A study on natural clinoptilolite for CO2/N2 gas separation

Based on its low cost and low water adsorption capacity, compared to synthetic zeolites (A-type, X-type and Y-type), natural, untreated clinoptilolite was examined as a potential adsorbent for a separation process targeting on removal of CO2 from flue gas. Taking into consideration typical flue gas composition and temperature, adsorptive properties of binary CO2/N2 mixtures were tested in the temperature range of 268 to 403 K and compared with literature data. The results showed that CO2 concentration, total pressure, and temperature strongly affect selectivity and working capacity, restricting the conditions under which the material could be used as an efficient adsorbent.