Synergetic Effect of Temperature and Partial Digestion of Cellulose on Conventional Biogas Production Rate

Abstract

In India and several other developing countries, small towns and village are using biogas for fulfillment of their daily household burning and electricity production. In biogas plant cattle dung is a key ingredient, along with other organic feedstocks. Cellulose containing feedstocks are one of the most commonly used and highly accepted substrate for methanogenesis. Degradation of cellulose under anaerobic conditions is a very slow process and results into lower production rate of gas. Therefore, an attempt was made to increase the rate of biogas production by providing partially digested cellulose rich feedstock to the fermentor vessel. Digestion was carried out by extracellular enzymes produced by thermophiles. The vessels were incubated at different temperatures to determine the effects of temperature on rate of methanogenesis. As a result of the study, it was found that the fermentor vessels fed with partially digested cellulose and thermophiles have great potential to produce significantly higher quantity of biogas at 55OC in half the incubation time required by conventional method. Rate of gas production under such conditions was found more than double in many cases. Not only this, a direct relationship was also observed between the rate of cellulose degradation and production of biogas.

Keywords

• two step methanogenesis, enzymatic digestion, rapid production method, double rate of production