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Two different configurations of electrically-heated catalyst systems were installed on two new production vehicles. A 1990 Buick LeSabre was evaluated with a heated catalyst placed directly in front of the main production catalytic converter while a 1990 Toyota Celica was evaluated with an electrically-heated catalyst placed between the main close-coupled catalytic converter and a smaller downstream production catalytic converter. Initial laboratory studies involved examination of heating strategies to minimize electrical energy requirements, a variety of off-board battery and recharging configurations for their effect on emissions, and multiple air injection strategies to achieve minimum hydrocarbon emissions while avoiding a NOx penalty. Final efforts involved installation of optimized, complete on-vehicle electrically-heated catalyst systems for subsequent on-road mileage accumulation.

The use of methanol as a “clean fuel” appears to be a viable approach to reduce air pollution. However, concern has been expressed about potentially high formaldehyde emissions from stoichiometrically operated light-duty vehicles. This paper presents results from an emission test program conducted for the California Air Resources Board (CARB) and the South Coast Air Quality Management District (SCAQMD) to identify and evaluate advanced catalyst technology to reduce formaldehyde emissions without compromising regulated emission control. An earlier paper presented the results of evaluating eighteen different catalyst systems on a hybrid methanol-fueled test vehicle. (1)* This paper discusses the optimization of three of these catalyst systems on four current technology methanol-fueled vehicles. Emission measurements were conducted for formaldehyde, nonmethane organic gases (NMOG), methanol, carbon monoxide, and oxides of nitrogen emissions.