Dissolution and Hydrolysis of Cellulose in Subcritical and Supercritical Water

Abstract

Listen

Translate article

Decomposition experiments of microcrystalline cellulose were conducted in subcritical and supercritical water (25 MPa, 320−400 °C, and 0.05−10.0 s). At 400 °C hydrolysis products were mainly obtained, while in 320−350 °C water, aqueous decomposition products of glucose were the main products. Kinetic studies of cellulose, cellobiose, and glucose at these conditions showed that below 350 °C the cellulose decomposition rate was slower than the glucose and cellobiose decomposition rates, while above 350 °C, the cellulose hydrolysis rate drastically increased and became higher than the glucose and cellobiose decomposition rates. Direct observation of the cellulose reaction in high-temperature water at high-pressure conditions by using a diamond anvil cell (DAC) showed that, below 280 °C, cellulose particles became gradually smaller with increasing reaction time but, at high temperatures (300−320 °C), cellulose particles disappeared with increasing transparency and much more rapidly than expected from the lowe...