport aérien où on exige un fort pouvoir calorifique par kg transporté. Les problèmes d’utilisation paraissent ainsi aisément surmontables. Les problèmes de production de ces produits intermédiaires, eux, conduisent à un jugement plus mitigé. Il est vrai qu’on sait brûler du bois de feu ou cultiver de la betterave et de la canne à sucre et en faire de l’alcool. Mais on sait aussi que l’on est loin de l’optimum. On pressent que d’autres espèces pourraient se montrer préférables selon les terrains, les climats et les conditions de culture. On sait qu’on va les faire évoluer génétiquement. On peut parier sans risque de se tromper sur d’importants progrès que vont accomplir aussi les procédés de transformation, dans la mesure où la biotechnologie est en plein mouvement. Disons en résumé que l’on dispose de filières agroindustrielles connues, et des chiffres nécessaires pour une évaluation économique, mais que ce ne sont pas encore les bonnes filières et les bons chiffres. Ces remarques étant faites, examinons maintenant la place que la biomasse pourrait se tailler dans le bilan énergétique et tout d’abord quantativement
Energy from biomass
10
Dans une étude non encore publiée, M.J.J.BECKER a évalué que les surfaces cultivées de la C.E.E. correspondant à la production d’excédents agricoles seraient de 9 millions d’ha en 1990. Sans porter atteinte à l’autosuffisance alimentaire aujourd’hui atteinte, on voit que la C.E.E. pourrait produire sur ces seules sources 35 Millions de tonnes d’éthanol, c’est-à-dire plus du quart de sa consommation de carburant, ou 45 MT de charbon de bois, c’est-à-dire, déduction faite de l’énergie consommée, beaucoup plus que la production française de charbon. Au plan économique, des évaluations sérieuses montrent que le méthanol et l’éthanol ne sont pas, au niveau technologique actuellement atteint par leurs filières, compétitifs avec l’essence et le gas oil. Il s’en faut d’un facteur 1,5 à 3. Le charbon de bois, lui, pourrait ne pas en être loin* (voir tableau 2, col. 4). La première conclusion à en tirer, c’est que si l’on met bout à bout les progrès qui peuvent être accomplis par la sélection des espèces, l’organisation des cultures (pour alimenter les usines toute l’année) et les procédés de transformation, le niveau de compétitivité est accessible, surtout si, comme on peut le penser, le prix du pétrole remonte dans les années 90. On devrait donc attendre que les recherches aient progressé. * Et l’on peut même dire déjà qu’il coûte beaucoup moins cher que le charbon national français de certains bassins. Nous pourrions avoir intérêt à transformer une partie de nos mineurs en bûcherons et charbonniers
Il ne s’agit pas là d’un rêve. Nous sommes dans un domaine scientifique en plein mouvement, et le rendement “éthanol” d’un hectare de terre s’élève aujourd’hui seulement à 0,1% de l’énergie solaire reçue. Mais les problèmes rencontrés par l’écoulement des excédents agricoles obligent à se demander s’il ne vaudrait pas mieux convertir, dès maintenant, une partie de nos terres vers des cultures énergétiques. On observe en effet que toute politique agricole qui dépasse l’autosuffisance est forcément coûteuse. Les excédents ne peuvent s’écouler que sur un marché de surplus où les produits sont bradés, tandis que les surplus des autres pays viennent frapper à nos frontières et pèsent, peu ou prou—en empruntant des detours—sur nos prix intérieurs. Le marché du pétrole, lui, n’est pas un marché de surplus. Or, on peut calculer que si l’on appliquait aux cultures énergétiques, les subventions appliquées actuellement aux excédents agricoles, les carburants de biomasse pourraient, alors, devenir compétitifs (voir tableau 2, col. 5).
Tableau 2 Coût des carburants et combustibles dans la C.E.E. Produit
Super Méthanol ex bois
(1) (2) Prix Pc H.T. F/t th/t 2 520
10 500 1 677 4 760
(3) Prix à la thermie
(4) Prix avec subvention équivalente (1•) F/T c/th
(5) Prix avec subvention èquivalente (2•) F/T c/th
24 35
750 à 1 380
16 à 29 525 à 1 285
11 à 27
La biomasse dans la competition energetique
Ethanol
11
4 314
6 67 1 930 à 3 330 30 à 52 495 à 2 890 7,7 à 45 390 LPG 3 126 à 3 11 28 à 33 683 000 Fuel domestique 2 240 10 22 150 Fuel lourd 2 136 9 22 600 Charbon 600 5 12 000 Lignite 150 2 7,5 000 Charbon de bois 1 350 7 19 430 à 890 6 à 13 −1 165 à −16,6 à 10,3 000 720 Bois taillis à 180 1 9,5 23 à 100 1,2 à 5 −175 à 147 −9,2 à 7,7 courte rotation 900 J.J.BECKER—thèse non publiée (1) Coût du substrat agricole évalué en supposant la conservation de la main d’oeuvre agricole sur l’exploitation (2) Coût du substrat agricole évalué en ne conservant que la main d’oeuvre nécessaire à l’activité énergétique
On devrait conclure qu’il convient de s’engager sans tarder dans cette voie. On peut prédire, cependant, que celle-ci risque d’être—tout comme la politique agricole commune actuelle—une nouvelle impasse si on ne trace pas dès le départ une politique qui doit s’attacher à résoudre en tout cas deux problèmes: Le premier est de donner aux aides de la Communauté une forme qui conduise la biomasse au progrès. Ces aides doivent être construites pour disparaitre au fur et à mesure que les filières énergétiques feront des progrès. Il faut qu’elles les poussent au progrès. Il ne faut pas raisonner seulement sur les moyens de financer un “coup sec” tel que la construction isolée d’une usine d’alcool. Il ne faut pas en faire un nouveau rachat d’excédents. Le deuxième problème dont il faut se préoccuper est la façon dont l’agriculture et l’industrie vont se raccorder pour faire réussir une filière agro-industrielle. L’agriculture ne pourra pas, seule, distribuer ses produits; l’industrie du pétrole ne sait ni faire pousser des plantes, ni les collecter, ni les conserver et les conditionner au besoin par une première transformation. Certains rêvent sans doute d’un Office d’Etat rachetant les alcools comme des surplus agricoles et les revendant, au besoin par la force des règlements, et à perte, aux distributeurs. Comment ne pas voir qu’un tel dispositif maximiserait plutôt la divergence des intérêts que leur convergence, condamnant ainsi le développement de la biomasse à l’échec. Il faut, au contraire, intéresser les différents partenaires au succès, chacun faisant ce pour quoi il est le plus compétent. En analysant le développement de la filière, on se dit que le bon point de raccordement se situe peutêtre au milieu du processus de transformation: la première étape, pratiquée dans un dispositif de type coopérative agricole, consisterait à élaborer des produits bruts aisément transportables qui seraient terminés dans des usines de type pétrolier.
Energy from biomass
12
Dans les PVD, la biomasse ne présente pas les mêmes caractères. Les rendements peuvent être, en certains endroits, plus élevés et les espèces utilisables ne sont pas les mêmes. La structure des coûts n’est pas non plus identique. Arithmétiquement, le problème de la surface disponible ne se pose pas car la consommation des produits pétroliers est généralement très faible comme le montre le tableau 3 sur quelques exemples. Ces chiffres montrent naturellement qu’il est parfaitement possible, en choisissant opportunément les filières, de ne pas empiéter sur les surfaces consacrées aux cultures alimentaires. Des végétaux tels que l’herbe de Napier (herbe à éléphant) ou l’eucalyptus pourraient donner de la matière sèche compétitive avec celle de la canne à sucre. Les obstacles rencontrés dans les PVD sont d’un autre ordre et sont malheureusement très variés. Malgré de grands efforts, la World Bank l’a constaté, il est très difficile de trouver un pays où l’un de ces obstacles au moins ne soit pas présent empêchant un projet industriel de se mettre en place. On peut citer:
TABLEAU 3 PAYS ETHIOPIE GHANA KENYA MAROC SOMALIE
(1) (2) SURFACE IMPORTATIONS NETTES KM2 PÉTROLIÈRES MILLIERS DE TEP 1 221 900 239 460 582 646 458 730 639 969
560 870 1 237 4 055 249
(3) SURFACE POUR BIOMASSE ÉQUIVALENTE 1 400 2 175 3 100 10 135 620
% SURFACE 0,11 0,91 0,53 2,21 0,09
– le fait que la culture qui serait favorable n’est pas encore suffisamment étudiée. (Un projet fondé sur le manioc en Nouvelle-Papouasie est dans ce cas; de même, on n’en sait pas assez long sur les végétaux adaptés aux zones arides). – la difficulté de modifier, fût-ce très peu, les engins d’utilisation (les fourneaux des ménagères, les voitures et les moteurs existants), simplement les habitudes (remplacer le kérosène par du charbon de bois). – l’inaccessibilité de nouvelles zones de culture, – le temps nécessaire pour former la main-d’oeuvre, – la faible taille des projets envisagés. On fait couramment par exemple les calculs sur une unité d’éthanol de 500T/j: c’est l’ordre de grandeur de la consommation d’essence de toute l’Ethiopie. Or, on ne peut pas convertir du jour au lendemain toutes les automobiles d’un pays, etc… etc… De ce fait, on doit être prudent à l’égard des évaluations économiques qui sont établies sur des cas théoriques ou même, sur celles qui correspondent à des projets assez détaillés, car il y a toujours une étape de ceux-ci qui comporte un certain pari. Cependant, les chiffres sont déjà favorables (tableau 4). Bien fabriqué, le charbon de bois est déjà deux à trois fois moins cher que le kérosène et le gas oil, quatre à cinq fois moins que les GPL. Le prix de gaz fabriqué dans un gazogène rivalise avec celui du gas
La biomasse dans la competition energetique
13
oil et serait ainsi utilisable pour les camions et les moteurs fixes. La fabrication de méthanol ou d’éthanol, dans des conditions convenables (taille suffisante, combinaison de cultures) pourrait être à peu près compétitive, comme l’a montré l’exemple brésilien.
TABLEAU 4 COUT DES CARBURANTSSET COMBUSTIBLES DANS LES PVD PRIX F/T Pcc TH/T PRIX À LA THERMIE C/TH SURERCARBURANT 2 500 À 5 000 METHANOL EX BOIS 800 À 1 300 ETHANOL 2 000 À 3 500 FUEL LOURD 1 500 À 3 000 CHARBON 450 À 900 BOIS 65 À 100 CHARBON BOIS 550 À 750 J.J.BECKER—thèse non publiée
10 500 4 750 6 390 9 600 6 000 1 900 7 000
24 À 48 17 À 27 31 À 55 15,5 À 31 7,5 À 15 3,5 À 5,3 8 À 11
Résoudre le problème devient ainsi une affaire de volonté et d’obstination. Quatre-vingt quatre nations en voie de développement représentant des milliards d’hommes importent ensemble environ 300 millions de tonnes d’hydrocarbures. Cela constitue pour beaucoup d’entre elles une charge énorme: 30%, 40%, parfois plus, du montant de leurs exportations, une charge annuelle pour leurs économies du même ordre de grandeur que le montant total de leur dette. C’est pourtant ce qu’il serait possible de produire sur 100 millions d’hectares seulement, alors que l’Ethiopie seule compte 8 millions d’hectares de forêts et 20 millions d’hectares de savane, et que la superficie du Brésil est de 850 millions d’hectares et celle de l’Afrique de 3 milliards d’hectares. Il n’est pas possible de rester indifférent devant cet enjeu et il faut souhaiter que la Banque Mondiale, qui en a mesuré l’importance et les difficultés, reçoive tous les concours nécesaires, financiers, industriels et scientifiques. Ainsi, que ce soit en Europe ou dans le Tiers Monde, le moment est venu pour la biomasse de commencer à faire son entrée dans le bilan énergétique. Les problèmes sont identifiés, il faut les résoudre.
