Emissions control
AssigneeJohnson Matthey Public Limited Company
InventorsGuy Richard Chandler, Martyn Vincent Twigg
Life of this patent
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Abstract
A cost-effective solution to removing particulates from diesel, especially light-duty diesel engines incorporates an oxidation catalyst (2) effective to convert NO in the exhaust from the engine to NO2 and a particulate trap (4) which traps no more than 85% by weight of the particulate, optionally by permitting gas to by-pass the trap.
Claims13
An emission control exhaust gas aftertreatment apparatus for exhaust gases from diesel engines comprising a source of NO2, a wall flow filter, means for directing flow of gases to a central portion of the filter, and an exhaust gas by-pass effective under all operating conditions, wherein a portion of the exhaust gases do not pass through the filter, such that up to 85 wt % of engine-out particulates are collected on the filter and combusted In the presence of said NO2 in the filter.
A method of controlling emissions from diesel engine exhaust gases by trapping and subsequently combusting particulate matter, the method comprising the steps of directing the flow of gases to a central portion of a particulate filter, trapping up to 85 wt % of particulate matter in the exhaust gas in the particulate filter, combusting the trapped particulate matter in the presence of NO2, and causing a portion of said exhaust gases to by-pass the particulate filter under all operating conditions.
An emission control exhaust gas aftertreatment apparatus for exhaust gases from light duty diesel engines comprising a source of NO2, a wall flow filter, means for directing flow of gases to a central portion of the filter, and an exhaust gas by-pass effective under all operating conditions, wherein a portion of the exhaust gases do not pass through the filter, such that up to 85 wt % of engine-out particulates are collected on the filter and combusted in the presence of said NO2 in the filter.
Dependencies are inferred from the claim text.