Hydrolysis of Cellulose using Supercritical Carbon Dioxide Fluid

초록

The explosion pretreatment of starch, hemicellulose and cellulose hydrolysis, by supercritical carbon dioxide increased the accessible surface area of the substrates to enzymatic hydrolysis. An increase in pressure facilitated the penetration of carbon dioxide molecules into the crystalline structures, and higher product yield was obtained from the substrate materials after the explosion pretreatment as compared to those without the pretreatment. The explosion pretreatment enhanced the hydrolysis rate of the starch and increased the reducing sugar yield(about 98% of theoretical yield) at atmospheric and at supercritical fluid conditions. The pretreated xylan was completely hydrolyzed in the acid hydrolysis at ambient pressure, resulting in the xylose concentration of about 100% of theoretical yield. In the hydrolysis of cellulose, however the pretreatment was less effective as compared to the hydrolysis of starch or xylan. This is believed due to the rigid cellulose structure which exerts resistance to the penetration of carbon dioxide molecules into the crystalline part of cellulose.