Method for forming fly-ash-based honeycomb type denitration catalyst ceramic carrier

Abstract

The invention belongs to the technical field of SCR denitration catalyst preparation and discloses a method for forming a fly-ash-based honeycomb type denitration catalyst ceramic carrier. Cheap and non-toxic fly ash serves as a carrier, additives and water are added, and the finished carrier product is prepared through mixing, ageing, filtering, pre-extrusion, ageing, extrusion molding, drying and forging. The catalyst carrier prepared through the method is low in mass, high in strength and large in specific surface area, and can meet requirements of industrial application. A loaded catalyst has high activity. The fly ash takes the place of titanium dioxide to serve as a main component of the carrier, the subsequent treatment problem of solid waste in coal-fired power plants is solved, waste is turned into wealth, recycling is achieved, cost is reduced, pollution caused by use of titanium dioxide is also avoided, forming of the carrier and loading of active components of the catalyst can be achieved at a time, and industrialization is easy.

Description

technical field [0001] The invention belongs to the technical field of SCR denitration catalyst preparation, and discloses a method for forming a fly ash-based honeycomb denitration catalyst ceramic carrier. Background technique [0002] In recent years, the environment has been deteriorating day by day, and the country has issued strict environmental protection laws and regulations. In order to improve the living environment and meet environmental protection requirements, SCR denitrification catalysts play an important role in atmospheric environmental protection. [0003] In industrial production, in order to achieve large-scale flue gas denitrification, honeycomb denitrification catalysts are usually used. When the honeycomb denitration catalyst is used, it is stacked in the form of modules and placed in the SCR reactor. Usually, the stacking method of the catalyst modules is designed according to the test results of the reactor flow field simulation, which requires the c...

AI Technical Summary

Problems solved by technology

At present, the commercial denitration catalysts on the market are mainly based on the V-W-Ti system, and its molding process is mature. In this system, TiO 2 The content of titanium dioxide reaches more than 85%, and its annual consumption is astonishing, and the price of titanium dioxide, the main raw material of the catalyst, is also rising due to the lack of mineral resources, resulting in an increase in costs.

At the same time, TiO 2 The development and production process also caused a lot of environmental pollution

[0004] In recent years, there have also been researches on replacing titanium dioxide with other materials. For example, CN102764657B announced a nano V 2 o 5 / Activated coke denitrification catalyst uses activated coke instead of titanium dioxide as a carrier, but in actual use, due to long-term exposure of activated coke to high temperature and aerobic conditions, it is easy to cause active coke to catch fire and burn, resulting in a huge loss

CN103191718B discloses the method for preparing honeycomb coal type denitration catalyst, utilizes acidified diatomite to replace part of titanium dioxide to reduce the content of titanium dioxide; although this method reduces the amount of titanium dioxide, it has not completely replaced after all, and may reduce the catalyst's denitrification activity, and the acid treatment in the process of this method will cause water pollution

CN1730431A discloses a cordierite honeycomb ceramic, which uses clay, talc, alumina, and magnesia as raw materials, and is calcined at 1280-1320°C after mixing and molding; the catalyst carrier obtained by this method is used for automobile exhaust purifiers, and the catalyst The carrier coats active components such as noble metal and rare earth material solutions on the surface of the carrier by adsorption; the catalyst obtained by this coating method is not resistant to erosion, and the loss of active components is large

[0005] CN102764671B discloses a method for obtaining an amorphous molecular sieve carrier by hydrothermal synthesis after water washing, pickling, and alkali treatment. Although this method uses relatively cheap and non-toxic fly ash base as raw material, pulverized coal The ash pretreatment process is cumbersome, costly, and easy to cause pollution, and the molecular sieve obtained by the hydrothermal synthesis method is difficult to meet the production needs of commercial honeycomb denitrification catalysts

Patent CN1607027A discloses a method for preparing a selective catalytic reduction denitration catalyst from boiler fly ash. This method also has the problem of acid pollution, and it is impossible to honeycomb-form the fly ash-based denitration catalyst.

[0006] CN103657737A discloses a catalyst carrier for low-temperature denitration and purification of flue gas, which uses fly ash as the carrier and iron oxide as the main catalyst component; although this method uses fly ash, it needs to add a crystallizable brine solution to improve its molding process. And the sintering temperature exceeds 1000°C, which is not suitable for the mixed calcination process of fly ash and metal nitrate

Due to the high calcination temperature of this method, the activity of the catalyst will be affected

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