Efficiency of agricultural wastes and weeds for biogas production.
Bench scale studies were carried out with some agricultural wastes and weeds to assess their possible use for biogas production. It was found that banana stem was more suitable for biogas production (94.86 L/kg total solids) than cowdung (70.46 L/kg T. S.). The performances of maize stone, paddy straw, wheat straw, sugarcane bagasse, water hyacinth (Eichhornia crassipes), Cannabis sativa, Croton sparsiflorus and Parthenium hysterophorus in biogas production were more or less similar (72.19 to 80.16 L/kg T.S.). A higher retention time (45 days) was required for maximum methane production from these wastes and weeds. During digestion, the pH dropped sharply in the initial stages (15 days) and the C/N ratio decreased rapidly with an increase in digestion period up to 45 days thereafter becoming constant.