Synthesis and application of high-permeable zeolite MER membrane for separation of carbon dioxide from methane

In this work, high-permeable zeolite merlinoite (MER) membranes were synthesized for separation of CO2/CH4. The effects of synthesis parameters (temperature, time, and coating number) on permeance and selectivity of synthesized membranes were investigated. The results showed that coating repetition of zeolite layer strongly increased membrane selectivity while decreased permeability for both gasses. Also, it was found that zeolite layers were thickened and larger crystals were formed at higher synthesis temperatures and times. In this research, zeolite MER membranes with reversal tradeoff effect, i.e., simultaneously increased permeability and selectivity, were prepared. The best membrane synthesized in this work showed a CO2/CH4 selectivity of 20.1 and a CO2 permeability of 2.5 x 10(-8) mol/m(2)/s/pa. Due to the upper Robeson's bound for the separation of CO2/CH4, the selectivities and permeabilities obtained in the current study were related to the points over the upper bounds, while the performance of commercial membranes used to separate CO2 from CH4 reported in the literatures is enclosed in the area below the upper bound. High-permeable zeolite MER membranes with reasonable CO2/CH4 selectivity were successfully synthesized in this work. It found as good choices for the separation of CO2 from CH4 in large-scale separation applications.