Ethanol-enhanced wash-coating of zeolite 13X on microchannel walls for CO2 capture

Minimizing the energy demand for capturing carbon dioxide (CO2) from air and post-combustion sources is critical to mitigate the effects of climate change. Adsorbent-coated microchannels have been shown to significantly enhance the performance of CO2 capture systems. A novel single-dip wash-coating approach is developed in this work using silica nanoparticles and various base solvents to create a uniform and porous zeolite 13X adsorbent layer on cordierite microchannels. Extensive exploration of base solvents is undertaken to enhance adsorption performance and structural integrity, culminating in identifying a 70 % ethanol mixture as the most effective solvent. The coatings are characterized through a materials characterization suite and image analysis in conjunction with CO2 adsorption performance to determine the optimum adsorbent loading conditions. Equilibrium adsorption performance tests are performed for the coated samples in CO2 capture systems. The specific surface area (SSA) of the powdered 13X, initially measured at 662 m2/g, decreased to 553 m2/g in the coated form (utilizing a 20 % solid fraction with 70 % ethanol as the solvent), which is consistent with the observed adsorption performance results. The results underscore the scalability potential of these coated microchannels, presenting a promising alternative for CO2 separation systems to the conventional packed adsorbent beds.