Catalyst for dealkylation in chlorine-containing environment as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for dealkylation in a chlorine-containing environment as well as a preparation method and application of the catalyst, and belongs to the technical field of catalyst reaction. The catalyst comprises a carrier and an active component, wherein the carrier comprises ZrO2 and MgFeO4; the active component comprises an auxiliary agent and a noble metal component, the auxiliary agent comprises a V2O5-WO3 composite oxide and a CeO2-MnO2 composite oxide, and the noble metal component comprises at least three of rhodium, ruthenium, platinum, palladium and gold. The noble metal components grow in mesopores of the carrier in a confined manner, and the auxiliaries with dechlorination and catalytic oxidation functions are uniformly distributed on the surface of the carrier, so that a two-step catalytic strategy of dechlorination and oxidation of chlorine-containing waste gas is realized, the poisoning phenomenon of the catalyst is effectively avoided, and an excellent catalytic effect is formed. Moreover, the catalyst is stable in property, still keeps an excellent catalytic function after being used for a long time, and is higher in practicability and better in economical efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst reactions, and particularly relates to a catalyst for hydrocarbon removal in a chlorine-containing environment, a preparation method thereof, and an application thereof. Background Art

[0002] Epichlorohydrin is a widely used basic organic chemical raw material and also the main raw material for synthesizing products such as epoxy resin and chlorohydrin rubber, occupying an important position in the national economy. The industrial production methods of epichlorohydrin are mainly the chlorohydrin method and the allyl alcohol method. During the production of epichlorohydrin, a large amount of waste gas is generated, including acrolein, epichlorohydrin, hydrogen chloride, monochloromethane, ethylene oxide, chlorobenzene, and other impurities. These waste gases have an irritating effect on the respiratory tract and mucous membranes, and damage the ozone and pollute the environment, not meeting the environmental protection requirements, and need to be purified.

[0003] The existing waste gas purification methods for organic substances mainly include the UV photolysis method, the activated carbon adsorption method, and the catalytic oxidation method. The UV photolysis method uses high-energy ultraviolet light to decompose organic substances into carbon dioxide and water, but the equipment cost is expensive and the usage cost is extremely high, which is not suitable for large-scale industrial applications.

[0004] The adsorption capacity of activated carbon is limited. In practice, it is often difficult to effectively remove waste gas even with a large amount of activated carbon, resulting in high usage costs; and as a broad-spectrum adsorbent, the adsorption capacity of activated carbon for specific compounds is limited; there is also a risk of secondary pollution.

[0005] The catalytic oxidation method is technically mature and widely used. It can achieve complete purification of VOCs gas at a relatively low temperature and there is no problem of secondary pollution. It is an effective purification means with high purification efficiency and wide application range. However, the existing catalysts generally have a general catalytic oxidation effect on chlorine-containing organic waste gas. The reason is that chlorine elements have a strong adsorption effect with the active metals on the catalyst surface during the catalytic process, forming stable metal chlorides or oxychlorides. These compounds cover the active sites of the catalyst, making it impossible for the catalyst surface to effectively adsorb and activate VOCs gas. That is, noble metal catalysts lose their redox ability due to the strong adsorption of chlorine in a chlorine-containing environment and are difficult to restore their activity through conventional regeneration means, which is commonly known as "catalyst poisoning". Catalyst poisoning makes it difficult to decompose and treat chlorine-containing organic waste gas by the catalytic oxidation method, and the costs of other methods are too high, becoming a difficult problem in environmental protection tail gas treatment. Summary of the Invention

[0006] In view of this, the purpose of the embodiments of the present application is to provide a catalyst for hydrocarbon removal in a chlorine-containing environment, its preparation method and application, so as to solve the problem in the prior art that when catalytically oxidizing chlorine-containing organic waste gas, the catalyst is prone to poisoning, losing or partially losing its catalytic ability, resulting in poor catalytic effect. Moreover, the catalyst provided by the embodiments of the present application has strong regeneration ability, can be regenerated through simple operations, and the catalytic effect of the catalyst will not be damaged after multiple uses after regeneration, with stronger practicability and better economy. The preparation method of the catalyst provided by the embodiments of the present application is simple, environmentally friendly, easy to operate and suitable for industrial application.

[0007] The embodiments of the present application are implemented as follows: A catalyst for hydrocarbon removal in a chlorine-containing environment, comprising a carrier and an active component: The carrier includes ZrO2 and MgFeO4; The active component includes a promoter and a noble metal component. The promoter includes a V2O5-WO3 composite oxide and a CeO2-MnO2 composite oxide, and the noble metal component includes at least three of rhodium, ruthenium, platinum, palladium, and gold.

