A dynamic study of the water-gas shift reaction over an industrial ferrochrome catalyst

• Published in: Journal of catalysis 1988-08, Vol.112 (2), p.345-356
• Main Authors: Salmi, T., Boström, S., Lindfors, L.-E.
• Format: Article
• Language: English
• Subjects: 01 COAL, LIGNITE, AND PEAT; ATMOSPHERIC PRESSURE; CARBON COMPOUNDS; CARBON DIOXIDE; CARBON MONOXIDE; CARBON OXIDES; CATALYSIS; Catalysts: preparations and properties; CATALYTIC EFFECTS; Catalytic reactions; CHALCOGENIDES; CHEMICAL PREPARATION; CHEMICAL REACTION KINETICS; CHEMICAL REACTIONS; CHEMICAL REACTORS; Chemistry; CHROMIUM; ELEMENTS; EQUATIONS; Exact sciences and technology; FLUIDS; GASES; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; HIGH TEMPERATURE; HYDROGEN; HYDROGEN COMPOUNDS; HYDROGEN PRODUCTION; IRON; KINETIC EQUATIONS; KINETICS; MATHEMATICAL MODELS; MATHEMATICS; METALS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; REACTION KINETICS; REGRESSION ANALYSIS; SHUTDOWNS; START-UP; STATISTICS; SYNTHESIS; Theory of reactions, general kinetics; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TRANSIENTS; TRANSITION ELEMENTS; VAPORS 010408 > Coal, Lignite, & Peat-- C1 Processes-- (1987-); WATER; WATER GAS PROCESSES; WATER VAPOR
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(88)90148-0

The water-gas shift reaction over an industrial ferrochrome catalyst (ICI 15-4) was studied by transient experiments in a gradientless spinning basket reactor at 563–638 K and atmospheric pressure. The responses of CO, CO 2, and H 2 were measured after step changes at the reactor inlet. The stationary kinetics were described with a first-order rate expression with respect to CO. The rate constants were determined at four temperatures. The CO 2 responses followed approximately a first-order behavior, whereas the dynamics of the H 2 liberation was always slower than the CO 2 evolution. Hydrogen formation was retarded by H 2O pretreatment of the catalyst. Two characteristic values of the total oxygen transfer through the catalyst were determined from the CO 2 and H 2 responses, corresponding to the catalyst pretreatments with the reactive gases (CO and H 2O) and with H 2O. The transient responses were modeled with a reaction mechanism involving rapid water adsorption and slow CO interconversion and H 2 desorption steps. The kinetic parameters of the simplified dynamic model were determined by regression analysis. The shift reactor start-up and shut-down could be predicted by the dynamic model developed.