咪唑类离子液体对木质纤维预水解液的脱毒  

Detoxification of lignocellulosic prehydrolyzate using imidazolium-based ionic liquid

作　　者：杨金龙[1] 荣亚运 高露[1] 朱均均[1,2] 徐勇[1,2] 勇强[1] 欧阳嘉[1] 余世袁[1,2] 

机构地区：[1]南京林业大学化学工程学院,江苏南京210037 [2]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：《化工学报》2016年第4期1490-1496,共7页CIESC Journal

基　　金：国家自然科学基金项目(31100432);'十二五'国家科技支撑计划项目(2015BAD15B09);江苏高校优势学科建设工程资助项目~~

摘　　要：针对燃料乙醇生物炼制过程中抑制物对酵母乙醇发酵的抑制作用,以水洗稀酸蒸汽爆破预处理玉米秸秆得到的预水解液为研究对象,采用新型绿色脱毒技术——离子液体进行萃取脱毒,研究比较了两种咪唑类离子液体[烷基咪唑六氟磷酸盐离子液体[C_nmim][PF_6](n=4,6,8)和烷基咪唑四氟硼酸盐离子液体[C_nmim][BF_4](n=6,8)]对预水解液的萃取性能。结果表明,随着咪唑类离子液体阳离子烷基链长度的增加,离子液体对抑制物的萃取性能下降,具有更强电负性的阴离子为4BF-的离子液体比阴离子为6PF-的离子液体萃取效率更高。通过比较糖与抑制物的萃取率,最终选择[C8mim][BF4]作为预水解液的萃取剂,结果显示其对主要抑制物甲酸、乙酸、5-羟甲基糠醛的萃取率分别为53.22%、47.53%和85.13%,总酚的萃取率为65.05%,而糖的损失率在6%以内。Aiming at the effect of inhibitors on yeast ethanol fermentation during the fuel ethanol biorefinery process, a new green detoxification technology-ionic liquid extraction was developed for detoxification of the prehydrolyzate obtained from washed acid-catalyzed steam-exploded corn stover（ASC）. The extractive performances of two kinds of imidazolium-based ionic liquids（alkylimidazolium hexafluorophosphate [Cnmim][PF6]（n = 4,6,8） and alkylimidazolium tetrafluoroborate [Cnmim][BF4]（n = 6,8）） for the ASC prehydrolyzate were investigated and compared. The results indicated that the extraction efficiency of the inhibitors decreased with the increase of alkyl chain length on the cation of ionic liquids. Ionic liquid with 4BF-anion had much higher extraction efficiency for the inhibitors than those with PF6^- anion because of the stronger effective charge in BF4^-. Compared to the extraction efficiency of sugars and inhibitors, [C8mim][BF4] was selected as the extractant for detoxification of the ASC prehydrolyzate. Its detoxification results indicated that 85.13% of 5-hydroxymethylfurfural, 53.22% of formic acid, 47.53% of acetic acid and 65.05% of total phenols could be removed, while the loss of sugars was less than 6%.

关 键 词：离子液体 生物质 生物燃料 抑制物 萃取 脱毒 

分 类 号：TQ353[化学工程]