[0008] Preferably, the mass percentage of the active component in the catalyst is 10-50%.

[0009] Preferably, the molar ratio of Zr, Mg, and Fe in the carrier is 1:0.5:1.

[0010] Preferably, the molar ratio of vanadium to tungsten in the active component is (2.5-3.5):1, the molar ratio of cerium to manganese is 1:(1.5-2.5), and the molar ratio of tungsten to cerium is 1:1.

[0011] The present application also provides a method for preparing the above-mentioned catalyst for hydrocarbon removal in a chlorine-containing environment, comprising the following steps: S1. Prepare a carrier with a large number of mesopores on its surface; S2. Immerse the carrier in a noble metal solution, evaporate in vacuum, dry and calcine to make noble metal ions distributed in the mesopores of the carrier, obtaining a semi-finished product; S3. Immerse the semi-finished product in a mixed solution of vanadium and tungsten, dry and calcine; then immerse it in a mixed solution of manganese and cerium, dry and calcine to obtain the finished catalyst.

[0012] Preferably, step S1 includes the following steps: S11. Dissolve zirconium salt solution, magnesium nitrate solution, iron nitrate solution and cetyltrimethylammonium bromide in ethanol and stir evenly; S12. Add ammonia water to adjust the pH value to 8-10, then raise the temperature to 40-60 °C and add ethylene glycol, and carry out a hydrolysis reaction for 2-4 h to obtain a wet gel; S13. The wet gel is cured at room temperature for 24 - 48 h, then washed and vacuum dried at 80 - 100 °C for 12 - 24 h; S14. It is calcined at 300 - 400 °C for 2 - 4 h, and then the temperature is raised to 550 - 700 °C and calcined for 4 - 6 h.

[0013] Preferably, in step S2, the noble metal solution includes at least three of rhodium solution, ruthenium solution, platinum solution, palladium solution, and gold solution, vacuum evaporated for 4 h, vacuum dried for more than 24 h, and calcined at 600 °C for 5 h in a nitrogen atmosphere.

[0014] Preferably, in step S3, the soaking is at room temperature; the drying temperature is 80 - 100 °C and the time is more than 8 h; the calcination temperature in a nitrogen atmosphere is 600 °C and the time is 5 h.

[0015] The present application also provides the use of the above - mentioned catalyst for dehydrocarbonization in a chlorine - containing environment or the catalyst prepared by the above - mentioned method in removing chlorine - containing organic compounds and organic compounds.

[0016] Preferably, the chlorine - containing organic compound includes at least one of epichlorohydrin and monochloromethane, and the organic compound includes at least one of acrolein and ethylene oxide.

[0017] Compared with the prior art, the beneficial effects of the present application are: 1. The catalyst for dehydrocarbonization in a chlorine - containing environment provided by the present application uses a carrier material with a large number of mesopores on the surface; the large number of mesopores on the surface increases the specific surface area in contact with organic gas and chlorine - containing organic gas, providing more active sites; and the unique carrier material formula, ZrO2 can resist the corrosion of chloride ions by virtue of its high thermal stability and acid resistance, and helps the carrier maintain a stable structure at high temperatures. The spinel structure of MgFeO4 provides basic sites, which can neutralize the acidic by - product HCl caused by chloride ions. It reduces the poisoning of chloride ions on noble metal components, etc., and improves the catalytic oxidation effect of hydrocarbon - containing gas in a chlorine - containing environment; and the carrier structure is stable, can be used for a long time without collapsing or caving in, and continuously maintains excellent catalytic effect.

[0018] 2. The catalyst for hydrocarbon removal in a chlorine-containing environment provided by this application has the promoter in the active component evenly distributed on the surface of the carrier through the normal-temperature impregnation method, while the noble metal component is distributed in the mesopores of the carrier. This design can effectively decompose and remove chloride ions, reduce the interference of chloride ions on the noble metal, and achieve continuous and effective catalytic performance. The principle is that WO3 in the promoter can preferentially adsorb chlorine-containing organic compounds, reducing the entry of chloride ions into the mesopores and their contact with the noble metal component, and reducing the adsorption of chlorine-containing organic compounds by other active components. The lattice oxygen of V2O5 can accelerate the cleavage of the C-Cl bond, and the multivalent vanadium-tungsten oxides can promote the redox reaction during the catalysis process, and a large amount of chloride ions generated are reduced to chlorine gas. During the redox process, cerium, as an oxygen storage material, provides active oxygen and improves the oxygen migration ability, while manganese ions promote the formation of oxygen vacancies, enhance the oxidation kinetics of chloride ions, and promote the process of reducing chloride ions to chlorine gas, reducing the occurrence of noble metal component chlorine poisoning. Moreover, the high electron mobility of manganese ions accelerates the deep oxidation process of intermediate products, effectively reducing the generation of dioxins. The combined use of the main phase and the secondary phase of the promoter, with the elements synergistically acting on each other, basically removes and decomposes chloride ions, greatly reducing the occurrence of chlorine poisoning and effectively improving the oxidation effect on organic gas. Detailed implementation mode

