2022 年 26 巻 3-4 号 p. 65-72
Enhancement of CO2 removal using adsorbent agents is a promising technique to reduce the atmospheric CO2 levels. The objectives of this study were to develop novel porous aluminum silicates with different Si/Al molar ratios and to investigate their properties for CO2 adsorption and recovery with the pressure swing adsorption (PSA) process. At a pressure less than 5 kPa, the amount of CO2 adsorption by the porous aluminum silicates at each pressure increased with decreasing the Si/Al molar ratios from 2.0 to 1.1. Adsorption of CO2 by the porous aluminum silicates is closely related to the number of ultra-micropores at a pressure less than 5 kPa and the specific surface area at a pressure greater than 8 kPa. At a CO2 partial pressure less than 18 kPa, Zeolite-13X has a greater CO2 recovery than any other porous aluminum silicates. Contrarily, the porous aluminum silicates have a greater CO2 recovery than Zeolite-13X at a CO2 partial pressure greater than 18 kPa. The efficient CO2 recovery by porous aluminum silicates at a pressure greater than 8 kPa requires a large number of pores with 1.3 to 2.9 nm in diameter and a large specific surface area.
