Methanol has been widely considered as a replacement for gasoline and diesel fuel when petroleum supplies become scarce or to improve air quality. The potential use of methanol, however, faces a significant cold start and cold operation problem. Methanol vehicles have difficulty starting at ambient temperatures below 10 degrees C because of methanol's low vapor pressure and high heat of vaporization. Even when the vehicles start, they have poor driveability and high CO and unburned hydrocarbon emissions. With Phase I funding, the investigators have begun the development of on-board dimethyl ether (DME) generation to solve the cold start problem. The highly volatile DME can be formed by catalytic dehydration of methanol. The reaction is exothermic but some heat input is required to bring the catalyst to operating temperature and to vaporize the methanol. The DME would be metered to the engine at the tim of the cold start and during cold operation. During Phase I, a very active and selective methanol catalyst has been synthesized and tested. Data from the tests were used to design a small electrically heated DME generating reactor. During Phase II, the investigators will fabricate this rector and test it on board a methanol-fueled vehicle. The commercial application of the DME generating reactor is to use it on methanol-fueled vehicles to assist cold start and cold operation. Although only a limited number of methanol-fueled vehicles have been built, the potential market is very large. It is believed that methanol will be a significant future fuel since emissions from methanol-fueled vehicles are generally less than gasoline vehicles and since methanol can be made at low cost from abundant feedstocks such as coal, natural gas and biomass.
