ONE hundred petrol stations in Vienna are experimenting with reformulated petrol this month in a bid to clean up the city鈥檚 summer smog.
Until the end of September, the petrol stations will be replacing their superunleaded petrol with 鈥渟ummer petrol鈥� in which a tenth of the aromatic hydrocarbons are replaced by fuel oxygenates such as methyl tertiary butyl ether, or MTBE. These additives prevent fuel in the cylinder from igniting uncontrollably, which causes the engine to knock.
MTBE helps fuel to burn more completely than fuel with only aromatic additives. The city authorities in Vienna hope this will reduce the emissions of volatile organic compounds from vehicles from 60 to 45 tonnes a day. VOCs, sunlight and nitrogen oxides react to produce high levels of ozone and photochemical smogs.
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MTBE also reduces emissions of nitrogen oxides because engines can operate at lower temperatures than those fuelled by petrol with aromatic additives, says Martin Dawson of ARCO Chemical, Europe鈥檚 biggest producer of MTBE.
Martin Bartenstein, Austria鈥檚 environment minister, says he hopes the petrol will prove popular, as he wants to introduce it permanently to reduce emissions from cars without catalytic converters.
In the autumn, the European Parliament will debate a proposed directive setting standards for fuel. But this would not come into force until 2005 at the earliest. Finland, Sweden and Austria are trying to force the European Commission鈥檚 hand by introducing their own reformulated petrol.