Casado-Coterillo Clara, Garea Aurora, Irabien Ángel
Department of Chemical and Biomolecular Engineering, Universidad de Cantabria, Av. Los Castros s/n, 39005 Santander, Spain.
Membranes (Basel). 2020 Dec 8;10(12):405. doi: 10.3390/membranes10120405.
Membrane technology is a simple and energy-conservative separation option that is considered to be a green alternative for CO capture processes. However, commercially available membranes still face challenges regarding water and chemical resistance. In this study, the effect of water and organic contaminants in the feed stream on the CO/CH separation performance is evaluated as a function of the hydrophilic and permselective features of the top layer of the membrane. The membranes were a commercial hydrophobic membrane with a polydimethylsiloxane (PDMS) top layer (Sulzer Chemtech) and a hydrophilic flat composite membrane with a hydrophilic [emim][ac] ionic liquid-chitosan (IL-CS) thin layer on a commercial polyethersulfone (PES) support developed in our laboratory. Both membranes were immersed in NaOH 1M solutions and washed thoroughly before characterization. The CO permeance was similar for both NaOH-treated membranes in the whole range of feed concentration (up to 250 GPU). The presence of water vapor and organic impurities of the feed gas largely affects the gas permeance through the hydrophobic PDMS membrane, while the behavior of the hydrophilic IL-CS/PES membranes is scarcely affected. The effects of the interaction of the contaminants in the membrane selective layer are being further evaluated.
膜技术是一种简单且节能的分离方法，被认为是用于二氧化碳捕集过程的绿色替代方案。然而，市售膜在耐水性和耐化学性方面仍面临挑战。在本研究中，评估了进料流中的水和有机污染物对二氧化碳/甲烷分离性能的影响，该影响是作为膜顶层的亲水性和选择性渗透特性的函数。所使用的膜为一种具有聚二甲基硅氧烷（PDMS）顶层的商用疏水膜（苏尔寿化工技术公司），以及一种在我们实验室开发的、在商用聚醚砜（PES）支撑体上带有亲水性[emim][ac]离子液体-壳聚糖（IL-CS）薄层的亲水性平板复合膜。在表征之前，将两种膜都浸入1M的氢氧化钠溶液中并彻底洗涤。在整个进料浓度范围（高达250 GPU）内，经氢氧化钠处理的两种膜的二氧化碳渗透率相似。进料气体中的水蒸气和有机杂质的存在极大地影响了通过疏水PDMS膜的气体渗透率，而亲水性IL-CS/PES膜的性能几乎不受影响。目前正在进一步评估污染物在膜选择性层中的相互作用的影响。
