The present invention pertains to a catalyst for use in the selective catalytic reduction (SCR) of nitrogen oxides comprising: • a monolithic substrate and • a coating A which comprises an oxidic metal carrier comprising an oxide of titanium and a catalytic metal oxide which comprises an oxide of vanadium wherein the mass ratio vanadium/titanium is 0.07 to 0.26.

Systems and methods for producing nitrates, nitric acid, salts thereof, or a mixture thereof are disclosed. The systems may include a feed conduit configured for receiving a feed stream comprising molecular oxygen and molecular nitrogen; an inlet conduit configured for receiving an inlet stream; a plasma reactor fluidically coupled to the inlet conduit, the plasma reactor fluidically coupled to a reactor-outlet conduit configured for receiving the reactor-outlet stream, the plasma reactor configured to produce oxidized nitrogen species; and an absorber fluidically coupled to the reactor-outlet conduit, the absorber configured to receive the reactor outlet stream and to produce nitrates, nitrites, nitric acid, salts thereof, or a mixture thereof from the reactor outlet stream. A recycle conduit may be fluidically coupled to the absorber and the inlet conduit, wherein the recycle conduit is configured to receive the gas-phase stream from the absorber and provide the gas-phase stream to the inlet conduit.

Methods and systems for treating volatile organic compounds (VOCs) generated in a hydrocarbon treating process are disclosed. An effluent stream containing the VOCs, as well as carbon dioxide (CO.sub.2) is combined with hot exhaust gas from a turbine and provided to a waste heat recovery unit (WHRU). The WHRU is adapted to contain a catalyst bed containing oxidation catalyst capable of effecting the oxidation of the VOCs. The temperature of the catalyzing reaction can be tailored based on the position of the catalyst bed within the temperature gradient of the WHRU. The methods and systems described herein solve the problem of effecting the removal of VOCs from the effluent. Heating the CO.sub.2-containing effluent in the WHRU also lend buoyancy to the effluent, thereby facilitating its dispersal upon release.

A SCR catalyst for removing nitrogen oxides comprises: a carrier prepared from a support in which Ti-PILC is mixed with titania; and a catalyst material on the carrier, wherein the catalyst material contains an active material of a vanadium component and a co-catalyst of a tungsten component. On the basis of the total weight of the catalyst, the support Ti-PILC is contained at 0.01-40 wt %, and the support titania is contained at 50 to 90 wt %. In addition, a method for producing a SCR catalyst for removing nitrogen oxides comprises the steps of: preparing a carrier by using a support in which Ti-PILC is mixed with titania; and supporting a catalyst material on the carrier. The present disclosure provides: a SCR catalyst for removing nitrogen oxides, which has an excellent nitrogen oxide removing performance and a high producing convenience; and a method for producing the same.

Systems are provided for a diesel oxidation catalyst. In one example, the diesel oxidation catalyst comprises a washcoat with different catalytically active portions for reacting with one or more of carbon containing compounds and NO.sub.x. The diesel oxidation catalyst is located upstream of a particulate filter in an exhaust passage.

Described herein are methods, systems, and compositions for providing catalysts for tail gas clean up in sulfur recovery operations. Aspects involve obtaining catalyst that was used in a first process, which is not a tailgas treating process and then using the so-obtained catalyst in a tailgas treating process. For example, the catalyst may originally be a hydroprocessing catalyst. A beneficial aspect of the described methods and systems is that the re-use of spent hydroprocessing catalyst reduces hazardous waste generation by operators from spent catalyst disposal. Ultimately, this helps reduce the environmental impact of the catalyst life cycle. The described methods and systems also provide an economically attractive source of high-performance catalyst for tailgas treatment, which benefits the spent catalyst generator, the catalyst provider, and the catalyst consumer.

The present invention refers to a method for the preparation of a shell type catalyst for mercury oxidation, the catalyst and the use of the catalyst. The catalyst is prepared by a method comprising mixing titanium dioxide, a compound of a promoter selected from molybdenum and tungsten, and a binder, to prepare a paste; shaping the paste, to obtain a shaped paste; drying and optionally calcining the shaped paste, to obtain a support material; impregnating the support material with an aqueous alkaline impregnation solution comprising a vanadium compound; drying and calcining the impregnated support material, to obtain the catalyst. The catalyst is useful for purifying exhaust gases from coal plants and other power plants where mercury emissions occurs.

A catalytic composition is disclosed, which exhibits an X-ray amorphous oxide with a spinel formula, and crystals of ZnO, CuO, and at least one Group VIB metal oxide, and preferably, at least one acidic oxide of B, P. or Si, as well. The composition is useful in oxidative processes for removing sulfur from gaseous hydrocarbons.

The present disclosure generally provides catalysts, catalyst articles and catalyst systems including such catalyst articles. In particular, the catalyst composition includes a metal ion-exchanged molecular sieve ion-exchanged with at least one additional metal, which reduces the number of metal centers often present in metal promoted zeolite catalysts. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems including a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant while minimizing the amount of dinitrogen oxide emission.

Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NOx compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NOx removal efficiency of the at least one filter medium after removal of deposits.