Pervaporation Separation of Cyclopentadiene/Methylcyclopentadiene Mixtures from Cracking C5 Fractions Using Polyimide Membranes

Abstract

Polyimide membrane pervaporation was introduced to separate the costly diene mixtures of cyclopentadiene/methylcyclopentadiene (CPD/MCPD) from cracking C5 fractions. Four kinds of membrane solutions were prepared and two kinds of polyimide homogenous membranes were fabricated by thermal imidizations using the dianhydrides (BPADAand PMDA) and the diamines (ODA and DDS). The effect of the casting solutions viscosity on the membrane formation was revealed, and the formation of functional groups and the synthesis mechanisms of the thermal imidizations were indicated by FT-IR. The adsorption behaviors and the pervaporation performances were studies for BPADA-ODA and PMDA-ODA membranes. The results show that the permeation fluxes are 164g∙m-2∙h-1 and 4.2g∙m-2∙h-1 for BPADA-ODA and PMDA-ODA membranes respectively, while the separation factor are 1.93 and 8.9 for these two membranes respectively. 88.5 wt% concentration of MCPD was achieved in the circulated feed side ultimately.