UNEP International Environmental Technology Centre 1 Converting
Waste Agricultural Biomass into Useful Energy Surya Prakash Chandak
Senior Programme Officer International Environmental Technology
Centre Division of Technology, Industry, and Economics United
Nations Environment Programme (UNEP DTIE IETC) HP: www.unep.org,
www.unep.fr, www.unep.or.jp Slide 2 UNEP International
Environmental Technology Centre 2 What is biomass Broad term
generally refers to any plant or animal matter. Waste Biomass Main
Categories Waste agricultural biomass Forestry residues Wood Animal
residues Organic waste from cities and dwellings Slide 3 UNEP
International Environmental Technology Centre 3 Why convert waste
agricultural biomass into energy/materials ? Reduced carbon
emission a)Due to obviating use of fossil fuels b)Due to avoidance
of open burning and rotting (methane emission) Enhanced energy
security Enhanced access to energy particularly in rural areas
Reduced problem of management, treatment and disposal Additional
revenue for farmers Job creation Slide 4 UNEP International
Environmental Technology Centre 4 Global availability of waste
agricultural biomass 1 Exa joule = 10 18 Joules : 1 KiloJoule =
0.239 Kcals: 1 EJ = 24 million tons oil (approx.) RegionMaize Straw
Wheat Straw Rice Straw BagasseTOTAL Africa0.480.250.200.541.47 US
& Canada 2.951.930.130.195.20 Latin America
0.710.380.293.584.94 Asia1.743.658.963.1917.54
Europe0.612.390.040.003.04 Oceania0.232.260.060.222.77
TOTAL6.7210.869.687.7231.98 (765 million tons oil (in EJ/year)
Slide 5 UNEP International Environmental Technology Centre 5
Geographic distribution of availability of waste agricultural
biomass RegionMaize*Wheat**RiceCottonSugar # Total China86153233
India3381318 All Asia13 395677 Brazil201148 All South America
5111513 Africa511119 TOTAL of Asia, S. America and Africa
231541712100 *including millet and sorghum **including barley #
including minor agro industry (in percent of total) Slide 6 UNEP
International Environmental Technology Centre 6 Technologies for
converting waste agricultural biomass into energy Waste
Agricultural Biomass to Energy Technology Options Basic ProcessType
of Technology Examples of types of waste handled Biochemical
(anaerobic) FermentationFruit and vegetable market waste, waste
from fruit/vegetable processing industries Biochemical (aerobic)
FermentationSugar/starch containing wastes like waste palm trees
Thermo- chemical PyrolysisCrop residues such as wheat straw, rice
straw, rice husk, coconut shell Thermo- chemical GasificationCrop
residues such as wheat straw, rice straw, rice husk, coconut shell
Thermo- chemical Direct Combustion Crop residues such as wheat
straw, rice straw, rice husk, coconut shell Physical Processing
BriquettingWaste saw dust, waste wood chips Slide 7 UNEP
International Environmental Technology Centre 7 Interesting
features of converting waste agricultural biomass into energy
Availability of energy source at the place which is energy- starved
and conventional energy (electricity and fossil fuels) systems are
difficult to reach there Abundant availability -- a large amount is
currently wasted by either burning open or by allowing it to rot in
the field Little or no pollution; generally no emissions of toxic
gases like sulfur oxides and nitrogen oxides Provides a clean fuel
for both domestic and commercial use current patterns of using WAB
directly in households usually gives rise to emission of smoke and
gases which are very harmful to human health Can provide and
alternative source of income to farmers Can spur rural economic
development due to enhanced energy availability thus generating
jobs Climate neutral Slide 8 UNEP International Environmental
Technology Centre 8 Constraints in converting waste agricultural
biomass into energy Dispersed availability spread over wide areas
hence challenges of collection Usually voluminous material hence
high transportation cost per unit weight compacting prior to
transportation may be required Lower calorific value as compared to
fossil fuels particularly oil and gas Some WAB has high moisture
content (e.g. fruit and vegetable waste) Some WAB is easily
putrescible (e.g. fruit and vegetable waste) Seasonal availability
and variations Matching of demand and supply of energy energy load
in rural areas varies widely over the day Slide 9 UNEP
International Environmental Technology Centre 9 Features for
considerations when converting waste agricultural biomass into
energy Systems required for collection and compacting
Considerations for future costs of WAB although it may be available
free at present Considerations for alternatives if WAB is being
used for some other purposes presently e.g. as domestic fuel,
animal feed, mulching for soil etc. Cost of transportation in case
of large size WAB2E systems Disposal of ash particularly for WAB
like rice husk Flexibility in WAB2E systems to use different WAB
Storage of WAB to meet the needs during lean seasons WAB2E systems
to have high turn down ratios and/or systems to store energy Slide
10 UNEP International Environmental Technology Centre 10 What needs
to be done for converting waste agricultural biomass into energy
Assessment of WAB quantities generated and quantity available for
conversion into energy careful consideration of seasonal variations
Characterization of WAB Study of possible systems for collection,
compaction and transportation Assessment of present cost structure
and projections into future, including cost of transportation
Assessment of present energy demand (type and amount) and
projections into future Assessment of funds availability Assessment
and selection of WAB2E technology Development of a management
system for sustainable operations Supportive policy framework Slide
11 UNEP International Environmental Technology Centre 11 What this
project on converting waste agricultural biomass into energy aims
at Building capacity on various aspects of WAB2E: assessment of
quantification and characterization, assessment of prevailing
management systems, assessment and selection of technologies
Provide hands-on experience by working at a selected site
Demonstration of an appropriate technology which can be further
replicated Getting together technology suppliers and entrepreneurs
to facilitate commercial uptake of WAB2E systems Support to
government on framing conducive policies Slide 12 UNEP
International Environmental Technology Centre 12 THANK YOU For
further information: http://www.unep.org