CN109126773B

CN109126773B - Catalyst for purifying waste incineration flue gas and preparation method thereof

Info

Publication number: CN109126773B
Application number: CN201811140384.1A
Authority: CN
Inventors: 邱敬贤; 刘强; 何曦
Original assignee: Aerospace Kaitian Environmental Technology Co Ltd
Current assignee: Aerospace Kaitian Environmental Technology Co Ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2021-08-13
Anticipated expiration: 2038-09-28
Also published as: CN109126773A

Abstract

The invention discloses a catalyst for purifying waste incineration flue gas, which takes vanadium pentoxide, platinum oxide and tungsten oxide as active components, gamma-alumina, titanium dioxide and carbon nano tubes as carriers and one or more of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide as active auxiliaries. The catalyst of the invention not only has the function of decomposing dioxin and chlorobenzene compounds, but also has the functions of denitration and sulfur resistance, and has excellent removal capability on dioxin and NOx at lower temperature. The invention also discloses a preparation method of the catalyst for purifying the waste incineration flue gas, and the preparation method has the advantages of simple operation, convenience and controllability and suitability for large-scale industrial production.

Description

Catalyst for purifying waste incineration flue gas and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of exhaust gas purification catalysts, and particularly relates to a catalyst for purifying waste incineration flue gas and a preparation method thereof.

Background

Along with the improvement of living standard of people, more and more domestic garbage is generated. The domestic garbage has large output, complex and various components, pollution, resource and social properties, needs harmless, resource and reduction treatment, and can pollute the environment, influence the environmental sanitation, waste resources and destroy the safety of production and life and the social harmony if the domestic garbage cannot be properly treated. At present, common household garbage disposal methods mainly comprise a sanitary landfill method, a high-temperature composting method, an incineration method and the like. Compared with the former two technologies, the incineration method is a relatively good treatment mode, the volume of the garbage treated by the incineration method can be reduced by 80-90%, the garbage is convenient to be buried in a follow-up mode, the land is saved, various pathogens can be eliminated, and toxic and harmful substances can be converted into harmless substances to a certain extent.

Incineration is increasingly used as an effective volume and weight reduction waste disposal means. However, the waste inevitably produces secondary pollution in the incineration process, especially dioxin, a highly toxic organic pollutant which has great harm to the environment. The lethal toxicity of dioxins and their possible long-term effects on humans have attracted widespread attention both at home and abroad. Along with the more strict domestic waste incineration flue gas emission standard of China, people begin to continuously explore dioxin disposal technologies with low pollution and operation cost saving. At present, the engineering mainly adopts active carbon to absorb dioxin in the flue gas of a garbage incinerator, and a flow-carrying type removing method of spraying active carbon powder into the flue gas and combining the active carbon powder with a cloth bag for dust removal is a widely used flue gas dioxin end treatment method due to the advantages of low investment, simple structure and high removing efficiency. However, the dioxin in the flue gas is adsorbed by the activated carbon and is only transferred to the activated carbon from the flue gas, the total amount of the dioxin is not reduced, and the activated carbon adsorbing the dioxin is dangerous waste and needs to be sent to a qualified dangerous waste treatment plant for treatment so as to prevent the dioxin from escaping. Therefore, how to effectively decompose dioxin becomes a hotspot in the field of environmental protection. The flue gas also contains chlorobenzene compounds which have the common characteristics that: long-term residual, bioaccumulative, semi-volatile, and highly toxic, leading to serious diseases such as endocrine disruption, reproductive and immune dysfunction, developmental disorders, and cancer in the body. Ortho-dichlorobenzene is considered a suspected carcinogen by the international agency for cancer research. Hexachlorobenzene belongs to one of 12 persistent organic pollutants which need to be eliminated preferentially from the first stocked in the stockholm convention on persistent organic pollutants, and chlorobenzene compounds are important precursors for generating highly toxic substances, namely dioxins (PCDD/Fs). At present, catalytic oxidation (SCO) technology is adopted to treat dioxin and chlorobenzene compounds abroad, and the dioxin and chlorobenzene compounds can be decomposed into HCl and CO₂、H₂O、SO₂Etc., and thus the heart of SCO technology is the catalyst.

