Kinetic simulation of steam reforming of methanol with CO formation

Abstract

There has been a general disagreement regarding the mechanism of carbon monoxide formation in steam reforming of methanol over copper-based catalysts. In this work, comparative simulation studies of the kinetics of steam reforming of methanol have been done using the recently proposed and widely accepted rate models incorporating CO formation. The models considered include those proposed by Peppley, et al. (1999) which is based on the reforming-decomposition-shift mechanism, and the models proposed by Lee, et al. (2004) and Purnama, et al. (2004) which are based on reforming-reverse WGS reaction scheme. The formation of carbon monoxide was considered in the reforming-reverse WGS reaction scheme by incorporating a power law rate model consistent with the observations of Lee, et al. (2004). All the simulated models are successful in predicting consistent profiles of concentration along the reactor. However, Peppley’s model simulates essentially negative extent of WGS reaction along the reactor and virtually zero rate of decomposition. On the other hand, Purnama’s and Lee’s models simulate highly oscillating intrinsic kinetics of reverse water-gas shift reaction. Thus the simulation studies clearly indicate that the CO formation is due to the RWGS reaction and the high-tendency for oscillation of the rate of this reaction itself is responsible for low CO concentration.