International Journal of Hydrogen Energy 33 (2008) 293 – 302 www.elsevier.com/locate/ijhydene Reaction swing approach for hydrogen production from carbonaceous fuels Tomasz Wiltowski a , b , Kanchan Mondal a , ∗ , Adam Campen a , Debalina Dasgupta a , Agnieszka Konieczny a a Department of Mechanical Engineering and Energy Processes, Southern Illinois University, Carbondale, IL, USA b Coal Research Center, Southern Illinois University, Carbondale, IL, USA Received 20 June 2007; accepted 9 July 2007 Available online 24 October 2007 Abstract The paper presents the results of the investigations on a reaction swing approach for the production of high purity hydrogen from syngas exploiting the Boudouard at temperatures ranging from 550 to 700 ◦ C and pressures ranging from 0 to 150 psig. The concept of the process is the sequential use of a catalyst, that enhances the CO disproportionation reaction in conjunction with the water gas shift reaction to completely eliminate the CO in the product stream, and a CO 2 removal agent for in situ capture of the produced CO 2 . The thermodynamic evaluation of the above system shows the potential of achieving greater than 99% hydrogen purity values in the product stream even at atmospheric pressures. The effects of temperature, pressure and steam addition on the hydrogen enrichment are reported. Experiments were also conducted to evaluate the effect of catalyst and CO 2 removal material loadings on the product gases. Increasing the pressure improved the purity and the duration of the enrichment cycle. The separation efficiency was maximized at a temperature of 650 ◦ C. A 1:2 ratio of the catalyst to CO 2 removal material was found to be sufficient to produce nearly carbon-free hydrogen for over an hour before regeneration. The use of 25% steam was found to increase the hydrogen yield by nearly 50% (due to the contribution of the water gas shift). The results from simultaneous coal gasification and hydrogen enrichment experiments in a single reactor are also presented. It was found that for a Fe 2 O 3 : coal ratio of 22:1 for effective gasification and over 99% pure hydrogen stream. Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy. Keywords: Hydrogen; Coal gasification; Separation; Boudouard reaction; Calcium oxide 1. Introduction Combustion of fossil fuels provides 86% of the world’s en- ergy [1,2]. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon diox- ide emissions, thought to be responsible for global warming, are now the subject of international treaties [3,4]. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting energy carrier, such as hydrogen. Hydrogen is an environmentally attractive energy carrier that has the potential to displace fossil fuels. Hydrogen, as a carbon-less fuel, forms no carbon dioxide or particulates during combustion. While carbon dioxide emission from vehicles is currently not regu- lated, the increased air and consequent temperature needed to ∗ Corresponding author. E-mail address: kmondal@siu.edu (K. Mondal). 0360-3199/$ - see front matter Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy. doi:10.1016/j.ijhydene.2007.07.053 efficiently burn particulates formed during the combustion of carbon-containing fuels causes NO x formation. This difficult balance between particulate and NO x formation is avoidable when hydrogen is the fuel of choice. Another advantage of hydrogen as an energy carrier is its flexibility. Localized pro- duction of hydrogen is feasible nearly everywhere from several sources. Hydrogen is already an important raw material in the chemical industries such as in the manufacture of ammonia, methanol, etc. The possibility of hydrogen as a future energy source in heating, electric power and transportation sectors will cause a huge increase in the hydrogen demand. Currently, the primary route for hydrogen production is the conversion of nat- ural gas and other light hydrocarbons. Coal and petroleum coke may also serve as raw materials for hydrogen production in the future. Currently, it is produced from natural gas by means of three different chemical processes: steam reforming (steam methane reforming—SMR), partial oxidation (POX), and au- tothermal reforming (ATR). Although several new production