Hydroxyl aluminium silicate clay for biohydrogen purification by pressure swing adsorption: Physical properties, adsorption isotherm, multicomponent breakthrough curve modelling, and cycle simulation

Abstract

Hydroxyl aluminium silicate clay (HAS-Clay) is a novel adsorbent in pressure swing adsorption for CO2 capture (CO2-PSA) and can also adsorb H2S. To investigate the performance of HAS-Clay as a CO2-PSA adsorbent, multicomponent breakthrough curves were determined using experimental measurements and theoretical models, and, based on those results, CO2-PSA simulations were conducted. The breakthrough curves produced from the theoretical models agreed well with those derived from experiment. CO2-PSA with HAS-Clay could purify biomass-gasification-derived producer gas of contaminants (carbon dioxide, methane, carbon monoxide, and hydrogen sulfide) with high CO2 recovery and low energy input. The CO2 recovery rate of CO2-PSA with HAS-Clay was 58.4%, and the CO2 purity was 98.4%. The specific energy demand was 2.83 MJ/kg-CO2. In addition, the H2S regenerability of HAS-Clay was investigated. The results show that HAS-Clay retained the ability to adsorb H2S at a steady-state value of 0.02 mol/kg for the regeneration cycles. Therefore, it is suggested that CO2-PSA with HAS-Clay is suitable for CO2 separation from multicomponent gas mixtures.