This PhD thesis reports new knowledge on hydrothermal decomposition mechanisms of fructose, glucose, cellobiose, cellulose and lignocellulosic biomass in hot-compressed water/gamma-valerolactone (GVL) mixtures under catalyst-free conditions. GVL is a biomass-derived solvent. The presence of GVL in hot-compressed GVL/water enhances the dehydration reactions but supresses the isomerization reactions of monomers. It also enhances hydrolysis reactions but suppresses the isomerization reactions of glucose polymers and cellulose
