过氧甲酸预处理对甘蔗渣酶解和发酵的影响

以甘蔗渣(SCB)为原料, 经过氧甲酸(PAP)预处理后加入酶进行水解, 并以水解液发酵产乙醇, 考察预处理时过氧化氢(HPP)浓度变化对甘蔗渣酶解和乙醇得率的影响。实验结果表明: 在甘蔗渣PAP预处理过程中, HPP与甲酸(FAP)体积比为1∶1时, 预处理甘蔗渣(PAP-SCB-1)的木质素脱除率达84.30%;在纤维素酶用量为10 FPIU/g(以预处理后的甘蔗渣质量计)时, PAP-SCB-1水解72 h葡萄糖得率为98.71%, 较单独过氧化氢预处理甘蔗渣(HPP-SCB, 葡萄糖得率9.11%)和单独甲酸预处理甘蔗渣(FAP-SCB, 葡萄糖得率7.06%), 分别提高了9.84和12.98倍; PAP-SCB-1水解液经24 h发酵后, 乙醇得率为84.06%, 比HPP-SCB(76.20%)和FAP-SCB(75.15%)均有增加。对预处理前后物料的化学成分变化、比表面积和结晶度进行测定, 结果显示: 经PAP预处理后可以显著脱除甘蔗渣中的木质素, 木质素的量由未经预处理的21.27%降低到10%以下; 比表面积和结晶度都有提高, PAP-SCB-1的比表面积和结晶度分别为13.01 m²/g和54.18%, 是HPP-SCB的10.66和1.11倍, FAP-SCB的11.39和1.15倍。

Effect of Peroxyformic Acid Pretreatment on Enzymatic Hydrolysis and Fermentation Efficiency of Sugarcane Bagasse

Sugarcane Bagasse(SCB) was used as raw material for enzymatic hydrolysis after pretreatd by peroxyformic acid(PAP). Ethanol was produced by fermentation with hydrolysate, and the effect of hydrogen peroxide(HPP) concentration on the efficiency of enzymatic hydrolysis and ethanol fermentation of SCB was investigated. The results showed that the delignification percentage of pretreated bagasse(PAP-SCB-1) reached 84.30% during PAP pretreatment of SCB when the volume ratio of HPP to formic acid(FAP) was 1∶1. Using the cellulase dosage of 10 FPIU/g(based on the mass of pretreated sugarcane bagasse), the glucose yield of PAP-SCB-1 after 72 h hydrolysis was 98.21%, which was 9.84 and 12.98 times higher than that of pretreated bagasse with hydrogen peroxide(HPP-SCB, glucose yield 9.11%) and formic acid(FAP-SCB, glucose yield 7.06%), respectively. The ethanol yield was 84.06% with the enzymatic hydrolysate fermentation for 24 h, which was higher than that of HPP-SCB(76.20%) and FAP-SCB(75.15%). The chemical composition, specific surface area and crystallinity of the materials before and after pretreatment were measured. The results showed that the lignin in bagasse could be significantly removed after pretreatment with PAP, and the lignin content was reduced from 21.27% without pretreatment to less than 10%. The specific surface area and crystallinity of PAP-SCB-1 were increased up to 13.01 m²/g and 54.18%, which were 10.66(11.39) and 1.11(1.15) times higher than those of FAP-SCB(HPP-SCB).