Contents Biogas processes for sustainable development Table of contents by Uri Marchaim MIGAL Galilee Technological Centre Kiryat Shmona, Israel The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. M-09 ISBN 92-5-103126-6 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 or otherwise, without the prior permission of the copyright owner Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, Italy. © FAO 1992 Contents http://www.fao.org/docrep/T0541E/T0541E00.HTM (1 of 7) [12/15/2007 9:44:51 AM] Contents Acknowledgment Chapter one: Preface and objectives of the review Sustainable development Chapter two: Introduction and overview Chapter three: Short historical background on anaerobic digestion Historical developments of anaerobic digestion technology Present interest in anaerobic digestion Chapter four: Microbiology biochemistry and physiology Microbiology and biochemistry Microbial metabolism in anaerobic digestion Methanogenic bacteria Homo-acetogenic bacterial metabolism Hydrolytic and fermentative bacteria Interspecies hydrogen transfer The methanogens - distribution and taxonomy Methanogens in hypersaline environments Influence of high salt levels on methanogenic digestion Growth substrates of methanogenic bacteria Nutritional and physiological requirements The effects of environaental fact ors on anaerobic digestion Influence of carbon/nitrogen ratio on digestion Biodegradability of digester feedstock Chapter five: Environmental pollution and pathogen control Environmental pollution The need for decontamination The role of blogas in improving rural development, environment and ecology. Chapter six: Aerobic versus anaerobic wastewater treatment http://www.fao.org/docrep/T0541E/T0541E00.HTM (2 of 7) [12/15/2007 9:44:51 AM] Contents Aerobic treatment Anaerobic treatment Anaerobic treatment systems for municipal wastewater Anaerobic filter studies Anaerobic extended and fluidized beds UASB studies Conclusions Chapter seven: Anaerobic processes, plant design and control Digester types Sizing of digesters Comparison of alternative design approaches Problems and solutions of feedstocks and effluents in full-scale biogas plants (based on hobson, 1987) Digester feedstocks Mechanical problems Chemical and biochemical treatments of feedstocks Digester effluent Control device in an anaerobic digestion process Process control Chapter eight: Output and its use I Biogas as an alternative energy source Domestic uses Agricultural and industrial uses Use of biogas for vehicle fuel The purification of biogas Physical and chemical properties of hydrogen sulohide The origins of hydroqen sulphide in biogas plants The effect of H S on the biogas plant and the gas-utilization equipment 2 http://www.fao.org/docrep/T0541E/T0541E00.HTM (3 of 7) [12/15/2007 9:44:51 AM] Contents Engines The odour of biogas Determination of the H S content of biogas 2 Methods for removing H S from biogas 2 Regeneration Biogas production and utilization in China Use of biogas in India Experience of full scale plant of biogas generation at Hambran, Punjab Effect of temperature variation on gas production Chapter nine: Output and its use II Digested slurry: the profit lies in the use of the effluent Biomass uses without anaerobic digestion The effect of use on the nitrogen present in the biomass is discussed below. Biomass uses following anaerobic digestion Land application of effluent Algae production The use of anaerobic fermentation treatment in livestock breeding Nutritional value of effluent in livestock diets Fish feeding with digested cow manure Effluent as a substrate for growing plants and crops Uses for horticulture Growth and rooting experiments Uses of effluent for mushroom production Composting processes Process alternatives for composting Is the composting profitable? Composition and digestibility of different sized fractions in cattle slurry Chapter ten: Integrated approach to the anaerobic digestion process http://www.fao.org/docrep/T0541E/T0541E00.HTM (4 of 7) [12/15/2007 9:44:51 AM] Contents Possible integrated systems Methodology to assess integrated systems Existing integrated systems Chapter eleven: The economics of anaerobic digestion Introduction Analysis of economic feasibility for biogas construction Economic analysis of simple biogas pit for household use in rural area Economic analyses of cement biogas pits for household use in chinese rural area. Economic analysis of community biogas plants in China. Community level plants in India Experience of economic evaluation in other countries Economic analysis on electricity generation with biogas in Chinese rural areas Industrial and commercial feedlots Feasibility estimate for a turn-key community plant Economic evaluation study for a full-scale village-community plant The products of the plant Feasibility estimate for a turn-key farm waste utilization system Economic analysis Summary and conclusions of a full-scale village-community plant Conclusion from the chinese experience Problems in evaluating the community indian plants Organic feedstocks Labour time involved in collection of organic materials and water, digester operation and maintenance Maintenance Economic evaluations Chapter twelve: Technical and social constraints in integrating biogas plants into farms Constraints delaying the diffusion of installations Requirements for an optimally integrated biogas installation http://www.fao.org/docrep/T0541E/T0541E00.HTM (5 of 7) [12/15/2007 9:44:51 AM] Contents New incentives to build biogas plants Chapter thirteen: Biogas programs in developing countries Experience with biogas in China Potential of biogas generation and biogas digester construction Biogas utilization Effluent utilization Economic aspects Financial support Training in biogas technology Organization of the biogas sector Potential for biogas generation and digester construction Experience with biogas in India Biogas plants Biogas production Use of biogas Utilization of effluent Cost of installation Annual costs and savings Financial assistance from government Organization of the biogas sector Organization of energy sector Utilization of effluent Costs and benefits Research and development Experiences with biogas Installations Effluent utilization Costs and benefits Experiences with biogas Organization of the biogas sector Africa Appendix 1: References Appendix 2: Glossary http://www.fao.org/docrep/T0541E/T0541E00.HTM (6 of 7) [12/15/2007 9:44:51 AM] Contents Appendix 3: Institutes and research workers http://www.fao.org/docrep/T0541E/T0541E00.HTM (7 of 7) [12/15/2007 9:44:51 AM] Ch01 Acknowledgment Contents - Next This review was initiated by Dr. Morton Satin in FAO Rome, Chief of the Food and Agricultural Industries Services in the Agricultural Service Division, as a result of many requests for information on BIOGAS TECHNOLOGY suitable for Developing Countries. The generous help and collaboration of the FAO staff during the preparation of the review and their help in contacting people in the Far East are gratefully acknowledged. The most important of all are the researchers and technologists who are involved in the Biogas development. They are the key people to achieve the sustainable development so many people are referring to. Their work and research which is quoted in this review presents only a small portion of the important progress in Biogas technology and all my thanks are due to them. In addition I am grateful to my colleagues in MIGAL, especially to George Ney who helped me so much in bringing this review to its final form. Contents - Next http://www.fao.org/docrep/T0541E/T0541E01.htm [12/15/2007 9:44:52 AM] Ch02 Chapter one: Preface and objectives of the review Contents - Previous - Next Sustainable development There is an increased recognition, in both developing and industrial countries, of the need for technical and economic efficiency in the allocation and exploitation of resources. Systems for the recovery and utilization of household and community wastes are gaining a more prominent place in the world community. Today, a new environmental agenda is emerging, which is now forcing itself on the attention of policy-makers and the public at large. Its concerns are both practical and urgent: they address the survival of human, animal and plant populations over vast sections of our globe. Today's issues arise from the spread of deserts, the loss of forests, the erosion of soils, the growth of human populations and industrialized animal husbandry, the destruction of ecological balances, and the accumulation of wastes. As a result, the politics needed to meet present and future challenges require a new vision and new diplomacy, new leadership and new policies. In a world that is daily more complex and economically interdependent, the economic and security interests of the Developing Countries must be understood in a broader, global context. These acute, relatively new problems of the world