Enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated reed canarygrass and switchgrass.

摘要

Enzymatic hydrolysis is a chemical process which extracts sugar polymers from lignocellulose by the addition of a water molecule. However, lignocellulosic biomass is resistant to enzymes as a result of the unreactive nature of cellulose to chemicals. The strong bonding between cellulose, hemicellulose, and lignin within the crystalline regions of lignocellulose makes it rather difficult to access the sugar polymers in the cell wall. An effective pretreatment is essential to permit cellulose to become susceptible to enzymatic hydrolysis thereby allowing the retrieval of these sugars. Ammonia Fiber Explosion (AFEX), a physiochemical pretreatment, has shown to decrease cellulose crystallinity and particle size, while increasing the surface area exposed to enzymatic attack. AFEX weakens the association among lignin, hemicellulose, and cellulose facilitating more hydrolysis.; In this study, reed canarygrass (RCG) and switchgrass (SWG) were pretreated using AFEX, enzymatically hydrolyzed, and analyzed for glucose and xylose. The pretreatment conditions tested were temperature and ammonia loading at constant moisture content (60%). The objectives of this study were to evaluate suitable AFEX pretreatment conditions and determine glucose and xylose yields possible at different stages of RCG and SWG growth.