Kinetics of the Non-catalytic Water Gas Shift Reaction in Supercritical Water

• Published in: Energy sources. Part A, Recovery, utilization, and environmental effects Recovery, utilization, and environmental effects, 2014-01, Vol.36 (24), p.2666-2672
• Main Authors: Picou, J., Stever, M., Bouquet, J., Wenzel, J., Lee, S.
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Carbon monoxide; Cobalt base alloys; Constants; Effluents; first-order kinetics; hydrogen; Moles; Nickel base alloys; Reaction kinetics; Shift reaction; Superalloys; supercritical water; Water gas; water gas shift
• ISSN: 1556-7036; 1556-7230
• DOI: 10.1080/15567036.2011.572137

A kinetic analysis of the noncatalytic water gas shift reaction in a supercritical water medium was investigated using a specially designed 383 mL Haynes Alloy 230 tubular reactor at a constant pressure of 24.12 ± 0.04 MPa, water to carbon monoxide molar feed ratios of 5 to 37 moles of water per mole of carbon monoxide, and at temperatures varying from 768 to 1,048 K. The carbon monoxide concentration in the effluent gas reached a minimum of one mole-percent at 1,048 K, which corresponds to a 98% carbon monoxide to carbon dioxide conversion. Using global first-order kinetics a frequency factor of 10 5.76 ± 1.42 s −1 and an activation energy of 139.8 ± 24.5 kJ/mol was determined. It was also found that the developed kinetic rate model closely fits the experimental reaction data, with a coefficient of determination of R 2 = 0.95, over a wide range of temperatures and reactant concentrations.