Micro-gasification: Cooking with gas from dry biomass
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ANILA stove by Prof. Ravi Kumar (India) Charring small biomass without electricity, just by natural draft. Design is a bit more challenging concerning craftsmanship, as some joints need to be made air-tight to avoid smoke escaping from the allothermal pyrolysis zone. Design consisting of two concentric cylinders of different diameters (see diagram). The inner is a TLUD, filled with chunky biomass that allows flaming pyrolysis with natural draft. The outer ring is filled with small-size biomass (like husks, sawdust etc.), which would not work in a TLUD without forced convection. The fire is lit on top in the center cylinder, the TLUD. Heat from the central fire pyrolyzes the concentric ring of small biomass fuel without flame (allothermal). The gases can only escape downward and to the center where they add to the cooking flame as the ring of biomass turns to char. The stove produces two types of char: autothermal from flaming pyrolysis in the TLUD-part, very pure allothermal char from the outer ring. Secondary air supply not shown in diagram. Developed by U.N. Ravikumar, at India‘s National Institute of Engineering. (Adapted from: http://www.biochar-international.org/technology/stoves)
http://www.bioenergylists.org/node/2203
http://www.bioenergylists.org/en/node/2201
More information on http://www.bioenergylists.org/anila, report with examples from use in communities in Tamil Nadu province in South-East India can be downloaded http://www.bioenergylists.org/stovesdoc/ravikumar/Biochar_Anila.pdf (9.8 MB) Anila type stoves were recently compared to other models in Cambodia, details on http://www.bioenergylists.org/content/testing-anila-stove. Over 2,500 units were made, see http://biocharinnovation.wordpress.com/2010/11/02/anila-stove-manufacture-2500/
HERA – GIZ Manual Micro-gasification Version 1.0 January 2011