阅读说明：本技术 一种协同脱除氮氧化物和二噁英功能的复合滤料及其制备方法 (Composite filter material with synergistic removal function of nitrogen oxides and dioxins and preparation method thereof ) 是由 徐海涛 支晓欢 徐天平 梅超强 沈强 于 2019-11-05 设计创作，主要内容包括：本发明提供了一种协同脱除氮氧化物和二噁英功能的复合滤料及其制备方法,属于复合滤料领域,旨在去除烟气中粉尘的同时脱除烟气中的NOx和二噁英。具体方法为：将混有钒、铈、钛氧化物的模板剂浸渍于滤料出气一侧,在滤料迎尘一侧进行抽滤负载NOx催化剂,通过干燥去除模板剂后得到复合滤料。该方法制备的滤料有效避免了NH<Sub>3</Sub>对催化氧化二噁英的影响,复合滤袋使用寿命长,污染物脱除效果好。(The invention provides a composite filter material with a function of cooperatively removing nitrogen oxides and dioxins and a preparation method thereof, belongs to the field of composite filter materials, and aims to remove dust in flue gas and simultaneously remove NOx and dioxins in the flue gas. The specific method comprises the following steps: soaking a template agent mixed with vanadium, cerium and titanium oxide on the air outlet side of the filter material, carrying out suction filtration on the dust facing side of the filter material to load an NOx catalyst, and drying to remove the template agent to obtain the composite filter material. The filter material prepared by the method effectively avoids NH 3 The influence on catalytic oxidation of dioxin and the long service life of the composite filter bag,the pollutant removing effect is good.)

1. A preparation method of a functional filter material for synergistically removing nitrogen oxides and dioxins is characterized by comprising the following steps: the method comprises the following steps:

a. dissolving chelate titanate and polyethylene glycol in water to form a solution a, and then dissolving V₂O₅、CeO₂And TiO₂Adding the mixture into the solution a, performing ultrasonic oscillation for 2-4 hours, and stirring for 10-12 hours after oscillation to obtain emulsion a;

b. pouring the emulsion a into a vessel, wherein the liquid level height is 1/5-1/2 of the height of the filter material, the filter material is dipped into the emulsion a with the dust-facing surface upward, so that the upper surface of the filter material is not immersed into the emulsion a, the filter material is taken out before the upper surface of the filter material is wet, the filter material is dried for 2-4h and weighed at the temperature of 80-110 ℃, and the dipping step is repeated until the loading amount a of the catalyst on the filter material reaches 100 plus 150g/m²；

c. Dissolving polyethylene glycol in water to form a solution b, adding at least one of oxides of manganese, iron, cerium, copper, nickel, zirconium, cobalt and molybdenum into the solution b, ultrasonically dispersing for 2-4h, and stirring for 10-12h to form an emulsion b;

d. putting the filter material catalyst prepared in the step b into a Buchner funnel with the dust facing surface facing upwards, slowly pouring the emulsion b, adjusting the relative vacuum degree to be-10 to-30 kPa for suction filtration, and enabling the denitration catalyst to be loaded on the dust facing side of the filter material, wherein the catalyst loading amount b is 150-²；

e. And d, drying the filter material treated in the step d in an oven at the temperature of 200-250 ℃ for 10-15h to finish the preparation of the composite filter material.

2. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step a, the filter material is a high-temperature-resistant filter material of a bag-type dust collector, and is made of one or more of PPS, Nomex, P84 and PTFE.

3. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 2, which is characterized in that: the filter material is P84 filter material.

4. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step a, the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600; the chelate titanate is di (diisooctyl pyrophosphoryl) methyl glycolate, di (diisooctyl phosphoryl) ethylene titanate or di (diisooctyl phosphoryl) methyl glycolate.

5. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step a, the mass ratio of the chelating titanate to the polyethylene glycol to the water is 0.1-10: 1-30: 80-95; preferably: the mass ratio of the chelating titanate to the polyethylene glycol to the water is 0.1-5: 5-20: 80-95.

6. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step a, the molar ratio of V to Ce is 1:1, and TiO₂Is of mass V₂O₅-CeO₂/TiO₂75-95% of the total mass of the catalyst; preferably: v₂O₅、CeO₂And TiO₂The mass ratio of the mixture to the solution a is 1-5: 100.

7. the preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step c, the mass ratio of the polyethylene glycol to the water is 0.1-5: 95 to 99.9.

8. The preparation method of the filter material for synergistically removing the nitrogen oxides and the dioxins according to claim 1, which is characterized in that: in the step c, the molar ratio of the metal oxide is 3:2 MnOx and CeO₂The mass ratio of the metal oxide to the solution b is 0.1-5: 100.

9. The filter material for synergistically removing nitrogen oxides and dioxins as claimed in claim 1, wherein: the filter material base cloth layer is a high-temperature resistant filter material of the bag type dust collector, and the catalyst layer is divided into a primary catalyst layer for removing NOx and a secondary catalyst layer for removing dioxin.

