The invention is directed to a process and apparatus for treating an off-gas from a lean burn engine comprising contacting said off-gas with an oxidizing compound, thus producing oxidized NOx compounds, followed by contacting the oxidized NOx compounds with water, by which at least part of said oxidized NOx compounds dissolves in said water. The process of the invention provides for a very efficient means of reducing NOx emission. The equipment for carrying out the process of the invention can be compact, so that it can be used on board without sacrificing too much valuable space and without increasing the weight of the ship too much.

An all-condition auxiliary denitration system and an operation method. thereof are provided. The system includes a heat-storage medium heater, a low-temperature reheater, an economizer, and an SCR denitration device which are successively interconnected, and further including a heat-storage medium tank and a heat-storage medium and feedwater heat exchanger. A flow of a cold heat-storage medium entering the heat-storage medium heater is regulated, so that heat absorption of the heat-storage medium is matched with a boiler load. Flows of hot heat-storage medium and feedwater, which enter the heat-storage medium and feedwater heat exchanger, are regulated through a feedwater regulating valve and a hot heat-storage medium outlet regulating valve. A total feedwater flow is regulated with assistance of a bypass feedwater regulating valve, so that a temperature of flue gas entering the SCR denitration device is kept in an optimal operation range under different boiler loads, and denitration efficiency is ensured.

This disclosure provides an apparatus and method for reducing emissions of nitrogen oxides (NO.sub.x) from a combustion source. For example, a method and apparatus for injecting a urea solution directly into the flue gas stream of a coal-fired power plant that utilizes Selective Catalytic Reduction (SCR) to lower NO.sub.x emissions.

Disclosed herein are systems and methods for reducing the particulate matter content of an exhaust gas from a carbon black process.

The present invention relates to a catalyst, comprising a carrier substrate of the length (L) which extends between two carrier substrate ends (a and b) and has two coating zones (A and B), wherein the coating zone (A) comprises a zeolite and palladium and, proceeding from the carrier substrate end (a), extends on a part of the length (L), the coating zone (B) comprises the same components as coating zone (A) and platinum and, proceeding from the carrier substrate end (b), extends on a part of the length (L), wherein L=L.sub.A+L.sub.B, wherein LA denotes the length of the coating zone (A) and L.sub.B denotes the length of the coating zone (B). The invention also relates to an exhaust system containing said catalyst.

An apparatus for treating exhaust gas of a thermal power plant according to the present invention includes: a diffusion module part controlling an exhaust gas flow between a duct disposed at a rear end of a gas turbine of the thermal power plant and the gas turbine to guide the exhaust gas flow toward an inner wall of the duct; a plurality of injection nozzles installed in a flow section in the duct in which the exhaust gas guided toward the inner wall of the duct from the diffusion module part flows, and protruding from the inner wall of the duct; a fluid supply pipe connected to the injection nozzles and extending outside the duct; a fluid supply part supplying a pollutant treatment fluid in liquid phase to the injection nozzles through the fluid supply pipe; and a catalyst module disposed at rear ends of the injection nozzles.

A photocatalyst filter is provided. The photocatalyst filter includes: a base in which an internal space is formed. The internal space is permeable to fluid, and a plurality of photocatalyst beads are provided in the internal space, wherein a surface of the internal space is reflective.

The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

The invention provides a method of reducing the amount of nitrogen oxide components in a process gas stream comprising: a) contacting a deNO.sub.X catalyst with the process gas in the presence of ammonia which results in the conversion of nitrogen oxide components as well as a decline in the NO.sub.X conversion over the deNO.sub.X catalyst; and b) regenerating the deNO.sub.X catalyst to improve the NO.sub.X conversion by contacting the deNO.sub.X catalyst at a temperature in the range of from 250 to 390 C. with a flow of ammonia that is reduced relative to the flow of ammonia in step a) and process gas, air or a mixture thereof.

A method for removing NO.sub.x from flue gas by SCR includes supplying a reagent for the SCR reaction of NO.sub.x into the flue gas, then contacting the flue gas with a catalyst. Supplying the reagent includes supplying a less than stoichiometric amount of reagent, and after contacting the flue gas with a catalyst a final NO.sub.x removal step is provided.