BIOMASS FUELS IN A EUROPEAN CONTEXT R.M.SELIGMAN, B.A. (Oxon) Member of the European Parliament for West Sussex, U.K. and Vice-Chairman of the Committee on Energy, Research, and Technology Summary Two and a half years after the European Parliament called for a 60 million ECU 5 year programme on Energy from Biomass, the Council of Ministers in Brussels has adopted such a programme, albeit a somewhat reduced one. The EEC, therefore, has to choose where to concentrate its efforts in the enormous field of Biomass energy. The writer considers that the areas where energy crops can make the most important economic and political impact are in Short Rotation Forestry for methanol production, and in root and cereal crops for Ethanol production, both to be used as ingredients of Motor Fuel. Biotechnology and improved equipment are causing Agricultural Productivity to increase relentlessly, producing unwanted food surpluses. Energy crops most replace these surpluses. The use of Agricultural oxygenates in Motor Fuel will not only reduce dependence on imported oil, it will improve the balance of payments, provide work for farmers, help the energy problems of the developing countries and, more recently, offer a solution to the octane and environmental problems of unleaded petrol. Major research efforts are now needed, using advanced biotechnology and process engineering, to reduce the cost of the agricultural oxygenates and to find profitable uses for the byproducts. Ways to sunmount the various political and economic obstacles, and the doubts and objections to the adloption of bio-energy, will be examined. 1.1 Introduction It is my intention today to comment on the political and economic realities which lie behind the move towards biomass energy. The oil crises of 1973 and 1979 greatly increased interest in Alternative Energy Sources. Unfortunately, it also increased the importance in alternative non-Opec oil sources, like Mexico and the North Sea. Non-Opec production increased in 4 years from 2.5m to nearly 9m Bpd. The World recession which resulted from high oil prices, combined with the new sources of oil, resulted in the present glut of oil. This oil glut then caused the
Biomass fuels in a european context
15
slowing down or abandonment of many very promising R and D projects in Alternative Energies—not least coal liquification and gasification, biomass, solar and geothermal energy. But my impression is that there is now a renewed interest in Alternative Fuels, because oil prices are expected to rise again in the next 10 years, as economic recovery accelerates. As Henry Kissinger said in the Sunday Times recently, “The present temporary respite from oil pressures must be used to expand conservation policies and to encourage the development of Alternative sources of energy—exactly the opposite of the present shameful trends. “Otherwise the 1990’s, once more facing an energy shortage, may well CURSE the BLINDNESS and the lack of foresight of Current Leaders”. Our generation Mr. President—will go down in history as immoral and grossly selfish. In the short space of 70 years—one short life time—we have squandered finite resources of oil and gas, in blissful disregard for future generations—spending pathetically little on research in Renewable energy and rejecting an energy or oil import tax, because it would inhibit the greedy guzzling of imported non-renewable fuel. The revenue from such a tax could well be used for research into energy conservation, and alternative renewable fuels, fuels which come from the Sun’s energy. I sometimes despair of short-sighted politicians. But, Mr. President, I think things are beginning to move our way. The political background to the growth of energy from Biomass is becoming daily more favourable. Not only is North Sea oil production reaching its peak, shortly to decline, but the world is becoming more environmentally conscious every day. Citizens are turning their minds away from the politics of war, and turning more towards the politics of fighting pollution. And every anti-pollution move brings us closer to Biomass energy. Not only does burning coal, oil and gas as a fuel, waste a large number of complex and valuable ingredients, which go up the chimney in smoke—it also generates sulphur and nitric acids which pollute the air we breaths and probably kills trees, lakes and fish as well. Nuclear power is probably one of the cleanest and safest forms of electricity generation, but you cannot use that for driving motor cars, motor boats or aeroplanes. The Green movement in Europe is gaining political influence, especially in Germany. This means that we have to listen to them. And their message on energy is contained in an amendment to the Energy Pricing policy of the EEC, which the Greens pushed through in Strasbourg last Week. “Parliament notes that Research indicates that biomass can be used to oover up to 20 per cent of Mamber States energy requirements, and that our agricultural surpluses can be eliminated through using biomass; calls, therefore, for the necessary initiatives to be taken at European level, to develop the use of Biomass”. 20 per cent may be on the high side, but I am very glad that the Council of Ministers in Brussels, has at last adopted a Biomass Energy programme—albeit, however, only for 20m BCU against 60 BCU demanded by the European Parliament 2½ years ago, when I was Rapporteur for a 5 year international programme in biomass energy. This conference is ideally timed to make suggestions for incorporatian. in that programme. The European Parliament realises that Biomass must come of age. It can no longer be a futuristic, hypothetical technology. It must fight in the market place on equal terms with
Energy from biomass
16
other technologies, We have to convince the authorities and the farmers that they can make a living out of energy crops. But a Biomass energy source which is suitable for one region, or climate may not be suitable for another. That is why I am delighted that this conference is drawing contributions from so many different countries. In particular, the Mediterranean, Scandinavia, Zimbabwe, Canada, Florida and China. Furthermore, different Biomass environments are discussed. Arable, industrial, aquatic and forests. The basic problem, however, is not technology, it is economics—it is MONEY. That is why there will be no massive swing into Biomass Energy, until the price of Hydrocarbons goes up again. We have to be ready for that moment. Basically, it is far better to use available land in the EEC and the Third World to produce energy crops that we need, rather than food surpluses which we don’t need, and that we have to sell off to the Russians and others at a substantial loss. It is costing the EEC somthing like 7 Bn BCU a year—just to get rid of the surplus food on World markets, and in free Food Aid. It must be sensible to replace this costly food surplus, with energy crops, if it can be done without costing more than it does now. 2. MOTOR AND TRACTOR FUEL The biggest prize in Biomass Energy at the moment is fuel for cars and tractors. But I understand that: cost estimates for producing Agricultural Alcohol are still far too high. An oil company told me that while conventional Motor spirit costs only 350 ECU a tonne/grain alcohol costs between 795 and 875 BCU per tonne to produce; sugar beet alcohol costs 675 BCU per tonne. I have no figure for artichoke alcohol. So one vital area of research is to find ways to make Agricultural Fuel Alcohol cheaper and more competitive with fossil fuel. I don’t believe we are anywhere near the end of the road in this sort of research. 3. RESEARCH IN SOUTH AFRICA In South AFrica, which I visited recently, the Government are hoping eventually to derive 15% of their liquid fuel requirements for cars and tractors from agricultural alcohol and plant oils. Since 50% of their fuel goes into Farm Tractors, they tend to concentrate on tractor fuel. 3.1 Ravno and Purchase of Durban University Agricultural Energy Institute, decided that the main obstacle to Ethanol in Motor Spirit, or tractor fuel, is the high cost of the raw mterials, which is 65% of the total cost. They are doing meaningful experiments to derive Alcohol directly from Bagasse, which otherwise accumulates as waste, and can be obtained very cheaply. Now maybe cane sugar bagasse is of little Interest to Europeans, but it certainly should be to the developing nations. The process seems to be to hydrolise the hemicellulose component, which is 35% of the waste by dilute H2 SO4 to Xylose, leaving a residue of cellulose and lignin. Xylose can then be fermented to alcohol.
Biomass fuels in a european context
17
The balance of Bagasse Cellulose is converted to glucose by enzymes. One third of the carbon of the Bagasse then remains as burnable. In this process 70% of the Bagasse, which costs only £10 a tonne, is made fermentable, meaning that the raw material for alcohol costs not much more than £15 a tonne. So that could be one way to cheapen Bio-ethanol. 3.2 The Department of Agricultural Engineering in Natal University at Pietermaritzberg have been blending diesel with up to 15% Ethanol (mark you South Africa has a warmer climate than ours). They store the ingredients separately to avoid phase separation. They do use Nitrates as CETANE improvers from the Ethyl Corporation, Baton Rouge, U.S.A. The Economics of mixing Ethanol with Diesel depends very much on the price charged by the Government for SASOL diesel. This research work is important strategically in case South Africa’s supply of imported oil is cut off. 3.3 Thirdly, many of those present will be aware of the successful work done in the Agricultural Engineering division of the Department of Agriculture in Pretoria by Fuls and others, on using degummed sunflower oil esterified by Ethyl Alcohol with a Sodium Hydroxide catalyst in a direct injection compression ignitition engine. Fuls is convinced that many different plant oils (including non-food plant oils), could be used in the same way to drive Third World tractors, and this lends interest to Unilever’s new Palm oil clones, which yield 30% more oil than traditional strains. These are examples of the endless search by scientists for solutions to the energy problems of our time. Research has to go on constantly seeking new ways through, or around, apparent technical road blocks. 4. THE ADVANTAGES OF BIO-ETHANOL The World needs an alternative transportable motor fuel to mineral oil. It may one day be hydrogen, generated by nuclear energy, but ethanol has so many economic and political advantages. 4.1 Firstly, it provides a solution to the problem of farm food surpluses, and be sure these surpluses are going to increase every year due to the march of agriculture science, in selective breeding, growth regulation, hormone management, tissue culture and better fertilisation. 4.2 Secondly, ethanol offers import savings to the EEC and Third World countries, who have to spend most of their own export earnings just to pay for their fossil fuel imports. 4.3 Thirdly, the higher value of the dollar has made imported crude oil much more expensive than it was, compared with alternative indigenous fuels. 4.4 Ethanol offers an alternative to lead in petrol, as an octane booster. 4.5 Fifthly, ethanol offers an environmental improvement by replacing hydrocarbons containing sulphur, which pollutes the urban air we breathe. If ethanol can be cheapened, and if it’s bad effect on cold starting and the motor octane number can be resolved, it is bound to be used more and more.
Energy from biomass
18
The practical problem with Ethanol lies in the reluctance of the international oil majors to using agricultural oxygenates. And after all, they are the people we have to persuade. They, and the motor manufacturers, have to take the action— they have to adapt their refining processes and engine designs to accommodate ethanol and methanol in their fuel. They have to be persuaded that their balance sheets at the end of the year will not suffer. How can this be done? This is an ideal job for the EEC Commission. The Commission should launch a research programme to provide answers to the specific objections raised
5. OBJECTIONS TO OXYGENATES 5.1 The first objection. I have heard that there is insufficient land in the EEC to produce the amount of Ethanol we would need. This must be nonsense. I am told that the Agricultural surpluses produced by the CAP occupy 8 to 9 million hectares out of a total of 152 million hectares. On one hectare, one could produce 4 tons of ethanol per year, plus one ton of biomass residues, which on 8 million hectares, would give us 32 million tonnes of ethanol per year. With 90 million tonnes of gasolene consumed per year in the EEC, 35% could theoretically come in the form of Ethanol from the land which at present is producing the unwanted food surpluses. In fact, with Ethanol likely to be limited in the EEC to 5% of motor fuel at present, we would have 7 times more land than we need. So don’t lets hear any more about the limitation of available land. 5.2 The second objection is—“How can you talk abcut converting good cereals into fuel alcohol, when these cereals are needed by the starving millions in Ethiopia and the Sahel?” Firstly, the EEC is planning to send 2.5 million tonnes per annum of cereals to Ethiopia and the Sahel. But the production surplus over requirements is more like 20 million tonnes a year. Most of this is sold abroad at World prices, which are tamporarily high—due to the high value of the American dollar. This may not last. In which case the cost of restitution, when we sell surplus cereals abroad, will go up again. If, and when, World cereal prices fall back again, it will become more difficult and more expensive to sell cereals on the World market and more will then be available for conversion into fuel alcohol. In any case, it would be quite wrong to regard Europe as the permanent granary for the starving world. To provide Emergency supplies in a crisis is a good humanitarian act. To plan to permanently dump our surplus food on the Third World would be quite wrong. We must help them to become self-sufficient in Food. In their own interest, we must help them to build up their agriculture and infrastructure by investing and giving them technological help. So I don’t see at all that the argument against using our surplus cereals for fuel alcohol instead of food has any validity at all. 5.3 The third objection is technical. It is that Ethanol as a substitute for lead is only a partial answer. If you have a high or medium compression engine, as we have in Europe, Ethanol will not eliminate high speed knock. There must be a research answer
Biomass fuels in a european context
19
to this. Furthermore, for each 1% of ethanol added, you only get 1/5th of an octane number improvement. This means you would need 25% ethanol to gain the improvement of 5 octane numbers needed to replace the 0.4 grams/litre of lead which is currently in use in the EEC. You would need abcut 10% ethanol to replace the future level of lead of .15 grams/litre. This would be permissible in the U.S.A.; but in the EEC, the Commission has been more cautious and wants to limit ethanol to 5%. So the current thinking in Europe is that 3% methanol derived from hydrocarbons is acceptable with 5% ethanol as a cosolvent. The question is whether Ethanol has yet been proved to be an adequate cosolvent. If it is, the Farmers and the C.A.P. have a good outlet for 5 million tonnes of ethanol per year on over a million hectares. If it is not, oil companies may prefer to use T.B.A., as a cosolvent, or M.T.B.E., an as an actane booster, neither of which would come cheaply from Biomass. 5.4 The fourth main objection is the one about Energy Balance. It says that you have to put more energy in to Ethanol production than you get out of it. I don’t consider this a valid argument. Cars and aeroplanes cannot run on coal or nuclear power. They need a liquid transportable fuel. What the Brazilians have done is to convert solid raw mterial—cane sugar into a convenient liquid transportable fuel—alcohol. Provided the energy imbalance is not unreasonable, Gasohol production from sugar is a sensible replacement for petrol. The Swedes in their Biostil plant at Skaraborg,, saccharify, ferment and distill surplus wheat in a continuous process which is engineered for maximum heat regeneration, which should greatly improve the energy balance of ethanol production from cereals. 5.5 A fifth objection to Bio Ethanol production for motor fuel is that the surplus subsidised ethanol might compete with the potable spirit industry. Clearly, the production process must be adapted to make the product undrinkable. 5.6 But the real objection by the oil mjors is the Economic one. And the corridors of power in the Commission in Brussels and in Bonn and Paris, are buzzing with this controversy. For a 5% ethanol as cosolvent for methanol in motor fuel, we need about 5 million tonnes of agricultural ethanol. I calculate that this alone would need a subsidy of well over 1 Bn BCU per year. As I said earlier, the production cost of 100% DRY ethanol from Beet Sugar is about 675 BCU per tonne and from cereals between 795–875 BCU per tonne. The oil companies don’t want to pay more than about 250 BCU per tonne for dry ethanol. This seems an unfairly low figure when petrol. costs 350 BCU per tonne to produce. At this rate, a subsidy of 425 BCU per tonne of Dry sugar beet alcohol, or 545 BCU per tonne of Dry wheat alcohol, (compared with the proposed 700 BCU per tonne subsidy for wine alcohol), would be necessary. At the moment due to the high dollar, very little restitution—perhaps 25 ECU/Tonne—has to be paid by the EEC on cereals sold on the World market, which indicates that it is much cheaper at present to sell as much cereal as possible on the World market with only a 25 ECU/tonne subsidy, than convert it into ethanol with a 545 ECU/Tonne subsidy! This my change, however, and the
Energy from biomass
20
dollar my fall again, and then World cereal prices will fall. Then the cost of restitution will increase, and a large subsidy on cereal alcohol for motor fuel will not look so out of line. Nor must we forget that the main alternative for oil companies is to change the oil refining process and invest in expensive reformers in order to reach the necessary octane number. This will consume more crude oil and cost more.
