Abstract: A method for controlling emissions in the exhaust gas of a diesel engine, the engine having an exhaust gas recirculation (EGR) system. The engine's exhaust aftertreatment system need have only an oxidation catalyst and a particulate filter (with no NOx reduction or adsorption device). In “normal” engine conditions, the engine is operated with a lean air-fuel ratio, with “normal” engine conditions being engine conditions other than transient load increase engine conditions. Also, during normal engine conditions, the EGR system is used to reduce engine-out NOx. During transient load increase engine conditions, the engine is operated stoichiometrically or near stoichiometrically and the use of EGR is interrupted.

Abstract: A method of modeling and testing the effectiveness of an EGR cooler. The cooler effectiveness is mathematically modeled as a function of various temperatures and over an operation history that includes one or more engine shut-downs.

Abstract: A method for controlling emissions in the exhaust gas of a diesel engine, the engine having an exhaust gas recirculation (EGR) system. The engine's exhaust aftertreatment system need have only an oxidation catalyst and a particulate filter (with no NOx reduction or adsorption device). In “normal” engine conditions, the engine is operated with a lean air-fuel ratio, with “normal” engine conditions being engine conditions other than transient load increase engine conditions. Also, during normal engine conditions, the EGR system is used to reduce engine-out NOx. During transient load increase engine conditions, the engine is operated stoichiometrically or near stoichiometrically and the use of EGR is interrupted.

Abstract: A method of modeling and testing the effectiveness of an EGR cooler. The cooler effectiveness is mathematically modeled as a function of various temperatures and over an operation history that includes one or more engine shut-downs.

Abstract: A method of reducing emissions by operating a diesel engine in a stoichiometric air-fuel ratio mode. To achieve an optimal stoichiometric mode, intake throttling, boost air intake control, fuel injection adjustments, and exhaust gas recirculation (EGR) are used. This mode of operation permits an aftertreatment system that has only an oxidation catalyst and a particulate filter.

Abstract: A method of reducing emissions by operating a diesel engine in a stoichiometric air-fuel ratio mode. To achieve an optimal stoichiometric mode, intake throttling, boost air intake control, fuel injection adjustments, and exhaust gas recirculation (EGR) are used. This mode of operation permits an aftertreatment system that has only an oxidation catalyst and a particulate filter.

Abstract: Uncontrolled regeneration in a Diesel particulate filter is prevented by controlling the concentration and mass flowrate of oxygen passing through the Diesel particulate filter during regeneration.

Abstract: A method and system for controlling the temperature of recirculated exhaust gas in an exhaust gas recirculation (EGR) system, such as those used in connection with diesel engines. An EGR loop (which may be either a high pressure loop or a low pressure loop) has a dual-leg segment with an EGR cooler on one leg and an EGR heater on the other leg. By means of a valve, the EGR gas may be diverted to either one leg or the other, thereby providing either cooled or heated EGR gas to the engine.

Abstract: A method of providing extra air to the exhaust stream of an internal combustion engine. A small flow of air is diverted from the output of an air-charging device, such as a turbocharger, to an entry point upstream of an emission control device. The air is supplied in a controllable fashion so as to improve the efficiency of the emission control device.

Abstract: A method of controlling a dual path NOx adsorber system. The amount of exhaust into the two paths of the system is controlled by a diverter valve at the beginning of each path. The valves are operated such that most of the time, the adsorbers are simultaneously in adsorption mode. The adsorbers alternate with each other to briefly enter a regeneration mode, during which they receive a very small amount of the exhaust flow and also receive supplemental fuel injection.

Abstract: A method of controlling a dual path NOx adsorber system. The amount of exhaust into the two paths of the system is controlled by a diverter valve at the beginning of each path. The valves are operated such that most of the time, the adsorbers are simultaneously in adsorption mode. The adsorbers alternate with each other to briefly enter a regeneration mode, during which they receive a very small amount of the exhaust flow and also receive supplemental fuel injection.

Abstract: Systems and methods for controlling diesel engine emissions, including, for example, oxides of nitrogen emissions, particulate matter emissions, and the like. The emission control system according to this invention is provided in the exhaust passageway of a diesel engine and includes a catalyst-based particulate filter; and first and second lean NOx trap systems coupled to the catalyst-based particulate filter. The first and second lean NOx trap systems are arranged in a parallel flow configuration with each other. Each of the first and second lean NOx trap systems include a carbon monoxide generating catalyst device, a sulfur trap device, a lean NOx device, a supplemental fuel injector device, and a plurality of flow diverter devices.

