Preparation of Poly(ether-6-block amide)/PVC Thin Film Composite Membrane for CO2 Separation: Effect of Top Layer Thickness and Operating Parameters

Abstract

In this work, novel thin film composite membranes (TFCs) of poly (ether-6-block amide) (Pebax-1657) on a polyvinyl chloride (PVC) ultrafiltration membrane as support were prepared using inclined coating method for CO₂ separation. Investigating the effects of top selective layer thickness formed by controlling the coating angle (15-60°) and polymer solution concentration (5-10 wt.%), and also, the effects of different operating pressure (2-10 bar) and temperature (25-50 °C) conditions were selected as challenging case study. Morphological considerations of the Pebax/PVC TFCs were evaluated by scanning electron microscopy (SEM) that revealed a defect-free thin selective layer of Pebax/PVC composite membrane. The single CO₂, CH4 and N2 gases' permeance carried out using constant-volume/variable-pressure method. The results suggested that the CO₂ permeance, CO₂/N₂ and CO₂/CH₄ selectivity of the membranes increase upon pressure and decrease with temperature increment. In addition, the permeations of CO₂, CH₄ and N₂ increased respectively 16.7, 21 and 18% in Pebax/PVC TFCs compared to the neat Pebax free stand membrane.