Enhancement Of CO2 Adsorption By Introducing Mesopores Into FAU Zeolite Using Acid-Base Leaching

Abstract

Carbon capture and storage has become a widespread concern as a key technology in the global commitment to tackle climate change. Adsorption, especially when the regeneration process is carried out through a pressure reduction (pressure swing adsorption – PSA) is one of the promising solutions for reducing energy consumption, environmental impact, and the cost of CO2 capture. In this paper, zeolite FAU (type X) was chosen to be modified into hierarchically porous structure by using top-down approach with the combination between Ethylenediaminetetraacetic acid (EDTA), NaOH and Cetyltrimethylammonium bromide (CTAB), which is expected to be used as a potential material adsorbent in pressure swing adsorption (PSA) system for CO2 adsorption. The study of CO2 adsorption at 30°C has shown that mesoporous structure helps to increase strongly not only the rate of CO2 adsorption but also the selectivity between CO2/CH4, CO2/N2 and the regeneration yield in the same amount of vacuuming time with the original zeolite X while only mitigating slightly the CO2 adsorption capacity. The mesoporous structure of materials was proved through XRD patterns and pore-size distribution results. The CO2 adsorption procedures at different temperatures (0°C, 15°C, 30°C) were also conducted to calculate the thermodynamic adsorption parameters. After ten-time reusing, the material retains more than 90% adsorption capacity compared with the first time.

Keywords

• mesoporous zeolite
• co2 adsorption
• acid-base leaching
• fau zeolite