Producing chromium carbide using reduction of chromium oxide with methane

In the present work, reduction of chromium oxide using methane is investigated. The thermogravimetric method was used to obtain kinetic parameters of the reaction in the temperature range of 870-975 degrees C under atmospheric pressure. The experimental data was analyzed using the grain model. The reaction product, chromium carbide, was observed to be produced at a temperature of about 140 degrees C lower than by other conventional methods. Carbon deposition, which is highly undesirable in the synthesis of chromium carbide, was negligible in the present experiments. The experiments were conducted in two modes, either under the conditions of reaction control or under the conditions of diffusion control for determining reaction rate constants and diffusion rates to study pore diffusion, respectively. The pore diffusion studies were carried out with and without considering the bulk flow effect. The gas phase diffusion coefficient through the product layer around the grains was calculated with an approximate method. (c) 2005 American Institute of Chemical Engineers.