CHAPTER 12 - Simulation of Hydrogen Purification by Pressure-Swing Adsorption for Application in Fuel Cells

Abstract

Hydrogen is a clean and sustainable energy resource that only emits water and heat resulting from the combustion. One of the important hydrogen applications is its use in proton-exchange membrane fuel cells (PEMFC), which have been considered an attractive technology for transportation, commercial building, home, and small-scale power generation. This chapter explains that single-component adsorption isotherms of CO2, CO, CH4, and H2 in activated carbon and zeolite 5A were experimentally measured and described by the Langmuir model. The two adsorbents exhibited various affinities and adsorption capacities for the selected probe species. Therefore, their respective effects on impurity removal from the PSA process had to be explained and clarified. A theoretical two-layered-bed PSA model has been developed for studying impurity removal from SMR off-gas for producing fuel-cell-grade hydrogen, where CO2, CO, and CH4 concentrations are required to be less than 100, 10, and 100 ppm, respectively. The optimization routines were also carried out to examine the optimal conditions for the separation of mixture using the single-bed PSA process with layered adsorbents operated in the Skarstrom cycle. Using the dynamic optimizer in gPROMS, the optimal operation conditions for the PSA process based on different objective functions could also be obtained. gPROMS proved to be an effective tool for PSA simulation and simple optimization. The chapter explains the simulation of hydrogen purification by pressure-swing adsorption for application in fuel cells.