Recent Developments
The big projects in China, India and Nepal were based on the use of animal dung as a feed stock. It has therefore been seen as a primarily rural technology, so has received less attention from governments more interested in helping people in rapidly growing urban areas.
More recent developments in India have used biogas technology to process food wastes, so the technology is gaining an urban dimension. One approach is the development of plastic floating drum plants for individual households. Three groups looking at this approach are ARTI in Pune, Maharashtra; VK Nardep in Kanyakumari, Tamil Nadu; and Biotech In Trivandrum, Kerela. People can save up to 30%of the LPG they use for cooking by processing their own wastes, or up to 100%, if they obtain waste food from elsewhere.
Biotech and also produce larger sized plants with steel drums to process food wastes and sewage from institutions such as schools to save. Similar systems can be used to process waste from markets, so local authorities in India are becoming very interested. There are a few systems processing domestic waste collected by local authorities in Kerala.
Rural biogas plants using animal dung have not had the success in Africa that they have enjoyed in Asia. However, two very successful projects use fixed dome designs to process human sewage. The KIST project has built plants in several prisons, most of which were housing over 10,000 inmates (now much fewer). BTWAL in Ghana use similar designs to deal with sewage from hospitals, schools, universities and hotels.
The processing of food wastes can cause problems with biogas plants, as fibrous materials
do not digest well and can clog up the system. Pre-
ARTI plastic domestic biogas plant
Biotech market waste biogas plant
Sewage biogas plant built by KIST
BTWAL school sewage biogas plant