PRODUCTION OF METHANE FROM GREEN PEA SHELLS IN FLOATING DOME DIGESTERS

The suitability of green pea shells for biogas production was evaluate d in floating dome digesters. The stepwise replacement of cow dung wit h green pea shells in the digesters enhanced the stability of the anae robic digestion system. Green pea shells formed a thick scum on the to p and thereby blocked the ports of the digesters, but ensilaging shell s for 6 months helped to overcome this problem. Ensilaging of green pe a shells for 15 days only caused the separation of fibrous constituent s from the soluble and suspended solids. The resultant liquid yielded 0.62 m(3)/kg VS biogas and reduced the hydraulic retention time from 3 0 to 10 days at a loading rate of 8% (TS). (C) 1997 Elsevier Science L td.