資源分布と技術特性を考慮した森林バイオマス小規模ガス化システムの経済性評価

抄録

Small-scale wood biomass gasification is considered as a suitable technology to utilize forest biomass such as logging residue and unused thinned wood. Recently, more than 10 demonstration plants have started to operate to verify both technical and economic feasibility of the system. This study analyzes the economic aspect of gasification system focusing on the regional distribution of biomass resources and technical characteristics such as scale merit.
The authors developed BiRReT tool, which conducts the economic analysis of biomass energy system in a local region by finding the optimal conditions, namely plant size, plant location, and the number of plants. Case study in Miyagi prefecture had been carried out. Firstly, the economics of gasification system is compared with the steam-turbine-based CHP system that utilizes grate or fluidized-bed combustion technology. The result shows that gasification system has strong advantage in terms of low fuel transportation cost. Secondly, the economic feasibility of the system in a region is analyzed. The system with logging residue fuel has the possibility to gain economic competitiveness if technology learning and cost reduction will be seen in the capital cost and the fuel production process. Thinned wood will not be utilized only for the energy purpose.