Conversion of biomass into methane gas

Abstract

Land, marine and agricultural residues were subjected to a bioassay for an ultimate methane yield. Bioassays were performed in 250 ml serum bottles, incubated at 35°C. Methane yields were calculated from the percent methane in the gases formed and the total volume of gas produced. Methane yields from woody plants were lower in general than from other plant resource groups. High methane yields were obtained from several aquatic plants, some crop residues, and some root and tuber plants. Because of potentially high biomass productivity and high methane yields, water hyacinth ( Eichhornia crassipes (Mart.) Solms) and Napiergrass ( Pennisetum purpureum L.) were selected for intensive study. Methane yield varied among different groups, various species within each group and different parts of the same plant species. Treatment of plants with various nutrients, especially N, during the growth period and the age of the plants at harvesting time affected the methane production.