Activated carbon for hydrogen purification by pressure swing adsorption: Multicomponent breakthrough curves and PSA performance

Abstract

In this work, multicomponent breakthrough experiments (binary H2-CO2, ternary H2-CO2-CO and five-component H2-CO2-CO-CH4-N2) were performed under different operating conditions in activated carbon extrudates to validate the mathematical model. A 10 steps one-column VPSA experiment was also performed. These experiments allow experimental validation of adsorption equilibrium predicted by the multicomponent extension of the Virial isotherm and a fixed-bed mathematical model. In the VPSA experiment, a 99.981% hydrogen purity stream (with 63ppm of CO contamination) was obtained with a hydrogen recovery of 81.6% and an adsorbent productivity of 101molH2kgads-1day-1. The mathematical model was also employed to assess the effect of operating conditions and the influence of step times and pressure equalizations in the PSA unit. It was verified that high-purity hydrogen (>99.99%) can be obtained using this adsorbent with recoveries higher than 75% and unit productivities of 160molH2kgads-1day-1. © 2010 Elsevier Ltd.