6. CONCLUSION Europe is getting increasingly excited about Bio-alcohol, as a substitute for lead in petrol. There are still a lot of hurdles to cross before it becomes a commercial reality. But there is a lot going for it. (a) Bio-Ethanol is environmentally more acceptable than lead, or Hydrocarbons. (b) Bio-Ethanol production would help to solve the problem of cereal surpluses. (c) Bio-Ethanol would help to reduce our excessive dependence on imported oil. (d) Bio-ethanol, is infinitely renewable, whereas liquid and gaseous fossil fuel reserves have only about 70 years to run. In its new Biomass progamme, or a separate one, the Commission must take each objection to the adoption in the EEC, and the Developing World, of Bio Ethanol and vegetable oils as fuels, analyse them and research for solutions, together with all interested parties. A new programme must bring together experts from the oil companies, the motor manufacturers and the farmers, to sponsor joint research to determine the facts, and finally come up with the solutions to these urgent problems. I am sure they can count on the full support of the European Parliament, if they do this. The Schleicher Resolution 1349/84 advocating Bio ethanol in motor vehicles for environmental reasons has wide support in the Christian Democrat, Conservatives and other Groups in the Parliament. The sooner we can adopt renewable motor and tractor fuels, the sooner will energy supplies for transport for future generations be assured. I look forward to the day, when, like Brazil, we have cars running on pure Alcohol. Meanwhile, I have one other quite different suggestion, which I want to make to the conference. It concerns the use of biotechnology for energy conservation. After all energy saving has been described as the fifth fuel. I think that the biomass programme should take under its wing the whole question of energy conservation, in food production by economising in the use of fertilisers, in the cost of fuel in horticulture, in selectibe breeding, or biotechnology, to accelerate growth rates and reduoe the heat and energy needed to achieve fully grown plants, flowers and vegetables. Biological energy conservation is a whole technology which should become part of the biomass energy programme.
THE ITALIAN BIOMASS SCENE by Prof. G.AMMASSARI Direttore Nuove Fonti d’Energia Ministero Industria Commercio Artigianato Roma, Italy 1. THE OBJECTIVES OF THE 1981 NATIONAL ENERGY PLAN IN THE BIOMASS SECTOR Italian energy policy is outlined in the National Energy Plan, which was approved by Parliament at the end of 1981 and which defines, by sector, objectives to be pursued, measures to be taken and resources available in the long-term, with three-yearly revisions. One of the main objectives of the National Energy PLan is the promotion of energy saving and the development of renewable energy sources as a means of reducing the consumption of primary resources. The other aims are the development of the nuclear, coal and natural gas sectors and the establishment of a programme for the petroleum sector. In the sector of renewable sources, particular emphasis is placed on the production of energy from biomass and the widescale promotion of the technologies which have already been developed. This is an extremely flexible sector in many ways, with a variety of sources of raw material (refuse, residues, agricultural/forestry crops etc.), conversion processes (biochemical, thermochemical, combustion) and final uses of t he product (heat, electricity, transport, agriculture) and with a number of advantages for the country and the environment. 2. THE BIOMASS POTENTIAL IN ITALY The most interesting sources of biomass in Italy, in view of the characteristics of the country and the structure of the agricultural and livestock systems, are: a) the organic fraction of urban and industrial waste b) green residues (cereal straw from corn stalks, beet tops and leaves etc.) c) livestock wastes (manure, slurry etc.), the recovery of which could Lead to a substantial reduction in the pollution of the environment, particularly the surface waters d) residues from forestry activities have some potential, although less than in other countries. a) It is difficult to assess how much urban waste is available nationwide. According to surveys carried out by the National Research Council (CNR) in 1980 for the first Specific Energy Project, Italy produces an estimated 14 million tonnes per year,
Energy from biomass
22
approximately, at an average daily rate of 700g per capita, with a calorific value of between 1000 and 1500kcal/kg. Approximately 65% of solid urban waste is dumped, approximately 25% incinerated and approximately 10% recycled. We can estimate, from the geographical distribution, that only 15% is subject to any form of treatment which would allow energy recovery, while most of it is dumped in more or Less controlled tips. At the end of 1984, approximately one hundred incinerators were in operation, but only a few were equipped for heat recovery and/or electricity generation. Some thirty were equipped for the preparation of compost for agricultural purposes and only a few for recycling, separation of paper, metals, glass and plastic and/or production of refuse derived fuel. Annual production of industrial waste was estimated by the CNR at 35 million tonnes. of this, only the organic waste with chemical and physical properties enabling it to be treated by the same processes used for organic waste and biomass is used for recovery of energy. The most useful part is the waste from the food industry, amounting to some 2.5 million tonnes. b) Vegetable wastes in Italy amount to approximately 20% of the principal crops grown, or an average of some 30 million tonnes/year with green residues accounting for 5– 7%. The quantity of green residue which could theoretically be recovered from a crop depends on a number of factors such as the capacity of the crop to produce biomass (e.g. the straw grain ratio), and the properties of the crop, which determine how the residue behaves when it is harvested and thus suitable. it is for recovery (falling leaves, stalks etc) . Technical and economic aspects of recovery also need to be considered, such as: – useful period of recovery, i.e. harvest season, the time allowed for harvesting etc.; – the organization of the farm, particularly as regards harvesting and storage capacity; – preservation of the soil’s fertility: if organic matter is removed, the soil will become impoverished so that more fertilizer is required, and this has to be taken into account in the overall economic balance-sheet. c) The estimated production of Livestock waste in Italy is about 20 million tonnes/year. In the past, Livestock wastes have been spread on the Land as fertilizer to improve the physical properties of the farming Land. However, changes over the Last few decades in the structure and management of Italian livestock farms have altered the former balance significantly. Intensive breeding concentrated in limited areas has made available substantial quantities of liquid manure, the disposal of which is causing environmental problems. This is the reason for the interest shown by farmers and public authorities in technologiés which, if correctly deployed on an industrial scale, will resolve the serious problem of sewage disposal and permit the recovery of energy and fertilizers.
The italian biomass scene
23
d) As regards forest residues, it is estimated that from a national average of approximately 8 million m3/year of firewood, there are 2.5 million tonnes/year of waste to which can be added approximately 0.5 million tonnes/year of wood wastes. However, the expense of collection and transport has to be borne in mind, and especially in the case of forest residue, where costs are particularly high in view of the Low energy content of the wood. The use of wood wastes would be more simple, particularly if carried out in situ.
3. TECHNOLOGIES FOR USING BIOMASS The technologies chiefly used in Italy for the production of energy from biomass are as follows: a) Incineration with recovery of energy from urban waste The waste collected is held in a storage area before being transferred to a combustion chamber, from which slag and fumes are emitted. The yield from urban waste is approximately 1.2 kg of steam per kg of waste, or approximately 0.4 kWh of electrical power per kg of waste, if the plant is also equipped for electricity generation. Combustion with energy production does not exclude the possibility of recovery of materials for recycling (metals, glass, paper etc.), after examination of t he cost benefit of the operation as a whole. The presence of harmful elements in the exhaust fumes can be a problem, but this can be overcome by limiting the combustion of industrial waste and including a post-combustion chamber in the thermal cycle to minimize the formation of harmful substances. Methods of mixing finely ground Solid urban waste with coal dust to obtain a fuel which can be used in conventional furnaces or brick ovens arecurrently being examined. Research in this field is now underway in the ENEL (National Italian Electricity Board) power station at S.Barbara. b) Anaerobic digestion, by means of which a gas comprising 50–70% methane with a total calorific value of kcal/Nm3 can be obtained from vegetable and livestock wastes. The effluent from the anaerobic digester also makes good fertilizer. The need to maintain the system at a constant temperature and to preheat the Load to be introduced, as well as the running of some of the mechanical equipment, mean that part of the gas produced is not available for further use. Between 25 and 35% of t he gas produced is used to fuel the plant itself. Depending on the method used, it is possible to obtain between 1 and 1.5 Nm3/day of biogas per m3 of digester. The benefit of these methods to the farm depends on a number of variables, primarily the continuing high cost of the equipment, which is partly due to the fact that gas-holders have to be used to cope with variations in demand. One of the biggest problems is the size of the plant and the energy generation/consumption ratio. The Livestock breeding structure in Italy, with a
Energy from biomass
24
large number of both small farms and Large industrial farms, means that a Large measure of flexibility is called for. This sector is, however, constantly changing, and a number of measures are being taken by state and private operators. One possible use for anaerobic digestion is to exploit the energy potential of seaweed, and a project is now being studied for the Lagoon of Venice. Its feasibility depends on the overall economic viability of the project and its effects on the ecosystem. c) Alcoholic fermentation: ethyl alcohol can be obtained from all the agricultural products and residues contained in sugars, cellulose and starches by hydrolysis. The alcohol produced can be used directly as a fuel in internal-combustion engines or mixed with petrol. Its use in Italy depends on the impact it would have on the present fuel production/marketing system and the limitations on its use in view of its purity. d) Direct combustion of forest residue and wood waste, straw, some crop waste. The incineration of green wastes and residues and wood wastes gives yields of approximately 50% for manual Loading equipment and approximately 65% for mechanical Loading equipment. Its economic viability depends on the type of product used, the size of the plant, and on making optimum use of the heat produced. e) Gasification of wood wastes and straw. This new process uses partial oxidization at high temperatures (900°C–1000°C) and injection of steam to produce a Low calorific value combustible gas (2500kcal/Nm3) with ash residue of 5% of original waste. Yield is around 65%. Gas produced in this way can be used to generate heat or electricity. In the latter case, in view of the high cost of the equipment, the system must be used intensively and the product must therefore be available virtually constantly throughout the year if it is to be economic.
4. MEASURES TAKEN IN THE PUBLIC SECTOR TO PROMOTE THE USE OF BIOMASS Between 1981 and 1984, on the basis of NEP information, national and local government and energy bodies introduced legislation and took specific measures to promote the use of biomass. The most important of these were: a) Law No 308/82 b) Presidential Decree 915/82 c) measures taken by the CNR with the ENEA and ENI’s first and Second Specific Energy Project d) EEC demonstration projects a) Chapter I of Law No 308/82 on the restriction of energy consumption and the development of renewable resources, provides for incentives for projects involving
The italian biomass scene
25
renewable energy sources, including the conversion of organic and inorganic solid waste and vegetable residues. Two types of projects can therefore be distinguished: 1) conversion of organic and inorganic solid waste; 2) generation of heat and electricity in incineration plants. The first group invcludes: 1) production of refuse derived fuel (RDF); 2) production of biogas from controlled tips or waste water purification plants; 3) recovery of material resources from waste sorted upstream or from recycling and processing plants downstream of collection. The second group comprises the thermal treatment of refuse, i.e. combustion or pyrolysis. A number of projects are now underway on the basis of specific Articles of this Law: – Article 10: part of the approximately Lit 20 000 million allocated was used for urban waste derived fuel projects, for electricity and/or heat generation and for plants using agricultural waste for combined heat and power generation. A Large number of urban waste projects were submitted by local authorities and firms involved in this field, so that optimum use can be made of this resource. There has also been a series of initiatives, particularly in the distilleries sector, to develop the use of processing waste (grape seed etc) and waste from other types of agricultural processing as fuel in suitable furnaces, to generate steam and electricity for use in the manufacturing process, thereby economizing on conventional fuels. There have been other useful applications in the wood working sector, where the incentives provided have encouraged energy recovery from wood wastes (shaviňgs and sawdusts). – Article 11 is designed to stimulate new technologiés in the field of renewable energy, providing for financing of 50% of the costs of demonstration projects on a nonreturnable basis. In this sector, there has been interest in new technologies for pyrolysis of industrial organic waste, anaerobic digestion and biogas production processes, the production of biogas from controlled Landfills etc. – Article 13 provides for a demonstration plan for the use of ethyl or methyl alcohol, in a mixture with motor gasoline. The plan has already commenced and comprises three tests: – a test to determine the movement of petrol with Low alcoholic level (3–5%) over a Limited but representative section of the present fuel supply circuit, to detect any possibility of pollution or separation of the fuel; – a fleet test to determiňe how suitable mixed fuels containing up to 10% alcohol are in practice, using a sample of motor vehicles representative of the types of vehicle on the road today;
Energy from biomass
26
– a test on a Limited number of new vehicles to examine and compare the results of the demonstration test above in particutarly difficult operating conditions. The success of the demonstration may enable the national automobile industry to try out devices and materials which could be incorporated into all motor vehicles subsequently manufactured to make them suitable for running on alcohol/petrol mixtures. – Article 12 on incentives for the generation of energy from renewable sources in the agricultural sector, under the responsibility of the Minister of Agriculture and Forests, provides for a total of 126 000 million of financial aid to farms for 50% of the capital expenditure and a total of 20 000 million for interest charges. In a number of Regions the administrative and organizational procedures needed to enable the aid to be committed to the biomass and other sectors have already been set up. b) Presidential Decree No 915/82: Italy has fallen behind other countries in Legislation in the sector of solid urban waste. In 1982, Decree No 915 was promulgated assimilating the EEC Directives and bringing Italy up to European Level. Presidential Decree No 915/82 goes beyond the idea of waste disposal to waste recovery. It provides for the treatment of waste, by which is meant reuse, regeneration, recovery and recycling, to be carried out in accordance with a number of general criteria, including monitoring the impact on the environment and public health, economic and regional planning, and the promotion of systems designed to recycle and reuse waste or to recover materials and energy from it, while bearing in mind the criteria of economic viability and efficiency. The State’s responsibilities in this sector includes, apart from directing, coordinating and supervising activities, the definition of measures designed to stimulate the recovery of energy, promotion study and research where necessary. c) Activities of the ENEA and the CNR The ENEA is involved in a number of activities in the biomass sector: technological research into various processes for converting biomass into energetic products, promoting the industrial-scale production of various systems and components, and demonstrating technologies already tested with a view to encouraging their wider use. It is also involved in the specific energy projects together with the CNR. The ENEA’s commitment for the period 1981–1983 was Lit 15 000 million, chiefly used to monitor anaerobic digestion, direct combustion, gasification and pyrolysis, new biotechnological energy carriers (for alcohol etc.) and biomass production processes. Under the five-year plan for 1985–1989, the ENEA will allocate approximately Lit 30 000 million to the biomass sector for internal and external research, promotion in industry, and demonstration plants, concentrating on biogas production plants, the improvement of thermochemical conversion of wood and lignocelluloses and refuse-derived energy using various processes including biotechnological methods.
