乙基和硝基纤维素/液晶复合空气分离膜

ETHYL CELLULOSE AND CELLULOSE NITRATE/LIOUID CRYSTAL COMPOSITE MEMBRANES FOR AIR SEPARATION

选用乙基纤维素(EC)、硝基纤维素(CN)分别与三种液晶(胆甾醇油烯基碳酸酯COC,烷基纤维素AC、混合液晶DYC)共混,制备了两大系列空气分离复合膜。用恒压容量分析法研究了有效分离面积为50cm^2膜的空气分离性能与膜组成、膜厚度、操作温度和压力的关系。结果表明,EC/液晶膜比CN/液晶膜具有较高的空气分离综合能力。减小膜厚或升高温度可以有效地提高一级富氧空气流量Q_(OEA),但膜厚过小或温度过高时,一级富氧空气的氧含量Yo_2会下降。而升高压力差可同时提高Q_(OEA),和Yo_2。在这两大系列复合膜中,EC/液晶膜能获得最高Q_(OEA)和Yo_2,分别为7.45×10^(-4)cm^3(STP)/s·cm^2和41％。

Air separation capabilities of the membranes preared from ethyl cellulose (EC), cellulose nitrate (CN) and three types of liquid crystals (LC) were studied by the improved volumetric method. The air separation performances through EC/LC and CN/LC membranes have been found to be strongly dependent on the composition and the thickness of the membranes, operating temperature and pressure difference. The highest flux Q_(OEA) and the highest oxygen concentration Y_(o_2) of the oxygen—enriched air (OEA) available through EC/LC membranes were 7.45×10^(-4)cm^3 (STP)/s·cm^2 and 41％, respectively.