Biogas production from traditional market waste to generate renewable energy

The increased energy consumption and limited fossil energy sources caused industry to find energy from renewable resources. Biogas is one of the renewable energy that has a good prospect in the near future. Traditional market wastes which were represented by green mustard and white mustard were undertaken in a laboratory experiment. To produce biogas, the raw material such as white mustard and cow manure, green mustard and rice straws were mixed until C to N ratio close to 20. Inoculums starter from biodigester effluent was put into digester then water was added until 350 ml. The initial pH was measured. Fermentation process was conducted at temperature of 35°C. Volume and pH of the biogas were observed daily. Methane, total solid and volatile solid were analyzed weekly. Fermentation process was observed for 7 weeks. The accumulation of biogas production at the day 42 for white mustard (S₁), white mustard with cow manure (S2), and mixed of green mustard and rice straw (S₃) were 0.111L, 0.901L and 0.390L respectively. The highest methane concentration in the biogas was achieved on the day 21, which were found of 62.18% and 63.15% for S₂ and S₃ respectively. Meanwhile for S₁ (white mustard only without cow manure) no methane was observed. In the first 7 days, the pH level were observed decrease and increase after the day of 28. However, at the end of digestion period the pH will slightly decrease. It was also developed to conduct a pilot plant within the tubular digester to generate energy in batik home industry, Imogiri, Yogyakarta, Indonesia.