The italian biomass scene
27
The research carried out by the CNR in the second Specific Energy Policy on biomass is concerned with the rationalization of woodland crops, the colonization of marginal areas, the classification of residues and wastes, trials with processes and components (incineration, biogas, fermentation etc.), for a cost of more than Lit 7 000 million. This research involves the main universities, local authorities and specialist firms. Finally, the ENI is working in the biomass sector with AGIP-GIZA which is involved in the secondary biomass market (residues, processing waste) and is concentrating on both the national and international markets, particularly in developing countries. The period 1981–1984 saw mainly anaerobic digesters (approximately 30) made for livestock waste or food processing effluent. Research activities concentrated on optimizing costs, performance, the fields of application (e.g. solid urban waste) and biomass technologies which could be of some use in developing countries, particularly in the sector of wood gasification. Approximately 10 projects on different technologies are underway. d) EEC demonstration projects: in the period 1981–1984, Italy partici-pated in EEC demonstration projects to promote and develop biomass. The projects submitted by Italy to the EEC are chiefly concerned with the use of biogas, thermal gasification and combustion. Italy has for years been involved in the EEC programme of demonstration projects, obtaining on average 16% of the total funds for biomass. In 1983 and 1984, 8 projects were approved for an overall cost of 27 000 million on: – treatment and production of energy from a central plant serving 62 Livestock farms; – recovery and central treatment of waste and residues; – direct and indirect production of energy, integrated with acquiculture; – production of sawdust as an alternative fuel; – industrial-scale plant for the recovery of energy from waste from the textile industry; – plant for the production of compost; – generation of electricity from biomass; – recovery of energy from distillation waste.
5. CONCLUSION There are now a number of methods developed or at the development stage for producing energy from biomass. The production of energy (generation of heat, biogas, Lean fuels) is nearly always accompanied by other potential uses (fodder, fertilizers, recovery of materials etc.) and by environmental, legislative, economic and administrative implications. Efforts made by the energy authorities and by industry have helped to identify and improve some promising methods. Apart from wood, which makes the most substantial contribution to the energy balance-sheet, agricultural, industrial and urban waste are the
Energy from biomass
28
major contributors to the production of energy from biomass in Italy. For the time being at [east, the use of “energy crops” as practiced in other countries seems unlikely. Considerations such as the protection of the environment and the elimination of waste have promoted the growth of biogas production plants, in view of the need to purify effluent from livestock farms. Further effort is needed by the authorities to coordinate research and cbvelopment to enable as much information as possible to be acquired and to identify the most suitable and promising technologies and build on the experience ecquired so far.
AVENIR DE L’AGRICULTURE EUROPEENNE ET VALORISATION DE LA BIOMASSE L.PERRIN Président de l’Assemblée Permanente des Chambres d’Agriculture C’est avec plaisir que j’ai accepté de participer à l’ouverture du troisième congrès sur la valorisation énergétique de la biomasse. Je remercie les organisateurs de m’avoir invité à cette conférence, me permettant ainsi d’exprimer le sentiment d’un agriculteur français sur l’avenir de l’agriculture et sur le rôle que peut y jouer la biomasse. Si vous le permettez, je ferai un rapide bilan de l’évolution de notre agriculture et des perspectives envisageables. Ceci pour vous expliquer l’impression de désarroi que nous ressentons mais aussi la volonté de réfléchir à notre avenir, de trouver des orientations qui permettent de faire vivre les agriculteurs et les campagnes. Les objectifs assignés à la P.A.C. par le traité de ROME étaient: – l’indépendance alimentaire; – la satisfaction des besoins des consommateurs; – une amélioration de la productivité; – une augmentation du revenu des agriculteurs. Ces objectifs, en tous cas, les trois premiers, ont été atteints avec un large succès. . En 1982–1983, le taux d’auto-suffisance était de 147% pour le sucre, 125% pour le vin, 118% pour les produits laitiers, 117% pour les céréales et 100% pour l’ensemble des viandes. La valeur de la production agricole de la Communauté a augmenté de 18% en termes réels, dans les dix dernières années, alors que la main-d’oeuvre agricole diminuait, elle, de 32%; peu de secteurs économiques ont réalisé de tels progrès de productivité. Les progrès prévisibles en génétique et technique de production permettent de penser que cette évolution est loin d’être terminée. Mais alors que l’Agriculture a encore un potentiel de production considérable: – la demande de produits alimentaires dans la communauté tend à stagner; – sur les marchés mondiaux, les perspectives de débouchés solvables sont limités et la concurrence très dure. Un autre facteur qui nous préoccupe est celui de l’évolution de la pyramide des âges des agriculteurs. Si nous prenons l’exemple de la France, on constate que deux agriculteurs sur cinq ont aujourd’hui plus de 55 ans et parmi ceux-ci, les 2/3 n’ont pas de successeur pour leur exploitation; ceci est vrai pour d’autres pays européens.
Energy from biomass
30
Si on laisse faire, cette éolution se traduira sans doute par une double tendance: – concentration des productions dans certaines régions avec accroissement de productivité; – extension des friches dans les régions les plus deshéritées avec comme conséquences: . une liquidation partielle de l’outil performant de production et de transformation que nous avons mis en place; . une suppression d’emplois agricoles et ruraux; . une accentuation de la désertification des campagnes. Cependant, d’autres alternatives sont possibles. Elles s’appuient sur une diversification des productions agricoles soutenue par une politique vigoureuse d’installation de jeunes agriculteurs et c’est dans cette perspective que s’inscrit le développement de la production de protéines dont nous sommes très déficitaires. Enfin, ces alternatives positives passent par le développement de débouchés non alimentaires pour les productions agricoles: ces débouchés existent déjà mais peuvent augmenter considérablement dans plusieurs secteurs (énergie, chimie, bio-industrie). Dans cette perspective, l’énergie et le domaine des carburants plus particulièrement, offrent certainement un débouché privilégié. Actuellement, les agriculteurs européens produisent des quantités suffisantes pour assurer leurs besoins alimentaires et ils peuvent désormais rendre disponible des surfaces pour la production d’énergie et de matières premières pour l’industrie. Il s’agit là d’une véritable révolution pour le monde agricole: les agriculteurs ne seront plus exclusivement ou quasi exclusivement des producteurs d’aliments. L’affectation de certaines surfaces agricoles pour des usages autres qu’alimentaires et pour des cultures énergétiques en particulier, pourrait donner une sérieuse “bouffée d’oxygéne” à l’ensemble des régions agricoles de l’Europe. Prenons l’exemple du blé. En France, nous produisons deux fois notre consommation et l’excédent augmente de 2 à 3 millions de tonnes chaque année. Les nouveaux débouchés envisageables en alimentation sont très limités. Or le prix du blé en fait une matière première de plus en plus compétitive pour l’industrie que se soient les industries traditionnelles comme l’amidonnerie ou de nouvelles transformations, comme la distillation en éthanol. L’installation d’unités d’éthanol dans des zones où une partie des terres serait réservée à des cultures énergétiques, permettrait de maintenir les surfaces céréalières de l’Europe. Diverses cultures énergétiques telles que les taillis à courte rotation, peuvent être envisagées mais d’ores et déjà de nombreux sous-produits des exploitations agricoles et du milieu rural, peuvent être mieux valorisés pour réduire les coûts de production et procurer de nouvelles ressources aux agriculteurs. La valorisation de la biomasse est un enjeu essentiel pour notre agriculture de demain. Elle peut contribuer à lui donner un nouveau souffle. Nous sommes à l’heure des choix: – soit un développement des débouchés et le maintien de l’outil de production; – soit une extension des friches dans certaines régions d’Europe avec les problèmes d’entretien et d’aménagement du territoire qui pourraient en dé-couler. Si ce choix est primordial pour les agriculteurs, il concerne aussi l’ensemble du milieu rural et des citoyens européens. En effet:
Avenir de l'agriculture europeenne et valorisation de la biomasse
31
le développement de nouveaux débouchés et la valorisation de la biomasse en particulier est un facteur favorable au maintien de l’emploi dans les exploitations agricoles et dans l’agro-industrie et au maintien du tissu rural. Une modification de l’utilisation des sols vers des productions dont les débouchés existent, induirait des économies importantes dans les dé-penses d’intervention du F.E.O.G.A. La production d’énergies à partir des biomasses agricoles et forestières permettrait des économies de devises: 10% de carburants substitués représentent en devises 5 milliards de francs. Il m’apparait donc qu’une mobilisation de tous: agriculteurs, industriels, chercheurs, agents de développement, sera déterminante. Je sais que vous êtes nombreux à travailler depuis plusieurs années avec enthousiasme afin de faire progresser les connaissances scientifiques et mieux maîtriser les techniques dans ce domaine. Pour diverses filières, nous en sommes à une possible étape de développement grâce aux travaux que vous avez menés et en raison de la situation économique et sociale actuelle. Cette nouvelle étape, nous devons la réaliser et la réussir ensemble: . démontrer que le choix de productions non alimentaires, et surtout de productions énergétiques sur les surfaces agricoles est un bon choix; . mettre en place les filières énergétiques en gardant leur maîtrise technique et économique afin de préserver l’environnement et la fertilité des sols en particulier; . travailler ensemble à vaincre les résistances. Il est bien évident que la décision du 31 mars 1984 de fixer des quotas laitiers, a été ressentie par les agriculteurs comme un véritable signal d’alarme. Les mesures en préparation en matière de distillation obligatoire pour le vin ainsi que la fixation d’objectifs de production pour les céréales, obligent l’agriculture européenne à voir au delà des débouchés traditionnels. L’agriculture européenne qui s’est développée durant les dernières décennies, en produisant toujours davantage, ne peut pas changer brutalement son rythme, d’où la nécessité de trouver des débouchés nouveaux. La filière biomasse doit constituer un des maillons nouveaux de la P.A.C.
THE COMMON AGRICULTURAL POLICY AND BIOMASS ENERGY John SCULLY Directorate-General for Agriculture Commission of the European Communities Throughout history biomass has been used by man to provide energy, either directly by the combustion of fuelwood or indirectly by animal traction. Industrial development in the 18th and 19th centuries depended principally on the use of fuelwood. In the 20th century, the use of fossil resources came to the fore. It seemed likely that man would break away from the use of biomass. But the successive crises of the 70s showed that fossil energy resources were not unlimited and that an alternative had to be found. Attention was once again focussed on agricultural and forest biomass. But, compared with previous uses of biomass, some major changes were introduced in the conversion processes and techniques. It is now ten years since biomass conversion processes have been a subject of research and the Commission of the European Communities has been funding studies and demonstration projects in this area. The main impetus has come form two Directorates-General: the Directorate-General for Science, Research and Development (DG XII) and the Directorate-General for Energy (DG XVII). I would like to congratulate them for the work they have done. Other Directorates-General have been involved as well, especially the Directorate-General for Environment, which has funded research on anaerobic digestion, in the context of dépollution and the Directorate-General for Regional Policy, which has been studying prospects for short-rotation coppicing in less-favoured areas of the Community. In 1984, the Directorate-General for Agriculture (DG VI), which I am representing at this Congress, also launched a research programme on the subject. The conversion of biomass to energy thus has a long history as well as contemporary relevance. Recent developments fall into three phases: – the first phase ran from 1975 to 1979, when pioneering work consisted in identifying the problems and exploring the main fields of interest. – the second phase, which ran from 1979 to 1983, witnessed the proliferation of ideas and the first results. The media seized on the promises and brought them to public’s attention. This was a difficult but enriching period. The difficulties stemmed from the fact that the widespread publicity raised high hopes among policy-makers in agriculture and other branches of the economy. – the third phase is the present one. Things have quietened down, research findings are being analysed with more calmness of mind and new projects are being launched. The Directorate-General for Agriculture has taken the opportunity to launch a programme
The common agricultural policy and biomass energy
33
of research on biomass conversion to energy. And it has the benefit of previous experience from which a number of lessons can be drawn. 1)—The problems presented by fossil fuel supplies seem to be less crucial today than some years previously. But resources are undeniably limited. Furthermore, price forecasts for conventional fuel in the long term (to the year 2000–2030) point to a significant increase in fuel prices. There is even some talk of 80 dollars a barrel. So oil prices will eventually be extremely high and research must be geared to finding alternatives in the long term. Time must be taken to identify more clearly the areas where biomass can compete with fossil fuels. The main solid fuel is coal; among the liquid fuels, there is methanol derived from coal or bituminous schists. Ethanol was initially regarded as a possible aternative fuel but is today regarded as an additive. It is a molecule which should eliminate lead. In this case, agricultural ethanol could compete with ethanol from oil. This is the most valid case for comparison and should be carefully analysed. For applications in 1990, emphasis must be placed on processes which will be ready for development in the short term. For applications in the year 2030, research can be continued in the laboratory without too much concern for immediate economic profitability, although this must be tackled in the medium term. 2)—There has already been a number of scientific publications on the conversion of biomass to energy and significant results have been obtained. When shortages seemed imminent, inventions proliferated but real innovation was less common. Inventions did not reach the stage of development and application in economic life. Except in rare cases, new technologies were not competitive. Well-conceived technologies failed to reach the development stage. For instance, straw combustion in France was developed very little or not at all, even in areas where straw was in plentiful supply. The reason seems to be that the stakes are too small for the parties concerned and they are reluctant to take risks. Conversion of biomass to energy remains a matter for the scientists and engineers. Economic aspects have received little attention and often prove insurmountable when full-scale applications are envisaged. There is one exception, namely dry residues used on the farm or in the wood industry (straw, wood wastes etc.) on a sub-commercial level, i.e. without passing through normal market channels. For wet feedstocks, anaerobic digestion may be of interest in some cases. The process consists in methane production from wastes with a low dry-matter content (3–10%) in cases where there is a demand for biogas coupled with a need for pollution control. The case arises mainly in factory farming, particularly pig units of more than 5.000 animals. The cost is still high for the user but lower than aerobic depollution. The countries most concerned are naturally those where pollution problems are acute and where the government regulations are very strict. But governmental attitudes vary considerably from one member country to another: the matter is subject to few rules in the countries of Southern Europe and very stringent rules in those of the North.
