2018 Volume 97 Issue 10 Pages 284-299
Because about 70% of the national land in Japan is covered with forests, Japan has abundant potential energy of woody biomass (WB). However, the energy use of WB is not advanced sufficiently. The cost of power generation by WB is higher than that of grid, and the supply and demand balances for the energy use is not established. In this study, we focused on the three types of power generation by WB, i.e., direct combustion, gasification, and chemical-looping combustion (CLC) which is one of the promising energy conversion technologies from carbon fuels based on the cyclic reduction and oxidation of metal oxide particles and with reduced energy for CO2 capture. We designed each power generation process, calculated the energy efficiency and power generation cost by the detailed bottom-up approach, and suggested the technological scenario to show innovation pathways to be solved and / or conditions to utilize more WB. We found that it was important to improve the energy efficiency of steam cycle by higher temperature and pressure with the cost reduction of WB itself, and thus power generation cost decreases less than ￥25 /kWh – target cost in this study, and CO2 sales by CLC is effective to reduce cost.