摘要:
An after-treatment system architecture and method for oxidizing the nitric oxide component of an exhaust stream from a hydrocarbon fueled power source operated with a fuel lean combustion mixture.
摘要:
A method for monitoring performance of a passive selective catalytic reduction system includes operating the internal combustion engine in a preconditioning mode. Subsequent to the preconditioning, an air/fuel excursion is introduced into the exhaust gas feedstream and a signal output from a sensor monitoring the exhaust gas feedstream in the selective catalytic reduction system during the air/fuel excursion is monitored. An operating effectiveness is determined for the selective catalytic reduction system correlated to the signal output from the sensor monitoring the exhaust gas feedstream.
摘要:
One embodiment of the invention may include a method comprising providing a product comprising a substrate comprising a perovskite catalyst, NOx stored in or on the substrate and particulate matter in or on the substrate; releasing at least some of the stored NOx and oxidizing the released NOx to form NO2, and reacting the NO2 with carbon in the particulate matter to form at least one of CO or CO2.
摘要:
A method for removing NOX from an oxygen-rich exhaust flow produced by a combustion source that is combusting a lean mixture of air and fuel may include passing the oxygen-rich exhaust flow through an exhaust aftertreatment system that includes a NOX oxidation catalyst that includes perovskite oxide particles, a NOX storage catalyst, and a NOX reduction catalyst.
摘要:
One embodiment of the invention includes a method of treating a gas stream comprising flowing the gas stream over a hydrocarbon reduction and NOx reduction catalyst first, and thereafter flowing the gas over a perovskite and NOx trap material for NOx oxidation and storage. In one embodiment, the hydrocarbon reduction and NOx reduction catalyst may include palladium. In one embodiment, the perovskite catalyst may have the general formula ABO3, AA′BO3, ABB′O3, or AA′BB′O3. The perovskite catalyst may be the only catalyst or a second non-perovskite catalyst may include at least one of palladium, platinum, rhodium, ruthenium or a catalyst system including one or more of the same or alloys thereof. In one embodiment, the NOx trap material may include at least one of alkali metals, alkaline earth metals such as barium, calcium, potassium, or sodium.
摘要:
Precursor cations of A and B elements of an ABO3 perovskite in aqueous solution are formed as an ionic complex gel with citric acid or other suitable polybasic carboxylic acid. The aqueous gel is coated onto a desired catalyst substrate and calcined to form, in-situ, particles of the crystalline perovskite as, for example, an oxidation catalyst on the substrate. In one embodiment, a perovskite catalyst such as LaCoO3 is formed on catalyst supporting cell walls of an extruded ceramic monolith for oxidation of NO in the exhaust gas of a lean burn vehicle engine.
摘要:
An exhaust aftertreatment system for a lean-burn engine may include a lean NOx trap that comprises a catalyst material. The catalyst material may remove NOx gases from the engine-out exhaust emitted from the lean-burn engine. The catalyst material may include a NOx oxidation catalyst that comprises a perovskite compound.
摘要:
A method for controlling a powertrain includes selectively initiating an ammonia generation cycle including injecting fuel into a combustion chamber of an engine before a primary combustion event to a calibrated air fuel ratio in a range lean of stoichiometry based upon generation of NOx within the combustion chamber, injecting fuel into the powertrain after the primary combustion event based upon an overall air fuel ratio in a range rich of stoichiometry and resulting generation of molecular hydrogen, utilizing a hydrogen forming catalyst to reform the injected fuel, and utilizing a catalyst device between the engine and the selective catalytic reduction device to produce ammonia.
摘要:
A method for controlling a powertrain includes selectively initiating an ammonia generation cycle, including injecting fuel into a combustion chamber of an engine before a primary combustion event to a calibrated air fuel ratio in a range lean of stoichiometry based upon generation of NOx within the combustion chamber, injecting fuel into the combustion chamber after the primary combustion event based upon an overall air fuel ratio in a range rich of stoichiometry and resulting generation of molecular hydrogen, and utilizing a catalyst device between the engine and a selective catalytic reduction device to produce ammonia.
摘要:
Following a cold start of a hydrocarbon-fueled engine operated in a lean-burn-combustion mode, several seconds and minutes may be required for the exhaust gas stream to heat exhaust treatment devices in the exhaust system and conduit to their effective operating temperatures. The warm-up period may be particularly long for a NOx reduction catalyst (SCR) located downstream in the exhaust flow system. Accordingly, a bed of absorbent material, such as a suitably sized bed of alumina particles, located upstream of the SCR, is used to temporarily absorb water and NOx from a relatively cold exhaust until the exhaust has suitably heated the SCR to its operating temperature. Then, the warmed exhaust will remove the water and NOx from their temporary storage material and carry them to the reduction catalyst.