HYDROGEN-PRODUCTION FROM THE LOW-TEMPERATURE WATER-GAS SHIFT REACTION - KINETICS AND SIMULATION OF THE INDUSTRIAL REACTOR

The kinetics of the water-gas shift reaction (WGSR) over a copper/zinc oxide/alumina catalyst have been studied. The experiments were carried out at 453-503 K and atmospheric pressure. A reactive mixture of similar composition to that employed in the industrial process was used. An integral reactor, an integral procedure and a data treatment valid for near equilibrium conditions were employed. A number of representative models were examined. It was found that only a Langmuir-Hinshelwood model, which considers the adsorption of four species (CO, CO2, H-2, and H2O) and the surface reaction as the controlling step, adequately describes the reaction behaviour at the temperature and concentration ranges investigated. Values of adsorption constants and adsorption heats for the four components involved in the WGSR are given. An algorithm for the simulation of an adiabatic fixed-bed reactor was developed with the aim of checking the kinetics expression. Both the industrial and simulated compositions agree. It is proved that the kinetic expression proposed which is in harmony with a Langmuir-Hinshelwood mechanism is useful in designing industrial low-temperature converters.