10. The filter material for synergistically removing nitrogen oxides and dioxins according to claim 9, wherein: the filter material is prepared by the following method:

a. dissolving chelate titanate and polyethylene glycol in water to form a solution a, and then dissolving V₂O₅、CeO₂And TiO₂Adding the mixture into the solution a, performing ultrasonic oscillation for 2-4 hours, and stirring for 10-12 hours after oscillation to obtain emulsion a;

b. pouring the emulsion a into a vessel, wherein the liquid level height is 1/5-1/2 of the height of the filter material, the filter material is dipped into the emulsion a with the dust-facing surface upward, so that the upper surface of the filter material is not immersed into the emulsion a, the filter material is taken out before the upper surface of the filter material is wet, the filter material is dried for 2-4h and weighed at the temperature of 80-110 ℃, and the dipping step is repeated until the loading amount a of the catalyst on the filter material reaches 100 plus 150g/m²；

c. Dissolving polyethylene glycol in water to form a solution b, adding at least one of oxides of manganese, iron, cerium, copper, nickel, zirconium, cobalt and molybdenum into the solution b, ultrasonically dispersing for 2-4h, and stirring for 10-12h to form an emulsion b;

d. putting the filter material catalyst prepared in the step b into a Buchner funnel with the dust facing surface facing upwards, slowly pouring the emulsion b, adjusting the relative vacuum degree to be-10 to-30 kPa for suction filtration, and enabling the denitration catalyst to be loaded on the dust facing side of the filter material, wherein the loading amount b is 150-²；

e. And d, drying the filter material treated in the step d in an oven at the temperature of 200-250 ℃ for 10-15h to finish the preparation of the composite filter material.

Technical Field

The invention relates to a functional composite filter material, in particular to a composite filter material with a function of cooperatively removing nitrogen oxides and dioxins and a preparation method thereof.

Background

NOx is one of the main pollution sources causing air pollution and has great harm to human health and ecological environment. NO stimulates eyes and respiratory system of human body to induce canceration; oxidation of NO to NO in air₂Reacting with ultraviolet to form photochemical smog; a large amount of nitrogen oxides are dissolved in rain and snow to form nitric acid rain, which erodes crops and buildings. Dioxins are a generic name for two classes of tricyclic aromatic organic compounds, the most carcinogenic potential substances discovered to date. Excessive ingestion by humans produces irreversible teratogenic, carcinogenic, and mutagenic "triprodogenic" effects.

As the use of the waste incineration power generation process in the disposal of household waste is more and more widespread, secondary pollution including dust, heavy metals, SOx, NOx, dioxin and the like generated in the waste incineration process becomes an important factor limiting the development thereof. In recent years, laws and regulations for environmental protection are gradually perfected, emission standards of conventional pollutants are stricter, and trace pollutants such as dioxin are also included in a monitoring range.

At present, the pollutants are generally controlled by adopting a single removal method, so that the occupied area of the flue gas treatment equipment of a factory is large, and the treatment cost is high. Therefore, a multifunctional filter material capable of removing dust, nitrogen oxide and dioxin simultaneously is researched and developed, so that the removal of the three pollutants can be completed when the flue gas passes through the bag type dust collector, and the equipment and operation cost are greatly saved.

A large number of researches show that the traditional vanadium and titanium commercial SCR catalyst has a very high effect of removing dioxin at the temperature of more than 200 ℃, but the flue gas contains high-concentration NH₃The catalyst loses dioxin removal activity in a short time, however, the SCR technology often adopts NH₃As a reductant to remove NOx, and the process requires NH₃Is generally higher to ensure adequate reduction of NOx.

Disclosure of Invention

The invention provides a composite filter material with a function of cooperatively removing nitrogen oxides and dioxins and a preparation method thereof aiming at the existing technical problems.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of a functional filter material for synergistically removing nitrogen oxides and dioxins comprises the following steps:

a. dissolving chelate titanate and polyethylene glycol in water to form a solution a, and then dissolving V₂O₅、CeO₂And TiO₂Adding the mixture into the solution a, performing ultrasonic oscillation for 2-4 hours, and stirring for 10-12 hours after oscillation to obtain emulsion a;

b. pouring the emulsion a into a vessel, wherein the liquid level height is 1/5-1/2 of the height of the filter material, the filter material is dipped into the emulsion a with the dust-facing surface upward, so that the upper surface of the filter material is not immersed into the emulsion a, the filter material is taken out before the upper surface of the filter material is wet, the filter material is dried for 2-4h and weighed at the temperature of 80-110 ℃, and the dipping step is repeated until the loading amount a of the catalyst on the filter material reaches 100 plus 150g/m²；

c. Dissolving polyethylene glycol in water to form a solution b, adding at least one of oxides of manganese, iron, cerium, copper, nickel, zirconium, cobalt and molybdenum into the solution b, ultrasonically dispersing for 2-4h, and stirring for 10-12h to form an emulsion b;

d. putting the filter material catalyst prepared in the step b into a Buchner funnel with the dust facing surface facing upwards, slowly pouring the emulsion b, adjusting the relative vacuum degree to be-10 to-30 kPa for suction filtration, and enabling the denitration catalyst to be loaded on the dust facing side of the filter material, wherein the catalyst loading amount b is 150-²；

e. And d, drying the filter material treated in the step d in an oven at the temperature of 200-250 ℃ for 10-15h to finish the preparation of the composite filter material.