[0019] To make the purpose, technical solution and advantages of this application clearer and more understandable, the following combines examples to further elaborate on this application. The illustrative implementation mode of this application and its description are only used to explain this application and do not limit this application. Any product that is the same as or similar to this application obtained by anyone under the inspiration of this application or by combining the features of this application with other existing technologies falls within the protection scope of this application.

[0020] For the specific experimental steps or conditions not specified in the examples, the operations or conditions of the conventional experimental steps described in the existing technologies in this field can be followed. For the reagents and other instruments not indicating the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0021] The embodiment of this application provides a catalyst for hydrocarbon removal in a chlorine-containing environment, which includes a carrier and an active component. The active component includes a promoter and a noble metal component. The mass percentage of the active component in the catalyst is preferably 10-50%, more preferably 15-25%. In the active component, the mass ratio of the promoter to the noble metal component is preferably (2-4):1, more preferably 2.5:1.

[0022] The carrier is a porous metal composite material, and its main component is ZrO2-MgFeO4 composite oxide; in ZrO2-MgFeO4, the molar ratio of Zr, Mg and Fe is preferably 1:0.5:1.

[0023] This carrier has a large number of mesopores, endowing it with a large specific surface area. Based on the structural design of this carrier, the noble metal components for catalyzing the oxidation of hydrocarbon-containing waste gas are confined to grow within the pores of the metal composite material, while the additives with dechlorination and catalytic oxidation functions are uniformly distributed on the surface and within the mesopores of the carrier, realizing a two-step catalytic strategy of first dechlorinating and then oxidizing the chlorine-containing waste gas, effectively avoiding the occurrence of catalyst poisoning and forming an excellent catalytic effect.

[0024] The additives include a main phase and a secondary phase. The main phase is specifically a vanadium-tungsten bimetallic oxide, namely a V2O5-WO3 nanocluster, where the molar ratio of vanadium to tungsten is preferably (2.5 - 3.5):1. The secondary phase is specifically a cerium-manganese composite oxide, namely a CeO2-MnO2 nanocluster, where the molar ratio of cerium to manganese is preferably 1:(1.5 - 2.5). Additionally, the molar ratio of tungsten to cerium is preferably 1:1.

[0025] The noble metal components include any three or more of rhodium, ruthenium, platinum, palladium, and gold. As an active single substance, the noble metal components can effectively catalyze hydrocarbon-containing organic gas, oxidize and decompose it into carbon dioxide and water, and achieve the effect of purifying the tail gas. Moreover, the noble metal has a long history as the active component of the catalyst, and technologies such as use, regeneration, and recycling are mature and convenient to use.

[0026] Since the bond energy of the C-Cl bond is lower than that of the C-H bond, during the catalytic oxidation process, the C-Cl bond breaks preferentially over the C-H bond and generates free Cl ions. When the chlorine-containing gas contacts the catalyst, it first contacts the outer carrier ZrO2-MgFeO4 and the additives distributed on the surface of the carrier. ZrO2 can resist the corrosion of chloride ions due to its high thermal stability and acid resistance, and helps the carrier maintain a stable structure at high temperatures. The spinel structure of MgFeO4 provides basic sites that can neutralize the acidic by-product HCl caused by chloride ions. This reduces the poisoning of the noble metal components and other substances by chloride ions and improves the catalytic oxidation effect of hydrocarbon gases in a chlorine-containing environment.

