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Initially simple first-order rate equations that predicted the rate of disappearance of methanol were used. The firstorder rate constant, however, depended on pressure and steam-to-methanol molar feed ratio (S/M) indicating the inadequacy of this approach. An attempt was made to improve on the simple first-order expression by including the reverse (synthesis) reaction and proposing an empirical expression for the concentration of CO in the product gas as a function of S/M and the methanol fractional conversion. A comprehensive kinetic model consisting of three rate expressions for each of three separate overall reactions has been developed. This model is able to predict the production rate of CO2, CO and H2 and is also reversible so that the equilibrium at high pressure is taken into account.

A simulation of a “fuel cell engine” (FCE) based on a proton exchange membrane (PEM) fuel-cell stack was developed using a process simulation software package. Rates of emissions of unburned methanol, formaldehyde, CO and NOx were calculated based on chemical equilibria. The predicted rates of emissions for unburned methanol, formaldehyde and CO were found to all be less than 1 μg/km. This is considerably less than has been reported in the literature but represents a theoretical limit which should be achievable as effective catalytic-combustion systems are developed for hydrogen/methanol fueled burners. The worst-case rate of NOx emissions was shown to be less than 0.03 g/km (0.05 g/mi.). It was found that increasing the rate of heat transfer in the steam reformer, which converts the methanol to a hydrogen-rich gas, significantly reduced the rate of NOx emission due to the lower burner temperatures which could be used.