Stability of amine loaded ZSM-5 for carbon capture

“To evaluate the steadiness of the synthesized materials for CO2CO2 capture, multiple cycles of the adsorption–desorption study were conducted with the 30-TETA-ZSM-5 adsorbent. The adsorption of CO2CO2 was performed at 30C30∘C and regeneration was performed at 120C120∘C. The adsorption process was continued for around 30 min for each cycle. After the adsorption experiment, nitrogen gas was sent to the reactor for 3 min to evacuate the gas mixture from the reactor and then the regeneration process was started. The concentration profiles of CO2CO2 for five continuous cycles are shown in figure 9.”

“The profile shows that the CO2CO2 concentration was nearly zero for 2.5 min during the adsorption process and then increased gradually to the feed level. However, during the regeneration process, the concentration of CO2CO2 increased slowly for the first 3 min, and then increased suddenly to a peak value of around 15 vol%. The calculated adsorption capacities of the sorbent for the 1st, 2nd, 3rd, 4th and 5th cycles are 47.1, 47.2, 45.9, 44.4 and 44.1 g of CO2/kgCO2/kg of sorbent, respectively. Similarly, the estimated amounts of desorbed CO2CO2 during regeneration cycles for the 1st, 2nd, 3rd, 4th and 5th cycles are 45.2, 44.7, 45.3, 42.1 and 42.7, respectively. The difference in the CO2CO2 amount between the adsorption and the corresponding desorption cycle lies in the range of 1.5–5.5%. It was also observed that for a particular cycle, the amount of CO2CO2 released during the regeneration process is less than the corresponding value of adsorption capacity. This shortfall may be due to the removal/elimination of the some amounts of adsorbed CO2CO2 during N2N2 flashing before starting the regeneration cycle. The reduction in the capture capacity with the number of cycles may be due to the combined effect of loss in the active surface area, incomplete regeneration or degradation of impregnated amine. Therefore, based on the study, it is observed that the materials are quite stable and capable of adsorbing CO2CO2 in multiple cycles.”


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