Matsumoto Michiaki, Panigrahi Abhishek, Murakami Yuuki, Kondo Kazuo
Department of Chemical Engineering and Materials Science, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan.
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
Membranes (Basel). 2011 May 13;1(2):98-108. doi: 10.3390/membranes1020098.
Biodegradable polymers have attracted much attention from an environmental point of view. Optically pure lactic acid that can be prepared by fermentation is one of the important raw materials for biodegradable polymer. The separation and purification of lactic acid from the fermentation broth are the major portions of the production costs. We proposed the application of supported ionic liquid membranes to recovering lactic acid. In this paper, the effect of ionic liquids, such as Aliquat 336, CYPHOS IL-101, CYPHOS IL-102, CYPHOS IL-104, CYPHOS IL-109 and CYPHOS IL-111 on the lactic acid permeation have been studied. Aliquat 336, CYPHOS IL-101 and CYPHOS IL-102 were found to be the best membrane solvents as far as membrane stability and permeation of lactic acid are concerned. CYPHOS IL-109 and CYPHOS IL-111 were found to be unsuitable, as they leak out from the pores of the supported liquid membrane (SLM), thereby allowing free transport of lactic acid as well as hydrochloric acid. CYPHOS IL-102 was found to be the most adequate (Permeation rate = 60.41%) among these ionic liquids as far as the separation of lactic acid is concerned. The permeation mechanisms, by which ionic liquid-water complexes act as the carrier of lactate and hydrochloric acid, were proposed. The experimental permeation results have been obtained as opposed to the expected values from the solution-diffusion mechanism.
从环境角度来看，可生物降解聚合物已引起了广泛关注。可通过发酵制备的光学纯乳酸是可生物降解聚合物的重要原料之一。从发酵液中分离和纯化乳酸是生产成本的主要部分。我们提出了应用支撑离子液体膜来回收乳酸。本文研究了Aliquat 336、CYPHOS IL-101、CYPHOS IL-102、CYPHOS IL-104、CYPHOS IL-109和CYPHOS IL-111等离子液体对乳酸渗透的影响。就膜稳定性和乳酸渗透而言，发现Aliquat 336、CYPHOS IL-101和CYPHOS IL-102是最佳的膜溶剂。发现CYPHOS IL-109和CYPHOS IL-111不合适，因为它们从支撑液膜（SLM）的孔中泄漏出来，从而允许乳酸和盐酸自由传输。就乳酸分离而言，发现CYPHOS IL-102在这些离子液体中是最适宜的（渗透速率 = 60.41%）。提出了离子液体 - 水络合物作为乳酸和盐酸载体的渗透机制。实验得到的渗透结果与溶液扩散机制的预期值相反。
