ABSTRACT
This chapter discusses the development process and present status of household biogas, specifically the opportunities and constraints of household biogas in rural China. There are several opportunities for household biogas development in rural China, including shortage of rural energy, the availability of biogas fermentation materials, national financial subsidies, legal and international clean development mechanisms. The research and use of biogas in China has a long history, and the use of hydraulic digesters has been in use for nearly 100 years. The ‘Three in One’ eco-agricultural model, which combines the biogas digester with a pigpen and toilet, is popular in southern China. The ‘Four in One’ eco-agricultural model, which combines the biogas digester, pigpen, solar greenhouse and toilet, has been proposed for northern China. The ‘Five in One’ eco-agricultural orchard model, which combines the biogas digester with solar-powered barns, water-saving irrigation system, water cellar, and toilet is proposed for north-west China.
