Modelling the catalytic steam reforming of methane: discrimination between kinetic expressions using sequentially designed experiments

摘要

The kinetics of steam reforming of methane on a fluidizable Ni/alpha-alumina catalyst is studied in a novel CREC riser simulator reactor. The Box-Hill discrimination function is used to design sequential experiments for discrimination between six candidate models for the rate of steam reforming of methane carried out over a fluidized bed of catalyst. Proposed models include one model in which the rate of reforming is dependent only on the partial pressure of methane (first order), a model in which the rate is dependent on the partial pressures of the products and of the reactants (power law) and four models with various adsorption effects. Models are expressed in a form such that the parameters are close-to-linear. Discrimination results indicate that the rate of methane reforming has a first order dependency on the partial pressure of methane in the numerator and the adsorption of methane in the denominator. Estimates of the close-to-linear parameters in the most probable model are made using 85 observations of the conversion of methane made over a 20wt% Ni/alpha-alumina catalyst. All parameters are found to be significant at the 95% confidence level and correlation between the parameters is found to be moderate ( < 0.84). (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 16]