Patent ID: 7163668

Claim:
A method of treating the NOx emissions from a diesel engine having at least one internal combustion chamber for combusting diesel fuel, a main fuel line that carries diesel fuel to the engine, and a main exhaust line that carries exhaust from the engine, the exhaust having a range of exhaust gas temperatures typical for a vehicular diesel engine, the method comprising: providing an auxiliary fuel line from the engine's diesel fuel supply source, separate from the main fuel line; introducing air, via an air intake line, into the auxiliary fuel line, thereby mixing fuel in the auxiliary fuel line with air; receiving the mixed portion of diesel fuel and air into a partial oxidation unit located external to the internal combustion chamber and off-line the main exhaust line; wherein the partial oxidation unit has at least a heat generating means; using the partial oxidation unit to receive air via the air intake line, to receive diesel fuel via the auxiliary fuel line, and to at least partially oxidize diesel fuel into a gas mixture containing hydrogen; delivering the gas mixture to the main exhaust line; placing a ruthenium-based hydrogen selective catalytic reduction (H-SCR) unit in-line on the main exhaust line, such that the H-SCR unit receives the exhaust and the gas mixture; and using the H-SCR unit to continuously convert NOx emissions to nitrogen; wherein the H-SCR unit is further operable to reduce the NOx emissions to nitrogen during diesel operating temperatures under the range of exhaust gas temperatures; determining the separate amounts of NO and NO2 in the exhaust; and metering the hydrogen delivered to the H-SCR unit to maintain a ratio of the hydrogen to NOx in the main exhaust line, on the basis of: desired ratio of hydrogen to NO, and a desired ratio of hydrogen to NO2.