Monoethanol amine modified zeolite 13X for CO2 adsorption at different temperatures

Zeolite 13X has been modified with monoethanol amine (MEA). MEA loadings of 0.5-25 wt % have been achieved using the impregnation method in different solvents. The mode of incorporation based on methanol with stirring at room temperature appears to be the most feasible. The adsorbent has been characterized for crystallinity, surface area, pore volume, and pore size. The thermal stability of the adsorbent is studied using a thermal analyzer. The CO2 adsorption capacity of adsorbents is evaluated using the breakthrough adsorption method with a packed column on a 10 g scale. The adsorption capacities of adsorbents are estimated in the temperature range 30-120 degrees C. The adsorbents show improvement in CO2 adsorption capacity over the unmodified zeolite by a factor of ca. 1.6 at 30 degrees C, whereas at 120 degrees C the efficiency improved by a factor of 3.5. For adsorption at these temperatures, different MEA loading levels were found to be Suitable as per the governing adsorption phenomena, that is, physical or chemical. The adsorbent is also studied for CO2 selectivity over N-2 at 75 degrees C. The MEA-modified adsorbent shows better CO2 selectivity, which was improved further in the presence of moisture.