Direct hydrolysis of cellulose to glucose using ultra-high temperature and pressure steam explosion

Hydrolysis of two cellulosic materials, i.e. microcrystalline cellulose powder (MC) and cuprammonium rayon fiber (BEMCOT), to glucose was carried out by steam explosion treatment with ultra-high temperature and pressure steam aiming at an effective usage of unutilized cellulosic materials. 50 g of cellulosic materials were charged in a sealed reactor (2 L) of the steam explosion apparatus kept at steam pressures of 50, 55, 60, and 62 atm for a steaming time of 1 min. The maximum yield of water soluble sugars, 52.8%, was obtained at a steam pressure of 62 atm and a steaming time of 1 min for MC. Furthermore, the maximum yield of water soluble sugars, 67.7%, was obtained at a steam pressure of 60 atm and a steaming time of 1 min for BEMCOT. This water soluble sugars contained 63.1% and 61.0% of glucose, respectively; they are corresponding to 33.3 g and 41.0 g of glucose contained in 100 g of dry steam-exploded cellulosic material.