An exhaust gas purification device including: a first case communicating with an exhaust manifold of an engine and internally including a first exhaust gas purification body for removing a carbon compound; and a second case communicating with an exhaust outlet of the first case and internally including second exhaust gas purification bodies for removing a nitrogen compound. The first case and the second case are arranged above the engine and in an L-shape to respectively extend along two side surfaces of the engine, the two side surfaces being adjacent to each other.

An exhaust gas purification device including: a first case communicating with an exhaust manifold of an engine and internally including a first exhaust gas purification body for removing a carbon compound; and a second case communicating with an exhaust outlet of the first case and internally including second exhaust gas purification bodies for removing a nitrogen compound. The first case and the second case are arranged above the engine and in an L-shape to respectively extend along two side surfaces of the engine, the two side surfaces being adjacent to each other.

The present invention relates to a particulate filter which comprises a wall flow filter of length L and two different catalytically active coatings Y and Z, wherein the wall flow filter comprises channels E and A that extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls which form the surfaces O.sub.E and O.sub.A, respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end. The invention is characterized in that the coating Y is located in the channels E on the surfaces O.sub.E and the coating Z is located in the channels A on the surfaces O.sub.A.

A method for controlling urea injection in an exhaust aftertreatment system includes injecting urea at a flow rate upstream of the first catalytic reduction device; measuring a level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device; controlling the flow rate of the urea injection until the measured level of nitrogen oxides fulfils a predetermined condition; if the measured level of nitrogen oxides is decreasing in response to reducing the flow rate of the urea injection, reducing the flow rate of the urea injection, and controlling a flow rate of urea injection using the second urea injector upstream of the second catalytic reduction device according to the measured level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device.

The present disclosure provides SCR catalyst compositions capable of reducing nitrogen oxide (NO.sub.x) emissions in engine exhaust. The catalyst compositions include a reducible metal oxide support containing ceria, one or more transition metal oxides as a redox promotor; and an oxide of niobium, tungsten, silicon, molybdenum, or a combination thereof as an acidic promotor. The redox promotor and the acid promotor are both supported on the reducible metal oxide support. Further provided are SCR catalyst articles coated with such compositions, processes for preparing such catalyst compositions and articles, an exhaust gas treatment system including such catalyst articles, and methods for reducing NO.sub.x in an exhaust gas stream using such catalyst articles and systems.

Defect detection systems include at least one nozzle for delivering a CO.sub.2 particulate fluid to an inlet end of a plugged honeycomb body. Defects in the honeycomb, if any, are determined by monitoring CO.sub.2 particulate flow at the outlet end of the honeycomb body. Methods for detecting defects in plugged honeycomb bodies are also disclosed.

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied, to: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius; cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period; and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.

An aftertreatment system for reducing constituents of an exhaust gas having a sulfur content includes: an oxidation catalyst; a filter disposed downstream of the oxidation catalyst; and a controller configured, in response to determining that the filter is to be regenerated and a desulfation condition being satisfied, to: cause a temperature of the oxidation catalyst to increase to a first regeneration temperature that is greater than or equal to 400 degrees Celsius and less than 550 degrees Celsius; cause the temperature of the oxidation catalyst to be maintained at the first regeneration temperature for a first time period; and after the first time period, cause the temperature of the oxidation catalyst to increase to a second regeneration temperature equal to or greater than 550 degrees Celsius.

An exhaust control system for a vehicle includes a temperature sensor positioned downstream of an exhaust burner and upstream of an SCR catalyst in an exhaust system. The temperature sensor is configured to generate a measurement signal indicative a temperature of exhaust flowing through the exhaust system at an outlet of a DPF positioned downstream of the exhaust burner. An exhaust control module is configured to turn the exhaust burner on to heat the exhaust, monitor the temperature of the exhaust based on the measurement signal, subsequent to turning the exhaust burner on, turn the exhaust burner off based on an upper threshold temperature of the exhaust, and, subsequent to turning the exhaust burner off, turn the exhaust burner on based on a lower threshold temperature of the exhaust. The lower threshold temperature is less than the upper threshold temperature.

A control device for an internal combustion engine including an upstream cleaning device and a downstream cleaning device that are provided in an exhaust gas passage and a temperature sensor that detects a temperature of exhaust gas between the upstream cleaning device and the downstream cleaning device is provided. The control device includes a first temperature estimating unit configured to estimate a temperature of the downstream cleaning device from the temperature of exhaust gas detected by the temperature sensor and a second temperature estimating unit configured to estimate a temperature of the downstream cleaning device without using the temperature of exhaust gas detected by the temperature sensor. An abnormality determining process for the upstream cleaning device is performed when at least the temperature of the downstream cleaning device estimated by the second temperature estimating unit is equal to or greater than a predetermined threshold value.