Production of the glycerol-impregnated hybrid coal and its characterization

Biomass recently has been blended with fossil fuels for the environment-friendly aspect such as reduction of carbon dioxide emissions. However, in coal-fired power plants, bituminous coal is blended with only the solid-phase biomass like wood chips for use of the existing coal feeding facility. Furthermore, as coal and biomass individually combust, it is difficult to use the existing coal boilers. In this study, to resolve these problems, glycerol was used as an additive to make a hybrid coal. Glycerol-impregnated hybrid coal is a new fuel technology in which glycerol play an important role in an artificial volatile matter by substituting inherent moisture in the coal pores with glycerol. When glycerol is simply blended with coal, the combustion behaviors of glycerol and coal are independent because glycerol evaporates at 443 K. However, if the coal pores are filled with glycerol, glycerol takes on a combustion behavior like that of a volatile matter, resulting in a two-in-one fuel having a single combustion behavior. These results makes it possible to use glycerol as a fuel for coal-fired power plants and reduce carbon dioxide emissions.