CN103349991A

CN103349991A - Carrier for denitration catalyst

Info

Publication number: CN103349991A
Application number: CN2013103244319A
Authority: CN
Inventors: 范林; 熊勇; 沈怀远; 李兵; 邵培丽; 程锡钱
Original assignee: CHONGQING XINHUA CHEMICAL Co Ltd
Current assignee: Chongqing Minfeng Chemical Co Ltd
Priority date: 2013-07-30
Filing date: 2013-07-30
Publication date: 2013-10-16
Anticipated expiration: 2033-07-30
Also published as: CN103349991B

Abstract

The invention discloses a catalytic carrier for a denitration catalyst. The carrier adopts metatitanic acid as a raw material, has more lasting thermal stability than other carriers for catalysts at the temperature of 1000 DEG C, can work in harsh environments for a long time, and has a broad-spectrum property in the catalytic ability after being mixed with other metals or metal oxides for forming.

Description

The denitrating catalyst carrier

Technical field

The invention belongs to the material of catalytic action, be specifically related to the denitrating catalyst carrier.

Background technology

Denitrating catalyst is that a kind of general reference is applied in power plant to be used for the ammonia SCR be NH ₃A kind of catalyst in the-SCR denitration technology, it can reduce the reaction temperature of nitrogen oxide and ammonia, thereby makes the nitrogen oxide in the flue gas be easy to be reduced into nitrogen by ammonia, thereby reduces the discharging of nitrogen oxide, reduce nitrogen oxide to the pollution of atmosphere, thereby reduce the harm of acid rain.

Theoretically, in the situation of not adding any catalyst, the reaction temperature of nitrogen oxide and ammonia is about 900 ℃, and contained nitrogen oxide main component is nitric oxide and nitrogen dioxide in the flue gas, and reaction equation with ammonia is as follows respectively for it,

4NO+4NH ₃+O ₂＝4N ₂+6H ₂O

6NO ₂+8NH ₃=7N ₂+12H ₂O

From following formula as can be known, no matter be nitric oxide or nitrogen dioxide, all can generate the less nitrogen G﹠W of contaminative behind itself and the ammonia gas react.But above-mentioned reaction needs 900 ℃ hot conditions just can carry out because the condition of reaction own is harsh, therefore, and existing NH ₃Often can use a kind of denitrating catalyst in the-SCR denitration technology, it can reduce the temperature that above-mentioned reaction needed is carried out, thereby reduces the difficulty of reaction condition.

Initial denitrating catalyst be with ceramic materials such as aluminium oxide as carrier, add the noble metals such as Pt or Pt-Rh as the catalyst activity composition; This denitrating catalyst the earliest has higher activity, can be so that the reaction temperature of nitrogen oxide and ammonia be lower, but because the cost of noble metal is higher, thereby limited the extensive use of this kind denitrating catalyst.

The most frequently used denitrating catalyst is with titanium dioxide TiO at present ₂Be carrier, with V ₂O ₅(WO ₃), Fe ₂O ₃, MgO, MoO ₃Mix with carrier Deng metal oxide or a symphyogenetic mixture, thereby obtain existing denitrating catalyst the most commonly used.This denitrating catalyst cost is lower, but its active denitrating catalyst not as precious metal, but its activity is not desirable especially, the heat endurance of its carrier, temperature tolerance etc. are unstable.

Summary of the invention

The technical problem to be solved in the present invention provides the denitrating catalyst carrier that a kind of heat endurance is strong, temperature tolerance is high.

In order to solve the problems of the technologies described above, the invention provides following technical scheme:

Technical scheme one: the denitrating catalyst carrier comprises following ratio of component, TiO ₂: 88-96%, SiO ₂: 3-7%, SO ₄: 1-5%.

The titanium silica flour of producing according to said ratio can reach following each parameter and standard, has powerful temperature tolerance, have the more lasting ability that lattice variations does not occur than other catalyst carriers under 1000 ℃, heat endurance is stronger, can work long hours in the environment of condition sternness; And behind other metals or metal oxide mixing and molding, has broad spectrum activity at catalytic capability.

Titanium silica flour product parameters:

Title	Unit	Value range
			BET	m ²/g	90-120
Total sulfur	％	1-5
			Calcination loss	％	＜7
Silica	%	3-7
			Fe ₂O ₃	ppm	＜100
Rutile content	%	＜0.5

Technical scheme two: the raw material of producing the titanium silica flour are metatitanic acids, and its parameter is BET 〉=250 m ²/ g, D ₅₀(um≤2.0), free acid (2-4%).The titanium silica flour as its name suggests, is the product of titaniferous and element silicon, and Ti content accounts for 88-96%, therefore selects the purer metatitanic acid of Ti content (butt TiO ₂〉=99.0%) is raw material.Metatitanic acid is, and to be raw material by ilmenite or high titanium slag make through operations such as acidolysis, sedimentation, press filtration, concentrated, hydrolysis, washing, bleaching, rinsings.Metatitanic acid has specific area height (BET 〉=250 m ²/ g) characteristics are as long as control particle diameter (D well ₅₀≤ 2.0 um) scope, free acid content just can obtain preferably titanium silica flour of quality by subsequent technique.Adding deionized water in metatitanic acid pulls an oar after solid content is 25-40%, add silica (3%-7%), enter calcined by rotary kiln (350-680 ℃) with uniform fluid form after stirring 2-4h, product after the calcining by mechanical disintegration to qualified particle diameter (D50: 0.8-1.6um) be finished product, raw material have clear and definite BET (specific area) requirement, the free sulfuric acid requirement, such raw material improve a lot Wear Resistance to the stability of the product of subsequent technique manufacturing.

