Selective reduction catalyst for nitrogen oxide in smoking gas, its preparation method and application

Abstract

The present invention provides a selective reduction catalyst of nitrogen oxide in flue gas. It uses iolite cellular ceramics, Al2O3 and TiO2 as carrier, and uses the following metal oxides as activecomponents: (A), V2O5; (B) MoO3; and (C) WO3. The preparation method of said catalyst includes the following steps: preparing compouind catalyst carrier on which Al2O3 and TiO2 are loaded; repeatedlyimpregnating said compound catalyst carrier with ammonium metavanadate, ammonium molybdate and ammonium tungstate mixed aqueous solution, drying until the set load quantity of V2O5, WO3 and MoO3 is reached; finally roasting for 1-5 hr. so as to obtain the invented catalyst. Said catalyst can be used in ammonia reduction method for removing nitrogen oxide from flue gas.

Description

technical field [0001] The invention relates to a catalyst technology, in particular to a catalyst for the selective reduction of nitrogen oxides in flue gas, its preparation method and application. Background technique [0002] The pollution of the atmosphere by nitrogen oxides (NOx) is a worldwide environmental problem. Its main impact on the atmosphere is the formation of acid rain and high ground ozone concentration, which poses a huge threat to human health and the ecological environment. Post-combustion flue gas treatment is essential, although various combustion modification techniques are applied to reduce NO x Emissions, but in order to meet increasingly stringent emission standards, the development of new and efficient catalysts to deal with various gaseous pollutants is also becoming more and more important. In recent years, the use of catalysts to convert nitrogen oxides in flue gas emitted from power stations and other pollution sourc...

AI Technical Summary

Problems solved by technology

The catalyzer that is applied to this method is called SCR catalyst, and many patents have been reported various formulations of this catalyzer; For example, patents such as US5,198,403, US4,085,193 disclose SCR catalyst and preparation method thereof; In these patents The structure, composition and preparation methods of catalysts have been widely used. They load active components such as vanadium, molybdenum, tungsten, etc. on inorganic oxides through homogeneous solution method, co-precipitation method, solution precipitation method, precipitation mixing method and other methods. Carriers such as titanium dioxide, alumina, silica and zirconia, etc., add binders for extrusion molding, and finally heat treatment; because the aforementioned technologies use extrusion molding, these catalysts have low mechanical strength, poor heat transfer performance, and start-up. Disadvantages such as slowness, small specific surface area of ​​active components, high cost due to the need for a large amount of active components