Preparation of acid-resistant PEI/SA composite membranes for the pervaporation dehydration of ethanol at low pH
Preparation of acid-resistant PEI/SA composite membranes for the pervaporation dehydration of ethanol at low pH
复制标题
低pH乙醇渗透汽化脱水耐酸PEI/SA复合膜的制备
DOI：
10.1016/j.seppur.2017.09.038
复制
发表时间：
2018-02-09
影响因子：
8.6
通讯作者：
Ji, Shulan
中科院分区：
文献类型：
--
作者：
Li, Jie;Si, Xinguo;Ji, Shulan
渗透蒸发是一种有效的生物质发酵过程中产生的生物乙醇的回收方法，其中通常含有乙醇，水和各种酸类化合物。然而，制备具有良好耐酸能力和高分离性能的渗透汽化膜仍然是一个重大挑战。为了在一定pH范围内分离由无机酸或有机酸组成的乙醇/水混合物，我们通过聚乙烯亚胺（PEI）和海藻酸钠（SA）之间的离子交联制备了聚乙烯亚胺/海藻酸钠多层膜。本研究采用动态层接层（LbL）技术，将PEI和SA交替沉积在超滤支撑膜上。使用FTIR证实了SA的COO-基团和PEI的-NH 2基团之间的离子交联。结果表明，多层膜在酸性条件下具有良好的渗透汽化性能。在60 ℃下，pH = 3的乙醇/水混合物脱水时，水含量可从10wt%富集到99.42wt%（β = 1542），渗透通量为1.203kg/（m2·h）。长时间运行表明，（SA/PEI）（1.5）/PAN膜的渗透通量稳定在0.88 kg/（m2 h）左右，渗透液含水率在99.3wt%以上波动，表明该膜具有良好的酸料脱水性能。
Pervaporation is an efficient process for recovering bioethanol produced from biomass fermentation, which often contains ethanol, water, and a variety of acids compounds. However, it is still a major challenge to fabricate pervaporation membranes with good acid resistance capability and high separation performance. In order to separate ethanol/water mixtures consisted of inorganic or organic acid over a range of pH environments, we prepared polyelectrolyte multilayer membranes via ionic cross-linking between polyethyleneimine (PEI) and sodium alginate (SA). In this study, PEI and SA were alternatively deposited on ultrafiltration support membrane by using dynamic layer-by-layer (LbL) technique. The ionic cross-linking between the COO- groups of SA and -NH2 groups of PEI has been demonstrated using FTIR. It was found that the multilayer membranes showed high pervaporation performance in acid conditions. The water content could be enriched from 10 wt% to 99.42 wt% (beta = 1542) and the permeate flux was 1.203 kg/(m(2) h) in the dehydration of ethanol/water mixture with pH = 3 at 60 degrees C. Long time operations showed that water content in permeate fluctuated above 99.3 wt%, and permeation flux stayed stable around 0.88 kg/(m(2) h), which indicated that (SA/PEI)(1.5)/PAN membrane has promising potential for dehydration of acid feed.