[0027] After the chlorine-containing waste gas comes into contact with the auxiliary agent, based on the Lewis acid-base theory, WO3 can preferentially adsorb chlorine-containing organic compounds, reducing the entry of chloride ions into the mesopores and their contact with the noble metal components, and decreasing the adsorption of chlorine-containing organic compounds by other active components; while the lattice oxygen of V2O5 can accelerate the cleavage of the C-Cl bond, and the multivalent vanadium-tungsten oxides can promote the redox reaction during the catalytic process, and a large amount of chloride ions generated are reduced to chlorine gas. During the redox process, cerium, as an oxygen storage material, provides active oxygen and improves the oxygen migration ability, while manganese ions promote the formation of oxygen vacancies, enhance the oxidation kinetics of chloride ions, and promote the process of reducing chloride ions to chlorine gas, reducing the occurrence of noble metal component chlorine poisoning. Moreover, the high electron mobility of manganese ions accelerates the deep oxidation process of intermediate products, effectively reducing the formation of dioxins. The combined use of the main phase and the secondary phase, with the elements synergistically interacting, basically removes and decomposes chloride ions, greatly reducing the occurrence of chlorine poisoning and effectively improving the oxidation effect on organic gas.

[0028] The noble metal components located deep inside the mesopores of the carrier have less contact with chloride ions and can achieve a sufficient catalytic oxidation effect on hydrocarbon-containing organic gases.

[0029] The catalyst provided by this application has passed the pilot test of catalytic oxidation of epichlorohydrin tail gas. The tail gas is detected to include the following components: acrolein, epichlorohydrin, chloromethane, ethylene oxide and other impurities, and the qualified rate of tail gas purification reaches 100%. Its structure is stable, with the advantages of both chlorine poisoning resistance and high-efficiency oxidation, and the actual use effect is excellent.

[0030] This application also provides a preparation method of the above-mentioned catalyst for hydrocarbon removal in a chlorine-containing environment, including the following steps.

[0031] First, prepare the carrier: S11. Take materials according to the molar ratio, dissolve 1 part of zirconium salt solution, 0.5 part of magnesium nitrate solution, 1 part of iron nitrate solution and 1.25 - 2.5 parts of cetyltrimethylammonium bromide in an appropriate amount of ethanol, and stir evenly to obtain a mixed solution; the zirconium salt solution is preferably one or more of zirconium nitrate, zirconium chloride or zirconium oxychloride. The three raw materials provide the zirconium source, magnesium source and iron source required for the carrier, and cetyltrimethylammonium bromide, as a template agent, can promote the porous structure of the product.

[0032] S12. Keep the mixed solution under stirring, add ammonia water to adjust the pH value to 8 - 10, raise the temperature to 40 - 60 °C, add an appropriate amount of ethylene glycol, and carry out a hydrolysis reaction for 2 - 4 hours to obtain a wet gel. Adding ethylene glycol can delay the hydrolysis rate and avoid the occurrence of metal precipitation.

[0033] S13. Let the wet gel stand and ripen at room temperature for 24 - 48 hours, and then wash the gel with absolute ethanol to remove the residual nitrate ions, chloride ions and template agent.

[0034] S14. Place the gel in a vacuum drying oven and dry it at 80 - 100 °C for 12 - 24 hours.

[0035] S15. Calcinate the dried gel at 300 - 400 °C for 2 - 4 hours to decompose and remove cetyltrimethylammonium bromide, ethylene glycol, etc.; then raise the temperature to 550 - 700 °C and calcinate for 4 - 6 hours to promote the crystal structures of ZrO2 and MgFeO4.

[0036] Based on the above steps, a support with a large number of mesopores on its surface is prepared; a support with a large number of mesopores on its surface can be prepared according to the above raw material dosages and the methods in the prior art, which should also be regarded as the protection scope of this application.

[0037] Then, confine the growth of the noble metal component within the mesopores of the support: S21. Select any three or more of rhodium solution, ruthenium solution, platinum solution, palladium solution, and gold solution, mix them evenly with an appropriate amount of ethanol, immerse the support in it, and evaporate under vacuum for 4 hours to obtain an intermediate product. The vacuum induction effect promotes the entry of noble metal ions into the mesopores of the support and their aggregation into nuclei, obtaining noble metal particles distributed within the mesopores of the support.

[0038] S22. Place the intermediate product in a vacuum environment and dry it for more than 24 hours, then take it out and calcinate it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a catalyst semi-finished product.

[0039] Finally, uniformly disperse the promoter on the surface and within the mesopores of the support: S31. Take materials according to the molar ratio, take 2.5 - 3.5 parts of an aqueous solution of vanadium, 1 part of an aqueous solution of tungsten, and mix them evenly with an appropriate amount of ethanol. Immerse the catalyst semi-finished product cooled to room temperature in it and impregnate for 20 - 24 hours.

