Abstract
Hydrothermal process is one of the most promising processes for the conversion of biomass waste into useful materials among several biomass conversion processes, because water of high temperature and high pressure has remarkable properties as a reaction medium. This report describes some recent advances in our research involving the production of acetic and lactic acids from biomasses and their some reaction mechanisms, mainly including (1) acetic acid production by controlling pathways of hydrothermal reaction, (2) oxidation pathways for some model compounds of biomass, (3) acid-base behavior of water in the subcritical region, and (4) influence of lignin and/ or phenol derivatives as oxidation retardant on the acetic acid production in WO of lignocellulosic biomass.