离子液体萃取大豆毛油中游离脂肪酸的研究

The Investigation Concerning Free Fatty Acids from Crude Soybean Oil by Ionic Liquids Extraction

本实验研究了离子液体(ILs)选择性萃取大豆毛油中的游离脂肪酸。研究发现,相比于纯有机溶剂,四丁基溴化膦(P4,4,4,4Br)、1-乙基-3-甲基咪唑磷酸二甲酯盐(EMIM(MeO)_2PO_2)、1-丁基-3-甲基咪唑二腈胺盐(BMIMN(CN)_2)3种ILs游离脂肪酸萃取选择优势明显。实验优化了萃取温度、平衡时间、油/离子液体质量比等工艺参数。结果表明,以EMIM(MeO)_2PO_2为萃取剂,油与IL质量比1∶5,70℃萃取3 min,大豆毛油一次脱酸率即达到85.78%。二次组合萃取脱酸后,脱酸率在88%~97%之间。特别地,首先用BMIMN(CN)_2(油/IL 1∶2)70℃萃取3 min,然后用EMIM(MeO)_2PO_2(油/IL 1∶1)相同温度下萃取3 min,毛油酸价从2.39降至0.08 mg/g,达到了国家(一级)食用油标准(酸价≤0.2 mg/g)。使用过的离子液体经简单处理即可重复使用,因此是一种经济、高效、绿色的食用油脱酸萃取剂。

In this paper, selective extraction of tree ratty aclos from cruue soybean oil by ionic liquids（ILs）, was studied. The study indicated that three ILs of tetrabutylphosphonium bromide （ P4,4,4,4Br）, 1 ethyl 3 methylimidazolium dimethylphosphate [ EM1M （MeO） 2 PO2 ] , 1 Butyl 3 methylimidazolium dinitrile amine salt [ BMIMN（CN）2 ] had obvious advantages for free fatty acid extraction compared to organic solvents. The process pa rameters, such as extraction temperature, equilibration time, oil/ionic liquid mass ratio were optimized in term of de acidification rate. The results indicated that EMIM （Met）2PO2 as extractant, the mass ratio of oil to IL was 1：5 and extracted for 3 minutes at 70℃, the first deacidification rate of 85.78% was reached immediately. Moreover, through two step extraction of free fatty acid, the deacidification rate of crude oil from 88% to 97%. Especially, it is first extracted by BMIMN（CN）2 with oil/IL mass ratio of 1：2 at 70℃ for 3 min, and then extracted with EMIM （MeO）2PO2（oil/IL mass ratio of 1： 2） for 3 more minutes, the acid value of crude oil was descended from 2.39 to 0.08 rag/g, which meet the national （first class） criteria value for edible oil standard in China （acid value≤0.2 nag/g）. After simple treatment, the ionic liquid can be recycled. So deacification by I｜s extraction is an economical, efficient and green process for edible oil refinement.