Investigation of a novel combination of adsorbents for hydrogen purification using Cu-BTC and conventional adsorbents in pressure swing adsorption

This study is an attempt to simulate and analyze a lab-scale two-bed pressure swing adsorption in order to investigate the performance of three different adsorbents (Cu-BTC as a new generation adsorbent, activated carbon, and zeolite 5A) with different feed compositions, and find a novel combination of layered bed. Four different flows of steam methane reforming reactor were considered as inlet feeds for hydrogen purification. Comparison of the feeds with different compositions showed that in the presence of high amounts of impurities, an adsorption bed of Cu-BTC produces hydrogen at a higher purity than activated carbon, zeolite 5A, or an activated carbon-zeolite 5A layered bed. The simulation results from feed 4 (H₂:CO₂:CO:CH₄ = 0.4574:0.3174:0.0622:0.1630) with high amounts of impurities, showed that the use of Cu-BTC leads to hydrogen purity of up to 97.22%, while activated carbon, zeolite 5A, and the layered bed cannot improve the purity beyond 86.46%. This work shows that Cu-BTC is capable of being used in the first layer of layered beds. This was confirmed by comparing the performance of the three combinations of Cu-BTC, activated carbon, and zeolite 5A. The first configuration of the three adsorbents, in which the Cu-BTC was used as the first layer, purified hydrogen up to + 99.99% and recovered it up to 21.25%.