A core-shell structure catalyst for simultaneous denitrification, mercury decarburization and its preparation method

Abstract

The invention discloses a core-shell structure catalyst for simultaneous denitration, demercuration and decarburization and a preparation method of the core-shell structure catalyst. The core-shell structure catalyst for simultaneous denitration, demercuration and decarburization has a formula MgaAlbCucNidSieTifOx, in the formula, a, b, c, d, e, f and x respectively represent atom numbers of Mg, Ag, Al, Cu, Ni, Si, Ti and O; the ratio of a:b:c:d:e:f is (20-25):(0-10):(15-30):(5-10):(10-15):(10-50); x is determined according to valences of different metal elements. By adoption of the core-shell structure catalyst for simultaneous denitration, demercuration and decarburization, the conversion efficiency of nitric oxides and carbon monoxide are up to 60-85% within a range of 200-350 DEG C, and the oxidation rate of mercury is 80-90%. The core-shell structure catalyst has good sulfur dioxide poisoning properties.

Description

technical field [0001] The invention belongs to the technical field of waste treatment, and in particular relates to a layered core-shell structure catalyst for simultaneous denitration, mercury and decarburization and a preparation method thereof. Background technique [0002] Fossil fuels such as coal and petroleum are the main forms of energy in my country, and the consumption of a large amount of fossil fuels leads to the emission of nitrogen oxides (NO x ), Mercury (Hg 0 ) and carbon monoxide (CO) emissions are increasing rapidly. These pollutants are important air pollutants in our country. They not only cause environmental problems such as acid rain, fine particle formation, and heavy metal pollution, but also have great harm to human health. Therefore, it is necessary to NO x , Hg 0 and CO emissions are strictly controlled. [0003] At present, selective catalytic reduction technology (SCR) is a relatively mature and widely used denitrification technology. Howe...

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Problems solved by technology

However, when this technology is applied to coal-fired flue gas in my country, especially in the denitrification of industrial boiler flue gas, it faces big problems: First, the technology is applicable to a narrow flue gas temperature window, which makes it difficult to adapt to large flue gas temperature fluctuations, especially difficult to apply to The working condition of the flue gas temperature is very low (2 Oxidation to SO 3 , corrode flue gas pipes and follow-up equipment; the third is commonly used reducing agent ammonia (NH 3 ) is easy to compare with SO 2 The reaction produces ABS, etc., which can not only deactivate the catalyst, but also cause blockage of the catalyst bed in severe cases, affecting the normal production

The problem with this technology is that the impact of the increase of bromine-containing substances in fly ash and wastewater on subsequent treatment facilities and the environment is still uncertain

But there are still obvious deficiencies in this method: (1) Hg 0 The oxidation efficiency is greatly affected by the addition of ammonia in the SCR device, and the presence of ammonia has a great influence on the Hg 0 Oxidation has obvious inhibitory effect; (2) The operating temperature range of this technology is limited, and the adaptability to working conditions with large fluctuations in flue gas temperature is poor

CO and NOx, Hg 0 Relatively lack of collaborative control technology for pollutants such as

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