Optimization of the gas separation performance of polyurethane-zeolite 3A and ZSM-5 mixed matrix membranes using response surface methodology

In the present work, the response surface method software was used with five measurement levels with three factors. These were applied for the optimization of operating parameters that affected gas separation performance of polyurethane-zeolite 3A, ZSM-5 mixed matrix membranes. The basis of the experiments was a rotatable central composite design (CCD). The three independent variables studied were: zeolite content (0-24 wt%), operating temperature (25-45 degrees C) and operating pressure (0.2-0.1 MPa). The effects ofthese three variables on the selectivity and permeability membranes were studied by the analysis of variance (ANOVA). Optimal conditions for the enhancement of gas separation performances of polyurethane-3A zeolite were found to be 18 wt%, 30 degrees C and 0.8 MPa respectively. Under these conditions, the permeabilities of carbon dioxide, methane, oxygen and nitrogen gases were measured at 138.4, 22.9, 15.7 and 6.4 Barrer respectively while the CO2/CH4, CO2/N-2 and O-2/N-2 selectivities were 5.8, 22.5 and 2.5, respectively. Also, the optimal conditions for improvement of the gas separation performance of polyurethane-ZSM 5 were found to be 15.64 wt%, 30 degrees C and 4 bar. The permeabilities of these four gases (Le. carbon dioxide, methane, oxygen and nitrogen) were 164.7, 21.2, 21.5 and 8.1 Barrer while the CO2/CH4, CO2/N-2 and O-2/N-2 selectivities were 7.8, 20.6 and 2.7 respectively. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.