Enhanced Natural Gas Sweetening with Ultralow H2S Concentration via Polycarbonate-Silica Mixed Matrix Membranes

Abstract

Mixed matrix membranes (MMMs) are brought up as prospecting media to sweeten natural gas in recent decades. But the majority of experiments have conducted on CO 2 /CH 4 gas pair separation and, H 2 S removal from CH 4 through MMMs has been paid less consideration. Thereupon, polycarbonate (PC) permeability and permselectivity as a cheap and abundant polymer and two PC-based MMMs were investigated under various operational conditions for this gas couple. The in uence of operational parameters including transmembrane pressure, feed temperature, H 2 S inlet concentration and physical aging on the permeability of mixed gas and selectivity of the H 2 S/CH 4 pair were assessed. It was observed that addition of silica nano particles causes more H 2 S permeability and selectivity. As a result, it can be used for methane upgradation. Membranes fabricated of silica modi ed by PDMS showed the highest permeability of H 2 S and also the superior selectivity of H 2 S/CH 4 . Therefore, it could be possibly applied to mitigation of H 2 S concentration in the outlet gas stream. Additionally, the two fabricated MMMs demonstrated H 2 S transport in a facilitative manner.

Mixed Matrix Membranes Based on MFI Zeolite Nanosheets with Tunable Thickness for CO2/CH4 and H2/CH4 Separation

“…The selectivity for CO 2 /CH 4 remained around 10 after 12 days of continuous operation. This may be associated with the zeolite nanosheet addition forming voids around the zeolite nanosheet aggregates in the matrix and excellent interfacial compatibility, which maintains the permeability. , After about 1 week, the gas permeability was almost unchanged, denoting the obtained MMMs have reasonable long-term stabilities.…”