疏水性离子液体[C_4mim][PF_6]对木质纤维预水解液的脱毒作用  

Detoxification of Lignocellulosic Prehydrolyzate by Hydrophobic Ionic Liquid [C_4mim][PF_6]

作　　者：程逸超 杨金龙[1,2] 朱均均[1,2,3] 徐勇 勇强[1,2] 余世袁 

机构地区：[1]南京林业大学江苏省林业资源高效加工利用协同创新中心,江苏南京210037 [2]南京林业大学化学工程学院,江苏南京210037 [3]江苏省生物质绿色燃料与化学品重点实验室,江苏南京210037

出　　处：《林产化学与工业》2017年第5期45-52,共8页Chemistry and Industry of Forest Products

基　　金："十二五"国家科技支撑计划资助(2015BAD15B09);江苏省普通高校研究生科研创新计划资助项目(SJLX_0406);江苏高校优势学科建设工程资助项目(无编号)

摘　　要：将稀酸蒸汽爆破预处理后的玉米秸秆进行预水解,以离子液体1-丁基-3-甲基咪唑六氟磷酸盐([C_4mim][PF_6])萃取脱除预水解液中的抑制物,并对萃取脱毒条件进行优化,进一步分析了离子液体的脱毒效果。研究结果表明,最佳萃取条件为:水油相体积比1∶2、35℃、250 r/min下萃取60 min。在此条件下,水解液中的主要抑制物甲酸、乙酸、乙酰丙酸、5-羟甲基糠醛、糠醛和总酚的去除率分别达到24.72%、21.84%、47.99%、82.76%、100%和39.70%,且可发酵性糖几乎无损失。通过对主要抑制物与离子液体脱毒性能分析可知,随着离子液体[Cnmim][PF6](n=4,6,8)中阳离子烷基碳链增长,离子液体对抑制物萃取能力下降;抑制物疏水性越强,与离子液体的氢键作用越强,萃取分离效果越好;p H值越低,对抑制物的去除效果越好;乙酸、5-羟甲基糠醛、4-羟基苯甲醛在[C_4mim][PF6]中去除率基本不随抑制物初始质量浓度改变而发生变化。In this study,a new green detoxification technology named-ionic liquid extraction was used for detoxification of the prehydrolyzate obtained from the washed acid-catalyzed steam-exploded corn stover in order to improve the ethanol fermentability of yeast. 1-butyl-3-methyl imidazole hexafluorophosphate（ [C4 mim][PF6]） was selected as the extraction agent and its extraction conditions had been optimized. The optimal extraction conditions were as follows： the ratio of aqueous to organic phase1∶ 2,35 ℃,250 r/min,and 60 min. Under these conditions,the removal rate of formic acid,acetic acid,levulinic acid,5-hydroxymethylfurfural,furfural and total phenols in the hydrolysate reached 24. 72%,21. 84%,47. 99%,82. 76%,100%and 39. 7% respectively,the extraction efficiencies of the main inhibitors were high and the loss of sugars was negligible. Theresults of detoxification mechanism indicated that the extraction efficiency of the inhibitors decreased with the increase of alkyl chain length on the cation of ionic liquid[Cnmim][PF6]（ n = 4,6,8）; the more hydrophobic the inhibitors were,the stronger the hydrogen bonding with ionic liquid was; the lower the p H value was,the better the extraction efficiency of inhibitors was. The removal rate of acetic acid,5-hydroxymethylfurfural and 4-hydroxybenzaldehyde in[C4 mim][PF6]did not change with the initial mass concentration of inhibitors.

关 键 词：木质纤维原料 抑制物 离子液体 萃取 脱毒 

分 类 号：TQ353[化学工程]