ALTERNATIVE FUELS: PAVING THE WAY TO ENERGY INDEPENDENCE

This article shows how car manufacturers are taking demands for emissions reduction and freedom from overseas sources of oil seriously by designing engines that can burn alternative fuels such as natural gas and methanol. Although these alternatives emit smaller quantities of the pollutants associated with petrol engines, they have some disadvantages. Methanol provides about half the mileage per gallon, its liquid form corrodes parts in conventional petrol engines, and engines using it emit toxic aldehydes. Compressed natural gas vehicles have a limited driving range of about 120 miles, the gas must be stored in tanks larger than petrol tanks, and there is public concern about safety. For the near future, most vehicles using methanol are likely to burn it in a mixture with at least 15% petrol. Methanol-fuelled engines are beginning to appear in trucks, buses and cars; significant prototypes are being built and tested, for example, by Detroit Diesel, Volvo Cars of North America, Ford and Chrysler. Relatively little work has been done on natural gas engines, although models are being developed by Detroit Diesel, General Motors and Ford. Natural gas utilities are working to expand the infrastructure of delivery stations, as part of an effort to make natural gas more widely available.