Fuel with flare

日期:2017-06-22 04:41:05 作者:贺兰畴 阅读:

By Jeff Hecht VOLATILE liquids burnt as waste at gas fields and coal mines could become a component of clean “designer fuels”. Fossil-fuel deposits often contain liquid short-chain hydrocarbons, including butane and other alkanes. But these hydrocarbons have a low octane rating, making them less useful as fuel, and also evaporate very easily. So they are usually flared off, rather than being collected and put to use. Stephen Paul of Princeton University in New Jersey, whose previous research has centred on nuclear fusion, realised that these waste hydrocarbons might still be useful as vehicle fuels if mixed with ethanol—which has a higher octane rating and evaporates less easily. Unfortunately, the two substances don’t mix well. But Paul has solved that problem by adding a third component to the mixture: methyltetrahydrofuran (MTHF), an ether highly soluble in both ethanol and the short-chain hydrocarbons. MTHF can be produced easily by fermenting wastes rich in cellulose or starch, such as corn husks, straw, sugar-cane waste or paper-mill sludge. Tests show that exhausts from vehicles powered by Paul’s designer fuel contain up to 50 per cent less unburnt hydrocarbon, and 20 per cent less carbon monoxide, than those produced by conventionally fuelled cars. The fuel, containing ethanol, the short-chain hydrocarbons and MTHF in roughly equal measures, can be used with “flexible-fuel” engines, designed to run on conventional petroleum or a mixture of petroleum and ethanol. Paul demonstrated this by driving a Dodge minivan from Princeton to the Boston meeting on one tank of the fuel, with enough remaining for his wife to take their children to local tourist attractions. That’s about the same as the vehicle achieves on a tank of petroleum, Paul says. Princeton has licensed the technology to the Pure Energy Corporation of New York, and in July,