Energy from biomass
34
The fact that in some countries there has been remarkable progress in certain technologies (straw in Denmark, wood in the Scandinavian countries) confirms that we must continue to attach importance to this work. 3)—It is important to be more realistic in our approach. The present situation must be analysed more carefully. Converting biomass to energy is a vulnerable activity except where the producer is also the consumer. Otherwise, the hazards are many: prices can drop, oil producers can change their tactics, and so on. Given the complex physical and chemical composition of biomass, there are undoubtedly several different conversion processes which could well be competitive. For instance, conversion to feedingstuffs (treatment of cellulose and lignin), industrial or chemical feedstocks (chemical treatment of cellulose and lignin) and energy (production of alcohol for use as a fuel additive, in particular) are all worthy of attention. Similar treatment is reserved for starch, which is processed for its nutritional properties in the agricultural and food industries, is converted into glue for industrial use, and may be converted into ethanol for energy purposes. This approach calls for measures in several different fields (scientific, industrial and economic). Measures are also needed at political level. The situation in this respect needs some clarification. Starch for use in food is subsidized under the common agricultural policy. Starch for non-food uses is not subsidized. It is therefore subject to competition from starch produced outside the Community. This raises the question of whether the Community should organize the markets for agricultural products for non-food uses. The question of whether the biomass market should be organized at Community level should be studied. It is against this background of unanswered questions that the research programme of the Directorate-General for Agriculture is being implemented. At this point I would like to outline its scope and contents. First, the cost: we have 8.500.000 ECU for energy research between 1984 and 1988. Perhaps you think this is very little. If I tell you that the total budget for agricultural research in the same period is 30 million Ecu, you will see that more than one-third is reserved for energy research although there are seven other programmes to be run. As regards content, the programme concerns itself with two aspects of energy— energy saving and energy production. We have ten working groups which have issued or will be issuing invitations to tender. The subjects are as follows: I.—integrated crop protection, for which contracts were awarded in December 1984; II.—fertilization, symbiotic nitrogen fixation, for which the invitation to tender was launched in February 1985; III.—breeding of new crops with low energy inputs, for which subjects are being researched in preparation for the invitation to tender; IV.—energy saving in glasshouses, which has been the subject of research for many years and will continue as a subject for coordinated research in the future, i.e. exchanges of scientists between EEC countries;
The common agricultural policy and biomass energy
35
V.—optimization of agricultural machinery, to be a subject for coordinated research activities; VI.—development of integrated agricultural systems, also a subject for coordinated research; VII.—energy production and energy crops: work is in hand to prepare the invitation to tender. The projects will be financed directly; VIII.—conversion of dry agricultural residues, such as straw, walnut shells, wood, as a subject of coordinated research; IX.—advisory services to farmers, with the making of a film and advisory brochures: the invitation to tender is planned for the end of 1985; X.—economic aspects, which are being studied with a view to an invitation to tender towards the end of 1985; This is the general picture of our research programme. There is still room for discussions and proposals to the officials in charge of the programme in the Directorate-General for Agriculture, whom you are invited to consult for any further information. In conclusion, it seems clear that the conversion of biomass to energy is not something very new. On the basis of previous and present experience, we can plan our work for the immediate and more distant future, for which the targets of research and application will be different. It also seems clear that, despite economic problems, interest in the subject is still significant although certain factors are taking on new importance. In the case of environment, priorities in Northern and Southern Europe diverge or even conflict with each. The importance of linking up with agricultural policies and industrial policies is indisputable. For the developing countries, which we have not mentioned until now, ideas are already being formulated and it is important to take part. Some projects are under way at the initiative of the Directorate-General for Development (DG VIII). Attention is focused in particular on the economical use of biomass, limited consumption of fuelwood, introduction of new types of cooking appliance, and so on. But, for the developing countries where biomass is already used in large quantities for energy, there are plans to replant trees in village areas to prevent desertification. For this part of the world, the problem is more complex than it seems and much work remains to be done. My concluding words, as far as Europe is concerned, may seem rather severe but nonetheless realistic. It is important not to be too hasty in evaluating ambitious projects, but rather to wait until techniques are properly operational and economic viability is assured.
KURZFRISTIGE VERFÜGBARKEIT VON FORSTLICHER BIOMASSE IN DER BUNDESREPUBLIK DEUTSCHLAND A.F.WEISMANN Ministerialrat und Beauftragter für nachwachsende Rohstoffe im Bundesministerium für Ernährung, Landwirtschaft und Forsten, Bonn ZUSAMMENFASSUNG: Die Entwicklung der Energiemärkte seit 1973 und die agrarische Überschuß-Produktion in der EG führten zur Frage nach Nutzungsalternativen. Die Erwartungen richten sich auf die verstärkte Verwendung der Stoffgruppen Stärke, Zucker, Öle/Fette außerhalb des Food-Sektors. Auch die Erschließung der Potentiale von Lignocellulose könnte angesichts des geringen Selbstversorgungsgrades bei Holz für bessere Nutzung der Ressourcen beitragen. Es folgt die Darstellung der Ausgangssituation und Rahmenbedingungen einschließlich der Risiken, die aus den neuartigen Waldschäden resultieren. Anschließend werden die nutzbaren Potentiale forstlicher Biomasse mit Hinweisen auf die Wett-bewerbsfähigkeit von Wald-Restholz quantifiziert. Als zusätzliche Quelle wird der Anbau schnellwachsender Baumarten in der Feldflur und auf Waldflächen diskutiert; das Potential könnte mittelfristig an das Aufkommen von Industrierestholz heranreichen. Das Fazit hebt hervor, daß die Probleme auf den Agrarmärkten keinen Aufschub dulden und Lignocellulose in den etablierten Verwendungsbereichen ohne Konkurrenz für agrarische Rohstoffe eingesetzt werden kann. Land- und Forstwirtschaft bedürfen bei ihren Anstrengungen der weiteren Untersetzung durch verstärkte Förderung von Forschung und Entwicklung sowie durch Anpassung der Rahmenbedingungen, wenn die Entwicklung in der EG nicht Schaden nehmen soll. I. EINFÜHRUNG Von Wald und Holz in der Bundesrepublik Deutschland soll die Rede sein; beide Begriffe sind in der deutschen Sprache einsilbige Wörter und Bezeichnungen für Naturphänomene, die auch heute noch voller Wunder und Rätsel sind, und zwar trotz des Gebrauchs durch die Menschen seit Beginn ihrer Geschichte sowie trotz intensiver Erforschung während der letzten Jahrhunderte. Dagegen ist das Them praktisch, nüchtern, nicht von gleicher Faszination wie das Naturphänomen Wald, aber mit Risiken und Unwägbarkeiten behaftet. Die bekannte Entwicklung auf den Energiemärkten seit der 1. Hälfte der 70er Jahre und die wachsende Überschuß-Problematik auf den wichtigen Agrarmärkten der
Kurzfristige verfugbarkeit von forstlicher biomasse in der bundesrepublik deutschland:
37
Europäischen Gemeinschaft haben die Frage nach Nutzungsalternativen außerhalb des Food-Bereiches in das politische Rampenlicht gerückt. Die Erwartungen der politisch Verantwortlichen, ferner der um ihre Existenz besorgten Landwirte und Waldbesitzer sind groß und hochgespannt; kaum geringer sind aber auch die Schwierigkeiten, die Wettbewerbskraft nachwachsender Rohstoffe für geeignete Produktlinien durch Züchtung, durch Optimierung der Bereitstellung und Konversionsverfahren in der gebotenen Zeit so zu verbessern, daß ausgewählte Nutzungsmöglichkeiten in die Praxis umgesetzt werden können. Hoffnungen verbinden sich nicht nur mit den Stoffgruppen Stärke, Zucker, pflanzlichen Ölen und Fetten, sondern auch mit den Lignocellulosen und ihren Komponenten Cellulose, Hemicellulose und Lignin. Die Ausführungen beschränken sich auf Holz, auch wenn das in den landwirtschaftlichen Betrieben nicht benötigte Stroh in einer Menge von ca. 5 Mill. t jährlich ein beachtliches Potential an technisch verwertbarer Cellulose darstellt. Die weitere Einschränkung auf die in der Bundesrepublik Deutschland kurzfristig verfügbare Holz-Biomasse wirft die naheliegende Frage nach den weltweiten Relationen und der Aussagekraft der Betrachtungen auf. Wenn von der gesamten Waldfläche der Erde mit ca. 4, 1 Mrd. Hektar (ha) nur 0,85% auf die Europäische Gemeinschaft entfallen und die Waldfläche in der Bundesrepublik nur etwa 22% der Waldfläche in der EG der 10 Staaten ausmacht, so können Sie die bescheidene Größe des hier in Frage stehenden Mosaiksteinchens aus globaler Sicht ermessen. Aus der Nähe unter einem anderen Blickwinkel betrachtet, stellt sich die Bedeutung anders dar: – In der stark mittelständisch geprägten Holzwirtschaft der Bundesrepublik Deutschland sind gegenwärtig 680.000 Mitarbeiter beschäftigt. Dieser Bereich erzielte 1983 einen Umsatz von über 92 Mrd. DM. Nicht mitgerechnet ist der Produktionswert der Forstwirtschaft, der rund 3 Mrd. DM ausmachte und von etwa 100.000 festen Beschäftigten und einer vielfachen Anzahl von Saisonarbeitskräften erzielt wurde. Einschließlich der Angehörigen der Beschäftigten gründet sich die unmittelbare Existenz einiger Millionen Menschen auf die Tätigkeit der beiden Sektoren. – Voraussetzungen dafür sind die Rohstoff- und Warenströme, wie sie sich in der nachstehenden Übersicht “Bilanz für Holz und Waren auf der Basis Holz in Rohholzäquivalenten” niederschlagen: 1982 1983 Bilanzposten Mio. m3 Erzeugung (Einschlag) Wiederverwendung von Altpapier (a.d. Inland) Einfuhr Bezüge aus der DDR Ausfuhr Lieferungen in die DDR Bestandsveränderung Inlandsverwendung Selbstversorgungsgrad einschließlich Altpapier a.d. Inland
28,9 27,5 9,9 10,3 43,8 48,5 1,7 2,0 23,4 24,5 0,2 0,2 0,9 0,3 61,6 63,9 in % 63,0 59,2
Energy from biomass
38
Die Datenübersicht spiegelt die potentiellen Nutzungsmöglich-keiten für forstliche Biomasse aber nur unvollständig wieder; darauf wird noch näher einzugehen sein. II. AUSGANGSSITUATION, RAHMENBEDINGUNGEN Vorweg scheint es zweckmäßig, einige Rahmenbedingungen zu skizzieren, nämlich: 1. die Position des Waldes in der Rechtsordnung; 2. Elemente der Forststruktur sowie Merkmle der Waldnutzung und Holzverwendung; 3. natürliche Kalamitäten und neuartige Waldschäden als ökologische und ökonomische Störfaktoren; 4. strukturelle Überschüsse auf wichtigen EG-Agrarmärkten; Konsequenzen? Ad 1): Welche ökologischen und ökonomischen Funktionen werden vom Wald in der Rechtsordnung erwartet? Teilnehmer und Interessenten, die nicht aus dem deutschen Sprachraum kommen, werden nicht so ohne weiteres mit den Rechtsnormen vertraut sein, die sich in Mitteleuropa seit Beginn einer planmäßigen Forstwirtschaft für den Wald als Ökosystem und Rechtsobjekt, aber auch für die Waldeigentümer in zunehmend strengerer Ausprägung ergeben haben. Sowohl das Bundeswaldgesetz von 1975 als auch die Forstgesetze der Länder bestimmen unter anderem: 1.1 Der Wald ist wegen seines wirtschaftlichen Nutzens und wegen seiner Bedeutung für die Umwelt, insbesondere für die dauernde Leistungsfähigkeit des Naturhaushaltes, für das Klima, den Wasserhaushalt, die Bodenfruchtbarkeit, die Agrar- und Infrastruktur und für die Erholung der Bevölkerung zu erhalten, erforderlichenfalls zu mehren. 1.2 Die ordnungsgemäße Bewirtschaftung des Waldes ist nachhaltig zu sichern. 1.3 Es bedarf des Ausgleichs zwischen dem Interesse der Allgemeinheit und den Belangen der Waldbesitzer. 1.4 Die gesetzlich verankerten Funktionen des Waldes sind von den Behörden bei allen Planungen und Maßnahmen angemessen zu berücksichtigen, sofern diese eine Inanspruchnahme von Waldflächen vorsehen oder in ihren Auswirkungen Waldflächen betreffen können. 1.5 Wald darf nur mit behördlicher Genehmigung gerodet oder in eine andere Nutzungsart umgewandelt werden. 1.6 Die Waldbesitzer sind verpflichtet, kahlgeschlagene Waldflächen oder verlichtete Waldbestände wieder aufzuforsten oder die Be-stockung zu ergänzen. 1.7 Wald kann mit weitergehenden Auflagen zu Schutzwald erklärt werden, wenn es zur Abwehr oder Verhütung von Gefahren erforderlich ist. Anders ausgedrückt: Raubbau am Wald ist im Allgemeininteresse untersagt. Neben den ökonomischen Funktionen kommt den ökologischen Funktionen ein hoher Rang zu. Das die Bewirtschaftung des Waldes dominierende und von den Waldbesitzern längst akzeptierte Prinzip der “Nachhaltigkeit” führt im Ergebnis dazu, daß die planmäßige Nutzung den Zuwachs an Holz nicht überschreiten darf und daß die Waldflächen nicht beliebig einer anderen Nutzungsart zugeführt werden können.
