Life Cycle Assessment of International Biomass Utilization: A Case Study of Malaysian Palm Kernel Shells for Biomass Power Generation in Japan

Palm kernel shell (PKS) is a by-product in palm oil milling during the extraction of crude palm oil from fresh fruit bunches. PKS is a promising solid fuel to replace coal with its high calorific value. As Japan is moving towards renewable power to reduce carbon dioxide emissions, importing biomass as fuel sources is trending. In the past decade, PKS has been imported extensively into Japan for biomass-power generation, replacing fossil fuels under the feed-in tariff. PKS is easiest to utilize in existing power plants from an economic perspective reducing the cost for energy transition. However, the environmental impact of transporting such biomass across long distances have not been systematically assessed. Therefore, this work presents a life cycle assessment (LCA) of power generation with PKS in Japan. The LCA study covers land conversion of palm cultivation in Malaysia to biomass power generation in Japan. Factors considered include greenhouse gas (GHG) emissions, eutrophication and water footprint. Eight Malaysian scenarios were analyzed, based on different boiler fuel applications in the palm oil mill. In addition, eight Japanese scenarios were also considered, based on imported PKS-dominant and local woodchip-dominant power generation. This work noted the significant effect of land use change on GHG emission. Based on results, imported PKS-dominant power generation in Japan is environmentally favorable than local woodchip-dominant power generation with careful selection of the biomass mix and power plant scale. PKS-based power generation contributes low GHG emissions which superior to fossil-based (coal, thermal oil, natural gas) power in Japan. Graphical Abstract