The waste incineration flue gas contains oxynitride (NOx) besides dioxin and chlorobenzene compounds, and the oxynitride is an important reason for forming photochemical smog and acid rain. The technology commonly used for treating the flue gas NOx at present is a Selective Catalytic Reduction (SCR) denitration technology, and the core of the SCR technology is still a catalyst. Therefore, it is urgently needed to develop a catalyst suitable for purifying waste incineration flue gas.

Disclosure of Invention

The present application is directed to solving at least one of the problems in the prior art. Therefore, an object of the present invention is to provide a catalyst for purifying waste incineration flue gas, which has an effect of decomposing dioxin and chlorobenzene compounds, an effect of denitration and sulfur resistance, and an excellent capability of removing dioxin and NOx at a lower temperature, and a method for preparing the same. The preparation method of the catalyst has the advantages of wide source of raw materials, low cost, simple operation, convenience and controllability, and suitability for large-scale industrial production.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a catalyst for purifying waste incineration flue gas takes vanadium pentoxide, platinum oxide and tungsten oxide as active components, gamma-alumina, titanium dioxide and carbon nano tubes as carriers and one or more of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide as active auxiliaries.

Furthermore, a mixture of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide is used as a promoter.

Furthermore, based on the total weight of the carrier, the loading amount of vanadium in the active component is 0.5-3 wt%, the loading amount of platinum is 0.2-2 wt%, and the loading amount of tungsten is 0.5-3 wt%.

Furthermore, the loading amount of the active assistant is 0.5-1 wt% based on the total weight of the carrier.

According to the catalyst for purifying the waste incineration flue gas, the carrier contains 20-30 wt% of gamma-alumina, 40-50 wt% of titanium dioxide and 20-30 wt% of carbon nano tubes.

A preparation method of a catalyst for purifying waste incineration flue gas comprises the following steps:

step 1, adding glacial acetic acid and absolute ethyl alcohol into deionized water, and uniformly stirring and mixing to obtain a solution A;

step 2, dissolving tetrabutyl titanate or titanium alkoxide in absolute ethyl alcohol, and uniformly stirring to obtain a solution B;

step 3, mixing the solution A and the solution B to obtain a solution C, and adding ammonium metavanadate, dinitrosoplatinum and oxalic acid into the solution C under a stirring state to obtain a solution D;

step 4, adding gamma-alumina powder and carbon nano tubes into the solution D under the stirring state to obtain a solution E;

step 5, adding sodium tungstate and the active auxiliary agent precursor into the solution E under the stirring state to obtain sol, and standing the sol to obtain gel;

step 6, putting the gel into an oven, grinding and sieving after water is evaporated to dryness to obtain a semi-finished catalyst;

and 7, calcining the catalyst semi-finished product to obtain a finished catalyst.

Further, the calcination process parameters in step 7 are as follows: raising the temperature from room temperature to 280-320 ℃ at the temperature raising rate of 4-6 ℃/min, keeping the temperature for 0.5-1.5h, then raising the temperature to 500-600 ℃ at the temperature raising rate of 8-12 ℃/min, calcining for 3-5h, and then reducing the temperature to room temperature.

Further, the temperature of the oven in the step 6 is set to be 100-.

Further, in step 5, the precursor of the coagent is selected from manganese nitrate tetrahydrate, ferric nitrate, cupric nitrate, tin oxide and cerium nitrate.

Further, the standing time in the step 5 is 8-16 h.

Further, adding gamma-alumina powder into the solution D under the stirring state, stirring for 1-2 h, then continuously adding carbon nanotubes under the stirring state, and stirring for 1-2 h to obtain a solution E.

Compared with the prior art, the invention has the beneficial effects that:

the invention has the following effects:

1. whether dioxin, chlorobenzene or nitroxide catalyzed degradation, involves two major steps, adsorption and degradation. The composite catalyst is prepared by combining an active component with good catalytic activity and a carrier with excellent adsorption capacity, the catalytic degradation energy of the active component and the adsorption characteristic of the carrier are cooperatively exerted, the capture energy of organic pollutants is enhanced, and the catalytic activity under the low-temperature condition is improved. The addition of another metal oxide as a promoter to a metal oxide catalyst to make the active component of the catalyst multi-valent is one of the main measures for improving the activity of the catalyst.

In conclusion of the mechanism of the catalytic reaction, Pt and V are selected as active components, wherein the noble metal Pt has the advantages of high excellent catalytic activity, and the transition metal V is selected to have low price and strong chlorine poisoning resistance; the addition of W can improve the activity and selectivity of the catalyst, improve the electronic action between the carrier and the active component and enlarge the reaction temperature window of the catalyst.