Kurzfristige verfugbarkeit von forstlicher biomasse in der bundesrepublik deutschland:
39
Ad 2): Elemente der Forst- und Agrarstruktur sowie Merkmle der Waldnutzung und Holzverwendung Der Waldanteil an der Fläche des Bundesgebietes beträgt 29,5%, d.s. über 7,3 Mill. ha; davon sind 31% mit Laubholz und 69% mit Nadelholz bestockt. Eigentumsverteilung: 56% Bund, Länder, Gemeinden, öffentl. Anstalten und Stiftungen; 44% Private. Zahl der Betriebe mit Wald: 473.000 (ohne 0,44 Mill. ha Waldfläche 30 TS Energy (kt/y) (ktoe/y)
Byproducts with C/N30) for direct combustion processes: E (mean energy content): 16,400kJ/kg TS for straw; 17,100kJ TS for pruning residues; η” (relative efficiency of utilization plant: biomass-fuelled burner replacing a Dieseloil burner): 0.88 C (mean energy outlay): 1700kJ/kg TS The above indicatively yields: – for byproducts having C/N≤30: P=0.088toe/t TS; – for byproducts having C/N>30: from herbaceous crops: P=0.30toe/t TS from tree crops & forests: P=0.31toe/t TS For those byproducts meant for anaerobic digestion, the energy value of process affluents is evidently also to be accounted for. These effluents, usable as fertilizers, can be assessed at 0.10–0.12toe/t TS; hence, P=0.20toe/t TS. ANNEX 2 1. The actual available animal byproducts for energy use were calculated on basis of equivalent livestock units as follows: Livestock Animal equivalent (AE) (kg) Excreta TS (kg/t on the hoof) VS (% TS) Cattle Swine Broilers Hens
450 100 0.8 1.7
8.5 6.0 13.0 13.0
73 75 70 70
Energy from biomass
120
(NB: 100kg was assumed per equivalent pig and 0.8kg per equivalent broiler to account for average residence time, average growth during residence and final selling weight. For cattle, account was taken of the ratio of milking cows to fattening cattle). The formula used is: TS=Σ[n.D.AE.365.δ.γ] (t/yr) where: – TS=total solids per year (t/y) – n=number of head equivalent – D=total solids per day and animal unit weight (kg/t.d) – AE=equivalent weight (t) –δ=reduction coefficient to exclude animal farms below a certain number of head equivalent (cattle: 250
250–300
>250 >300 >300 >300
450 350 0–50 300–350
An economic analysis of the energy valorisation of cereal straw in france
1155
* with grants
Table 4—Straw pellets Use
Straw required
Al ternative proposal
Interest price FF/t
Animal feed – l ucern 600–700 Individual heating 10–12t/year oil 500–650 Collective heating 5t/accomodation heavy Fue 1 oi1 450 – the price of pellets is ≥ 600FF/t – treshold cost of straw pellets produced in dehydratation factories is minor than they are produced in specific Factories.
INTEGRATION AND ASSESSMENT OF BIOMASS RESEARCH INFORMATION BY USE OF SYSTEM ANALYSIS J.W.Mishoe Professor of Agricultural Engineering University of Florida Gainesville, Florida 32611 USA Summary The Institute of Food and Agricultural Sciences (IFAS) at the University of Florida, in cooperation with the Gas Research Institute is operating a research program to develop an econonically feasible system to produce and convert biomass to methane for use as energy. The research methodologies include using systems modeling and computer simulation to aid the researchers in setting research priorities and to assess the impact of new information on the performance of the system. The interactive systems model, BIOMET, consist of process oriented models for the crops of Napiergrass and waterhyacinth and we are currently including reactor driven conversion models. In addition, biomass transportation, biomass harvesting, economics and energetics are included to produce simulated outputs of systems economics, energetics, methane yield and biomass yield as influenced by management and environmental conditions. Simulation studies indicate that water-hyacinth yields vary from 37t/ha to 63t/ha in response to harvest schedule. Transportation cost for Napiergrass contribute significantly to gas cost, however by increasing yields on fields sites close to the conversion facility can help reduce the total cost.
1. INTRODUCTION Biomass is a source of energy that can provide an important contribution to the energy supply in developed countries with regions having a favorable climate. Feedstocks can be derived from various sources including waste and biomass grown specifically for energy production. Options exist that combine biomass production with other necessary operations such as using waterhyacinth to aid in cleanup of waste water or eutrophic lakes by growing the crop directly in the enriched water. The resultant biomass can then be converted to high quality energy by the use of anaerobic digestion for methane production. The University of Florida in cooperation with the Gas Research Institute is conducting a research program with the goal of developing a commercially viable system for the
Integration and assessment of biomass research information by use of system analysis
1157
production and conversion of biomass feedstocks to pipeline quality methane gas (4). As part of the research program a systems analysis project was implemented to assess the cost sensitive parameters to allow priority research to focus on areas with the greatest potential of reducing gas cost. Members of the systems teams consist of engineers, economists, statisticians, and computer specialists working with the experimentalists. The system under study consists of a central conversion system with biomass produced on a regional basis and transported to the conversion facility after harvest. The components of the system can be defined as the biomass production, harvesting, transportation, and conversion. To analyze the system we have defined the economic and energetic characteristics of each component and in the case of the crop production and the conversion, we also model the performance of the component in response to component design, management, and environmental inputs. The objective of this paper is to describe the approaches and methodologies used by the systems group and to present selected preliminary results of the analysis. 2. METHODOLOGY The component models have been integrated into an overall system level model called BIOMET (3). The first operation in the interactive model BIOMET is to define the configuration of the system to be simulated. The options include crop selection, field size and location, conversion reactor type, harvester type and size, transportation type and size, costing parameters, economic parameters, and gas demand (Figure 1). BIOMET uses this information to select the number of trucks and harvesters needed and to estimate a harvest demand schedule. With this configuration the simulation begins and the ability of the system to preform as demanded is determined. If any component becomes limiting, the appropriate economic and energetic factors are recorded. The output reports summarize the actual performance of the system, reporting biomass and gas yields and the respective costs. BIOMET differs from essentially all analysis procedures found in the biomass literature in that the simulation of the physical and biological processes are included in the analysis. This capability is important because it allows for the analysis of various management factors that cannot be considered otherwise. For example, variations of sequential management inputs such as fertilizer application, harvest rates, planting density, etc. can be used to determine the resultant crop growth because the crop model can integrate the accumulative effects of weather and management. Currently BIOMET includes crop models for Napiergrass and water-hyacinth. Each crop model consist of component models to maintain the growing medium balance for nitrogen and water and for carbon, water, and nitrogen balance of the plant. Each of the crop models are different based upon the functional and parametric changes necessary to accurately describe each crop, however the basic carbon balance structure of the model can be expressed in a generic format. For each crop (1) where dw/dt is the rate of biomass accumulation, Pg is gross photosynthesis, Ro is the are the conversion coefficient of maintenance respiration, W is the total biomass,
Energy from biomass
1158
efficiency terms and S is the rate of biomass loss form the crop due to senescence. For a given crop type, the coefficients can be defined as a function of crop stage and environmental temperatures. Pg is defined as a function of light interception and the crop stresses. This takes the form of Pg=K R fNfWfTfL (2) where K is a crop coefficient, R is the ambient solar radiation and fN, fW, fT, and fL are functions ranging in value from 0 to 1 that are related to plant nitrogen, plant water, air temperature, and crop light interception, respectively. Figure 2 compares waterhyacinth model simulations to measurements of waterhyacinth growth for the conditions used in the simulation.
Figure 1. Block diagram summarizing available menu selections from the BIOMET program The simulation of the conversion process in the current example analysis is limited to an overall efficiency of the conversion system based upon the quantity of biomass input. The conversion type and size was held constant and the economics were based upon the utilization of the selected facility. In BIOMET an estimator model uses the monthly gas
Integration and assessment of biomass research information by use of system analysis
1159
demand to determine the total annual biomass requirements. From the biomass demand and the user-supplied monthly gas demand, a monthly biomass demand is computed. Once the simulation begins, if biomass demand cannot be met the gas output is reduced and the variable cost are computed based upon the actual throughput. The BIOMET cost model calculates the initial investment (for biomass feedstocks and methane production) prior to simulation based upon user-defined scenarios, and then accumulates the variable costs during simulation. The levelized cost model uses these costs to calculate the levelized-cost-of-service price. Initial investment and variable cost are calculated separately for Napiergrass production, harvesting, and for conversion. Waterhyacinth costs are based on a winch-boom design (5). The user is limited to a choice of four sizes estimated to produce feedstock for 0.1, 0.5, 1.0, and 3.0 10BTU/year conversion plants. Capital investment and variable cost are estimated based on the usersupplied geometry, size, and operating parameters. Napiergrass production, harvesting, and transportation costs include both capital investment and variable operating costs. Components of the initial capital investment include: harvester, trucks, and initial land rental, crop management (fertilizer, pesticides, etc.), labor, fuel, and machine operating maintenance.
Figure 2. Example simulation using the waterhyacinth model from BIOMET (Data collected by Reddy (1)). 3. RESULTS AND DISCUSSION To examine the cost sensitivity of biomass due to transportation, BIOMET was used to simulate a 3200ha farm with the conversion cost, numbers of harvesters, and production cost held constant. In Table 1 only the number of trucks varied to meet the distance requirements. The biomass cost increased from $2.11 $/10BTU using six trucks to 4.63
Energy from biomass
1160
$/10BTU using 70 trucks with to distance was changed from 0.1km to 100km. In the second example the distance was help fixed at 20km and the number of trucks were varied from 9 trucks to 31 trucks (Table 2). Below 19 trucks the transportation was limiting and above this excess trucks were available. Because capital cost are a minor part of the total production cost results indicate that capital intensive transportation that reduce variable cost can reduce total transportation cost. From a cost viewpoint it is important not to allow transportation to limit the system.
Table 1. A 3200ha Napiergrass farm various distances from the conversion site (2). DISTANCE TRUCKS DISTANCE TRAVELED CAPITAL1 COST VARIABLE1 COST Km 103km —$/106 BTU— 0.1 10 30 60 100
6 12 25 44 70
60 1212 3540 7031 11686
0.12 0.12 0.15 0.18 0.21
1.99 2.24 2.73 3.46 4.42
Table 2. Simulations of a 3200ha Napiergrass system 20km from the conversion site (2). NUMBER BIOMASS OF TRUCKS HARVESTED t/ha
DISTANCE TRAVELED 103km
CAPITAL1 VARIABLE1 SYSTEM2 COST COST COST 6 —$/10 BTU—
9 13.5 567 0.12 12 20.1 1102 0.12 15 26.3 1778 0.13 19 31.9 2376 0.14 31 31.9 2376 0.15 1. The capital and variable cost included are for biomass production. 2. Includes a constant cost of 4.39 $/10BTU for conversion.
4.05 3.06 2.60 2.48 2.49
10.04 8.23 7.32 7.01 7.03
The development of BIOMET is an on going activity that has not been completed. It however is a very useful tool for integrating new research information and determining the impact on the overall performance of the system. Results indicate that methane produced from biomass can be cost competitive with other energy sources. It however will require the continuation of focused research efforts to develop the necessary technologies and the procedures to manage these technologies. 4. REFERENCES 1. Lorber, M.N., J.W.Mishoe and K.R.Reddy. 1984. Modeling and analysis of waterhyacinth biomass. Ecol. Modeling 24:61–77. 2. Mishoe, J.W., W.G.Boggess and D.W.Kirmse. 1984. BIOMET: A simulation model for study of biomass to methane systems. Proceeding of the IGRC. Washington. D.C. USA. 10 pages.
Integration and assessment of biomass research information by use of system analysis
1161
3. Mishoe, J.W., M.N.Lorber, R.M.Peart, R.C.Fluck and J.W.Jones. 1984. Modeling and analysis of biomass production systems. Biomass 6: 119–130. 4. Smith, W.H., P.H.Smith and J.R.Frank. 1982. Biomass feedstocks for methane production. In: Proceeding of 2nd EC Conference on Energy from Biomass. Applied Science Publ., New York, USA. pp122–126. 5. Warren, C.S., etal. 1984. Evaluation of the lake apopka natural gas district task report. RSH, 6737 Southpoint Dr. S., Jacksonville, Fl.
CONVERSION OF LIGNOCELLULOSIC MATERIAL TO ETHANOL INFLUENCE OF RAW MATERIAL YIELD AND HEMICELLULOSE UTILIZATION ON SALES PRICE OF ETHANOL J.Felber, M.Schiefersteiner and H.Steinmüller VOEST-ALPINE AG, P.O. Box 2, 4010 Linz/AUSTRIA Summary In the late 70’s an Austrian Consortium consisting of the STEYRERMÜHL-PAPIERFABRIKS- und VERLAGS AG, the VOESTALPINE AG and the Universities of Graz was formed to develop a new process for the production of monosaccharides from renewable carbohydrate sources, in particular lignocellulosic material. After detailed examination of various hydrolytic processes it was decided to intensify work on enzymatic hydrolysis. The composition of this group brought the great advantage that it could focus not only on one problem but could also research into the total process. This included pretreatment, enzyme production, hydrolysis, by-product utilization and energy supply. The raw materials studied most thoroughly in our program were waste paper and wheat straw, since these lignocellullosics are available in large quantities in Austria. Until now all endevour to produce ethanol out of lignocellulosic biomass on an industrial scale failed due to uneconomical production. Thus it is evident that the economy of such a process is very dependent not only on the yield of sugar, which is strongly affected by the respective pretreatment, but also on the utilization of the hemicellulose. Summarizing it can be said that the cellulose has to be degregated to a high extent and that the hemicellulose must be utilized to reach a feasible project.
