Composite catalytic-permselective membranes: Modeling analysis for H 2 purification assisted by water–gas-shift reaction Elva Lugo Romero, Benjamin A. Wilhite ⇑ Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843-3122, USA highlights " Composite catalytic-permselective membrane (CCP) investigated for H 2 purification. " CCP compared with gas permeation membrane and packed-bed membrane reactor designs. " Simulations indicate superior H 2 recovery using Pd films via CCP design. " CCP design with polymeric films aid CO 2 –CO separation, reduce CO 2 –H 2 separation. article info Article history: Available online xxxx Keywords: Hydrogen purification Water–gas-shift Membrane reactor Palladium Polymer Membrane abstract Composite catalytic-permselective (CCP) membrane designs, wherein a catalytic film is applied to the retentate surface of a permselective film, are capable of enhancing gas permeation rates and permselec- tivities by modifying the gas composition in contact with the permselective film surface via reaction– diffusion within the catalytic layer. Isothermal, two-dimensional models are employed to compare performance of a CCP membrane system against (i) an un-modified permselective film in a gas purifica- tion membrane (GPM) system, and (ii) an equivalent packed-bed membrane reactor (PBMR) system, for coupling water–gas-shift reaction with H 2 purification from a typical heavy hydrocarbon reformate mix- ture (9%CO, 28%H 2 , 15%H 2 O, 3%CO 2 ). Analysis is provided for the case of (i) an infinitely H 2 -permselective Pd film, for exploring the potential for alleviating surface inhibition via CO using the CCP design, and (ii) a moderately CO 2 -permselective polymeric film, for exploring the potential for enhancing CO/CO 2 separa- tion via CCP design as compared to PBMR designs. For the former case, the CCP design is capable of enhancing overall permeation rates in GPM and PBMR configurations via alleviation of surface inhibition. In the latter case, simulations predict up to a 40% enhancement in reaction product-reactant (CO 2 –CO) separation, at the cost of reduced product-product (CO 2 –H 2 ) separation. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Advances in H 2 purification technologies have been driven by an expanding global energy demand, dwindling fossil resources and increasing concerns regarding the environmental impact of electrical energy and fuels production. Hydrogen production re- mains a critical challenge in the petrochemical industry owing to its use both for catalytic upgrading of petroleum distillates to transportation and logistics fuels, and the catalytic removal of sul- fur and nitrogen from increasingly ‘sour’ crudes populating the market [1–3]. The advent of biorefineries producing commodity chemicals and fuels from biomass is expected to further increase H 2 demands, as the high oxygen content of carbohydrate-derived biofuels require additional hydrotreating to achieve combustion properties comparable to their petroleum-derived counterparts [4–6]. Hydrogen has also been recognized for its potential as a universal fuel, derivable from both renewable (biomass, biogas) and non-renewable (petroleum, natural gas, coal) hydrocarbon resources [5,7,8].H 2 -driven fuel cells are capable of achieving significant improvements in fuel efficiencies as compared to exist- ing internal combustion engines, without locally producing any emissions associated with hydrocarbon fuels combustion (volatile organic compounds, nitrogen oxides, sulfur oxides, particulates) [9–11]. The polymer electrolyte fuel cell (PEMFC) has been favored for transportation and portable applications due to its high power density and near-ambient operating temperatures (60–90 °C) [12,13]. Hydrogen is typically produced via oxidative reforming of hydrocarbons [1–3,7], which results in a reformate mixture con- taining significant amounts of steam, carbon dioxide and carbon monoxide. The latter is a significant poison both to several catalytic 1385-8947/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cej.2012.07.016 ⇑ Corresponding author. E-mail address: benjaminwilhite@mail.che.tamu.edu (B.A. Wilhite). Chemical Engineering Journal xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej Please cite this article in press as: E.L. Romero, B.A. Wilhite, Composite catalytic-permselective membranes: Modeling analysis for H 2 purification assisted by water–gas-shift reaction, Chem. Eng. J. (2012), http://dx.doi.org/10.1016/j.cej.2012.07.016