The activity and stability of the catalyst are determined by active components, the carrier plays a role in the activity and stability of the catalyst irrespectively by influencing the dispersity of the active components on the surface of the carrier and the synergistic effect between the carrier and the active components, and the adsorption capacity of the catalyst is improved and the activity of the catalyst is further improved by utilizing the characteristics of larger specific surface areas of alumina and titanium dioxide materials and the addition of carbon nano tubes with large specific surface areas and large pore diameters. The interaction between the carbon nano tube and dioxin molecules is strong, and the chemical energy required by desorption of dioxin from the carbon nano tube is 315kJ/mol, which is 3 times of the chemical energy required by desorption from the surface of activated carbon.

2、TiO₂As a carrier, on the one hand, the active component V can be increased₂O₅The dispersity on the surface of the catalyst is beneficial to improving the activity of the catalyst; TiO 2₂With SO₂The reaction is weak, the generated sulfate is reversible and the reaction is stableThe regeneration is easy, and the small amount of sulfate can increase the surface acidity of reagent, which is also beneficial to improving the activity of reagent.

3. The catalyst not only has the function of decomposing dioxin chlorobenzene compounds, but also has the functions of denitration and sulfur resistance due to a catalytic system formed by the main active component V-Pt-W and the metal auxiliary agent Mn-Fe-Cu-Sn-Ce, and Ce is added₂O can improve the oxygen storage performance of the catalyst and improve the activity of the catalyst.

4. The preparation method of the catalyst has the advantages of wide source of raw materials, common industrial chemical raw materials of carriers such as gamma-alumina and the like, auxiliary components such as manganese oxide and the like and active components such as vanadium and the like in the components of the catalyst, convenient purchase and low price, adopts an impregnation method in the preparation method of the catalyst, is simple to operate, has low requirement on equipment, is convenient and controllable, does not generate secondary pollution in the preparation process, and is suitable for large-scale industrial production.

Detailed Description

The present invention will be further described with reference to specific embodiments.

The invention provides a catalyst for purifying waste incineration flue gas, which takes vanadium pentoxide, platinum oxide and tungsten oxide as active components, gamma-alumina, titanium dioxide and carbon nano tubes as carriers and one or more of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide as active auxiliaries; based on the total weight of the carrier, the loading amount of vanadium in the active component is 0.5-3 wt%, the loading amount of platinum is 0.2-2 wt%, the loading amount of tungsten is 0.5-3 wt%, the loading amount of the active additive is 0.5-1 wt%, the proportion of gamma-alumina in the carrier is 20-30 wt%, the proportion of titanium dioxide is 40-50 wt%, and the proportion of the carbon nano tube is 20-30 wt%.

In the technical scheme, vanadium pentoxide, platinum oxide and tungsten oxide are used as active components, one or more of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide are used as active auxiliaries, gamma-alumina, titanium dioxide and carbon nano tubes are used as carriers, so that the catalyst has good effects on decomposition of dioxin and chlorobenzene compounds, sulfur resistance and denitration, can remove dioxin, chlorobenzene compounds, sulfur and nitrate in flue gas, and can be widely applied to catalytic purification of flue gas of a garbage incinerator.

The invention provides a preparation method of a catalyst for purifying waste incineration flue gas, which comprises the following steps:

calculating and weighing corresponding precursors according to the amounts of the active components and the active auxiliary agents, wherein: the active component precursor is ammonium metavanadate, dinitroso diammine platinum and sodium tungstate; the active assistant precursor is manganese nitrate tetrahydrate, ferric nitrate, copper nitrate, tin oxide and cerium nitrate; the precursor of the carrier titanium dioxide is tetrabutyl titanate or titanium alkoxide;

The calcination process parameters in the step 7 are as follows: raising the temperature from room temperature to 280-320 ℃ at the temperature raising rate of 4-6 ℃/min, keeping the temperature for 0.5-1.5h, then raising the temperature to 500-600 ℃ at the temperature raising rate of 8-12 ℃/min, calcining for 3-5h, and then reducing the temperature to room temperature.

In the step 6, the temperature of the oven is set to be 100-.