Abstract: A method for controlling diesel engine emissions is disclosed. The diesel engine's exhaust system has a NOx oxidation catalyst, a diesel particulate filter (DPF), and a lean NOx trap (LNT). The DPF is monitored to determine the need for regeneration. The LNT is monitored to determine the need for regeneration or desulfurization. A fuel injector is used to inject fuel upstream of the LNT under certain conditions, and a bypass may be used to bypass exhaust around the oxidation catalyst to provide richer or hotter exhaust to the LNT.

Abstract: A method for controlling diesel engine emissions is disclosed. The diesel engine's exhaust system has a diesel particulate filter (DPF) and a lean NOx trap (LNT). The DPF is a filter and is monitored to determine the need for regeneration. The LNT is monitored to determine the need for regeneration or desulfurization. A fuel injector is used to inject fuel upstream of the LNT under certain conditions, and a bypass may be used to bypass exhaust around the DPF to provide richer or hotter exhaust to the LNT. The sensor outputs and controls for providing the appropriate heat or fuel mix for regeneration and desulfurization may be controlled with enhancements to existing engine control circuitry.

Abstract: A method for controlling diesel engine emissions is disclosed. The diesel engine's exhaust system has a NOx oxidation catalyst, a diesel particulate filter (DPF), and a lean NOx trap (LNT). The DPF is monitored to determine the need for regeneration. The LNT is monitored to determine the need for regeneration or desulfurization. A fuel injector is used to inject fuel upstream of the LNT under certain conditions, and a bypass may be used to bypass exhaust around the oxidation catalyst to provide richer or hotter exhaust to the LNT.

Abstract: Systems and methods for controlling diesel engine emissions, including, for example, oxides of nitrogen emissions, particulate matter emissions, and the like. The emission control system according to this invention is provided in the exhaust passageway of a diesel engine and includes a catalyst-based particulate filter; and first and second lean NOx trap systems coupled to the catalyst-based particulate filter. The first and second lean NOx trap systems are arranged in a parallel flow configuration with each other. Each of the first and second lean NOx trap systems include a carbon monoxide generating catalyst device, a sulfur trap device, a lean NOx device, a supplemental fuel injector device, and a plurality of flow diverter devices.

Abstract: A method of treating exhaust from an internal combustion engine having an emission reduction device, such as a lean NOx trap. Exhaust from the engine is directed to a first sulfur trap, which treats the exhaust and discharges exhaust that is substantially free of sulfur. The exhaust from the first sulfur trap is normally directed to the emission reduction device, but is diverted to a second sulfur trap when the first sulfur trap is saturated. During this diversion, a reducing agent introduced upstream of the first sulfur trap aids in purging the first sulfur trap and in reducing metal sulfates and metal sulfites in the first sulfur trap to hydrogen sulfides, which are then treated by the second sulfur trap. When the first sulfur trap is thus purged, the exhaust gas is again directed to the emission reduction device.

Abstract: A filtration system adapted to prevent diesel soot carried with recirculated exhaust gas from being recirculated through internal combustion engine. The filtration system provides continuous elimination of soot, thus reducing its negative impact on engine life, lubrication oil quality, and on components in the exhaust gas recirculation system. The filtration system comprises a non-thermal plasma generator that periodically, or continuously, oxidizes carbon deposited, or trapped, within a carbon filter disposed downstream of the non-thermal plasma generator.

Abstract: An integrated system for reducing the Nitrogen oxide (NOx) and particulate matter (PM) emissions from an engine released into the atmosphere includes a cooled exhaust gas recirculation system, a selective catalytic reduction system, and a passive diesel particulate filter.

Abstract: A method of treating exhaust from an internal combustion engine having an emission reduction device, such as a lean NOx trap, such that sulfur dioxide does not pass through the emission reduction device. Exhaust from the engine is directed to a first sulfur trap, which treats the exhaust and discharges exhaust that is substantially free of sulfur. The exhaust from the first sulfur trap is normally directed to the emission reduction device, but is diverted to a second sulfur trap when the first sulfur trap is saturated. During this diversion, a reducing agent introduced upstream of the first sulfur trap aids in purging the first sulfur trap and in reducing exhaust in the first sulfur trap to hydrogen sulfides, which are then treated by the second sulfur trap. When the first sulfur trap is thus purged, the exhaust gas is again directed to the emission reduction device.