Role of mixed low rank coal during fuel conversion of woody biomass by using hydrothermal treatment

The hydrothermal treatment tests of Beluga coal, Cryptomeria Japonica, and their mixtures were conducted by using a circulating and batch equipment. The added coal in the mixture increased the content of lactic acid in the liquid phase and the content of acetone insoluble char in the solid phase due probably to rearrangement and fixation of acetone soluble. However, the gross calorific value of the solid phase of the mixture showed negligible change independent of the biomass mixing ratio. In addition, it is worth mentioning that the continuous hydrothermal treatment of the mixture was successfully conducted with no trouble by using bench-scale continuous equipment.