And adding gamma-alumina powder into the solution D under the stirring state, stirring for 1-2 h, then continuously adding the carbon nano tubes under the stirring state, and stirring for 1-2 h to obtain a solution E.

The catalyst prepared by the technical scheme has good effects on decomposition of dioxin and chlorobenzene compounds and sulfur and denitration resistance, can remove the dioxin, the chlorobenzene compounds, sulfur and nitrate in flue gas, and can be widely applied to catalytic purification of the flue gas of a waste incinerator.

Example 1

A catalyst for purifying waste incineration flue gas takes vanadium pentoxide, platinum oxide and tungsten oxide as active components, gamma-alumina, titanium dioxide and carbon nano tubes as carriers, and a mixture of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide as an active auxiliary agent;

wherein the proportion of gamma-alumina in the carrier is 20 wt%, the proportion of titanium dioxide is 50 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 1.5 wt%, the loading amount of platinum is 0.5 wt%, and the loading amount of tungsten is 2 wt%; the loading of the coagent was 0.5 wt%.

Calculating and weighing corresponding precursor materials of ammonium metavanadate, dinitroso diammine platinum, sodium tungstate, tetrabutyl titanate (or titanium alkoxide), manganese nitrate tetrahydrate, ferric nitrate, copper nitrate, tin oxide and cerium nitrate according to the amount of vanadium pentoxide, platinum oxide, tungsten oxide, titanium dioxide, manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide, adding glacial acetic acid and absolute ethyl alcohol into deionized water, stirring uniformly to obtain a solution A; dissolving tetrabutyl titanate or titanium alkoxide in absolute ethyl alcohol, and uniformly stirring to obtain a solution B; mixing the solution A and the solution B, stirring for 1h to obtain a solution C, adding ammonium metavanadate, dinitrosoplatinum and oxalic acid into the solution C under the stirring state, and stirring for 2h to obtain a solution D; adding gamma-alumina powder into the solution D under the stirring state, stirring for 2 hours, then continuously adding the carbon nano tubes under the stirring state, and stirring for 1 hour to obtain a solution E; adding sodium tungstate and the active auxiliary agent precursor into the solution E under the stirring state to obtain sol, and standing the sol for 8 hours to obtain gel; placing the gel in an oven, setting the temperature of the oven to be 110 ℃, taking out the gel after the moisture is evaporated to dryness, grinding the gel, and sieving the gel with a 60-mesh sieve to obtain a semi-finished catalyst product; and placing the obtained semi-finished catalyst in a muffle furnace for calcination, setting a temperature rise program to be 5 ℃/min to 300 ℃, keeping for 1h, then raising to 550 ℃ at 10 ℃/min, calcining for 4h, then cooling to room temperature, and taking out to obtain a powdery finished catalyst.

The catalyst prepared in the example 1 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 200 ℃. The experimental results show that: the dioxin removal rate is 99.5%, the chlorobenzene removal rate is 98.9%, and the denitration rate is 97.6%, and after 24h, the dioxin removal rate, the chlorobenzene removal rate and the denitration rate are respectively 98.6%, 98.1% and 95.1%. The experiment results show that the catalyst of the embodiment has high efficiency and good stability, and can effectively remove harmful substances such as dioxin, chlorobenzene, nitrate and the like in waste incineration flue gas.

Example 2

wherein the proportion of gamma-alumina in the carrier is 30 wt%, the proportion of titanium dioxide is 40 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 1.5 wt%, the loading amount of platinum is 0.5 wt%, and the loading amount of tungsten is 2 wt%; the loading of the coagent was 0.5 wt%.

