Reduced-emissions combustion utilizing multiple-component metallic combustion catalyst and lightly catalyzed diesel particulate filter
First Claim
1. A method for reducing particulate emissions from a diesel engine while also controlling emissions of NO2 as a percent of exhaust total nitrogen oxides, comprising:
- adding a fuel borne catalyst comprising platinum and cerium and/or iron at a total metal concentration of from 2 to 15 ppm in the fuel to a diesel fuel; and
passing exhaust produced by the combustion through a diesel particulate filter having substrate with a precious metal catalyst thereon, the catalyst be present on the substrate in an amount of less than 15 grams per cubic foot of substrate.
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Abstract
An improved, robust diesel emission control system employs a lightly diesel particulate filter (DPF), preferably with a platinum containing fuel borne catalyst (FBC) in the fuel. The DPF is preferably of wire mesh construction and at least partially lightly catalyzed with precious metal catalyst, e.g., platinum group metal, having a metal loading of from about 3 to 15 grams per cubic foot to minimize formation of NO2 in the exhaust gas. Preferred fuel borne catalyst levels will be low, e.g., from 0.05 to 0.5 ppm for platinum and 3 to 8 ppm for cerium and/or iron, thereby providing effective engine out emissions reductions without discharging excessive amounts of NO2 to the atmosphere.
30 Citations
13 Claims
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1. A method for reducing particulate emissions from a diesel engine while also controlling emissions of NO2 as a percent of exhaust total nitrogen oxides, comprising:
- adding a fuel borne catalyst comprising platinum and cerium and/or iron at a total metal concentration of from 2 to 15 ppm in the fuel to a diesel fuel; and
passing exhaust produced by the combustion through a diesel particulate filter having substrate with a precious metal catalyst thereon, the catalyst be present on the substrate in an amount of less than 15 grams per cubic foot of substrate. - View Dependent Claims (2, 3, 4, 7, 8, 9, 10, 11)
- adding a fuel borne catalyst comprising platinum and cerium and/or iron at a total metal concentration of from 2 to 15 ppm in the fuel to a diesel fuel; and
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5. A system for reducing particulate emissions by over 30% while controlling the emissions of NO2 to below 37% of exhaust nitrogen oxide species and minimizing the loading of precious metal catalyst, e.g., platinum group metal, to less than 15 grams per cubic foot of substrate installed in the exhaust of a diesel engine when used with an FBC comprising platinum and/or cerium and/or iron at a total metal concentration of less than 15 ppm in the fuel.
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6. An improved diesel emissions control system comprising:
- means for supplying diesel fuel containing a platinum, cerium or iron containing FBC and a lightly catalyzed exhaust treatment device.
- 12. A robust diesel particulate control system comprises providing a lightly catalyzed wire mesh filter on the exhaust system of a diesel engine and operating the diesel engine so equipped with a diesel fuel containing a low dose rate fuel borne catalyst comprising platinum in combination with cerium and/or iron at total fuel borne catalyst levels of under 15 ppm and preferably 4-8 ppm.
Specification