Denitration and mercury removal catalyst for coal-fired flue gas, method for preparing denitration and mercury removal catalyst and application thereof

Abstract

The invention provides a denitration and mercury removal catalyst for coal-fired flue gas, a method for preparing denitration and mercury removal catalyst and application thereof. The denitration and mercury removal catalyst comprises a carrier and an active component. The carrier is F-doped titanium dioxide, the active component is V<2>O<5> (vanadium pentoxide), the specific surface area of the catalyst is 60-80 m<2>/g, and the mass of the active component V<2>O<5> is 0.5-5wt.% of the mass 100wt.% of the denitration and mercury removal catalyst; the molar weight of F is 0.5-5at.% of the molar weight of titanium dioxide. The denitration and mercury removal catalyst, the method and the application have the advantages that the method for preparing the denitration and mercury removal catalyst is simple, and the denitration and mercury removal catalyst can be prepared by means of one-step calcination; the denitration and mercury removal catalyst is good in simultaneous removal activity for NO<x> and Hg<0> in the coal-fired flue gas, accordingly, the transformation cost of existing devices can be saved, atmosphere pollution can be reduced, and the denitration and mercury removal catalyst, the method and the application have high industrial application value.

Description

technical field [0001] The invention belongs to the technical field of resources and environment, and relates to a catalyst for simultaneous denitrification and demercuration of coal-burning flue gas, a preparation method and application thereof. Background technique [0002] Coal accounts for as much as 75% of my country's energy structure. my country's annual coal consumption is about 2 billion tons, of which more than 70% are used for coal-fired power generation. Coal-fired flue gas contains many pollutants, among which the heavy metal mercury Because of its characteristics of persistence, easy migration and high bioaccumulation, it has caused great harm to human beings and the ecological environment. [0003] Mercury in coal combustion flue gas exists in three forms: zero-valent mercury (Hg 0 ), oxidized mercury (Hg 2+ ), particulate mercury (Hg p ). Among them, Hg p Easy to be removed by dust removal device; Hg 2+ It is water soluble and therefore can be removed by...

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Problems solved by technology

Among the existing patents, CN102294248A discloses a simultaneous denitrification and demercuration ferromanganese composite oxide catalyst, with TiO 2 as carrier, with MnO 2 -Fe 2 o 3 Catalysts with active components have high catalytic activity, but the catalyst's activity temperature window is not high, which limits its industrial application

CN104415766A discloses a composite catalyst for flue gas denitrification and mercury removal in coal-fired power stations and its preparation method. The composite catalyst of the invention has a high removal rate of NOx in the flue gas, but the preparation process is complicated, and diatomite needs to be processed many times. Sub-modification, at the same time due to the need to introduce borate glass and plasticizers, etc., the cost is high

CN103657636A discloses a plate-type catalyst for simultaneous denitrification and mercury removal and its preparation method. The active components are coated on the skeleton to achieve simultaneous denitrification and mercury removal, but the catalyst lacks stability, and the active components are easy to fall off when operating at high space velocity

CN103480371A discloses a simultaneous denitrification and demercuration catalyst and its preparation method and application. By mixing and contacting a ruthenium-containing substance, a titanium-based denitration catalyst and hydrogen peroxide, the contacted mixture is dried or not dried and then roasted. The obtained catalyst is more effective than a single-function The NOx removal efficiency of the titanium-based catalyst was significantly improved, and the Hg 0 The oxidation efficiency is very high, but this patent uses precious metals as active components, which has high cost and has high requirements for the purity of flue gas. It is easy to be poisoned in the high-temperature denitrification and demercury reaction, and has poor adaptability to harsh operating conditions.

However, this catalyst has not been applied to the simultaneous denitrification and mercury removal of coal-fired flue gas.

[0007] Zhang Shule et al. (dx.doi.org / 10.1016 / j.cej.2014.04.045) reported the preparation of F-doped TiO by sol-gel 2 support, F-doped V 2 o 5 / TiO 2 Catalyst samples, which were roasted twice during the synthesis process of the catalyst, and the denitrification performance of the catalyst in the low temperature range (120-240°C) was mainly studied, and the catalyst was not applied to simultaneous denitrification and mercury removal of coal-fired flue gas

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