METHANE PRODUCTION BY ANAEROBIC DIGESTION OF ALGAE. II. PRODUCTION OF ALGAE.

Algae have been grown in waste luke-warm waters at temperatures between 20 degree and 35 degree C in order to recuperate calories by increasing the yield of biomass and to produce methane at the expense of the calories. The algae have been cultivated in lagoons (2200 m**2) irrigated by the water of the river Meuse warmed up by circulating through the 3rd cooling circuit of Tihange nuclear power-plant. The culture yielded in the order of 10 T dry biomass. hectare** minus **1. year** minus **1. A rate of biogas production of 1. 7 m**3 gas. m** minus **3//M//L. d** minus **1, with a methane concentration of 65% can be obtained. The process achieves a chemical and a thermal depollution of the water, a circumstance which may represent a spare of expenses for the process. The different operations which are involved in the biomass harvest have been fully assessed.