Optimizing CO2/CH4 separation performance of modified thin film composite Pebax MH 1657 membrane using a statistical experimental design technique

In this research, statistically based experimental design (central composite design, CCD) was applied to analyze and optimize the effect of PEG-ran-PPG (10–50 wt%) as a blending polymer and CuBTC (0–20 wt%) which is a metal organic framework (MOF) as a nano filler on the CO2 permeance and CO2 /CH4 ideal selectivity of Pebax MH 1657/polysulfone thin film composite membrane. In fact, the beneficial properties of polymer blending and mixed matrix membranes (MMMs) have been combined. Based on the regression coefficients of the obtained models, the CO2 permeance was notably influenced by PEG-ran-PPG mass content, while the mass content of CuBTC has the most significant effect on the CO2 /CH4 ideal selectivity. Experimental and statistical results showed that under the optimum conditions (PEG-ran-PPG: 32.76 wt% and CuBTC: 20 wt%), nearly 620% increase in the CO2 permeance and 43% enhancement in the CO2/CH4 ideal selectivity was observed compared to the neat Pebax membranes.