Preparation method of low-temperature catalyst for selective catalytic reduction of nitrogen oxide

Abstract

The invention provides a method for preparing a catalyst which can selectively catalyze and reduce nitrogen oxides at a low temperature, and belongs to the technical field of material preparation and waste gas treatment. In the method, chromium and cerium are taken as main components, and the catalyst which can effectively catalyze NH3 and reduce NOx into N2 at a low temperature is obtained by the coprecipitation method or dipping method and burning the main components; the catalyst has high low-temperature activity, and can be used at a temperature of between 80 and 150 DEG C, and can also tolerate the interference of as high as 6 percent of CO in the system, so that the catalyst has better application prospect in the denitration operation of sintered flue gas.

Description

technical field [0001] The invention relates to a method for preparing a catalyst for selectively catalytically reducing nitrogen oxides at low temperature, and belongs to the technical field of material preparation and waste gas treatment. Background technique [0002] Nitrogen oxides (NO x , including NO and NO 2 ) emissions have become one of the most important sources of air pollution in my country. my country is the world's largest steel producer, and steel sintering flue gas NO x Emissions account for about NO x 10% of the total discharge has not been treated with denitrification, which has seriously threatened the ecological environment and hindered the sustainable development of economy and society. The composition of sintering flue gas is complex and contains NO x , CO, O 2 , N 2 , SO 2 and a small amount of HCl, and the temperature of the sintering flue gas is relatively low, generally at 80-150°C. These factors make it difficult to treat the sintering flue...

AI Technical Summary

Problems solved by technology

In this method, the low-concentration NO in the flue gas is first passed through the catalyst x Catalytic oxidation and absorption, and then regenerating the catalyst with a reducing agent at a higher temperature, is essentially an oxygen-enriched denitrification technology. There have been reports on the use of M-Ba-Al and other ternary systems for NSR operations (M stands for precious metals) (Appl.Cataly.B: Environ., 2008, 84(3-4):514-523), however, its application is limited due to the use of expensive precious metals

In addition, there is a large amount of carbon monoxide in the sintering flue gas, the concentration of which is between 0.5% and 6% (5000ppm~60000ppm). The existence of such a large amount of reducing components makes it almost impossible for NSR technology to treat sintering flue gas