A catalyst for treating an exhaust gas comprising SO.sub.2, NO.sub.x and elemental mercury in the presence of a nitrogenous reductant comprises a composition containing oxides of: (i) Molybdenum (Mo) and/or Tungsten (W); (ii) Vanadium (V); (iii) Titanium (Ti), and (iv) an MFI zeolite, wherein the composition comprises, based on the total weight of the composition: (i) 1 to 6 wt % of MoO.sub.3 and/or 1 to 10 wt % WO.sub.3; and (ii) 0.1 to 3 wt % V.sub.2O.sub.5, and (iii) 48.5 to 94.5 wt % TiO.sub.2; and (iv) 35 to 50 wt % MFI zeolite.

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of spraying an aqueous solution with a pH of 7 or more onto a used denitration catalyst while the denitration catalyst is set in a denitration device to remove a surface of the denitration catalyst. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more. The denitration catalyst after recycling is used for denitration at 200 C. or lower.

The present invention relates to a catalyst comprising at least one oxide of vanadium, at least one oxide of tungsten, at least one oxide of cerium, at least one oxide of titanium and at least one oxide of antimony, and an exhaust system containing said oxides.

An ozonation-based method for producing a cementitious material comprises the steps of: (1) mixing a flue gas with an ozone-containing gas to form a mixed flue gas; and introducing the mixed flue gas into an absorption tower, where the mixed flue gas undergoes dry desulfurization and denitrification by reacting with a powdered desulfurizing and denitrificating agent and becomes a treated flue gas; (2) subjecting the treated flue gas to dust removal to generate by-products; and (3) uniformly mixing raw materials that comprise the first by-product, magnesium oxide, fly ash and an additive to give a cementitious material, wherein on the basis of 100 parts by weight of the cementitious material, the first by-product is 20-60 parts by weight, magnesium oxide is 16-33 parts by weight, the fly ash is 15-35 parts by weight, and the additive is 1-15 parts by weight.

Provided is a catalyst washcoat comprising (i) a molecular sieve loaded with about 1 to about 10 weight percent of at least non-aluminum promoter metal (wherein the promoter metal weight percent is based on the weight of the molecular sieve); and (ii) about 1 to about 30 weight percent of a binder having a d90 particle size of less than 10 microns (wherein the binder weight percent is based on the total weight of the washcoat). In another aspect of the invention, the catalyst washcoat is applied to a wall-flow filter to form a catalyst article. In another aspect of the invention the catalyst article is part of an exhaust gas treatment system. And in yet another aspect of the invention, provided is a method for treating exhaust gas using the catalyst article.

There is provided a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A denitration catalyst is obtained by coating a substrate with a catalyst component. The catalyst component contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more. The denitration catalyst is used for denitration at 200 C. or lower.

There is provided a method for recycling a catalyst that exhibits a high denitration efficiency at a relatively low temperature and does not cause oxidation of SO.sub.2 in a selective catalytic reduction reaction that uses ammonia as a reducing agent. A method for recycling a denitration catalyst includes a step of removing a used denitration catalyst from a denitration device and then coating the used denitration catalyst with a catalyst component. The catalyst component contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more, and the denitration catalyst after recycling is used for denitration at 200 C. or lower.

Provided are a mercury oxidation catalyst support structure with which a mercury oxidation reaction can be carried out while inhibiting the oxidation reaction for SO.sub.2 included in exhaust gas and a method for manufacturing the same. This mercury oxidation catalyst structure is characterized by vanadium being unevenly supported on the surface of the support structure. The method for manufacturing the mercury oxidation catalyst structure includes a step of incorporating an inactive support throughout from the inside to the surface of the structure using an inactive support-containing liquid and a step of immersing the structure having been subjected to the step in a liquid containing vanadium or applying the same liquid to the surface of the same structure, followed by drying and calcinating, thereby supporting vanadium on the inactive support present in the surface of the structure.

A vanadium oxide based honeycomb SCR catalyst composed of a plurality of corrugated sheets stacked upon one another to form a plurality of flow through channels, the corrugated sheets are provided with an inert inner core layer and an outermost layer containing a SCR catalyst composition.

An exhaust gas heating unit for an exhaust system of an internal combustion engine includes a jacket heating conductor element (12) with a jacket (16) and with an electrical heating conductor (14). The electrical heating conductor (14) extends in the jacket (16) and is surrounded by insulating material (18). A heat transfer surface formation (20) is arranged on an outer side of the jacket (16) and is in heat transfer contact with same.