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

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.