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An emission control system for reducing NOx in the exhaust of a diesel engine. A partial oxidation system receives diesel fuel from the engine's fuel tank and partially oxidizes the diesel fuel into hydrogen. The hydrogen is then introduced into the main exhaust line and the hydrogen-enhanced exhaus

An emission control system for reducing NOx in the exhaust of a diesel engine. A partial oxidation system receives diesel fuel from the engine's fuel tank and partially oxidizes the diesel fuel into hydrogen. The hydrogen is then introduced into the main exhaust line and the hydrogen-enhanced exhaust is delivered to a hydrogen selective catalytic reduction unit, which uses the hydrogen to convert the NOx to nitrogen.

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What is claimed is: 1. A system for treating NOx emissions from a diesel engine that has at least one internal combustion chamber for combusting diesel fuel and has a main exhaust line that carries exhaust from the engine, the exhaust having a range of exhaust gas temperatures typical for a vehicul

What is claimed is: 1. A system for treating NOx emissions from a diesel engine that has at least one internal combustion chamber for combusting diesel fuel and has 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 system comprising: an auxiliary fuel line from the engine's diesel fuel supply source, separate from the main fuel supply line to the engine; a partial oxidation unit located on the auxiliary fuel line, external to the internal combustion chamber and off-line the main exhaust line; an air intake line for delivering air to the partial oxidation unit; an output line for delivering a hydrogen-enhanced gas mixture from the partial oxidation unit to the main exhaust line; wherein the partial oxidation unit is operable to receive air via the air intake line, to receive diesel fuel via the auxiliary fuel line, and to at least partially oxidize the fuel to produce the hydrogen-enhanced gas mixture; a ruthenium-based hydrogen selective catalytic reduction (H-SCR) unit, located in-line on the main exhaust line, operable to receive the hydrogen-enhanced gas mixture from the partial oxidation unit, and to use hydrogen in the hydrogen-enhanced gas mixture to continuously reduce NOx emissions in the exhaust line to nitrogen; wherein the H-SCR unit is further operable to reduce the NOx emissions to nitrogen under the range of exhaust gas temperatures; means for determining the ratio of NO to NO2 in the exhaust gas; and a metering device on the output line for maintaining a ratio of the hydrogen to NOx in the main exhaust line, on the basis of: the ratio of NO to NO2 a substantially 1:1 molar ratio of the hydrogen to NO, and a substantially 2:1 molar ratio of the hydrogen to NO2. 2. The system of claim 1, wherein the partial oxidation unit is a non-stoichiometric burner. 3. The system of claim 1, wherein the partial oxidation unit has a catalyst. 4. The system of claim 3, wherein the partial oxidation unit is a nickel-based catalyst. 5. The system of claim 3, wherein the partial oxidation unit is a rhodium-based catalyst. 6. The system of claim 1, wherein the partial oxidation unit is a combination of a non-stoichiometric burner and a catalyst. 7. The system of claim 1, further comprising a water gas shift catalyst downstream of the partial oxidation unit and upstream the catalytic unit, operable to generate further hydrogen from the gas mixture. 8. The system of claim 7, wherein the water gas shift catalyst is located off-line the main exhaust line. 9. The system of claim 1, wherein the H-SCR unit comprises ruthenium and magnesium. 10. The system of claim 1, wherein the H-SCR unit comprises ruthenium and aluminum. 11. A system for treating NOx emissions from a diesel engine that has at least one internal combustion chamber for combusting diesel fuel and has 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 system comprising: an auxiliary fuel line from the engine's diesel fuel supply source, separate from the main fuel supply line to the engine; a partial oxidation unit located on the auxiliary fuel line, external to the internal combustion chamber and off-line the main exhaust line; an exhaust gas intake line for delivering a portion of the engine exhaust gas from the main exhaust line to the partial oxidation unit; an output line for delivering a hydrogen-enhanced gas mixture from the partial oxidation unit to the main exhaust line, downstream the exhaust gas intake line; wherein the partial oxidation unit is operable to receive the portion of the engine exhaust via the exhaust gas intake line, to receive diesel fuel via the auxiliary fuel line, and to at least partially oxidize the fuel to produce the hydrogen-enhanced gas mixture; a ruthenium-based hydrogen selective catalytic reduction unit, located in-line on the main exhaust line operable to receive the hydrogen-enhanced gas mixture from the partial oxidation unit, and to use hydrogen in the hydrogen-enhanced gas mixture to continuously convert the NOx emissions in the exhaust line to nitrogen; wherein the H-SCR unit is further operable to reduce the NOx emissions to nitrogen under the range of exhaust gas temperatures; means for determining the ratio of NO to NO2 in the exhaust gas: and a metering device on the output line for maintaining a ratio of the hydrogen to NOx in the main exhaust line, on the basis of: the ratio of NO to NO2, a substantially 1:1 molar ratio of the hydrogen to NO, and a substantially 2:1 molar ratio of the hydrogen to NO2. 12. The system of claim 11, wherein the partial oxidation unit is a non-stoichiometric burner. 13. The system of claim 11, wherein the partial oxidation unit is a catalyst. 14. The system of claim 13, wherein the partial oxidation unit is a nickel-based catalyst. 15. The system of claim 13, wherein the partial oxidation unit is a rhodium-based catalyst. 16. The system of claim 11, wherein the partial oxidation unit is a combination of a non-stoichiometric burner and a catalyst. 17. The system of claim 11, further comprising a water gas shift catalyst downstream of the partial oxidation unit and upstream the catalytic unit, operable to generate further hydrogen from the gas mixture. 18. The system of claim 17, wherein the water gas shift catalyst is located off-line the main exhaust line. 19. The system of claim 11, wherein the H-SCR unit comprises ruthenium and magnesium. 20. The system of claim 11, wherein the H-SCR unit comprises ruthenium and aluminum. 21. The system of claim 11, wherein the exhaust gas intake line is a bypass line off the main exhaust line.