Combined alkali pretreatment for enhanced enzymatic saccharification of sugarcane leaf

The alkalis sodium ethoxide and calcium hydroxide were combined to pretreat the abundant agricultural waste sugarcane leaf (SCL). The pretreatment conditions were optimized using single factors and orthogonal array, and the results of material's chemical compositions and enzymatic hydrolysis were investigated. The optimized conditions were pretreating SCL with C 2 H 5 ONa:Ca(OH) 2 volume ratio of 4:1 at 121 °C for 30 min. Under these conditions, the lignin removal rate of SCL was 86.26%, while the total reducing sugars and total enzymatic efficiency of enzymatic hydrolysis could reach 14.82 g/L and 80.02% respectively. These pretreating and hydrolysis results were similar compared with those of SCL pretreated with strong base C 2 H 5 ONa alone. But the strong base dosage was saved 20% and the pretreatment time was shortened to 30 min. Therefore the combined alkali pretreatment could significantly save energy and reduce environmental pollution, which made it a promising method in large-scale production.