CO2 separation from binary mixtures of CH4, N2, and H2 by using SSZ-13 zeolite membrane

Due to the importance of gas mixture composition in CO2 separation process and the lack of sufficient studies in the literatures for SSZ-13 zeolite membrane, in this paper, the effect of various mixed gas compositions was investigated in CO2 separation from light gases like CH4, N2, and H2 by using a synthesized SSZ-13 zeolite membrane. Single gas permeance was measured for CO2, N2, CH4 and H2 in a wide range of temperature (30–80 °C), feed pressure (up to 600 kPa) and different feed composition for gas mixtures (25:75, 50:50, 75:25). The results of single gas showed really good performance, i.e., CO2 permeance of 7.34 × 10-7 mol m−2 s−1 Pa−1 and CO2/CH4 selectivity of 60 at 30 °C and 200 kPa of feed pressure. For equimolar mixed gas, the CO2 permeance was almost the same for single gas while the CH4 permeance was reduced by 75% and hence CO2/CH4 selectivity was increased by three times, i.e., from 60 to 183. Similarly, the selectivity of CO2/N2 and CO2/H2 were doubled and increased by more than 5 times, respectively. For other compositions (25:75, 75:25) the CO2/CH4, CO2/N2 and CO2/H2 mixture selectivity were decreased with increase in CO2 concentration of feed keeping always higher gas selectivity than the single gas tests.