[0040] S32. Dry it in an environment of 80 - 100 °C for more than 8 hours, then take it out and calcinate it at 600 °C for 5 hours in a nitrogen atmosphere.

[0041] S33. Take 1.5 - 2.5 parts of an aqueous solution of manganese, 1 part of an aqueous solution of cerium, and mix them evenly with an appropriate amount of ethanol. Immerse the product obtained in step S32 in it and impregnate for 20 - 24 hours.

[0042] S34. Dry the product obtained in step S33 in an environment of 80 - 100 °C for more than 8 hours, then take it out and calcinate it at 600 °C for 5 hours in a nitrogen atmosphere to obtain the finished catalyst for dehydrocarbonation in a chlorine-containing environment.

[0043] In step S31, the aqueous solution of vanadium is preferably one or more of vanadium nitrate and vanadium difluoride; the aqueous solution of tungsten is preferably a soluble tungsten fluoride complex. In step S33, the aqueous solution of manganese is preferably one or more of manganese sulfate, manganese nitrate, and manganese acetate; the aqueous solution of cerium is preferably one or more of cerium chloride, cerium sulfate, and cerium nitrate.

[0044] After two impregnation and calcination operations, the main phase and the secondary phase in the promoter are evenly distributed on the surface of the carrier. And the natural impregnation at room temperature enables the metal ions in the main phase and the secondary phase not to cover the entire surface of the carrier, leaving certain gaps, which does not affect the contact between the noble metal component, the carrier component and the chlorinated organic waste gas deep in the mesopores.

[0045] Through the above steps, a catalyst for dehydrocarbonation in a chlorine-containing environment can be obtained, presenting a stable structure with the active component promoter on the surface of the carrier and the active component noble metal component in the mesopores. The ZrO2-MgFeO4 crystal structure provides a stable granular carrier, and there are a large number of mesopores in the carrier. The promoters V2O5-WO3 and CeO2-MnO2 in the active components are mainly distributed on the surface of the carrier, and the noble metal components in the active components are mainly distributed in the mesopores based on the vacuum induction effect. The active components are evenly distributed and dispersed, having a large specific surface area and a large number of active sites. It is beneficial for the chlorinated organic gas (hydrocarbon) to quickly contact the catalyst, and then exhibit excellent catalytic performance.

[0046] This application also provides the application of the above catalyst in the field of removing chlorinated organic compound tail gas. It is suitable for catalytically removing hydrocarbon organic gases and decomposing chlorinated gases in a chlorine-containing environment, especially the chlorinated organic waste gas generated in the production of epichlorohydrin, and the catalytic oxidation effect is excellent.

[0047] Specifically, the chlorinated organic compound gas is contacted with the above catalyst, and the chlorinated organic gas at least includes epichlorohydrin and chloromethane; further, the chlorinated organic gas includes acrolein, epichlorohydrin, chloromethane, and ethylene oxide. Using the catalyst provided by this application can not only avoid the poisoning of the catalyst by chloride ions, enable the organic gas and the chlorinated organic gas to be fully catalytically decomposed, but also reduce the catalytic reaction temperature. At a reaction temperature of 250-400 °C, an excellent catalytic decomposition effect can be achieved. The catalytic reaction temperature is more preferably 250-280 °C.

[0048] This application places no restrictions on the catalytic reactor or the packing position of the catalyst in the reactor. Any structure that allows the raw material gas to fully pass through the catalyst is acceptable. The catalytic reactor includes at least an inlet and an outlet. The inlet is used to input the tail gas (raw material gas) of the chlorinated organic gas, and the outlet is used to discharge the clean gas (emission gas) after catalytic decomposition. The catalytic reactor also includes a heating device and a temperature control device for controlling the reaction temperature during the catalytic process. The space velocity of the catalytic reactor selected in this application is 4500m 3 ·h -1 。

[0049] The activation temperature of the catalyst provided by this application is preferably 200 - 300 °C. Before the catalytic process, the reactor needs to be slowly heated to keep the catalyst in an active state. First, heat from room temperature to 150 °C and maintain for a certain time. When 150 °C is detected at the reactor outlet, then heat up again. Heat from 150 °C to 300 °C and maintain for a certain time until 200 °C is detected at the outlet. Continuously detect the outlet temperature and keep it above 200 °C, then the raw material gas can be introduced. The temperature of the raw material gas is not limited, and this application preferably selects 40 - 300 °C. The flow rate of the raw material gas is preferably 25 - 40 Nm 3 / h。

[0050] During the catalytic reaction process, since the raw material gas has a certain temperature and the temperature may vary, it is necessary to continuously monitor the reactor outlet temperature to avoid affecting the catalytic effect. If the temperature exceeds 400 °C, at this time the catalytic effect has already decreased and shows a deteriorating trend, and it is necessary to stop inputting the raw material gas; wait until the temperature drops to about 300 °C and then introduce the raw material gas.

