The present invention relates to a method and a system for catalytic oxidation of a lean H.sub.2S stream. More specifically, the invention concerns a novel way of removing sulfur dioxide (SO.sub.2) formed by catalytic oxidation of hydrogen sulfide (H.sub.2S) with the purpose of removing H.sub.2S from a gas. This catalytic oxidation of H.sub.2S yields sulfur dioxide (SO.sub.2) through the use of known catalysts, so-called SMC catalysts.

A combustible gas from carbon black production is utilized in a gas engine by adding an oxygen-containing gas to the combustible gas, passing said mixed gas over a selective catalyst, which is active for oxidizing H.sub.2S to SO.sub.2 but substantially inactive for oxidation of CO, H.sub.2 and other hydrocarbons with less than 4 C-atoms, passing the converted gas through an SO.sub.2 removal step, and passing the cleaned gas to a gas engine or to an energy recovery boiler. This way, the tail gas from carbon black production, which is normally combusted in a CO boiler or incinerated, can be utilized to good effect.

The present disclosure discloses a dry desulfurizing and denitrificating agent and its preparation method and applications. The desulfurizing and denitrificating agent is made of raw materials comprising the following components based on 100 parts by weight of the desulfurizing and denitrificating agent: 30-60 parts by weight of TiO.sub.2, 10-30 parts by weight of ZrO.sub.2, 2-10 parts by weight of V.sub.2O.sub.5, 2-10 parts by weight of CoO, 1-8 parts by weight of Co.sub.2O.sub.3, 2-10 parts by weight of Fe.sub.2O.sub.3, 5-15 parts by weight of MnO.sub.2, and 2-10 parts by weight of KMnO.sub.4. The desulfurizing and denitrificating agent of the present disclosure has a good catalytic oxidation performance on sulfur dioxide and nitrogen oxides of flue gas, and a high rate of desulfurization and denitrification.

The present invention provides: an interior material having a surface layer which has visible light-responsive photocatalytic activity and which contains two types of titanium oxide microparticles, the two types of titanium oxide microparticles comprising first titanium oxide microparticles, in which a tin component and a transition metal component for enhancing visible light responsiveness (excluding iron group components) are in solid solution, and second titanium oxide microparticles, in which an iron group component is in solid solution; and a method for manufacturing the interior material. The present invention makes it possible to provide an interior material in which visible light-responsive photocatalytic titanium oxide microparticles, which make it possible to easily produce a surface layer (photocatalyst thin film) having high transparency and expressing photocatalytic activity even in response to visible light (400-800 nm) only, are applied onto a surface, whereby it is possible to obtain, under indoor illumination, excellent photocatalytic properties such as an antimicrobial property and a property of breaking down chemical substances in indoor air without adversely affecting the design quality of the article in question.

The present invention is directed to selective catalytic reduction catalysts that combine SCR activity with NOx absorber activity. In particular, the disclosed catalytic article includes a substrate having a first and a second material disposed thereon, wherein the first material includes a selective catalytic reduction (SCR) catalyst composition and the second material includes a nitrogen oxides (NOx) absorber composition, wherein the NOx absorber composition does not substantially oxidize ammonia, and wherein the catalytic article is effective to abate NOx from an engine exhaust gas stream. Emission treatment systems for treating an exhaust gas including a catalytic article of the invention are provided, particularly systems that include an injector adapted for the addition of ammonia to the exhaust gas stream located upstream of the catalytic article.

Method for the preparation of a monolithic catalyst for the reduction of nitrogen oxides VOC and carbon monoxide in an off-gas, the catalyst comprises at least one platinum group metal, vanadium, titania and optionally tungsten oxide.

Provided is a nitrogen oxide (NO.sub.X) reduction catalyst including an active site including at least one of a metal vanadate expressed by [Chemical Formula 1] and a metal vanadate expressed by [Chemical Formula 2], and a support for loading the active site thereon.

(M.sub.1).sub.XV.sub.2O.sub.X+5[Chemical Formula 1] (where M.sub.1 denotes one selected from among manganese (Mn), cobalt (Co), and nickel (Ni), and X denotes a real number having a value between 1 and 3.)

(M.sub.2).sub.YVO.sub.4[Chemical Formula 2] (where M.sub.2 denotes one selected from among lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and Y denotes a real number having a value between 0.5 and 1.5.)

Method of preparing monolithic SCR catalyst with a plurality of gas flow channels comprising the steps of (a) providing a monolithic shaped substrate with a plurality of parallel gas flow channels; (b) coating the substrate with a wash coat slurry comprising vanadium oxide precursor compounds and titania and optionally tungsten oxide precursor compounds; and (c) drying the thus coated substrate with a drying rate of 5 mm/min or less along flow direction through the gas flow channels; and (d) activating the dried coated substrate by calcining.

Installation and method for treating a flow comprising hydrogen sulfide The invention relates to an installation and a method for treating hydrogen sulphide. In particular, the invention relates to an installation and a method comprising at least one system for oxidizing hydrogen sulfide to sulfur (S) and water (H.sub.2O) with a solid reagent and at least one oxidizing system with an agent for oxidizing the solid reagent present in the reduced state, wherein the system of oxidizing the hydrogen sulfide to sulfur and the system for oxidizing the solid reagent, are so arranged that the hydrogen sulfide is not brought into contact with the agent oxidizing the solid reagent.

A sorbent composition for removing mercury from flue gas is provided. The sorbent composition contains at least a powdered sorbent, an oxidant and a catalyst. Methods of cleaning flue gas are also provided, which includes injecting the sorbent composition into the flue gas, wherein the powdered sorbent has a fifty percent distribution particle size of from about 25 micrometers to about 75 micrometers.