GENERAL DESCRIPTION The raw materials studied most thoroughly in our program were waste paper and wheat straw, since these lignocellulosics are available in large quantities in Austria. From the wide range of possible materials we also tested rice husks, sugar cane bagasse, palm oil residues and cotton stems. The theoretically possible quantity of sugars obtainable from waste paper and wheat straw—as estimated by our standard method (Esterbauer et al, 1982) is:
Conversion of lignocellulosic material to ethanol influence of raw material yield and hemicellulose
1163
(per 100gr dry matter rice husk waste paper wheat straw Glucose Mannose xylose Galactose Arabinose
38,3 4,0 18,5 1,2 2,7
48,0 11.4 4,9 1,4 0,9
42,00 0,38 25,50 1,90 4,30
Our program has now reached a stage where the available data can be used for a feasibility analysis of a full scale industrial plant based on wheat straw. This plant is designed for the daily production of 80,000litres of ethanol and single cell protein, furfural or furfurylic alcohol. The necessary enzymes are produced by the fermentation of hydrolysis residue with Trichoderma reesei SVG 22, a residue adapted mutant of QM 9414. The following picutures show the linkage of the respective processing areas:
Energy from biomass
1164
The main sugars in the biomass fibres are glucose in the form of cellulose and xylose in the hemicellulose fraction. In considering the economics of a process it is important to have exact information with respect to the potential available sugars of the raw material under consideration. If one takes MSW for example: In the USA it usually contains more than 50 % cellulose, however, MSW from Austria has only about 25 % cellulose. Thus it is evident that the economy of such a process is very dependent not only on the sugar yield, which is strongly affected by the respective pretreatment, but also on the utilization of the hemicellulose. Effect of pretreatment on glucose yield from wheat straw and newspaper. The pretreated material (100 g/l) was treated with cellulase enzyme (2 g/l) for 72 h. Theoretical yield 42 g (wheat straw) and 48 g (newspaper) per 100 g dry matter. wheat straw newspaper treatment glucose % of treatment glucose % of th. th. soaked in NaOH, steamed at 180– 200°C hydrothermolysis 180–200°C steamed at 180–200°C autoclaved, 200°C cutter reflection plate mill Wiley mill hammer mill no pretreatment
73–95
diagonal knife refiner, CaO
73–78
90 80 65 38
disk refiner reflection plate mill hammer mil1 soaked in NaOH, steamed at 235°C cutter steamed at 235°C hydrothermolysis 190°C no pretreatment
70–73 72 60 30–45
29 21 18 16
48 34 34 17
Conversion of lignocellulosic material to ethanol influence of raw material yield and hemicellulose
1165
In summary it can be said that when using a raw material with a high content of hemicellulose (cereal straw, hard wood, etc.) the utilization of xylose is indispensible, since it contributes up to 30% of the dry matter, Xylose can be converted by known chemical procedures to furfural and its consecutive products. The fermentation of xylose is not as well developed as glucose fermentation, with the exception of a few processes, e.g. the production of single cell protein. It is expected that
Energy from biomass
1166
future research in this area will improve the yield and productivity of xylose fermentation procedures. Assumptions for the feasibility calculation of a largescale industrial plant:
Results: Return on Investment: Break-even point:
17% (10 years of production) 80% of nameplate cap.
For further reduction of production cost in the near future our main activities will be to improve the enzyme production and recovery and to optimize the energy supply.
BIOENERGY IN REGIONAL ENERGY SYSTEMS—A CASE STUDY FROM HADELAND IN NORWAY A.LUNNAN Department of Forest Economics Agricultural University of Norway Box 44, N-1432 As-NLH, Norway Summary Up to now biomass in Norway is mainly used non-commercially as firewood in households and as mill residues in the forest industry. There are on the market commercial bioenergy systems that should be economically feasible. The hypothesis is that there exist institutional barriers that make a further development at the commercial bioenergy sector difficult. The Hadeland project studies this problem on a regional level. A regional bioenergy commission consisting of representatives from the most important interest groups serves as reference group for the project. The commission tries to establish press contacts, to inform local politicians and to stimulate potential bioenergy investors. The research project consisting of a systems study and a study of the work in a bioenergy commission, is planned to be completed by the end of 1985. Preliminary figures show that there exists a large unused bioenergy potential in the region. The systems study will hopefully identify feasible projects to utilize a part of this potential. The work in the commission has so far been fruitful and it seems that at least some of the barriers initially discussed could be overcome through cooperation and discussion between the interest groups at the bioenergy sector.
1. INTRODUCTION Bioenergy is not likely to play a major role in the national energy system in Norway. On the regional level, however, the impact of bioenergy might be considerable. Up to now biomass is mainly used non-commercially as firewood in households and as mill residues in the forest industry. What possibilities does biomass have as a commercial energy source? After five years of bioenergy research in Norway we have some technical and economical knowledge about bioenergy systems. We also think that some of these systems are competitive in the market. When starting the project we identified the most important barriers for commercial bioenergy utilization to be: 1. Bioenergy is a complex field which involves forestry (or agriculture), industry, energy sector and consumers. There has been limited contact between the sectors.
Energy from biomass
1168
2. The electric utility sector has up to now looked upon bioenergy as a competitor, not as a challenge. In the Hadeland project we want to study what we can do to decrease these barriers. Another aim of the project is to identify the social and environmental impacts of increased use of biomass as an energy source. 2. DESCRIPTION OF REGION To study the problems described initially we decided to make a case study in Hadeland, a region in Southern Norway (see map).
Figure 1. Map of Hadeland 3. REGIONAL REFERENCE GROUP Without local involvement from the beginning such a study would be meaningless. We therefore contacted some selected “resource people” and it was decided to set up a “Hadeland bioenergy commission”. The commission has six members representing: electric utility sector, technical division in the communes, forest owners, forest industry (saw-mills), forest and agricultural extension service and a forest engineer serving as secretary for the group. The Department of Forest Economics, Agricultural University of
Bioenergy in regional energy systems-a case study from hadeland in norway
1169
Norway serves as an engine in the commission and we also work with special analysis such as resource base, systems analysis and market analysis in cooperation with the commission. The secretary of the commission is responsible for press contact and we have already got good public relations in Hadeland. Politicians and local population start to be aware of the commission and this is important for our political contacts in the next phase of the project. To get acquainted in the bioenergy field the commission has arranged study tours in Norway and above all to Sweden. Financial support for these tours has been given by the communes, electric utility sector, industry, banks, forest owners federation and some other local organizations. Most study tours are reported in the local press. 4. RESULTS SO FAR; RESOURCE BASE
Table 1. Primary energy consumption Hadeland Electricity 300 Gwh 82% oil 36Gwh 9% Bioenergy Firewood 23Gwh Sawmill residues 12Gwh 35Gwh 9% Total (excl. transport) 371Gwh 100% of this as heat 231Gwh 62%
Table 2. Bioenergy potential in Hadeland. (Net energy, losses due to combustion, distribution etc. are included) Forest industry residues 35Gwh Forest residues 37Gwh Straw 33Gwh Manure 11Gwh Urban refuse 18Gwh Total 134Gwh —Consumed today 35Gwh Bioenergy potential 99Gwh
Tables 1 and 2 show that it should be possible to provide more than 50% of Hadeland’s demand for heat energy from biomass. It should be added that the forestry figures in table 2 are preliminary and conservative estimates, most probably they should be higher. 5. FURTHER WORK We are these days working with a market study which will be completed in May 1985. A rough systems study of different ways to convert biomass to energy is also underways. This study will give us cost and employment data. We can already today identify some five interesting projects to continue with. Different members of the commission have
Energy from biomass
1170
their own fields of responsibility and they provide us with valuable information for the final report. The final report from the project is going to be written in autumn 1985. We then plan press conferences and meetings with local politicians and population. The next phase of the project will then be concrete work with special projects. This is of course a task for the investors in question. It is not yet decided if the commission shall continue its work in phase 2. 6. PRELIMINARY EXPERIENCES AND CONCLUSIONS The project is not yet completed, but our experiences so far have been good. We are now making a snow-ball, time will show whether it will be rolling. The expected conservatism in the electric utility field has not been present and we have had very fruitful discussions in the commission. We have created enthusiasm and hopefully this will lead to results. We will also try to make some guidelines for the work of a bioenergy commission in a region. This would be of some interest for the bioenergy work in other parts of the country.
POSSIBILITIES OF RELIEVING THE EEC AGRICULTURAL MARKET THROUGH ENERGY PRODUCTION E.G. RAPE AND SHORT-ROTATION FORESTRY R.Apfelbeck TU—MUNICH Bayer. Landesanstalt für Landtechnik D—8050 Freising Summary In the European Community, an excess of 10–16mio ha of farmland for agricultural production is expected by 1990. Presently, the expenditures for regulating the market due to overproduction run at 850–1300DM per ha of equivalent export land. The production of energy sources, both short-rotation forestry and rape cultivation can result in net savings of more than 700DM/ha only if the energy is utilised locally by the producer. The overproduction of agricultural products is continually becoming a larger problem in the European Community. In 1984, the Community harvested 150mio t of grain, which represents a degree of self-sufficiency of 130%. The calculatory overproduction of wheat is 24mio t. On the other hand, the annual consumption of about 400mio t of crude oil is almost completely imported. The production of biomass on excess land could partly replace the energy imports. According to HEIDRICH’S calculations, an equivalent import surface of 5.8mio ha for food production was still required in 1973 for self-sufflciency, while in 1982 an excess of 4.2mio ha already existed. From Figure 1 it is clear that by 1990, the overproduction will represent 10–16miot. The production increases have led to continually increasing subsidues derived from the Community budget (see Fig. 2), such that the expenditures will soon exceed incomes.
Energy from biomass
1172
Figure 1: Trend and projected values of the supply situation in the EEC-9 converted to surface equivalents (according to HEIDRICH) In Figure 3 it can be seen that a subsidy of 850–1300DM per ha of surface equivalent already arises; for sugar beets up to 4.100DM.
Figure 2: Development of expenditures of the common market listed according to purpose.
Possibilities of relieving the ec agricultural market through energy production
1173
Figure 3: Producing area, export area and market subsidies in the EEC-9 (according to HEIDRICH) These expenditures reach a level, which corresponds to a half to one gross margin. As a possible alternative to reduce the overproduction, the cultivation of biomass crops is to be discussed. If biomass could be produced on the entire agricultural area at 2t of crude oil equivalent per ha, 40% of the crude oil imports could be substituted. The percentage of bioenergy on agricultural excess lands would be max. 5%. Apart from ethanol production, rape cultivation and short-rotation forestry can be considered, since the products produced could be used directly at the farm site. SHORT-ROTATION FORESTRY With this alternative, 10.000–12.000 poplar slips are planted per hectare. After 2 years of weeding and annual fertilization, the entire wood material is harvested in 5 year-intervals as chips. The lifetime of such a system is estimated at 15 years. At the Hessischen Forstlichen Versuchsanstalt, Hann. Münden, the average annual dry-weight growth was 10–15t per ha in the period 1979–83. The best varieties even reached 25–30t (dry matter). The advantages of this production method: – Wetland sites are possible (high precipitation, pastures) – Reduced use of weed killers – Soil erosion is hindered – Harvest time in the winter months
Energy from biomass
1174
These are offset by the disadvantages: – Production techniques in trial stage – Storage and drying not yet determined – Large transport capacities required – Extended capital binding, liquidity problems – Market introduction as a product necessary In Figure 4, the expenditures are illustrated for a 1ha short-rotation forestry plot. The initial costs in the first year are about 8.000DM, harvest costs 100DM/t (dry matter) and the costs for ventilation drying are 25DM/t (dry matter). An interest rate of 7% for debts and 5% for credits is assumed. As a substitute for oil, the wood chips are to be used at the farm site and the cost is set at 260DM/t (dry matter).
Figure 4: Simplified balance sheet for a short-rotation forestry plot of 1 ha over 15 years With the above assumptions, a satisfactory income or savings can be expected only if the initial productivity is above 15tdry matter/ha annually. Cost reductions are possible in the harvesting and drying processes. Detailed results from the test plantings should be awaited. RAPE CULTIVATION The cultivation of rape is well known. Figure 5 shows the composition of the plant and its uses.
Possibilities of relieving the ec agricultural market through energy production
1175
Figure 5: Composition and the possible uses of rape The method has the following advantages: – Production techniques known – Fuel production for vehicular power (substitute for diesel) – Production of protein-rich fodder Disadvantages are: – Rape oi1 usable only in special engines – Production restricted to arable land If rape oil is not chemically treated (trans-esterification), only few diesel engines can be considered (Elko, KHD). Rape straw can substitute heating oil and rape meal can be fed to livestock. Figure 6 shows the range of possible substitution or saving values with the use of rape as an energy crop.
Figure 6: Economic evaluation of the energetic use of rape at the farm site
Energy from biomass
1176
Depending on market situation and the given farm operation, net savings of 700– 1200DM/ha are possible with the local use of rape products at the farm. Further investigations of both energy crops are necessary for an exact economic analysis. Even under more unfavourable conditions as considered here, a transfer of market subsidues into energy crops can lead to savings in the EEC budget. With a change of direction toward energy production, however, considerable organizational problems are also to be expected. REFERENCES (1) BATEL, W.: Pflanzenöle für die Kraftstoff- und Energieversorgung, Grundlagen der Landtechnik, Bd. 30, Nr. 2, 1980 (2) BUSCH: Mündliche Mitteilung, 1985 (3) DIMITRI, L.: Schriftliche Mitteilung, 1984 (4) ELSBETT, L.: Prospektmaterial, 1984 (5) v.GELDERN, W.: Rund neun Mio. Tonnen Weizen nicht absetzbar, Süddeutsche Zeitung, 09.01.1985 (6) HOFSTETTER, E.M.: Feuerungstechnische Kenngrößen von Getreidestroh, Dissertation, Weihenstephan 1978 (7) KHD-Information: Prospektmaterial 1984 (8) SCHÄFER, R.; E.HEIDRICH: Einfluß und Nutzung von Biomasse als Energieträger auf die arbeitswirtschaftliche Lage, die Energiesituation und die Agrarmarktprobleme der Europäischen Gemeinschaften, Endbericht zum Vorhaben ESE-R-065-D (B), Studie 2/1, 1984 (9) WEISGERBER, H.: Klonvergleichsprüfungen bei Schwarz- und Balsampappeln im Kurzumtrieb, Vortrag auf Tagung “Ad-hoc Committee on Biomass Production System in Salicaceae, Ottawa, Kanada, 1984
THE ECONOMICS OF THERMOCHEMICAL ROUTES FROM WOOD TO LIQUIDS L.A.MICHAELIS Cambridge Energy Research Group Cavendish Laboratory Madingley Road Cambridge, UK CB3 OHE Summary Several research groups and companies are working on the technologies for converting wood to liquid fuels. The technologies include those for producing synthesis gas followed by methanol, gasoline or FischerTropsch liquids, as well as direct liquefaction using a solvent and catalyst. Process yields, capital costs and running costs have been predicted, with varying degrees of confidence. Most predictions suggest that at the present price of fuels from petroleum, none of the technologies is likely to be economic. Central estimates for the best developed, indirect methods give fuel costs at around $11/GJ, which compares with a price of around $5/GJ for internationally traded gasoline. Improvements in processes seem unlikely to reduce costs below $8/GJ. A simple spreadsheet programme designed for comparative assessment of fuel conversion technologies in developing countries is applied here to liquid fuel production. It is seen that countries with foreign exchange problems—either an overvalued currency or worsening terms of trade— may find these technologies attractive. Discounted cash flow analysis is used to compare the effects of technology improvements with those of the economic environment on fuel cost. The results make clear the attractiveness of a direct liquefaction process, if one was developed to a commercially viable stage.