[0051] Next, the preparation method and actual effects of the catalyst for hydrocarbon removal in a chlorine-containing environment provided by this application will be further described in combination with examples.

[0052] Example 1: First, prepare a support with multiple mesopores: S11. Take materials according to the molar ratio. Dissolve 1 part of zirconium nitrate solution, 0.5 part of magnesium nitrate solution, 1 part of iron nitrate solution, and 1.25 parts of cetyltrimethylammonium bromide in an appropriate amount of ethanol, and stir evenly to obtain a mixed solution.

[0053] S12. While keeping the mixed solution stirred, add ammonia water to adjust the pH value to 8, heat up to 40 °C, add an appropriate amount of ethylene glycol, and carry out a hydrolysis reaction for 2 hours to obtain a wet gel.

[0054] S13. Let the wet gel stand and cure at room temperature for 24 hours, and then wash the gel with absolute ethanol.

[0055] S14. Place the gel in a vacuum drying oven and dry at 80 °C for 12 hours.

[0056] S15. Calcinate the dried gel at 300 °C for 2 hours to decompose and remove cetyltrimethylammonium bromide, ethylene glycol, etc.; then raise the temperature to 550 °C and calcine for 4 hours to obtain a support with a ZrO2-MgFeO4 composite crystal structure.

[0057] Then, confine the growth of the noble metal component within the mesopores of the support: S21. Select rhodium solution, ruthenium solution, platinum solution and mix them evenly with an appropriate amount of ethanol. Immerse the support in the mixture and evaporate it under vacuum for more than 4 hours to obtain an intermediate product.

[0058] S22. Dry the intermediate product in a vacuum environment for more than 24 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a catalyst semi-finished product.

[0059] Finally, uniformly disperse the promoter on the surface and within the mesopores of the support: S31. Take materials according to the molar ratio. Take 2.5 parts of vanadium difluoride, 1 part of soluble tungsten fluoride complex and mix them evenly with an appropriate amount of ethanol. After cooling the catalyst semi-finished product obtained in step S22 to room temperature, immerse it in the mixture and impregnate for 20 hours.

[0060] S32. Dry it at 80 °C for 8 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere.

[0061] S33. Take 1.5 parts of manganese nitrate, 1 part of cerium nitrate and mix them evenly with an appropriate amount of ethanol. Immerse the product obtained in step S32 in the mixture and impregnate for 20 hours.

[0062] S34. Dry the product obtained in step S33 at 80 °C for 8 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a finished catalyst for dehydrocarbonation in a chlorine-containing environment.

[0063] Example 2: First, prepare a support with multiple mesopores: S11. Take materials according to the molar ratio. Dissolve 1 part of zirconium nitrate solution, 0.5 part of magnesium nitrate solution, 1 part of iron nitrate solution and 2.5 parts of cetyltrimethylammonium bromide in an appropriate amount of ethanol, and stir evenly to obtain a mixed solution.

[0064] S12. While keeping the mixed solution stirred, add ammonia water to adjust the pH value to 10, raise the temperature to 60 °C, add an appropriate amount of ethylene glycol, and carry out a hydrolysis reaction for 4 hours to obtain a wet gel.

[0065] S13. Let the wet gel stand and ripen at room temperature for 48 hours, then wash the gel with absolute ethanol.

[0066] S14. Place the gel in a vacuum drying oven and dry it at 100 °C for 24 hours.

[0067] S15. Calcinate the dried gel at 400 °C for 4 hours to decompose and remove cetyltrimethylammonium bromide, ethylene glycol, etc.; then raise the temperature to 700 °C and calcine for 6 hours to obtain a support with a ZrO2-MgFeO4 composite crystal structure.

[0068] Then, confine the growth of the noble metal component within the mesopores of the support: S21. Select rhodium solution, palladium solution, platinum solution and mix them evenly with an appropriate amount of ethanol. Immerse the support in it and evaporate under vacuum for 5 hours to obtain an intermediate product.

[0069] S22. Dry the intermediate product in a vacuum environment for 24 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a catalyst semi-finished product.

