Two adsorbents are studied in this work for ethylene/ethane separations. The first, AgNO3/SiO2, has been considered in previous work to be a very promising adsorbent for olefin/paraffin separations in industry. The second, CuCl/SiO2, has been created based on the high affinity of Cu+ ions for olefins among the π-complexation metal group. Previous adsorbents had been used with Cu+ ions impregnated within zeolites or activated carbons, but there was nothing prevalent on the impregnation of silica gel with copper ions. This is mostly due to the difficulty of finding a method that will successfully implement the impregnation. Wet impregnation was used for the preparation of AgNO3/SiO2, while wet impregnation and thermal monolayer dispersion were used for the CuCl/SiO2 adsorbent preparation to see which case was more effective in impregnating the silica gel.
Volumetric experiments were conducted with the two adsorbents for ethylene and ethane at temperatures of 34°C and -73°C. Langmuir, Toth, and TD-Toth isotherms were used to model the data and binary adsorption behaviour predictions were made accordingly using the Extended-Langmuir model. An economic analysis was conducted for the addition of a Pressure Swing Adsorption system to a cryogenic distillation column.