2008 年 4 巻 4 号 p. 318-323
Objective. The project to produce BDF from waste cooking oil has started in some autonomous communities, Japan. In this study, the waste cooking oil potential was estimated by using data obtained by questionnaire survey and demonstration of collection from household. Furthermore, we apply life cycle analysis for accounting the environmental load of BDF production project. The variation of environmental load was showed by each uncertain factor in this analysis and the way of decreasing environmental load was considered.
Result and Discussion. Tahara city in Aichi prefecture was selected as the case study area. The recoverable waste cooking oil was estimated to be 2.4kL per year in Tahara city. CO2 emission and energy consumption were estimated in the life cycle of BDF production system. The result shows that environmental load by transport between household and collection point was biggest factor in the life cycle when evaluate by using the default value. The condition of low environmental load was changed by the uncertain factors that are the distance between household and collection point, and the amount of waste cooking oil from household. The result showed that if collection frequency change to every two months, CO2 emission became lower than diesel and it can get the net energy.
Conclusions. BDF production system was analyzed by applying life cycle analysis and we considered the conditional equations about CO2 emission and net energy value. It was found that there is the situation of increasing environmental load by the project of BDF production from household waste cooking oil. It is important to consider about the uncertain factors in the BDF project.