Microporous carbon coated zeolite particles for efficient carbon capture from wet flue gas

Abstract

Carbon capture plays an important role in reducing CO2 emissions, and selective adsorption of CO2 is attracting more and more attention. Consider the fact that the actual flue gas always contains the water molecule which is preferentially adsorbed onto the pore surface of adsorbent, resulting in a significant reduction of CO2 capacity and selectivity. In this contribution, we design and prepare a series of microporous carbon coated commercial zeolite 13X particles (13X@MPC) by pyrolysis of polyvinylidene fluoride (PVDF) where the uniform microporous layer is coated on the surface of zeolite 13X beads. After coated with microporous carbon layer, zeolite 13X turns into hydrophobic from hydrophillic. An optimized sample (13X@MPC(25,550)) displays a high CO2 uptake (76.2 cm3 g−1) similar to 13X (80.5 cm3 g−1) and a low H2O uptake (157.1 cm3 g−1) half to 13X (315.2 cm3 g−1). The ideal CO2/N2 selectivity is predicted as 215 by using the ideal adsorption solution theory. The breakthrough separation experiment further verifies the excellent carbon capture ability of 13X@MPC(25,550) from wet flue gas, where the CO2 capacity (26.5 cm3 g−1) and CO2/N2 selectivity (56.2) are greatly improved to zeolite 13X (6.8 cm3 g−1 and 12.5) under the same condition. The results of this paper can be extended to other water-containing gas separation, such as air separation, natural gas purification, etc.