[0070] Finally, uniformly disperse the promoter on the surface and within the mesopores of the support: S31. Take materials according to the molar ratio, take 3.5 parts of vanadium nitrate, 1 part of soluble tungsten fluoride complex and mix them evenly with an appropriate amount of ethanol. After cooling the catalyst semi-finished product obtained in step S22 to room temperature, immerse it in the mixture and impregnate for 24 hours.

[0071] S32. Dry it at 100 °C for 9 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere.

[0072] S33. Take 2.5 parts of manganese acetate, 1 part of cerium chloride and mix them evenly with an appropriate amount of ethanol. Immerse the product obtained in step S32 in it and impregnate for 24 hours.

[0073] S34. Dry the product obtained in step S33 at 100 °C for 8 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a finished catalyst for dehydrocarbonation in a chlorine-containing environment.

[0074] Example 3: First, prepare a support with multiple mesopores: S11. Take materials according to the molar ratio, dissolve 1 part of zirconium chloride solution, 0.5 part of magnesium nitrate solution, 1 part of iron nitrate solution and 2 parts of cetyltrimethylammonium bromide in an appropriate amount of ethanol, and stir evenly to obtain a mixed solution.

[0075] S12. Keep the mixed solution stirring, add ammonia water to adjust the pH value to 9, raise the temperature to 50 °C, add an appropriate amount of ethylene glycol, and carry out a hydrolysis reaction for 3 hours to obtain a wet gel.

[0076] S13. Let the wet gel stand and ripen at room temperature for 36 hours, then wash the gel with absolute ethanol.

[0077] S14. Place the gel in a vacuum drying oven and dry it at 90 °C for 18 hours.

[0078] S15. Calcinate the dried gel at 350 °C for 2.5 hours to decompose and remove cetyltrimethylammonium bromide, ethylene glycol, etc.; then raise the temperature to 600 °C and calcine for 5 hours to obtain a support with a ZrO2-MgFeO4 composite crystal structure.

[0079] Then, confine the growth of the noble metal component within the mesopores of the support: S21. Select rhodium solution, ruthenium solution, platinum solution, palladium solution, gold solution and mix them evenly with an appropriate amount of ethanol. Immerse the support in the mixture and evaporate it under vacuum for more than 4 hours to obtain an intermediate product.

[0080] S22. Dry the intermediate product in a vacuum environment for 24 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a catalyst semi-finished product.

[0081] Finally, uniformly disperse the promoter on the surface and within the mesopores of the support: S31. Weigh the materials according to the molar ratio, take 3 parts of vanadium nitrate, 1 part of soluble tungsten fluoride complex and mix them evenly with an appropriate amount of ethanol. After cooling the catalyst semi-finished product obtained in step S22 to room temperature, immerse it in the mixture and impregnate for 22 hours.

[0082] S32. Dry it at 90 °C for 8 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere.

[0083] S33. Take 2 parts of manganese nitrate, 1 part of cerium nitrate and mix them evenly with an appropriate amount of ethanol. Immerse the product obtained in step S32 in the mixture and impregnate for 22 hours.

[0084] S34. Dry the product obtained in step S33 at 90 °C for 8 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain the finished catalyst for dehydrocarbonation in a chlorine-containing environment.

[0085] Example 4: S11. Select rhodium solution, palladium solution, gold solution and mix them evenly with an appropriate amount of ethanol. Immerse the support obtained in Example 1 in the mixture and evaporate it under vacuum for 6 hours to obtain an intermediate product.

[0086] S12. Dry the intermediate product in a vacuum environment for 26 hours, then take it out and calcine it at 600 °C for 5 hours in a nitrogen atmosphere to obtain a catalyst semi-finished product.

[0087] Then, uniformly disperse the promoter on the surface and within the mesopores of the support: S21. Weigh the materials according to the molar ratio, take 2.8 parts of vanadium nitrate, 1 part of soluble tungsten fluoride complex and mix them evenly with an appropriate amount of ethanol. After cooling the catalyst semi-finished product obtained in step S22 to room temperature, immerse it in the mixture and impregnate for 23 hours.

[0088] S22. Dry for 8 hours at 100 °C, then take out and calcine at 600 °C for 5 hours in a nitrogen atmosphere.

[0089] S23. Take 1.8 parts of manganese sulfate, 1 part of cerium sulfate and mix them evenly with an appropriate amount of ethanol. Immerse the product obtained in step S32 therein and impregnate for 22 hours.

[0090] S24. Dry the product obtained in step S33 at 95 °C for 12 hours, then take out and calcine at 600 °C for 5 hours in a nitrogen atmosphere to obtain the finished catalyst for dehydrocarbonation in a chlorine-containing environment.

