Single-Stage Pressure Swing Adsorption for Producing Fuel Cell Grade Hydrogen

Abstract

High-purity hydrogen is needed for the growing market of hydrogen-based technologies, in particular for the automotive industry. Thus, efforts are needed to enhance the PSA performance to fulfill the needs of this emerging market. In the present work, a selective adsorbent for carbon monoxide was developed from a commercial activated carbon by wet impregnation of CuCl2 center dot 2H(2)O. Several samples were prepared and characterized concerning adsorption isotherms for H-2, CO2, CH4, and CO. The CO capacity was increased from 0.35 mol kg(ads)(-1) in the commercial sample to 1.25 mol kg(ads)(-1) in Cu-AC-2, at 40 degrees C and 1 bar. To attest the Cu-AC-2 performance, fixed-bed experiments were conducted namely mono- and multicomponent breakthrough. Finally, the adsorbent was tested in a 4-column lab-scale PSA unit for purifying a synthetic reformate mixture of 70% H-2, 25% CO2, 4% CH4, and 1% CO. After optimization, hydrogen with a purity +99.97% was obtained with a CO content of 0.17 ppm at a recovery of 76.2%. Such results meet the requirements for automotive industry regarding CO impurities.