CN106000392A

CN106000392A - Novel diesel vehicle exhaust denitration catalyst and preparation method thereof

Info

Publication number: CN106000392A
Application number: CN201610338621.XA
Authority: CN
Inventors: 王丽娜; 张新华; 闫坤鹏; 於承志
Original assignee: TIANHE (BAODING) ENVIRONMENTAL ENGINEERING Co Ltd
Current assignee: TIANHE (BAODING) ENVIRONMENTAL ENGINEERING Co Ltd
Priority date: 2016-05-19
Filing date: 2016-05-19
Publication date: 2016-10-12

Abstract

The invention discloses a novel diesel vehicle exhaust denitration catalyst and a preparation method thereof. A final product prepared by the preparation method refers to that catalyst compositions V2O5, WO3 and MO3 are distributed on a composite support composed of SiO2 and kaolinite. The novel diesel vehicle exhaust denitration catalyst is integrally formed with the catalyst compositions mixed in paste, the paste is directly formed by squeezing without ceramic carriers, and accordingly preparation cost is reduced remarkably; selective reduction serves as a denitration mechanism herein, and a reducing agent is high in denitration efficiency under the action of the catalyst.

Description

A kind of novel diesel tail gas denitrating catalyst and preparation method thereof

Technical field

The invention belongs to the catalysis material field of exhaust gas from diesel vehicle denitration, relate to a kind of novel diesel tail gas denitration catalyst Agent and preparation method thereof.

Background technology

Adding up according to AUTHORITATIVE DATA, in current environmental pollution factors, exhaust emissions is a very important influence factor, its In be divided into Road Transportation and non-rice habitats transportation, non-rice habitats transportation is mainly various engineering car, agricultural large-scale Facility, substantially all for diesel vehicle, exhaust emissions contribution rate accounts for 1/2；In Road Transportation, transport class vehicle is the most complete Portion is diesel vehicle, and exhaust emissions contribution accounts for 1/4；Diesel engine accounts for the total amount of 1/3 with quantity, but exhaust emissions contribution rate Accounting for the 3/4 of all exhaust emissions, diesel engine vent gas is administered significant.

Along with the enforcement at the beginning of 2015 of exhaust gas from diesel vehicle discharge state four of China regulation, the diesel vehicle producer of numerous domestic is all Face the renewal upgrading of gas emission device, the most most important most crucial be then catalyst.

Current domestic exhaust gases of internal combustion engines processes mainstream technology three kinds:

The first three-effect catalysis device, ultimate principle is that carrier pottery coordinates three-element catalytic agent material to make, and it makes work Skill is divided into again vacuum adsorption and activity immersion-type；Primary apply in gasoline car industry；Due to its carrier ceramic making technology and Catalyst manufacturing technology is substantially at technical monopoly state, domestic is substantially and foreign capitals cooperation or generation processing, and catalyst Composition contains noble metal, and cost of manufacture is the highest.

The second carrier pottery coordinates self-control catalyst material, and its processing technology is divided into again vacuum adsorption and activity dipping Type；It is mainly used in gasoline and diesel vehicle industry；Wherein carrier pottery is for adopt outward, and self-control catalysis material mostly is vanadium and other auxiliary materials Mixing；

The third non-selective catalytic reduction technology, i.e. SNCR technology.This kind of technology is without catalyst, at uniform temperature bar Under part, reducing agent (ammonia, carbamide etc.) is sprayed into, nitrogen oxides in effluent is reduced into nitrogen and water；It is mainly used in heavy duty vapour Oil garage industry, is also the more technology that uses at present, but this technology reduction efficiency is low, there is ammonia secondary pollution risk.

But, three-effect catalysis device and carrier pottery add self-control catalyst and all use carrier pottery, and its cost of manufacture is higher, Technology is abroad monopolized substantially；Non-selection catalytic reduction technique is the technology that current diesel vehicle denitration catalyst market uses, but Its reduction efficiency is low, only 30%-60%, and requires higher, also to nitrogen oxides in effluent concentration requirement relatively to reaction temperature , there is the risk of ammonia secondary pollution for improving denitration efficiency raising ammonia spraying amount in height.

