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Swiss develop cleaner diesel engine

The new technology reduces pollution from diesel engines Keystone

Swiss scientists have unveiled a device for diesel engines that can dramatically cut the emission of harmful air pollutants in both old and new vehicles.

The Swiss environment agency presented the emission control system – which can be used on lorries, buses and construction machinery – on Monday.

The device can cut emissions of nitrogen oxides, one of six principal air pollutants, by up to 90 per cent.

Nitrogen oxides – a generic term encompassing nitrogen dioxide and nitrogen monoxide – play a major role in the production of smog and can trigger serious respiratory problems.

They also contribute to the formation of acid rain and global warming.

Philippe Roch, director of the environment agency, said it was the first emission control system which could seriously reduce nitrogen oxides produced by diesel engines.

The denitrification system is available immediately and costs SFr30,000 ($23,000), but officials say they expect the price to drop.

It is made up of a particle filter and two catalytic converters, and can be fixed to any heavy goods vehicle regardless of age.

A substance is added to the catalytic converter that changes nitrogen oxides into non-harmful gases and steam.

Big challenge

Heiri Hafner, project leader at the Environmental Technology Institute in Rapperswil, which developed the system in conjunction with partners from industry, told swissinfo that the technology already existed for large-scale installations,

“Our main challenge was to make it smaller for individual diesel engines,” he said.

The Swiss Association for Transport and the Environment has welcomed the development but expressed concern that it would not be introduced widely.

“The new system changes things but we are sceptical. We have to force people to equip their vehicles with the systems and I don’t know if this is possible,” said Emmanuelle Robert, spokesman for the association.

For the past 18 months the system has been tested on buses in canton St Gallen. The buses were well within emission standards that will come into force in 2009.

Hafner says he expects the device to be available eventually for a few thousand francs.

The environment agency paid 40 per cent of the project’s costs, while the remainder was financed by private firms.

Roth said the project was an excellent example of collaboration between the environment authorities, businesses and universities.

swissinfo, Karin Kamp

Nitrogen oxides is a collective term used to refer to two types of nitrogen – nitric oxide and nitrogen dioxide.

Nitric oxide is a colourless, flammable gas. Nitrogen dioxide is a reddish brown, non-flammable.

In significant concentrations it is highly toxic, causing serious lung damage with a delayed effect.

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SWI - a branch of Swiss Broadcasting Corporation SRG SSR

SWI - a branch of Swiss Broadcasting Corporation SRG SSR