Technical scheme three: the technique of producing the titanium silica flour comprises the steps, 1. produces by the metatitanic acid reaction and obtains the titanium silica flour; 2. making beating is stirred, and adding the deionized water solid content of pulling an oar in the titanium silica flour is 25-40%, stirs simultaneously to add powder silica (3%-7%); 3. calcining, with uniform fluid form charging calcining, calcining heat is 350-680 ℃ behind the stirring 2-4h; 4. pulverize, it is D that product is carried out mechanical disintegration to particle diameter ₅₀0.8-1.6um graininess.

Adopt rotary kiln from kiln tail uniform feeding, from the kiln hood uniform discharge, combustor places kiln hood, the heat energy that supplies must be stablized, and could the thermograde in rotary kiln be consistent, and guarantee metatitanic acid crystalline form changes consistent, the BET of the product that it is calcined out just can control to certain limit, if temperature fluctuation is larger, this index of BET will be very sensitive, causes defective.

Above-mentioned technique has following advantage with respect to prior art: 1, the making beating solid content is conducive to the saving of water resource, the energy at 25-40%; 2, with the D that is controlled at of granule size ₅₀0.8-1.6um and extrusion modling has good raising to Kaolinite Preparation of Catalyst to pulverize (micropowder grinding) with special equipment, catalytic effect and granule size are without direct relation, the uniformity of its granularity determines the quality of extrusion modling in the Kaolinite Preparation of Catalyst process, if granularity is inhomogeneous, during the catalyst extruding, easy-formation does not easily crack, even breaks; 3, calcining manners is different, adopts uniform fluid form charging calcining, so that the titanium silica flour has the more lasting ability that lattice variations does not occur than other catalyst carriers under 1000 ℃, can work long hours in the environment of condition sternness; Behind other metals or metal oxide mixing and molding, has broad spectrum activity at catalytic capability.

The specific embodiment

The denitrating catalyst carrier comprises following ratio of component: TiO ₂: 88-96%, SiO ₂: 3-7%, SO ₄: 1-5%, what raw material adopted is metatitanic acid, its parameter is BET m ²/ g(〉=250), D ₅₀(um≤2.0), free acid (2-4%) are manufactured as follows, 1. produce by the metatitanic acid reaction and obtain the titanium silica flour; 2. making beating is stirred, and adding the deionized water solid content of pulling an oar in the titanium silica flour is 25-40%, stirs simultaneously to add powder silica (3%-7%); 3. calcining, with uniform fluid form charging calcining, calcining heat is 350-680 ℃ behind the stirring 2-4h; 4. pulverize, it is D that product is carried out mechanical disintegration to particle diameter ₅₀0.8-1.6um graininess.1, the making beating solid content is conducive to the saving of water resource, the energy at 25-40%; 2, with the D that is controlled at of granule size ₅₀0.8-1.6um and extrusion modling has good raising to Kaolinite Preparation of Catalyst to pulverize (micropowder grinding) with special equipment; 3, calcining manners is different, adopts uniform fluid form charging calcining, so that the titanium silica flour has the more lasting ability that lattice variations does not occur than other catalyst carriers under 1000 ℃, can work long hours in the environment of condition sternness; With other metals or metal oxide (as: V ₂O ₅(WO ₃), Fe ₂O ₃, MgO, MoO ₃) behind the mixing and molding, have broad spectrum activity at catalytic capability.

Above-described only is preferred embodiment of the present invention, should be understood that for a person skilled in the art, under the prerequisite that does not break away from structure of the present invention, can also make some distortion and improvement, these can not affect effect of the invention process and practical applicability.

Claims

1. the denitrating catalyst carrier is characterized in that: comprise following ratio of component, TiO ₂: 88-96%, SiO ₂: 3-7%, SO ₄: 1-5%; The preparation denitrating catalyst is metatitanic acid with the raw material of carrier, and the parameter request of metatitanic acid is BET 〉=250 m ²/ g, D ₅₀≤ 2.0, free acid: 2-4%.

2. prepare the denitrating catalyst claimed in claim 1 method of carrier, it is characterized in that: comprise the steps,

1. produce by the metatitanic acid reaction and obtain the titanium silica flour;

2. making beating is stirred, and adding the deionized water solid content of pulling an oar in the titanium silica flour is 25-40%, stirs simultaneously to add powder silica (3%-7%);

3. calcining, with uniform fluid form charging calcining, calcining heat is 350-680 ℃ behind the stirring 2-4h;

4. pulverize, it is D that product is carried out mechanical disintegration to particle diameter ₅₀0.8-1.6um graininess.