Summary of the invention

For the problems referred to above, the present invention provides a kind of novel diesel tail gas denitrating catalyst and preparation method thereof, passes through Reasonable disposition raw material ratio, targetedly calendering process, it is achieved the preparation of creme, and creme is by extrusion straight forming, nothing Needing carrier pottery, cost of manufacture has substantially reduction.

A kind of novel diesel tail gas denitrating catalyst, including: TiO₂, ammonium paratungstate, ammonium heptamolybdate, kaolinite, glass Fiber (hereinafter referred to as glass), ammonia, polyethylene glycol oxide (polyethylene oxide, PEO), lactic acid, carboxymethyl cellulose (Carboxy Methyl Cellulose, CMC), stearic acid, 2-phosphate-1,2,4-butane tricarboxylate (2- Phosphonobutane-1,2,4-tricarboxylic acid, PBTCA), deionized water and ammonium metavanadate solution, each component Proportioning is as follows:

Material	Proportioning (weight portion)
		TiO₂	70-80
Ammonium paratungstate	1-2
		Ammonium heptamolybdate	1-2
Kaolinite	5-10
		Glass fibre	0.1-0.2
Polyethylene glycol oxide	0.2-0.4
		Carboxymethyl cellulose	0.2-0.4
Lactic acid	0.1-0.2
		Stearic acid	0.5-1
Ammonia	3-5
		2-phosphate-1,2,4-butane tricarboxylates	0.1-0.2
Deionized water	20-25
		Ammonium metavanadate solution	2-5

Kaolinite granularity requirements 200-350 mesh in said components；Specific surface area >=30m³/g；

In said components, glass fibre length requires 2-3mm；

Weight concentration (the i.e. NH in ammonia spirit of ammonia in said components₃Weight account for the percentage of ammonia spirit gross weight Number) it is 15%；

In said components, (i.e. in lactic acid aqueous solution, the weight of lactic acid accounts for lactic acid aqueous solution gross weight to the weight concentration of lactic acid Percent) it is 25%；

Weight concentration (the i.e. weight of ammonium metavanadate solid in ammonium metavanadate aqueous solution of ammonium metavanadate solution in said components Account for the percent of the gross weight of ammonium metavanadate aqueous solution) it is 21%.

A second aspect of the present invention provides the preparation method of a kind of novel diesel tail gas denitrating catalyst, including:

1) by TiO₂, kaolinite is dry mixed 5-10min, adds ammonium heptamolybdate and ammonium paratungstate is dry mixed 5-10min；Add one Portions of de-ionized water, stirs 20-40min, adds ammonium metavanadate solution, stirs 30-40min；Add ammonia, stir 10- 20min；Add lactic acid, stir 3-5min；Add stearic acid, stir 3-5min；Add glass fibre, stir 10-20min；Add Enter and remain deionized water, reverse agitating function 10-15min, add polyethylene glycol oxide and carboxymethyl cellulose, stir 40-60min, Rear addition 2-phosphate-1,2,4-butane tricarboxylates, stir 10-20min, reverse agitating function, dehumidifying, obtain standard moisture 25-35%, pH scope is at 7-10, the pug of plasticity 11-14.

2) pug coating or extrusion will be mixed out, obtain catalyst prod in the calcining of 550-650 degree.

Above-mentioned being dry mixed uses mixing roll or kneader.

Beneficial effects of the present invention is as follows:

The charging sequence and the compounding process that there is provided according to the present invention are mixing, it is ensured that the plasticity of mixing creme and viscosity. After present invention calcining, finished product is by SiO₂, kaolinite composition complex carrier on, be uniformly distributed catalyst component V₂O₅、WO₃With MO₃；The catalyst of the present invention is integrated, and catalyst component is blended in creme, and creme is by extrusion straight forming, nothing Needing carrier pottery, cost of manufacture has substantially reduction；And denitration mechanism of the present invention is selective reduction, reducing agent is made at catalyst Under with, denitration efficiency is high.

