Biogas
Challenges
- Biogas production may need insulation or earth sheltering when used in cold climates witch could oterwise lead to breakdown of microbial populations. With CEB-blocks and insulation and option of heating, this is a design issue.
- Biogas can contatin some sulfur (that smells like rotting eggs) and it is then not reccomended to be used in egines for a prolonged time. The sulfuric acid can accumulate in the engine oil and it will need replacing and or clening after a while. To avoid some of this do not feed the digester with ojects that generate this gas like plasterwalls.. There exists some addetive that can limit this but should not be needed in this case. When used for direct burning like with a gas-nozle for coocking it can be used directly. But some dont like that smell when cooking.
- Biogas need cleaning (upgrading) to remove as mutch as possible of the contained sulfur and carbon dioxide for use in engines for gas-car transportation or electrical generaton. It is perferable need to be upgraded first to limit corosion and wear of motors. It is also possible to recover some heat from the motor and feed the carbon dioxide to the green house. Howto, more to come....
- Compessing into gascylinders if needed for mobile transportation and more easy handeling.
Simple Open Source Biogas System
Supergas - In 1996-97 Superflex collaborated with biogas engineer Jan Mallan to construct a simple, portable biogas unit that can produce sufficient gas for the cooking and lighting needs of an African family. The system has been adapted to meet the efficiency and style demands of a modern African consumer. It is intended to match the needs and economic resources that we believe exist in small-scale economies. The orange biogas plant produces biogas from organic materials, such as human and animal stools. For a modest sum, a family will be able to buy such a biogas system and achieve self-sufficiency in energy. The plant produces approx. 3-4 cubic meters of gas per day of the dung from 2-3 cattle. This is enough for a family of 8-10 members for cooking purposes and to run one gas lamp in the evening.
Applications and Product Ecology
- biogas for cooking, heating
- electrical generation and heating at the same time
- Guastavino masonry or plain CEBs to build biogas digester and holding tank for stored biogas. One holding tank could be used for the storage of biogas and Compressed fuel gas.
- methane for the production of Direct reduced iron from rust or high-grade iron ore.
- compressed biogas for transportation / internal combustion engine
- liquid slurry from biogas tank can be used to fertilize duckweed pond
- solid contents coming out of digester can be composted (vermicompost, BSF compost, biochar compost)
- when biogas is burned inside a greenhouse, the CO2 enrichment can provide a boost to plant growth (CO2 concentrations up to 1500ppm are beneficial). This is effect widely used by commercial growers, but unfortunately they are using mostly fossil methane.
- various uses in metallurgy
- process bulky biomass before it can go into a digester, using hammer mill
External Links
- Appropedia Category: Biogas
- Appropedia main biogas page
- Wikipedia: Biogas
- p2pfoundation Category:Biofuel
- DIY Biogas - Germany