Abstract: A system is described for storing ammonia and injecting it into the exhaust gas stream of an engine to reduce nitrogen oxides. The ammonia is stored as a liquid mixture (70) of ammonia and water in a container (50). In one system, the mixture passes through a hot nozzle and is injected into an upstream portion of the exhaust gas pipe.

Abstract: A system is provided that reduces nitrogen oxides in the exhaust gases of an engine by converting nitric oxide (NO) in the exhaust gases to nitrogen dioxide (NO2) prior to injecting ammonia (NH3) into the exhaust gases, and then passing the exhaust gases through a vehicle catalytic converter. Much of the nitric oxide (NO) is converted to nitrogen dioxide (NO2) by passing the exhaust gases first through a catalyzed particulate filter (CPF) such as one containing a nitric oxide catalyst. In cases where the exhaust gases must pass from the exhaust gas manifold through an exhaust conduit portion of a length of at least one-eighth meter before reaching the catalyzed particulate filter, that exhaust conduit portion is heavily insulated to result in a high exhaust gas temperature at the downstream end of that conduit portion by at least 30° C. over the temperature without insulation.

Abstract: An engine assembly of the type that includes a conduit (16) extending from the exhaust manifold outlet (14) to the atmosphere (20), an ammonia injection station (22) along the conduit, and a catalytic assembly (24) lying along the conduit and downstream of the ammonia injection station. The catalytic assembly includes a surface wash coat (50) of a nitric-oxide catalyzing material that converts nitric oxide (NO) to nitrogen dioxide (NO2), and passages coated with SCR (selective catalyst reduction) catalyst that reacts ammonia with NO2 to produce nitrogen and water. The catalytic assembly includes multiple elements such as fibers, coated with the SCR catalyzing material, with the elements lying in a mass and with passages, or pores lying between the elements. The mass lies in a tube (90) of the conduit, and has conical inside and outside surfaces (42, 40) to provide a large area through which gasses flow.

Abstract: A diverter (60) is provided, which is of low cost and which is effective in more evenly distributing exhaust gasses passing from a small diameter upstream exhaust gas pipe section (42) into a much larger diameter catalytic converter assembly (20). The diverter includes a diverter element (70) and mounting brackets (72). The diverter element has a central hole (82) and has conical walls with an included angle of at least 70°, the conical walls having a plurality of holes (90). The large conical angle (G) of the diverter effectively directs exhaust gases to the periphery of the large diameter catalytic converter but blocks a radially intermediate portion of the catalyst, while the holes in the conical diverter walls allow sufficient exhaust gases to reach the radially intermediate portion of the catalyst.

Abstract: A diverter (60) is provided, which is of low cost and which is effective in more evenly distributing exhaust gasses passing from a small diameter upstream exhaust gas pipe section (42) into a much larger diameter catalytic converter assembly (20). The diverter includes a diverter element (70) and mounting brackets (72). The diverter element has a central hole (82) and has conical walls with an included angle of at least 70°, the conical walls having a plurality of holes (90). The large conical angle (G) of the diverter effectively directs exhaust gases to the periphery of the large diameter catalytic converter but blocks a radially intermediate portion of the catalyst, while the holes in the conical diverter walls allow sufficient exhaust gases to reach the radially intermediate portion of the catalyst.

Abstract: In the operation of a diesel engine, a mixture of air and fuel is flowed into each cylinder during the intake stroke when air alone normally would be flowed in. However, the mixture is lean so it does not ignite as the mixture is compressed and heated. Sufficient additional fuel is injected into the cylinder near the top of the compression stroke to increase the amount of fuel so the hot mixture ignites. As a result, most of the air and fuel has intimately mixed prior to ignition.

Abstract: In the operation of a diesel engine, a mixture of air and fuel is flowed into each cylinder during the intake stroke when air alone normally would be flowed in. However, the mixture is lean so it does not ignite as the mixture is compressed and heated. Sufficient additional fuel is injected into the cylinder near the top of the compression stroke to increase the amount of fuel so the hot mixture ignites. As a result, most of the air and fuel has intimately mixed prior to ignition.