摘要:
According to one aspect of the present invention, a catalyst assembly is provided for treating an exhaust from an engine. In one embodiment, the catalyst assembly includes a first catalyst material catalytically active at a first temperature and loaded at a first catalyst material loading, the first catalyst material including a first base metal loading, and a second catalyst material catalytically active at a second temperature lower than the first temperature and loaded at a second catalyst material loading, the second catalyst material including a second base metal loading, wherein the second base metal loading is higher than the first base metal loading.
摘要:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.
摘要:
Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25: 1 to about 1:1.
摘要:
The invention provides a method for purification of exhaust gas from a diesel engine in a system, which comprises a device for selective catalytic reduction and a diesel particulate filter preferably at least partially covered by a catalytic layer installed downstream of the device for selective catalytic reduction. A device for catalytic oxidation is installed upstream of the device for selective catalytic reduction and/or between the device for selective catalytic reduction and the diesel particulate filter. A device for injection of a controlled amount of reductant is installed inlet of the device for selective catalytic reduction, and a device for injection of a controlled amount of hydrocarbon is installed inlet of the catalytic oxidation.
摘要:
Disclosed are, inter alia, methods of forming coated substrates for use in catalytic converters, as well as washcoat compositions and methods suitable for using in preparation of the coated substrates, and the coated substrates formed thereby, which in some cases use iron-exchanged zeolite particles that provide enhanced performance such as lower light-off temperatures and lower pollutant levels in exhaust gases. The catalytic material is prepared by a plasma-based method, yielding catalytic material with a lower tendency to migrate on support at high temperatures, and thus less prone to catalyst aging after prolonged use. Also disclosed are catalytic converters using the coated substrates, which have favorable properties as compared to catalytic converters using catalysts deposited on substrates using solution chemistry. Also disclosed are exhaust treatment systems, and vehicles, such as diesel vehicles, particularly light-duty diesel vehicles, using catalytic converters and exhaust treatment systems using the coated substrates.
摘要:
An alkylation catalyst having a zeolite catalyst component and a binder component providing mechanical support for the zeolite catalyst component is disclosed. The binder component is an ion-modified binder that can include metal ions selected from the group consisting of Co, Mn, Ti, Zr, V, Nb, K, Cs, Ga, B, P, Rb, Ag, Na, Cu, Mg, Fe, Mo, Ce, and combinations thereof. The metal ions reduce the number of acid sites on the zeolite catalyst component. The metal ions can range from 0.1 to 50 wt % based on the total weight of the ion-modified binder. Optionally, the ion-modified binder is present in amounts ranging from 1 to 80 wt % based on the total weight of the catalyst.
摘要:
A method of manufacturing a catalyst body which includes: soaking at least part of a fired zeolite-based body in a transition metal oxide solution; removing the body from the transition metal oxide solution; exposing the body to a humidified atmosphere at one or more temperatures above 20° C.; then drying the body; and calcining the body.
摘要:
A catalyst and a method for selectively reducing nitrogen oxides (“NOx”) with ammonia are provided. The catalyst includes a first component comprising a zeolite or mixture of zeolites selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof; a second component comprising at least one member selected from the group consisting of cerium, iron, copper, gallium, manganese, chromium, cobalt, molybdenum, tin, rhenium, tantalum, osmium, barium, boron, calcium, strontium, potassium, vanadium, nickel, tungsten, an actinide, mixtures of actinides, a lanthanide, mixtures of lanthanides, and mixtures thereof; optionally an oxygen storage material and optionally an inorganic oxide. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at high temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of low levels of nitrogen oxides in exhaust streams. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from gas turbines and gas engines, although the catalyst and the method have broad application to a wide range of gas streams that have excess oxygen and high temperatures. The temperature of exhaust gas from gas turbines and gas engines is high. Both the high temperature and the low levels of inlet NOx are challenging for selective catalytic reduction (SCR) catalysts.
摘要:
Disclosed is a urea solution reformer and an exhaust gas purifier using the same, configured to heat a carrier gas supplied from a carrier gas source by a carrier gas heating unit (16), to inject the carrier gas heated by the carrier gas heating unit from a carrier gas injecting nozzle (17), and to cause a urea solution (18) to be supplied by a first urea solution supply nozzle (21) to a tip end of the carrier gas injecting nozzle so that the urea solution is atomized by the carrier gas injected from the carrier gas injecting nozzle. Provided to face toward the carrier gas injecting nozzle is a catalyst unit (23) for decomposing the atomized urea solution to reform it into an ammonia gas. Further provided is an ammonia gas supply nozzle (24) attached to an exhaust pipe (12) of an engine so as to supply the ammonia gas discharged from an outlet of the catalyst unit into the exhaust pipe. The urea solution is sufficiently atomized, and thus reformed into an ammonia gas by the catalyst unit with a good efficiency.
摘要:
The present invention describes a method for hydrocracking and/or hydrotreating hydrocarbon-containing feeds using a catalyst comprising at least one hydro-dehydrogenizing metal selected from the group made up of group VIB and non-noble group VIII metals of the periodic table and a support comprising at least one zeolite having at least pore openings containing 12 oxygen atoms, modified by a) at least a stage of introducing at least one alkaline cation belonging to groups IA or IIA of the periodic table, b) a stage of treating said zeolite in the presence of at least one molecular compound containing at least one silicon atom, c) at least one stage of partial exchange of said alkaline cations by NH4+ cations in such a way that the proportion of alkaline cations remaining in the modified zeolite at the end of stage c) is such that the alkaline cation/aluminum molar ratio ranges between 0.2:1 and 0.01:1, and d) at least one thermal treatment stage.