1. INTRODUCTION Evaluation of fuel conversion technologies hinges on the economics. The normal method used is discounted cash flow analysis, giving the product price needed to pay for the project costs. Several organisations have made assessments of wood conversion technologies. These indicate that the cost of transport fuels from wood is likely to be two or three times the price of internationally traded fuels from oil (now about $5/GJ). For this reason much attention is being paid to finding ways of reducing the cost. As capital comprises 50% of the conversion cost for most processes, most attention is paid to this
Energy from biomass
1178
factor. Process efficiency is also extremely important. Plant costs depend almost entirely on the amount of wood processed, not on the output level, so product cost is inversely proportional to yield. While lowering costs brings forward the time at which these products can compete with fuels from oil in affluent countries, some may already be attractive in countries experiencing severe economic difficulties. In order to facilitate assessment of different technologies in diverse economic climates, a spreadsheet programme has been written using cost-benefit analysis. The programme calculates the price of internationally traded oil for which the product is a desirable substitute. It allows for variations in capital costs, wage rates and so on, as well as for different rates of escalation of wages, energy prices, plant costs etc. This paper demonstrates the kind of results obtained when such analysis is used on four technologies producing transport fuels from wood. 2. THE TECHNOLOGIES The technologies considered here are; 1) Gasification of wood in a Winkler or Westinghouse type fluid bed gasifier, followed by methanol synthesis by the ICI or Lurgi low pressure process. 2) Methanol production as in 1), followed by conversion to gasoline by the Mobil process. 3) Gasification followed by Fischer-Tropsch synthesis in a liquid phase reactor, and then upgrading to transport fuels. 4) Direct liquefaction of wood by the PERC process. Capital costs and efficiencies are given in table I. The technologies are reviewed in detail in ref.(1), except Fischer-Tropsch synthesis which is reviewed in ref. (6).
TABLE I: Investment and Product Yields for Reference Technologies Technology:
Methanol synthesis Gasoline synthesis Fischer-Tropsch PERC process
Investment (1984$m) Feed rate (TJ/day) Product (TJ/day): Methanol Gasoline Diesel LPG Chemicals Total Product Efficiency (h.h.v.) *1000 dry tonnes wood/day
125 18.5*
150 18,5*
150 18.5*
8.28
4.55 2.90 0.47 0.66 8.58 46.4%
120 18,5*
10.5
1.45 10.5 56.8%
9.73 52.6%
10.4
10.4 56.2%
Methanol synthesis is the best established process, and although as a whole it is not in commercial use, gasification and methanol synthesis are practised at a commercial level. The literature is extensive, and only three references (1–3) are given here. There is broad agreement about capital costs; the figure of $125m (1984 US$) used here is representative of values obtained after extensive use of the Chemical Engineering Plant
The economics of thermochemical routes from wood to liquids
1179
Cost Index, and scaling plant size to 1000 t/d. (Ref. 4 shows that investment is related to output Q by I=IoQ0.8.) The Methanol-to-Gasoline process is less well established, and not yet commercially proven. Capital costs are estimated (1) at around 17% on top of methanol synthesis costs. The efficiency of the MTG process is high, and heat recovery allows the loss of thermal efficiency in the overall process to be as low as 2% (5). The cost and efficiency used here are representative of values from the literature. Fischer-Tropsch synthesis has been considered less for wood because of high capital cost and low efficiency. However the process is commercially established for the conversion of coal in South Africa. The presence of deisel fuel in the product may be an advantage in some countries. There are several versions of the process, which catalytically converts synthesis gas to hydrocarbons. The version used here is the liquid phase process. This has several advantages over the Synthol and Arge processes used in South Africa, including a low H2:CO requirement in the synthesis gas, lower capital cost and higher selectivity in the product. The data used here is based on ref. (6), and data for wood gasification on ref.(1). Refining of the product is about 50% of the cost, although this might be reduced by refining the product from several plants at a central refinery. The PERC process is at a very early stage of development, and costs and yields are correspondingly uncertain. Although the figures used here from ref. (1) imply excellent yields and low cost compared with other processes, there are several technical difficulties which may be costly to overcome. The process, like coal liquefaction, involves slurrying wood in recycled oil, which acts as a solvent while the wood is reduced at high CO pressure. The product is high in oxygenates and low in hydrogen, and upgrading comprises 50% of capital costs. The product is diesel or jet fuel, which would be preferable to methanol or gasoline in many countries. Running costs for the processes vary between sources. Operation and maintenance charges are normally assumed to cost a percentage of plant investment per annum. Labour and feedstock costs are dependent on location and vary by an order of magnitude. The base values used here are given in table II.
TABLE II: Assumptions for D.C.F. Calculations Construction period 3 years Plant life 20 years Discount rate 10% Load factor 80% Annual costs: Materials 4% of Investment Utilities 2% of Investment Catalysts 1% of Investment Labour @ $50/shift; $0.79m/annum Feedstock cost $25/dry tonne @18.5 GJ/tonne
3. ECONOMICS Table III gives the results of discounted cash flow calculations for projects using the four technologies.
Energy from biomass
1180
TABLE III: Breakdown of Product Cost: 1984$/GJ (%) Technology Methanol synthesis Gasoline synthesis Fischer-Tropsch PERC process Capital O&M Feedstock Labour Total
5.21 2.58 2.28 0.26 10.33
(50.5) (25.0) (22.0) (2.5) (100.0)
6.72 3.34 2.45 0.29 12.80
(52.5) (26.1) (19.2) (2.3) (100.1)
7.61 3.78 2.78 0.33 14.50
(52.5) 5.00 (49.9) (26.1) 2.48 (24.7) (19.2) 2.29 (22.8) (2.3) 0.26 (2.6) (100.1) 10.03 (100.0)
It is seen that capital costs comprise about 50% of product cost for each process. Capital related costs, including maintenance materials etc., comprise 75% of the total. Feedstock cost is relatively unimportant and direct labour costs are very small. Product cost is determined mainly by the plant investment and process efficiency. Capital costs are highly uncertain. Ref. (1) estimates the range in the region of −20 to +50% for untried technologies, with an additional ±20% due to location (for freight etc.). This range is larger than that of central estimates for different technologies. For this reason sensitivity analyses are given for just one base case investment. Table IV shows the results of some sensitivity tests. Also shown are the effect of varying feedstock and labour costs together, and capital cost and yield together. The first is significant as low labour costs will lead to labour intensive forestry and low cost wood. Improvements in processes are likely to give both lower capital costs and higher efficiencies; for instance, the use of steam gasification, with combustion in a separate reactor, can eliminate the need for oxygen generation in methanol synthesis. The result is lower cost and higher efficiency. 20% reduction in capital and 10% increase in yield probably represents the best case attainable.
TABLE IV; Sensitivity of Product Cost Base case; Plant investment $125m Product 10 TJ/day Labour $0.79m/yr Discount rate 10% Feedstock $25/t Base case cost $10.83/GJ Item varied Product cost $/GJ Capital Discount rate Feedstock Labour Labour & feed
−20% to +50% 9.2 to 14.9 5% to 15% 9.0 to 13.0 −50% to +50% 9.6 to 12.0 $0.1m to $4m 10.6 to 12.0 $0.1m & −50% 9.4 to $4m & +50% to 13.2 Yield 11 to 9TJ/dy 9.8 to 12.0 Yield & capital 11TJ/dy & −20% 8.4 For comparison; cost of gasoline from oil is currently $5/GJ
Discounted cash flow analysis can be modified for government projects, to take account of influences other than simple cash benefits on the investment decision. Shadow wages, prices and exchange rates can be used to reflect the true value of each item to the decision
The economics of thermochemical routes from wood to liquids
1181
maker. Allocation of shadow prices is subjective and complex, and this paper only attempts to illustrate the results from such allocation. For a full discussion see ref. (7). Table V shows the effect of different shadow exchange rates, and also of different benefits from the products. Some countries are experiencing worsening terms of trade and large foreign debts. In many cases this leads to an overvalued currency. The effect of discounting domestic expenditure in the project by an appropriate factor is shown. Process plant is assumed to be imported, but civil engineering costs are treated as domestic, as are feedstock and labour. Where a country can produce its own plant the product cost will be reduced in proportion to the discount factor, so a factor of 2 would make the project viable. The combination of improvements in technology and a discount factor of 1.6 could also make the technology viable in such a country. The effects of worsening terms of trade are also shown. These have the effect of increasing the cost of future oil imports, as well as some of the process running costs. Shadow pricing also has to take account of the value of the product to the economy. Diesel, which is used for freight and public transport, is of more value than gasoline, which is used for private cars. Methanol can only be used in blends of up to 3% in gasoline in unmodified engines. LPG can only be used in modified engines. Modifications are only likely to be worth-while for heavy users, such as light goods vehicles. Differential taxes are unlikely to reflect the differences in costs adequately (i.e. through higher gasoline prices) because of the strength of the private motoring political lobby, To account for this the benefit from gasoline sales is discount-ed relative to diesel by different amounts in table V.Fischer-Tropsch synthesis becomes more attractive than the MTG process if the discount is more than 30%, but both processes become increasingly unattractive. Methanol would become even less attractive than MTG because of the cost of engine modifications and changes in distribution infrastructure. Although the PERC process appears extremely attractive by comparison, the figures used for efficiency and cost were speculative, and rely on successful development of the process.
TABLE V: Economic Influences on Cost “Cost”* $/GJ Domestic currency discounted by 2 to 4 8.1 to 6.7 Terms of trade deteriorate 1, 2, 3%/annum 9.9, 9.0 or 8.2 Domestic currency discounted by 1.5 and terms of trade deteriorate 1, 2%/annum 8.2 or 7.5 Gasoline discounted 10, 20, 30, 40% effect for; MTG 14.0, 15.4, 17.2, 19.4 Fischer-Tropsch 15.3, 16.2, 17.2, 18.4 PERC 10.0, 10.0, 10.0, 10.0 *Oil import price at which government backed project becomes viable
Energy from biomass
1182
4. CONCLUSIONS While liquid fuels from wood are likely to cost twice as much as oil products in the forseeable future, the technologies may still be desirable in certain circumstances. Improvements in technology could make them viable in countries with foreign exchange problems able to build their own plant. Although the PERC process appears the most desirable in this analysis it is not sufficiently developed, and the data is too uncertain, for the results to be meaningful. The results do show that successful commercialisation of the process would be beneficial. The overall effects of a project on the economy need to be taken into account in its assessment. This paper illustrates the effect such consideration can have. A proper assessment requires extensive evaluation of these effects. REFERENCES 1.) U.S.DOE. “Technical & Economic Evaluations of Biomass Utilization Processes; Technical Report no. 1” Sept. 1980. DOE/ET/20605-T4. 2.) Wan E.I., Simmons J.A., Price J.D., “Economic Evaluation of Indirect Biomass Liquefaction Processes for Production of Methanol & Gasoline” in Energy from Biomass & Wastes VI, Florida Jan. 1982, 3.) Brandon O.H., King G.H., Kinsey D.V. “The Role of Thermochemical Processing in Biomass Exploitation” in Thermochemical Processing of Biomass ed. A.V.Bridgwater. Butterworths 1984. 4.) Reed T.B. “Biomass Gasification: Principles & Technology” ch. 13. SERI Golden, Colorado. 5.) Lurgi Express Information. “Gasoline Production from Natural Gas or Coal” presented at KTI Symposium, Nov. 1980, Los Angeles. 6.) Holmes J.M., Hemming D.F., Teper M. “The Cost of Liquid Fuels from Coal Part II: FischerTropsch Liquids” IEA Coal Research Nov. 1984. 7.) Squire L., van der Tak H.G. “Economic Analysis of Projects” The World Bank 1975.
CHEMICAL INVESTIGATIONS IN THE SWEDISH AGROBIOENERGY PROJECT O.THEANDER Department of Chemistry and Molecular Biology Swedish University of Agricultural Sciences P.O. Box 7016, S-750 07 UPPSALA, Sweden Summary The chemical characterization of a series of crops from the Swedish Agrobioenergy Project—including cereals, sugar beets, fodder beets, Jerusalem artichoke, Salix clones, lucerne and garden orach—and of botanical fractions such as grain and straw or residues after biogas production, is presented. The chemical composition and yield per hectare of individual chemical components within a type of crop show a large variation between varieties, cultivation site and time of harvesting. We have, for instance, found starch values in the grain of winter wheat varieties to vary between 63–73% of dry matter. For ash, cellulose, hemicellulose and Klason lignin in straws from wheat, barley and oats the ranges are generally 3–11, 33–40, 29–33 and 16–21%, respectively. The yields of straw from these experimentally cultivated cereals have varied between 8.6 and 16.9 tonnes dry matter/ha. This indicates a great potential for increasing and controlling the yields of various chemical components in the future by plant breeding and suitable choice of variety and cultivation system. In connection with the project new improved methods have been developed for the analytical determination of sucrose (in beet crops), starch and the lignocellulose components in various plant materials. We have, for instance, found that the conventional automatic method for sucrose analysis of sugar beets, based on optical rotation, gives too high values when applied on fodder beets.
1. THE ANALYTICAL METHODOLOGY When we work with chemical characterization of plant materials in connection with animal and human foods or with crops or fractions from agriculture or forestry of interest as raw products for fuels or other technical products, we generally follow the fractionation—analysis scheme summarised in Fig. 1. For the extraction with aqueous ethanol or acetone and the organic solvents we have found that ultrasonic treatment (at >1 the option is promising; for R1 >>1 >>1 >>1 >1