Abstract
The purpose of the study is to design a woody biomass energy system and application to coal co-firing, and to evaluate the system considering the three dimensions of energy, economic, and environmental impact. The study targets five types of woody biomass; forest wood residues, forest thinnings, sawmill wood residues, construction wastes and pruned branches of fruit trees. The system contains of collecting of biomass, transporting raw materials, producing wood fuels, transporting wood fuels, and coal co-firing. The study evaluates six cases that differ in wood fuel production location and the type of wood fuel. The results of case study show that the potential of the biomass resource is 37 PJ/year and the availability is 3.6 PJ/year in Tohoku area. The case that pellets produced at the resource generation points has the lowest amount of energy consumption 0.9 PJ/year, wood fuel supply cost 3.2 JPY/MJ and CO2 emissions 0.66×103 t-CO2/year. It is also obtained that the drying process and transportation process have dominant effect on energy consumption and cost.
