Provided are a selective reducing catalyst for diesels and a diesel exhaust gas purification apparatus in which deterioration of NO.sub.x removal performance due to phosphorus poisoning is less likely to occur.

The selective reducing catalyst for diesels is arranged in a diesel engine, adsorbs ammonia and brings the ammonia into contact with nitrogen oxides in an exhaust gas discharged from a diesel engine to perform reduction, the selective reducing catalyst comprises: a catalyst carrier; a catalyst region provided on at least the catalyst carrier; and a phosphorus trapping region provided on at least the catalyst region, wherein the catalyst region comprises one or more selected from the group consisting of a zeolite-based catalyst containing at least zeolite and a transition metal element supported on the zeolite, a W—Ce—Zr composite oxide-based catalyst, and a vanadium-based catalyst, and the phosphorus trapping region comprises at least one or more selected from the group consisting of alumina and a rare earth-based basic oxide.

The filter according to the present invention is based on the combined action of two materials: tungsten trioxide (WO3), used for implementing the photocatalytic reactor, and a solution of copper (Cu) nanocluster. In a preferred embodiment of the present invention, these materials are applied to suitable supports (filters), one of a mesh/grid made of metal (or other material, e.g. plastics material) for the photocatalyst and the other of fabric made of cotton (or other hydrophilic material), for sanitizing the fluids by way of the use of said supports in systems for air treatment (devices which take the air from the environment and/or from the exterior, filter it, and reemit it after passage through the filtration system in question) and/or water filtration.

The present invention has high efficiency and is a significant innovation, including on the basis of the efficacy tests performed in the present period of health emergency, including on the infective virus COVID-19.

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 reducing the content of nitrogen oxides NOx and nitrous oxide N2O in an input gas, comprising the steps of: treating said gas with a first amount of a NOx reducing agent in a first de-NOx catalytic bed; treating the effluent of said first de-NOx catalytic bed in at least one de-N2O catalytic bed for removal of N2O; treating the effluent of said at least one de-N2O catalytic bed with a second amount of a NOx reducing agent in a second de-NOx catalytic bed.

Visible-light response hybrid aerogel and a preparation method and application thereof in waste gas processing are disclosed. Dicyandiamide is taken as a precursor and is calcined in two times to prepare a carbon nitride nanosheet; the carbon nitride nanosheet is dispersed in water, silver metavanadate quantum dots are subjected to in-situ growth to prepare a silver metavanadate quantum dot/carbon nitride nanosheet composite material; the silver metavanadate quantum dot/carbon nitride nanosheet composite material and graphene oxide carry out hydrothermal reaction, and are then frozen and dried to prepare silver metavanadate quantum dot/carbon nitride nanosheet/graphene hybrid aerogel which is the visible-light response hybrid aerogel. The problems of large reduction dosage, serious secondary pollution, complexity in operation and the like generated when waste gas is processed by a traditional flue gas denitration technology are overcome.

Disclosed is a filter regenerating apparatus of a denitrification facility, the apparatus including: a body module disposed above a filter installed in the denitrification facility, and capable of reciprocating in a first direction; a nozzle support module supported by the body module, and capable of reciprocating in a second direction crossing the first direction; a coating material spray nozzle detachable from the nozzle support module, and capable of spraying a coating material toward the filter disposed below; and a power control module configured to control operations of the body module and the nozzle support module so that the coating material spray nozzle is transferred along the filter in the first and second directions.

Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent.

This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects ash dust/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which an oxygen atom is deficient in a crystal structure of the vanadium pentoxide.

It is an object to provide a regenerated denitration catalyst whose denitration performance is restored compared with a denitration catalyst before use, utilizing a spent denitration catalyst, and a method for manufacturing the same. In a regenerated denitration catalyst according to the present disclosure, a spent denitration catalyst including a first titanium oxide as a main component, and a second titanium oxide are mixed. The spent denitration catalyst is already used in a denitration reaction in which nitrogen oxides in a gas are decomposed into nitrogen and water using a reducing agent. The second titanium oxide has a larger specific surface area per unit weight than the first titanium oxide. A content of the second titanium oxide based on a total weight of the first titanium oxide and the second titanium oxide is preferably 10% by weight or more and 90% by weight or less.

A method for preparing an active catalyst for high-efficiency denitration is disclosed. The method includes: a catalyst raw material is charged into a denitration reactor, NH.sub.3 and an inert gas are introduced and then heating is performed, and the temperature is held and then natural cooling is performed, thereby obtaining the catalyst. The active catalyst can greatly improve the denitration activity in low temperature range, and can not only improve the denitration efficiency under the condition without SO.sub.2 and H.sub.2O, but also can improve the denitration efficiency under the condition with both SO.sub.2 and H.sub.2O. The service life of the catalyst is prolonged under the premise of not changing the existing catalyst preparation process, and the economic benefit is significant. The denitration efficiency of a powder catalyst can be increased by 25%, and the denitration efficiency of a honeycombed catalyst or a corrugated catalyst can be increased by 20%.

Chromium particulate emissions in flue gas can be reduced or minimized by incorporating a thin layer bed of a catalyst within the flue gas flow path of a furnace, boiler, or other furnace environment that includes Cr-containing surfaces. The thin layer bed of catalyst can correspond to, for example, a honeycomb monolith with catalyst supported on the monolith surface, so as to provide a high contact area while forcing all of the flue gas to pass through the catalyst bed. The honeycomb monolith structure and the depth of the bed can be selected to provide a reduced or minimized pressure drop across the catalyst bed, such as a pressure drop of 0.25 kPa (1.0 inches of water) or less. Exposing the Cr-containing flue gas to the thin layer catalyst bed can result in a treated flue gas with a lower content of Cr.