Reaction of Nonphenolic fi-O-4 Type Lignin Model Compound under GreenLiquor Pretreatment Conditions

摘要

To examine why green liquor (GL) pretreatment of lignocellulosic materials effectively facilitates enzymatic saccharification under conditions milder than those of a common alkaline cooking process, dimeric fi-O-A type lignin model compounds with andwithout free phenolic hydroxyl group were reacted in several alkaline solutions including a model solution of GL, which mainly contains Na2CC>3 and Na2S. The fi-O-A bond of the phenolic model compound was cleaved with a sufficient rate in the model solution of GL. The (3-0-4 bond cleavage of the non-phenolic model compound was more frequent in the model solution of GL than in other alkaline solutions. These results suggest that fi-O-A bonds present in lignocellulosic materials are effectively cleaved ina GL pretreatment. It was also suggested that HS" contributes to the fi-O-A bond cleavage of the non-phenolic model compound synergistically with CC>32~ under GL pretreatment conditions.