METHANOL ENGINES

Dr Werth and colleagues suggest four ways of introducing methanol into the transportation market. The first is to use gasoline-methanol blends with perhaps as much as 20% methanol; but blends absorb water, and the gasoline would have to be designed to have a high water tolerance.

"Neat" methanol requires carburetors and starting systems altered so that the car can run on pure methanol, as race cars are already doing today.

A third method is to overcome the water absorption problem by adding methanol to a gasoline-water emulsion. Ordinarily, gasoline floats on water, but in an emulsion it is suspended in tiny droplets in the water. There are several methods for emulsification, the use of ultra-sound, for example (this method is often used for preparing a well known emulsion: ketchup). However, there is not yet a gasoline-water emulsion that is both stable and cheap.

The fourth method is a two-phase adaptive fuel system. A special fuel tank accepts gasoline, methanol and water; the methanol-water phase settles at the bottom and the gasoline floats on the top. Two computer-controlled fuel pumps inject the right amount of fuel, usually of the methanol-water mixture. However, for starting, only gasoline would be "approved" by the computer.

"Computer-controlled" no longer means exactly what it meant some years ago. Microprocessors are tiny little chips, with "read-only" memories (in this case) that enable a special program to be built in once and for all at the factory. They are relatively cheap, and in spite of inflation, their price is constantly coming down. They now run about $100; but some optimists predict a price of $3 in 6 or 7 years.

It is not known which of these methods is best; but with the development of microprocessors, it could well be the last method.