Engineers are creating a new exhaust trap that uses a rhodium-based catalyst to extract pollutants and turn them into hydrogen and carbon monoxide, which can then be pumped back into diesel engines.

The new technology is being developed by workers at Birmingham and Brunel universities, in collaboration with environmental catalyst manufacturer Johnson Matthey.

Although a fully-functioning prototype is not expected to emerge for another 18 months, it is believed that the new trap will provide a valuable fuel mixture, while also reducing consumption and emissions.

Athanasios Tsolakis, the project's principle investigator, explained that the system is unique as it does not require additional air and water to reform exhaust gas for onboard hydrogen production.

He said: "We need oxygen, water, carbon dioxide and heat for this process and enough of those things for our reformer are contained in exhaust gas.

"So the main advantage is you don't need a lot of hardware, as is the case with other methods."

The engineers believe that the trap could achieve a 90 per cent reduction in hydrocarbon, carbon monoxide and particulate matter emissions, plus a 70 per cent decrease in nitrogen oxide emissions.

Mr Tsolakis added that a ten per cent improvement in fuel efficiency could be attained and that the system could lead to the redesigning of valve and fuel injection timing in diesel engines.

"When the hydrogen and carbon monoxide burn in the engine, there will be a reduced amount of diesel fuel injected into the combustion chamber," he said.

"So in a way the engine could work as a dual fuel engine."



Source:

Emission control (12/11/08)
http://www.theengineer.co.uk/Articles/308790/Emission+control.htm