Vision for utilization of livestock residue as bioenergy resource in Japan

Utilization of livestock residue is important not only for energy recovery and material recycling but also for preventing environmental pollution. This paper focuses on the following options from the viewpoint of the Law on Promoting Proper Management and Use of Livestock Excreta and the Kyoto protocol: energy use from livestock residue, reductions in CO2 emissions resulting from substitution of fossil fuels, and reduction of other greenhouse gas emissions through appropriate treatment of livestock residue. Bioenergy potential of livestock residue in Japan was estimated to be 167 PJ in the year 2000. This is equivalent to about 0.7% of total primary energy supply. Biogas production with methane fermentation and burning poultry residue at power plants can produce 4.1 TWh of electricity and 46 PJ of heat. The amount of CO2 substitution for fossil fuels is 6.9 Mt-CO2. This corresponds to about 0.6% of total CO2 emissions in 1990. This also has an additional effect of reducing other greenhouse gas (CH4 and N2O) emissions from conventional treatment of livestock residue. Development of biogas plants, promotion of biogas utilization, and effective use of fertilizer components extracted from livestock residue are expected to gain importance in the future.