Detailed description of the invention

Embodiment 1

By 70 parts of TiO₂, 10 parts of kaolinites put into mixing roll and 5-10min are dry mixed, then by 1 part of ammonium heptamolybdate and 1 part of para-tungstic acid Ammonium puts into mixing roll, and 5-10min is dry mixed；Adding 15 parts of deionized waters, stir 20-40min, adding 3 parts of weight concentrations is 21% Ammonium metavanadate solution, stir 30-40min；Adding 3 parts of weight concentrations is the ammonia of 15%, stirs 10-20min；Add 0.2 Part weight concentration is the lactic acid of 25%, stirs 3-5min；Add 0.2 part of stearic acid, stir 3-5min；Add 0.2 part of glass, stir Mix 10-20min；Add 10 parts of deionized waters of residue, reverse agitating function 10-15min, add 0.3 part of PEO and 0.3 part of CMC, stirring 40-60min, is eventually adding 0.1 part of PBTCA, stirs 10-20min, reverse agitating function, dehumidifying, has reached the pug standard water of requirement Divide content 25%, pH8.5, plasticity 13.

Will mix out pug coating or extrusion, 550-650 degree calcining obtain catalyst prod, after calcining finished product be by SiO₂, kaolinite composition complex carrier on, be uniformly distributed catalyst component V₂O₅、WO₃And MO₃。

Embodiment 2

By 75 parts of TiO₂, 10 parts of kaolinites put into mixing roll and 5-10min are dry mixed, then by 1 part of ammonium heptamolybdate and 1 part of para-tungstic acid Ammonium puts into mixing roll, and 5-10min is dry mixed；Adding 15 parts of deionized waters, stir 20-40min, adding 3 parts of weight concentrations is 21% Ammonium metavanadate solution, stir 30-40min；Adding 3 parts of weight concentrations is the ammonia of 15%, stirs 10-20min；Add 0.2 Part weight concentration is the lactic acid of 25%, stirs 3-5min；Add 0.2 part of stearic acid, stir 3-5min；Add 0.2 part of glass, stir Mix 10-20min；Add 10 parts of deionized waters of residue, reverse agitating function 10-15min, add 0.3 part of PEO and 0.3 part of CMC, stirring 40-60min, is eventually adding 0.1 part of PBTCA, stirs 10-20min, reverse agitating function, dehumidifying, has reached the pug standard water of requirement Divide content 31%, pH7, plasticity 14.

Embodiment 3

By 80 parts of TiO₂, 5 parts of kaolinites put into mixing roll and 5-10min are dry mixed, then by 1 part of ammonium heptamolybdate and 1 part of para-tungstic acid Ammonium puts into mixing roll, and 5-10min is dry mixed；Adding 15 parts of deionized waters, stir 20-40min, adding 3 parts of weight concentrations is 21% Ammonium metavanadate solution, stir 30-40min；Adding 5 parts of weight concentrations is the ammonia of 15%, stirs 10-20min；Add 0.2 Part weight concentration is the lactic acid of 25%, stirs 3-5min；Add 0.2 part of stearic acid, stir 3-5min；Add 0.2 part of glass, stir Mix 10-20min；Add 10 parts of deionized waters of residue, reverse agitating function 10-15min, add 0.3 part of PEO and 0.3 part of CMC, stirring 40-60min, is eventually adding 0.1 part of PBTCA, stirs 10-20min, reverse agitating function, dehumidifying, has reached the pug standard water of requirement Divide content 35%, pH10, plasticity 11.

Embodiment 4

By 75 parts of TiO₂, 7 parts of kaolinites put into mixing roll and 5-10min are dry mixed, then by 1 part of ammonium heptamolybdate and 1 part of para-tungstic acid Ammonium puts into mixing roll, and 5-10min is dry mixed；Adding 15 parts of deionized waters, stir 20-40min, adding 3 parts of weight concentrations is 21% Ammonium metavanadate solution, stir 30-40min；Adding 4 parts of weight concentrations is the ammonia of 15%, stirs 10-20min；Add 0.2 Part weight concentration is the lactic acid of 25%, stirs 3-5min；Add 0.2 part of stearic acid, stir 3-5min；Add 0.2 part of glass, stir Mix 10-20min；Add 10 parts of deionized waters of residue, reverse agitating function 10-15min, add 0.3 part of PEO and 0.3 part of CMC, stirring 40-60min, is eventually adding 0.1 part of PBTCA, stirs 10-20min, reverse agitating function, dehumidifying, has reached the pug standard water of requirement Divide content 31%, pH8.5, plasticity 14.

