2019 Volume 49 Issue 2 Pages 171-184
After the Tohoku Earthquake of 2011, converting biomass resources to electrical energy hasbecome a major focus in Japan. The government encourages local governments to use biogasplants to recycle organic waste. This study evaluates the biogas and liquid compost plants managedby local governments using life cycle assessment （LCA）, and includes a comparative analysisof greenhouse gas（ GHG） emissions with respect to the economic cost of each plant. For theLCA, the amount of GHG emissions was calculated by dividing the whole process implemented bythese plants into three stages : carrying and transporting organic waste, plant operations, andtransporting and spraying liquid fertilizer. The results showed that the plant operations stageaccounted for the highest proportion of GHG emissions. Furthermore, transporting and sprayingliquid fertilizer had the lowest percentage of GHG emissions for both plant types. In terms ofthe carbon content of raw materials, it was confirmed that the GHG emissions from the biogasplant were about 38% those of the liquid compost plant. In addition, the economic cost of thebiogas plant was superior to that of the liquid compost plant.
JEL Classifications:Q53, Q54, Q42
