| Abstract:In the study of ethanol production from lignocellulosic materials, the raw materials are prone to produce inhibitors such as furfural, 5-hydroxymethylfurfural, hydroquinone, and resorcinol during the pretreatment process of dilute phosphoric acid impregnation and steam explosion. These inhibitors will affect the cellulase enzymatic hydrolysis efficiency resulting to a reduction of reducing sugar concentration and ethanol production. Through single-factor experiments, the optimal enzymatic conditions for cellulase enzymatic hydrolysis were determined as enzymatic hydrolysis temperature of 50℃, enzymatic solution dosage of 30 U/mL, solid-liquid ratio of the enzymatic hydrolysis system of 1∶11, and pH value of enzymatic hydrolysis system of 4.8. The contents of above four kinds of inhibitors produced during the pretreatment process were determined, which were 0.031 g/L for furfural, 0.029 g/L for 5-hydroxymethylfurfural, 1.51 g/L for hydroquinone, and Hydroquinone 1.242 g/L. The effect of the above inhibitors alone or in combination on the enzymatic hydrolysis efficiency of cellulose was expolred. The results showed that the phenolic inhibitors produced during the pretreatment process were more than the aldehydes, and the influence of the phenolic inhibitors on the enzymatic hydrolysis was higher than the aldehyde inhibitors during the enzymatic hydrolysis. The synergistic effect of multiple inhibitors on the degradation rate of cellulose was higher than the effect of a single inhibitor. The influence intensity of the inhibitors on enzymolysis in the enzymatic hydrolysis solution from strong to weak was in order of hydroquinone, resorcinol, and 5-hydroxymethylfurfural , and furfural. |
