Life cycle assessment for co-firing semi-carbonized fuel manufactured using woody biomass with coal: A case study in the central area of Wakayama, Japan

Reducing the use of fossil fuel is one of the prime tasks for preventing climate change. The worst fossil fuel in this regard is coal, which is the largest CO2-emitting fossil fuel in terms of weight. Although decreasing the use of coal is difficult because of its increasing demand in worldwide, there is still a possibility of effectively reducing greenhouse gas (GHG) emissions by substituting biomass, even for a subset of coal. One way to reduce the use of coal is to implement co-firing of biomass with coal at coal thermal power stations. In this study, the business impact of GHG reduction from semi-carbonized fuel produced by co-firing woody biomass with coal in thermal power plants is evaluated from the perspective of life cycles, using the life cycle assessment (LCA) methodology. The case study area is the central region of Wakayama prefecture, Japan. In this study, a new business is considered whose operations would co-fire the woody biomass with coal. A life cycle inventory (LCI) analysis and a life cycle impact assessment are conducted to evaluate the GHG emissions, taking into account processes such as cutting timber, manufacturing semi-carbonized fuel, and co-firing with coal. LCI data was collected and calculated on the basis of the feasibility study and literature survey. The spatial distribution of the woody biomass was ascertained using a geographic information system, and the location of several facilities and a road transportation network were determined. Results showed that an annual reduction in GHG emissions of approximately 46,700Â tonnes in the case study area is possible if the business is executed. The environmental impact taking into account climate change, acidification and land use was also reduced. As the result, this business is in fact advantageous to reduce GHG emissions as well as the environmental impact.