Calculating and weighing corresponding precursor materials of ammonium metavanadate, dinitroso diammine platinum, sodium tungstate, tetrabutyl titanate (or titanium alkoxide), manganese nitrate tetrahydrate, ferric nitrate, copper nitrate, tin oxide and cerium nitrate according to the amount of vanadium pentoxide, platinum oxide, tungsten oxide, titanium dioxide, manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide, adding glacial acetic acid and absolute ethyl alcohol into deionized water, stirring uniformly to obtain a solution A; dissolving tetrabutyl titanate or titanium alkoxide in absolute ethyl alcohol, and uniformly stirring to obtain a solution B; mixing the solution A and the solution B, stirring for 2 hours to obtain a solution C, adding ammonium metavanadate, dinitrosoplatinum and oxalic acid into the solution C under the stirring state, and stirring for 1 hour to obtain a solution D; adding gamma-alumina powder into the solution D under the stirring state, stirring for 2h, then continuously adding the carbon nano tubes under the stirring state, and stirring for 2h to obtain a solution E; adding sodium tungstate and the active auxiliary agent precursor into the solution E under the stirring state to obtain sol, and standing the sol for 10 hours to obtain gel; placing the gel in an oven, setting the temperature of the oven to be 100 ℃, taking out the gel after the moisture is evaporated to dryness, grinding the gel, and sieving the gel with a 80-mesh sieve to obtain a semi-finished catalyst product; and placing the obtained semi-finished catalyst in a muffle furnace for calcination, setting a temperature rise program to be 4 ℃/min to rise to 280 ℃, keeping for 1.5h, then rising to 600 ℃ at 8 ℃/min, calcining for 3h, then cooling to room temperature, and taking out to obtain a powdery finished catalyst.

The catalyst prepared in the embodiment 2 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 190 ℃. The experimental results show that: the dioxin removal rate is 99.3%, the chlorobenzene removal rate is 99.1%, and the denitration rate is 98.7%, and after 24h, the dioxin removal rate, the chlorobenzene removal rate, and the denitration rate are respectively 98.2%, 98.3%, and 96.2%. The experiment results show that the catalyst of the embodiment has high efficiency and good stability, and can effectively remove harmful substances such as dioxin, chlorobenzene, nitrate and the like in waste incineration flue gas.

Example 3

wherein the proportion of gamma-alumina in the carrier is 30 wt%, the proportion of titanium dioxide is 40 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 0.2 wt%, the loading amount of platinum is 0.1 wt%, and the loading amount of tungsten is 0.2 wt%; the loading of the coagent was 0.2 wt%.

Calculating and weighing corresponding precursor materials of ammonium metavanadate, dinitroso diammine platinum, sodium tungstate, tetrabutyl titanate (or titanium alkoxide), manganese nitrate tetrahydrate, ferric nitrate, copper nitrate, tin oxide and cerium nitrate according to the amount of vanadium pentoxide, platinum oxide, tungsten oxide, titanium dioxide, manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide, adding glacial acetic acid and absolute ethyl alcohol into deionized water, stirring uniformly to obtain a solution A; dissolving tetrabutyl titanate or titanium alkoxide in absolute ethyl alcohol, and uniformly stirring to obtain a solution B; mixing the solution A and the solution B, stirring for 2 hours to obtain a solution C, adding ammonium metavanadate, dinitrosoplatinum and oxalic acid into the solution C under the stirring state, and stirring for 1 hour to obtain a solution D; adding gamma-alumina powder into the solution D under the stirring state, stirring for 2h, then continuously adding the carbon nano tubes under the stirring state, and stirring for 2h to obtain a solution E; adding sodium tungstate and the active auxiliary agent precursor into the solution E under the stirring state to obtain sol, and standing the sol for 10 hours to obtain gel; placing the gel in an oven, setting the temperature of the oven to be 100 ℃, taking out the gel after the moisture is evaporated to dryness, grinding the gel, and sieving the gel with a 80-mesh sieve to obtain a semi-finished catalyst product; and placing the obtained semi-finished catalyst in a muffle furnace for calcination, setting a temperature rise program to be 5 ℃/min to 300 ℃, keeping for 1.5h, then raising to 600 ℃ at 8 ℃/min, calcining for 4h, then cooling to room temperature, and taking out to obtain a powdery finished catalyst.

The catalyst prepared in the example 3 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 250 ℃. The experimental results show that: the dioxin removal rate was 76.3%, the chlorobenzene removal rate was 75.7%, and the denitration rate was 81.2%, and after 24 hours, the dioxin removal rate, the chlorobenzene removal rate, and the denitration rate were 75.3%, 72.1%, and 79.3%, respectively.

Example 4, example 5, example 6 are similar to example 3, except that:

the catalyst of example 4 comprises the following components: the proportion of gamma-alumina in the carrier is 30 wt%, the proportion of titanium dioxide is 40 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 0.5 wt%, the loading amount of platinum is 0.2 wt%, and the loading amount of tungsten is 0.5 wt%; the loading of the coagent was 0.5 wt%.

