Product recovery from ionic liquids by solvent-resistant nanofiltration: application to ozonation of acetals and methyl oleate
作者:Charlie Van Doorslaer、Daan Glas、Annelies Peeters、Angels Cano Odena、Ivo Vankelecom、Koen Binnemans、Pascal Mertens、Dirk De Vos
DOI:10.1039/c003956j
日期:——
In this work we tackle the problematic separation of reaction products from ionic liquid media. Solvent-resistant nanofiltration proves to be an attractive technique for the separation of non-volatile polar products from ionic liquids. In view of the high compatibility between ozone and ionic liquids, two ozone-mediated model reactions were chosen: firstly the oxidation of acetals to esters in the presence of ozone and secondly the ozonation of methyl oleate to monomethyl azelate and pelargonic acid. The objective was to retain the ionic liquid phase by means of a solvent-resistant nanofiltration membrane, while the organic reaction products permeate through the polymeric membrane. First, the ozonations were studied in order to know the characteristic product compositions. Next, a screening of membranes was performed on synthetic product mixtures. The second generation polyimide-based DuraMem™ membranes showed the highest rejection, up to 96%, for the evaluated ionic liquids. These DuraMem™ membranes also proved suitable for the separation of the products on real reaction mixtures, even in a single filtration step.
在本工作中,我们解决了从离子液体介质中分离反应产物的问题。耐溶剂型纳滤技术被证明是用于从离子液体中分离非挥发性极性产品的有吸引力的技术。考虑到臭氧与离子液体之间的高度相容性,选择了两种臭氧介导的模型反应:首先是乙缩醛在臭氧存在下的氧化成酯反应,其次是油酸甲酯的臭氧氧化生成单甲基壬二酸和壬酸反应。目标是通过耐溶剂型纳滤膜保留离子液体相,而有机反应产物通过聚合物膜渗透。首先,研究了臭氧反应以了解特征产物组成。随后,对合成产物混合物进行了膜的筛选。以第二代聚酰亚胺为基础的DuraMem™膜显示出对所评估的离子液体的最高排斥率,高达96%。这些DuraMem™膜也被证明适合于实际反应混合物中产物的分离,甚至在单次过滤步骤中也是如此。