Experimental and Numerical Study of CO2/CH4 Separation Using SAPO-34/PES Hollow Fiber Membrane

Abstract

The poor compatibility between polymeric matrix and inorganic filler in mixed matrix membrane (MMM) generates interfacial defects that reduce the gas selectivity. In this work, the defects in poletherysulfone (PES)/silicoaluminophosphate (SAPO)-34 zeolite mixed matrix membrane was prepared by dry–wet spinning technique for the separation of CO2/CH4 mixtures. In this regard, the synthesized PES/SAPO-34 mixed matrix membranes (MMMs) were characterized via FESEM, TGA and DSC analyses. The response surface methodology (RSM) was applied to find the relationships between several explanatory variables such as air gap distance, jet strech ratio and zeolite content and CO2 permeance as responses. The results were validated with the experimental data, which the model results were in good agreement with the available experimental data. The effects of feed temperature and feed pressure on permeation and CO2/CH4 selectivity of membranes were investigated. The MMMs showed better performance than the neat PES membrane. Two dimensional countercurrent mathematical model for membrane separation has been incorporated with Aspen HYSYS as a user defined unit operation in order to optimize and design the membrane system for CO2 capture from natural gas. Parameter sensitivities, along with process economics, have been studied for different design configurations (including recycle streams and multiple stages). It has been observed that double stage with permeate recycle system gives the optimum design configuration due to minimum process gas cost involved with it. Permeation results manifested that the PES/SAPO-34 fabricated at optimum conditions has incredible worth from the prospective of industrial separations of CO2 from flue and natural gas.