Utilize the catalyst prod that above-described embodiment makes, detect its thermal expansion factor；Test according to GB/T31587-2015 Method, detects intensity；

The catalyst prod utilizing above-described embodiment to make carries out denitration performance test.Experimental condition is as follows: this is urged Agent is when with ammonia for reducing agent, by the NH of the NO of 500ppm, 500ppm₃, 10% oxygen, 5% carbon dioxide, 4.5% water Steam, remaining reaction gas is nitrogen, and reaction velocity is 40000h^-1, under 350 degree of simulated flue gas parameters, measure denitration efficiency.

With reference to the automobile-used spark-ignition engine of GB14762-2002 and dress spark-ignition engine automobile exhaust pollutant discharge Limit value and measuring method.

Detection data see table:

	Denitration efficiency %	Thermal expansion factor/DEG C	Axial strength/MPa	Radial strength/MPa
					Embodiment 1	97.73	1.73×10^-6	13.66	5.11
Embodiment 2	98.49	2.41×10^-6	13.07	3.91
					Embodiment 3	98.79	3.17×10^-6	13.45	3.04
Embodiment 4	98.57	1.21×10^-6	13.14	4.82

It is appreciated that by upper table data:

In embodiment 4, catalyst formulation performance is optimal.

Claims

1. a novel diesel tail gas denitrating catalyst, including: TiO₂, ammonium paratungstate, ammonium heptamolybdate, kaolinite, glass fibers Dimension, ammonia, polyethylene glycol oxide, lactic acid, carboxymethyl cellulose, stearic acid, 2-phosphate-1,2,4-butane tricarboxylates, deionization Water and ammonium metavanadate solution, each component proportion is as follows:

Material Weight TiO₂ 70-80 Ammonium paratungstate 1-2 Ammonium heptamolybdate 1-2 Kaolinite 5-10 Glass fibre 0.1-0.2 Polyethylene glycol oxide 0.2-0.4 Carboxymethyl cellulose 0.2-0.4 Lactic acid 0.1-0.2 Stearic acid 0.5-1 Ammonia 3-5 2-phosphate-1,2,4-butane tricarboxylates 0.1-0.2 Deionized water 20-25 Ammonium metavanadate solution 2-5

。

2. novel diesel tail gas denitrating catalyst as claimed in claim 1, it is characterised in that described kaolinite granularity is 200-350 mesh；Specific surface area >=30m³/g。

3. novel diesel tail gas denitrating catalyst as claimed in claim 1, it is characterised in that described glass fibre length is 2-3mm。

4. novel diesel tail gas denitrating catalyst as claimed in claim 1, it is characterised in that the weight concentration of described ammonia It is 15%.

5. novel diesel tail gas denitrating catalyst as claimed in claim 1, it is characterised in that the weight concentration of described lactic acid It is 25%.

6. novel diesel tail gas denitrating catalyst as claimed in claim 1, it is characterised in that described ammonium metavanadate solution Weight concentration is 21%.

7. the preparation method of the novel diesel tail gas denitrating catalyst as described in claim 1-6 is arbitrary, including:

1) by TiO₂, kaolinite is dry mixed 5-10min, adds ammonium heptamolybdate and ammonium paratungstate is dry mixed 5-10min；Add a part Deionized water, stirs 20-40min, adds ammonium metavanadate solution, stirs 30-40min；Add ammonia, stir 10-20min；Add Enter lactic acid, stir 3-5min；Add stearic acid, stir 3-5min；Add glass fibre, stir 10-20min；Add residue to go Ionized water, reverse agitating function 10-15min, add polyethylene glycol oxide and carboxymethyl cellulose, stir 40-60min, be eventually adding 2- Phosphate-1,2,4-butane tricarboxylates, stir 10-20min, reverse agitating function, dehumidifying, obtain mixing out pug；

8. the preparation method of novel diesel tail gas denitrating catalyst as claimed in claim 7, it is characterised in that described in be dry mixed Use mixing roll or kneader.

9. the preparation method of novel diesel tail gas denitrating catalyst as claimed in claim 7, it is characterised in that step 1) in Obtain mixed go out pug standard moisture 25-35%, pH scope is in 7-10, plasticity 11-14.

10. the preparation method of novel diesel tail gas denitrating catalyst as claimed in claim 7, it is characterised in that step 2) In the catalyst prod that obtains be by SiO₂, kaolinite composition complex carrier on, be uniformly distributed catalyst component V₂O₅、WO₃ And MO₃。