Predicted Emissions from a Methanol-Fueled “Electrochemical Automobile Engine” Based on a PEM Fuel Cell

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 NO_x 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 NO_x 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 NO_x emission due to the lower burner temperatures which could be used.

The results indicate that, in terms of emissions reduction, a methanol fueled FCE is an excellent long-term alternative to the ICE.