Pure and Binary Adsorption Equilibria of Carbon Dioxide and Nitrogen on Silicalite

For different separation applications of CO2 and N-2, pure and mixture adsorption isotherms of these gases on silicalite adsorbent were determined experimentally. Constant volume and concentration pulse chromatographic techniques were used for the determination of pure and binary adsorption behavior, respectively. Pure component isotherms were determined up to 5 bar pressure for the temperature range (40 to 100) degrees C. Binary adsorption behavior for CO2 and N-2 mixtures, covering the whole concentration range, were determined experimentally for a total pressure of 1 bar for the same temperature range. The applicability of different pure adsorption isotherm models was discussed for the pure isotherms, and ideal separation factors were determined. For the mixture adsorption isotherms, three binary concentration pulse methods, HT-CPM (Harlick and Tezel-Concentration Pulse Method), MTT-CPM (Modified Triebe and Tezel-Concentration Pulse Method), and MVV-CPM (Modified Van der Vlist and Van derMeijden-Concentration Pulse Method) were considered, and HT-CPM was found to be the most applicable one for this particular system. The experimental binary isotherms were compared to the predicted ones by using different binary adsorption models for this system. The results obtained showed that silicalite is a promising adsorbent for the separation of CO2 and N-2.