Microchannel zeolite 13X adsorbent with high CO2 separation performance

Abstract

• Microchanneled zeolite monoliths for removal of CO 2 through phase separation. • CO 2 dynamic uptake of 3.4 mmol g −1 was obtained for 13X monoliths. • The monoliths present markedly low pressure drop under fast flow rate. • Mass transfer resistance in monolith significantly lower than those for beads. • Ultra high mechanical strength and thermal conductivity for zeolite adsorbent. Uniform 13X films with thicknesses of 3 and 11 µm were grown on supports in the form of steel monoliths with a cell density of 1600 cpsi and microchannels width of 0.5 mm. Sharp breakthrough fronts and a dynamic uptake of 3.4 mmol CO 2 g −1 zeolite were observed in the forwarding step of breakthrough experiments for a feed of 10% CO 2 in N 2 with a high flow rate at 293 K and 1 bar. Numerical modeling showed that the adsorption process was very fast and that the transport of CO 2 in the thin zeolite layer was the rate-limiting step, the mass transfer resistance for the 11 µm film is 2.2 times lower than zeolite 13X pellets and 100 times lower than zeolite 4A beads. Axial dispersion, pressure drop, and gas film resistance were shown to be negligible. The steel monolith support provides good mechanical strength and excellent thermal conductivity for the 13X films. The combination of properties makes this adsorbent a good performer when compared with other types of structured zeolite adsorbents in reported literatures. This microchannel adsorbent is a promising alternative to traditional adsorbents in processes of fast CO 2 separation with short cycle times.