Up to 1982 there were approximately 1,000 biogas plants in Thailand which were built by various state and private organisations. Greatest involvement here was by the Ministry for Public Health with its Sanitation Division which had good infrastructure through the Preventive Health Centres, and which disseminated fixed-dome plants of the Chinese type. After disencouraging experience with floating-drum plants mainly erected in Buddhist monasteries which had an average service life of less than two years according to a report in 1979, the emphasis was obviously changed to fixed-dome plants. Due to the high level of groundwater in the south, floating-drum plants were erected above ground and "red mud plastic" fermenters were built. Apart from these classic types of construction there were a large number of home developments and experiments which did not turn out to be suitable for dissemination. The activities have today all extensively died down or have been completely stopped.
Thai-German Biogas Programme
In 1988, the GTZ/GATE began cooperation with the Chiang Mai University in the Department of Mechanical Engineering and the Department of Agricultural Extension of the Ministry of Agriculture in the form of the Thai-German Biogas Programme. Until 1992, 150 biogas plants were in operation of which some were large-scale plants for pig farms. The total potential of household plants is estimated to be approx. 200,000 in the 5 provinces.
The Thai-German Biogas Programme is assigned to the university and the Department of Agricultural Extension of the Ministry of Agriculture. Work division has, in fact, arisen whereby the university with its Department of Mechanical Engineering is responsible for R & D and for the larger-scale biogas plants and the Ministry of Agriculture with its District Agricultural Extension Service is in charge of disseminating the standardised household plants.
Type of Plant
The CAMARTEC plantTanzania was taken over with only minor changes. The plants, as a standard, are to be connected directly to stabling with a hard floor.
Household plants are offered in standard sizes of 8, 12, and 16 m3 digester volume of which 12 m3 is the most frequent. The standard ratio digester volume/gas storage volume amounts to 8:1. In addition to the household plants, larger units of 30 - 80 m3 digester volume were built for pig farms according to the same technical principle to which two or three flat compensation chambers as vault constructions are connected.