The catalyst prepared in the example 4 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 200 ℃. The experimental results show that: the dioxin removal rate is 94.1%, the chlorobenzene removal rate is 96.3%, and the denitration rate is 97.2%, and after 24h, the dioxin removal rate, the chlorobenzene removal rate and the denitration rate are respectively 95.1%, 95.7% and 96.9%.

The catalyst formulation of example 5 was as follows: the proportion of gamma-alumina in the carrier is 30 wt%, the proportion of titanium dioxide is 40 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 2.5 wt%, the loading amount of platinum is 1.5 wt%, and the loading amount of tungsten is 2.5 wt%; the loading of the coagent was 1 wt%.

The catalyst prepared in the example 5 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 220 ℃. The experimental results show that: the dioxin removal rate is 99.1%, the chlorobenzene removal rate is 98.7%, and the denitration rate is 98.1%, and after 24h, the dioxin removal rate, the chlorobenzene removal rate and the denitration rate are respectively 98.1%, 97.9% and 97.1%.

The catalyst formulation for example 6 was as follows: the proportion of gamma-alumina in the carrier is 30 wt%, the proportion of titanium dioxide is 40 wt%, the proportion of carbon nano tube is 30 wt%, and based on the total weight of the carrier, the loading amount of vanadium in the active component is 3.5 wt%, the loading amount of platinum is 2.5 wt%, and the loading amount of tungsten is 3.5 wt%; the loading of coagent was 2.5 wt%.

The catalyst prepared in the example 6 is applied to purification and catalysis of waste incineration flue gas, and the temperature of the flue gas is maintained at 250 ℃. The experimental results show that: the dioxin removal rate is 90.1%, the chlorobenzene removal rate is 90.5%, and the denitration rate is 92.1%, after 24h, the dioxin removal rate, the chlorobenzene removal rate, and the denitration rate are respectively 87.8%, 87.6%, and 88.3%.

The experimental results show that the catalyst of the embodiment has high efficiency and good stability, can effectively remove harmful substances such as dioxin, chlorobenzene, nitrate and the like in waste incineration flue gas, can also show that the change of the proportion of the catalyst has important influence on the catalytic performance through the embodiments 1-6, and can achieve a dioxin removal rate, a chlorobenzene removal rate and a denitration rate of over 95 percent after 24 hours under the synergistic effect of a carrier, an active component and an active auxiliary agent which are proper components.

The above examples are merely illustrative for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Nor is it intended to be exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims

1. A catalyst for purifying waste incineration flue gas is characterized in that: the catalyst takes vanadium pentoxide, platinum oxide and tungsten oxide as active components, gamma-alumina, titanium dioxide and carbon nano tubes as carriers, and a mixture of manganese oxide, iron oxide, copper oxide, tin oxide and cerium oxide as an active auxiliary agent;

based on the total weight of the carrier, the loading capacity of vanadium in the active component is 0.5-3 wt%, the loading capacity of platinum is 0.2-2 wt%, the loading capacity of tungsten is 0.5-3 wt%, and the loading capacity of the active additive is 0.5-1 wt%;

the carrier comprises 20-30 wt% of gamma-alumina, 40-50 wt% of titanium dioxide and 20-30 wt% of carbon nano tubes.

2. The preparation method of the catalyst for purifying waste incineration flue gas, according to claim 1, is characterized by comprising the following steps:

3. The method of claim 2, wherein: the calcination process parameters in the step 7 are as follows: raising the temperature from room temperature to 280-320 ℃ at the temperature raising rate of 4-6 ℃/min, keeping the temperature for 0.5-1.5h, then raising the temperature to 500-600 ℃ at the temperature raising rate of 8-12 ℃/min, calcining for 3-5h, and then reducing the temperature to room temperature.

4. The method of claim 2, wherein: in the step 6, the temperature of the oven is set to be 100-.

5. The method of claim 2, wherein: in the step 5, the precursor of the active auxiliary agent is selected from manganese nitrate tetrahydrate, ferric nitrate, copper nitrate, tin oxide and cerium nitrate.

6. The method of claim 2, wherein: and 5, standing for 8-16 h.

7. The method of claim 2, wherein: the specific steps of the step 4 are as follows: and adding gamma-alumina powder into the solution D under the stirring state, stirring for 1-2 h, then continuously adding the carbon nano tubes under the stirring state, and stirring for 1-2 h to obtain a solution E.