Construction and operation of a demonstration biogas plant, problems and prospects

This paper discusses the design, construction and operation of a low-cost, small, farm-scale digester in which cattle wastes were used. The biogas produced contained about 65% CH4 by volume. Production quantities and qualities were measured for a period of more than six months, both in summer and in winter. Biogas as used in two different systems: an instant, gas water-heater used to generate hot water for farm use, and a modified piston engine driving an electrical generator of one phase, 1 kW output, fuelled directly by the gas. Operation of both systems was satisfactory. The unit is being used to demonstrate the technology for potential users (mostly farm owners).