Abstract:

Alkaline sulfite was used to pretreat eucalyptus lignocellulose,and the product was investigated by means of FT-IR,SEM and XRD. The results show that,after the pretreatment,some lignin and hemicellulose hydrolyze,the relative crystallinity of cellulose decreases by 14. 34%,the carbohydrate in eucalyptus becomes incompact,the pit membrane breaks and more fiber fragments form,thus greatly improving the accessibility of the cellulase in the later treatment. Moreover,it is found from the further enzymatic hydrolysis that,after the pretreatment,the mass of xylose and glucose amounts respectively to 67. 33% and 88. 11% of that of the raw eucalyptus,that the corresponding yields are respectively 7. 51 and 4. 33 times higher than those without pretreatment,and that 52. 39% of lignin in the raw eucalyptus can be reused from the enzyme solution scraps.

Key words: eucalyptus, alkaline sulfite, pretreatment, xylose, glucose, enzymatic hydrolysis