Abstract:
The invention provides a method employing a fuel additive to improve the operation of a pass-through oxidation catalyst over long periods of time with continued catalytic activity and without the undesirable conversion of SO2 to SO3. A pass-through catalyst support is continuously, selectively catalyzed by the combustion of a fuel containing a platinum group metal composition which burns to release the catalyst metal in active form. The effectiveness of the process is attributed to improved combustion in the engine by the catalyst and the treatment of the catalytic oxidizer with active catalyst metal released during combustion such that, in the exhaust system, the soluble organic fraction of the particulates and the levels of gaseous unburned hydrocarbons and carbon monoxide are significantly reduced. The catalysts conditioned by the present invention cause minimal conversion of SO2 to SO3. The platinum group metal compositions soluble or dispersible in the diesel fuel and are added in amounts effective to provide concentrations of the metal in the fuel of less than 1 part per million (ppm).
Abstract:
A method of operating a diesel engine (10) through the use of a NOx-reducing additive (52) injected into the cylinders (at 54) of the engine. NOx reduction occurs at that point and downstream in the exhaust system (20) where an NOx-reducing catalyst (30) is employed.
Abstract:
A method to improve the operation of a diesel trap through the use of a fuel additive comprising fuel-soluble compositions of platinum group metal in effective amounts to lower the emissions of unburned hydrocarbons and carbon monoxide from the trap. The catalyst is selective and reduces the oxidation of SO2 to SO3. The platinum group metal compositions are preferably added in amounts effective to provide concentrations of the metal in the fuel of less than 1 part per million (ppm). Lithium and/or sodium compositions can be used in amounts effective to reduce the trap regeneration temperature, e.g. concentrations to provide about 1 to 100 ppm lithium metal, and/or 1 to 30 ppm sodium metal.
Abstract:
A method improves the operation of a diesel engine (10) through the use of a fluel additive in container (50), a diesel particulate trap (20) and an NOx-reducing catalyst in chamber (30). The operation of the NOx-reducing catalyst is enhanced by the introduction of urea or like compound upstream in mixing device (60) of the catalyst at temperatures effective for non-catalytic NOx reduction and the generation of ammonia. The additive comprises fuel-soluble compositions of platinum group metal in effective amounts to lower the emissions of unburned hydrocarbons and carbon monoxide form the trap. The catalytic activity provided to the exhaust system (20 and 30) by the fuel additive is selective and preferably reduces the oxidation of SO2 to SO3. The platinum group metal compositions are preferably added in amounts effective to provide concentrations of the metal in the fuel in fuel tank (40) of less than 1 part per million (ppm). Lithium and/or sodium compositions can be used in amounts effective to reduce the trap regeneration temperature, e.g. concentrations to provide about 1 to 100 ppm lithium metal, and/or 1 tp 30 ppm sodium metal.
Abstract:
The invention relates to a process for reducing nitrogen oxides emissions from a diesel engine. The process comprises preparing an emulsion of water (20) and urea (26) in a mixer (24) and then blending the emulsion with diesel fuel (40) in a mixer (30), and then supplying the emulsion to a diesel engine for combusting therein, whereby combustion of the emulsion leads to a reduction in the nitrogen oxides emissions from the diesel engine when compared with combustion of diesel alone.
Abstract:
The invention presented relates to a method for reducing the emission of nitrogen oxides from a diesel engine without significant loss of fuel efficiency and without significant increases in carbon monoxide and hydrocarbon emissions. The method involves preparing a diesel engine such that the injection timing thereof is set at a point sufficient to obtain reductions in the nitrogen oxides emissions from the engine; and firing the diesel engine with a diesel fuel having admixed therein an additive which comprises a fuel soluble organometallic platinum group metal coordination composition.
Abstract:
Platinum group metal fuel additives are effective in fuel environments which make the exclusion of water impractical. The fuels additives comprise a platinum group metal compound and a water-functional composition selected from the group consisting of lipophilic emulsifiers, lipophilic organic compounds in which water is miscible and mixtures of these. The additives are preferably effective in fuel compositions having water contents of at least about 0.01 % water by weight.
Abstract:
The invention presented relates to a method for regenerating a diesel engine particulate trap. Specifically, the invention involves providing a diesel engine having associated therewith a diesel engine particulate trap which collects particulates from the exhaust of the diesel engine; and firing the diesel engine with a diesel fuel having admixed therein an additive which comprises a fuel soluble, organometallic platinum group metal coordination composition.