Catalyst for denitration by SCR method with low cost and preparation method thereof

Abstract

The invention provides a low-cost SCR method denitration catalyst and a preparation method thereof. The weight percentage of the components of the catalyst is as follows: 52-55% of slag micropowder, 2.7-2.9% of plaster, 1.3-1.5% of ammonium metavanadate, 5.5-5.7% of ammonium paratungstate, 2.6-2.8% of silica sol, 1.6-1.8% of clay, 2.5-3.0% of fiber glass filament, 2.7-2.9 % of methylcellulose, 1.3-1.5% of polyethylene oxide, 2.7-3.0% of monoethanolamine and 20-23 % of distilled water. Firstly, the slag and the plaster are pulverized and activated in high-temperature water vapor to prepare carrier; secondly, the carrier is evenly blended with other components to prepare slurry; the slurry is prepared into the semi-finished product of the catalyst according to the shape requirements of the catalyst, and then the semi-finished product is dried and calcined to prepare the finished product of the catalyst. The invention has simple production technique, and the catalyst has good activity and anti-abrasion performance and long service life, thus effectively lowering the production cost of the catalyst and operation expense of denitration treatment.

Description

technical field [0001] The invention relates to the technical field of environmental protection for flue gas purification, in particular to an SCR denitrification catalyst using slag fine powder as a carrier and a preparation method thereof. Background technique [0002] Selective catalytic reduction method (SCR method), because of its high denitrification efficiency and mature technology, is currently the most widely used in flue gas denitrification projects at home and abroad. The SCR method is a reducing agent (NH 3 , urea) under the action of catalyst, selectively react with NO in flue gas x N 2 and H 2 O without being O 2 Oxidation, so it is called "selectivity". Its main response: [0003] 4NH 3 +4NO+O 2 =4N 2 +6H 2 o [0004] 8NH 3 +6NO 2 =7N 2 +12H 2 o [0005] In the prior art, the catalyst commonly used in the SCR method generally uses titanium dioxide (TiO 2 ) as carrier, vanadium pentoxide (V 2 o 5 ) as the active ingredient and adding tungsten...

AI Technical Summary

Problems solved by technology

This catalyst was first invented by Japan in the 1970s. Its advantages are high denitrification activity and small side reactions, but the carrier titanium dioxide (TiO 2 ) higher manufacturing cost

Due to the high loss on ignition of fly ash in the process of coal combustion in my country, free calcium oxide (CaO), magnesium oxide (MgO), sulfur trioxide (SO 3 ) is also relatively high, and the general load fluctuation of boiler operation is relatively large, causing problems such as catalyst blockage, poisoning, and abrasion failure in the existing SCR system device during operation, which must be replaced regularly, resulting in high operating and investment costs

In recent years, low-cost materials such as fly ash have been used to prepare catalyst carriers. For example, the Chinese patent No. 200310100420.9 discloses a method for preparing selective reduction and denitrification catalysts using boiler fly ash. Coal ash is the carrier. The preparation of the carrier needs to be pickled first, then soaked in concentrated nitric acid solution to shape, and then washed with distilled water to filter the formed fly ash particles to neutrality, and finally sent to the drying box for a drying process to form fly ash particles. Ash-modified SCR denitration catalyst carrier; then immerse the prepared carrier in a metal oxide salt solution composed of unsaturated copper nitrate solution, so that the metal oxide is loaded on the carrier as an active component, and then dried twice and calcined to obtain a catalyst; although the cost of this catalyst is lower than that of traditional catalysts, it is still relatively high, and the preparation process is relatively complicated, and when it is applied to high-dust flue gas, it is difficult to popularize due to the poor abrasion resistance of the carrier application