Removal of C2H4 from a CO2 Stream by Adsorption: A Study in Combination of ab Initio Calculation and Experimental Approach

Removal of C2H4 from a CO2 stream is very important in ultrapurification of CO2 for its application and utilization. However, it is difficult to remove C2H4 completely from a CO2 stream via conventional cryogenic distillation because the volatility of C2H4 is similar to that of CO2. Another choice is the catalytic combustion method, but it is an energy-inefficient process, especially when it is coupled with the cryogenic distillation. Selective adsorption for removing C2H4 might be a promising alternative one. A great effort has been made in olefin/paraffin separation and recovery of olefin. There are, however, few reports about the removal of a trace of C2H4 from a CO2 stream. In this study, ab initio calculations have been conducted to screen the potential adsorbents. We found that AgNO3 exhibits a much higher adsorption affinity for C2H4 through a π-complexation interaction, indicating that the AgNO3-modified zeolite might be a promising adsorbent. Furthermore, the AgNO3-modified NaY zeolite was prepar...