The technical scheme of the invention is as follows: in the step a, the filter material is a high-temperature-resistant filter material of a bag-type dust collector, and is made of one or more of PPS, Nomex, P84 and PTFE. Preferably, the method comprises the following steps: the filter material is P84 filter material.

The technical scheme of the invention is as follows: in the step a, the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600; the chelate titanate is di (diisooctyl pyrophosphoryl) methyl glycolate, di (diisooctyl phosphoryl) ethylene titanate or di (diisooctyl phosphoryl) methyl glycolate.

The technical scheme of the invention is as follows: in the step a, the mass ratio of the chelating titanate to the polyethylene glycol to the water is 0.1-10: 1-30: 80-95; preferably: the mass ratio of the chelating titanate to the polyethylene glycol to the water is 0.1-5: 5-20: 80-95.

The technical scheme of the invention is as follows: in the step a, the molar ratio of V to Ce is 1:1, and TiO₂Is of mass V₂O₅-CeO₂/TiO₂75-95% of the total mass of the catalyst; preferably: v₂O₅、CeO₂And TiO₂The mass ratio of the mixture to the solution a is 1-5: 100.

the technical scheme of the invention is as follows: in the step c, the mass ratio of the polyethylene glycol to the water is 0.1-5: 95 to 99.9.

The technical scheme of the invention is as follows: in the step c, the molar ratio of the metal oxide is 3:2 MnOx and CeO₂And metal oxide and solution b substanceThe amount ratio is 0.1-5: 100.

The filter material base cloth layer is a high-temperature resistant filter material of the bag type dust collector, and the catalyst layer is divided into a primary catalyst layer for removing NOx and a secondary catalyst layer for removing dioxin.

In some specific embodiments: the filter material is prepared by the following method:

a. dissolving chelate titanate and polyethylene glycol in water to form a solution a, and then dissolving V₂O₅、CeO₂And TiO₂Adding the mixture into the solution a, performing ultrasonic oscillation for 2-4 hours, and stirring for 10-12 hours after oscillation to obtain emulsion a;

b. pouring the emulsion a into a vessel, wherein the liquid level height is 1/5-1/2 of the height of the filter material, the filter material is dipped into the emulsion a with the dust-facing surface upward, so that the upper surface of the filter material is not immersed into the emulsion a, the filter material is taken out before the upper surface of the filter material is wet, the filter material is dried for 2-4h and weighed at the temperature of 80-110 ℃, and the dipping step is repeated until the loading amount a of the catalyst on the filter material reaches 100 plus 150g/m²；

c. Dissolving polyethylene glycol in water to form a solution b, adding at least one of oxides of manganese, iron, cerium, copper, nickel, zirconium, cobalt and molybdenum into the solution b, ultrasonically dispersing for 2-4h, and stirring for 10-12h to form an emulsion b;

d. putting the filter material catalyst prepared in the step b into a Buchner funnel with the dust facing surface facing upwards, slowly pouring the emulsion b, adjusting the relative vacuum degree to be-10 to-30 kPa for suction filtration, and enabling the denitration catalyst to be loaded on the dust facing side of the filter material, wherein the loading amount b is 150-²；

e. And d, drying the filter material treated in the step d in an oven at the temperature of 200-250 ℃ for 10-15h to finish the preparation of the composite filter material.

The technical scheme of the invention is as follows: the particle size of the metal oxide in the catalyst is 150-250 μm.

The invention has the beneficial effects that:

(1)NH₃is greatly consumed in the process of catalyzing and degrading NOx, and the subsequent influence on catalyzing and oxidizing dioxin is reduced.

(2) Before the filtration, the emulsion mixed with the secondary catalyst is loaded on the air outlet side of the filter material, the aperture of the air outlet filter material is reduced, and primary catalyst particles in the filtration process are intercepted and loaded on the dust facing side of the filter material.

(3) And e, drying the filter material, fixing primary catalyst particles on one hand, removing the template agent on the gas outlet side of the filter material on the other hand, increasing pore channels of the catalyst, increasing the contact area with gas and improving the catalytic effect.

(4) The catalyst loaded by adopting the suction filtration method has the characteristic that the loading capacity is gradually increased from the dust facing surface to the middle layer of the filter material, the wear resistance of the composite filter material is effectively improved, and the service life is prolonged.

Drawings

FIG. 1 is a schematic diagram of a composite filter of example 1.

A denitration layer A and a dioxin removal layer B.

Fig. 2 is a testing device for denitration and dioxin removal of the composite filter material.

Wherein: 1.N₂Bottle, 2.O₂Bottle, 3.NH₃The device comprises a bottle, 4. a NO bottle, 5. a pressure reducing valve, 6. a mass flow meter, 7. a micro-injection pump, 8. a gasification mixing chamber, 9. a quartz tube, 10. a composite filter material, 11. a tube furnace and 12. a flue gas analyzer.

Detailed Description

The invention is further illustrated by the following examples, without limiting the scope of the invention: