摘要
渗透汽化膜技术替代传统精馏工艺分离环戊二烯/甲基环戊二烯碳五馏分同系物。以丙酮为非极性成膜添加剂,水为凝胶介质,采用溶胶-凝胶二步法合成BPADA-ODA非对称聚酰亚胺膜,利用FT-IR表征聚酰胺酸和非对称膜组成,SEM表征膜表面和断面结构形貌,并探讨膜厚、原料液流量等膜工艺参数对分离性能的影响。结果表明:BPADA与ODA化学亚胺化完全,膜表面无孔致密,膜断面为致密皮层和指状多孔支撑层构成,膜厚增加,膜分离因子增大而渗透通量减小,最优膜厚为110μm,原料流量为30 m L·min-1。膜分离性能长期稳定,32 h渗透通量可达236.6 mg·m-2·h-1,CPD分离因子达1.61,原料液可分离提纯96.2%(wt)的甲基环戊二烯。
Pervaporation membrane process was investigated for separating a homologues system of cyclopentadiene/methylcyclopentadiene（CPD/MCPD） from cracking C5 fractions instead of traditional distillation. BPADA-ODA asymmetric polyimide membranes were prepared by two-step sol gel method using nonpolar acetone as an additive and water as gel medium. The prepared membranes were applied to separate methylcyclopentadiene and cyclopentadiene mixtures with the preferential permeation of CPD. The characterizations of FT-IR spectrum and SEM indicate that chemical imidization of BPADA and ODA is complete, and the membranes present asymmetric construction with a dense skin layer and finger-like porous supporting layer. The results of pervaporation show that the separation factor of CPD increases and the permeation fluxes decrease with the increase of membrane thickness. The optimal membrane thickness is 110 μm, and optimal feed flux is 30m L·min^-1. The separation performance of the membranes is long-term stabilization in 32 h. The total flux and the separation factor of CPD are 236.6 mg·m^-2·h^-1 and 1.61, respectively. MCPD with purity of 96.2%（wt） can be obtained for the pervaporation of the industrial grade CPD/MCPD mixtures from a cracking C5 fraction.
出处
《当代化工》
CAS
2015年第5期885-888,共4页
Contemporary Chemical Industry
基金
国家自然科学基金资助项目(No.51173203)
中央高校基本科研业务费专项资金(No.27R1204004A)
