An after treatment method for a lean-burn engine is disclosed. The after treatment method is configured to control an after treatment system sequentially equipped with an ammonia production catalyst module, a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows and which is connected to a lean-burn engine. In the after treatment method, a rich air/fuel ratio (AFR) is controlled in multiple phases in response to detecting that conversion to the rich AFR is desired.

A multi-functional composition of matter that is useful for injection into a flue gas stream to rapidly and efficiently remove mercury from the flue gas streams, particularly at above average flue stream temperatures of about 340 F. or higher. The multi-functional composition of matter may include a fixed carbon content of at least about 20 wt. %, a mineral content of from about 20 wt. % to about 50 wt. %, a sum of micropore plus mesopore volume of at least about 0.20 cc/g, a micropore volume to mesopore volume ratio of at least about 0.7, and a tapped density of not greater than about 0.575 g/ml. These compositions may be further characterized by number of particles per gram of the composition of matter such that the composition may have at least about 0.8 billion particles per gram, or even as many as 1.5 billion particles per gram. These physical and chemical properties may enhance (1) the oxidation reaction kinetics for the oxidation of mercury species, (2) frequency of contact events, and (3) capture and sequestration of mercury, to achieve efficient mercury capture by the composition even in high temperature flue gas streams.

A selective catalytic reduction system applying diesel oil as reductant for converting nitrogen oxides by means of a catalyst into diatomic nitrogen and water in a diesel engine is provided. The selective catalytic reduction system includes an oil injection system, a reactor and a number of selective catalytic reduction catalysts provided in a first section. The selective catalytic reduction system includes at least one additional section including a number of selective catalytic reduction catalysts. The at least one additional section is provided in a non-zero from the first section.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

Provided are a novel form of AFX zeolite, a novel synthesis technique for producing pure phase small pore zeolites, a novel synthesis method for producing a zeolite with an increased Al pair content, a catalyst comprising the AFX zeolite in combination with a metal, and methods of using the same.

A fuel tank inerting system is disclosed. The system includes a fuel tank and a catalytic reactor with an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from a fuel flow path in operative communication with the fuel tank and oxygen from an oxygen source, and to catalytically react a mixture of the fuel and oxygen along the reactive flow path to generate an inert gas. An inert gas flow path provides inert gas from the catalytic reactor to the fuel tank. An adsorbent is disposed along the fuel flow path or along the reactive flow path.

An after treatment system is disclosed. The after treatment system may include a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows. The CUC may include a zeolite in which Cu and Fe are ion-exchanged and CeO.sub.2 in which Pt is supported, wherein a weight ratio of the CeO.sub.2 to a total weight of the CUC is 30-70 wt % such that the CUC purifies NH.sub.3 at a lean air/fuel ratio and purifies NH.sub.3 during a delay time at a rich air/fuel ratio.

An after treatment system is disclosed. The after treatment system may include an exhaust pipe through which an exhaust gas flows; a three-way catalyst (TWC) mounted on the exhaust pipe and purifying HC, CO, and NOx contained in the exhaust gas, an ammonia production catalyst (APC) mounted on the exhaust pipe at a downstream of the TWC, storing NOx at a lean air/fuel ratio, and generating H.sub.2, releasing the stored NOx, and generating NH.sub.3 using the released NOx and the generated H.sub.2 at a rich air/fuel ratio, and a selective catalytic reduction (SCR) catalyst mounted on the exhaust pipe at a downstream of the APC, storing the NH.sub.3 generated in the TWC and the APC, and reducing the NOx contained in the exhaust gas using the stored NH.sub.3.

An after treatment method is disclosed. The after treatment method may include: operating an engine at a lean air/fuel ratio; calculating an amount of NH.sub.3 stored in an SCR catalyst; calculating an amount of NOx which will flow into the SCR catalyst; determining whether conversion to a rich air/fuel ratio is desired; calculating, when the conversion to the rich air/fuel ratio is desired, a rich duration for which the rich air/fuel ratio is maintained and a target air/fuel ratio; and operating the engine at the target air/fuel ratio for the rich duration.

An after treatment method for a lean-burn engine is disclosed. The after treatment method is configured to control an after treatment system sequentially equipped with an ammonia production catalyst module, a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows and which is connected to a lean-burn engine. In the after treatment method, a rich air/fuel ratio (AFR) is controlled in multiple phases in response to detecting that conversion to the rich AFR is desired.