[0091] Comparative Example 1: Take the semi-finished catalyst obtained in step S22 of Example 1 as the control catalyst. This catalyst also presents a porous microsphere structure, and the noble metal components are confined and distributed in the mesopores based on the vacuum effect; only the promoter is lacking.

[0092] Comparative Example 2: According to the raw material dosages in Example 1, dissolve 1 part of zirconium nitrate solution, 0.5 part of magnesium nitrate solution, and 1 part of iron nitrate solution in deionized water, add ammonia water with a mass concentration of 20%, and use the co-precipitation method to obtain a colloidal precipitate. Wash and dry the precipitate, and calcine at 550 °C for 4 hours to obtain a support. After grinding, the support is in a microsphere structure with very few surface mesopores, and the active components can only be dispersed on the surface of the support.

[0093] According to the methods and raw materials of steps S21 - S22, S31 - S34 in Example 1, impregnate the noble metal component, the main phase of the promoter, and the secondary phase of the promoter on the support by the impregnation method respectively to obtain a catalyst.

[0094] Test the catalysts obtained in Examples 1 - 2 and Comparative Examples 1 - 2: The total flow rate of the raw material gas is 40 Nm 3 / h, add 3.5 Nm of air 3 / h, and introduce it into the catalytic reactor for catalytic reaction; the raw material gas includes acrolein, epichlorohydrin, methyl chloride, ethylene oxide and impurity gas, and its initial temperature is 20 - 35 °C. The reaction pressure is slightly pressurized, the inlet temperature of the reactor is 210 - 230 °C, and the outlet temperature of the reactor is 130 - 160 °C. The designed space velocity of the reactor is 4500 m 3 ·h -1 .

[0095] Select the catalysts prepared in Examples 1 - 4 and Comparative Examples 1 - 2, and add them to the catalytic reactor. Except for the different types of catalysts, the catalyst dosage, the packing position, etc. are all kept the same. Detect the gas components and contents at the inlet (raw material gas) and outlet (exhaust gas) respectively, and then evaluate the catalytic effect of the catalyst.

[0096] Table 1: Detection Result Data of Feed Gas and Exhaust Gas

[0097] From the data in the above table, it can be seen that: The catalysts obtained in Example 1 and Example 2 have extremely high removal rates for organic hydrocarbon gases and chlorinated organic gases. The chlorine component in the gas has no effect on the catalytic decomposition process, and the organic matter content in the final exhaust gas is less than 120 mg / m 3 , meeting the national environmental protection requirements, and the qualified rate reaches 100%. However, the catalyst provided in Comparative Example 1 lacks the active components of the main phase V2O5-WO3 and the secondary phase CeO2-MnO2, and cannot effectively eliminate the poisoning effect of chloride ions on the noble metal active components, resulting in a significant decline in the catalytic effect. Although the catalyst provided in Comparative Example 2 has the same composition as that in Example 1, the support lacks a mesoporous structure, making all the active components distributed on the surface of the support, and the multi-step impregnation method may cause a part of the noble metal active components impregnated first to be covered by the promoter active components impregnated later. Therefore, it can be seen that its catalytic effect is reduced, but the reduction amplitude is lower than that of Comparative Example 1 (the active components are poisoned and cannot function).

[0098] In addition, Table 2 below discloses the information on the catalytic effect of the catalyst provided in Example 1 during long-term operation. It can be seen that the catalyst provided in this application has stable properties, can be continuously used for a long time and stably exert its effect, and will not gradually deactivate due to chlorine poisoning, and has an excellent catalytic effect.

[0099] Table 2: Detection Results of Feed Gas and Exhaust Gas Detection Changing with Time

[0100] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A catalyst for hydrocarbon removal in a chlorine-containing environment, characterized in that, Comprising a carrier and an active ingredient: The carrier comprises ZrO2 and MgFeO4; The active ingredient comprises a promoter and a noble metal component. The promoter comprises a V2O5-WO3 composite oxide and a CeO2-MnO2 composite oxide, and the noble metal component comprises at least three of rhodium, ruthenium, platinum, palladium, and gold.

2. The catalyst for hydrocarbon removal in a chlorine-containing environment according to claim 1, wherein, The mass percentage of the active ingredient in the catalyst is 10-50%.

3. The catalyst for hydrocarbon removal in a chlorine-containing environment according to claim 1, characterized in that, The molar ratio of Zr, Mg, and Fe in the carrier is 1:0.5:

1.

4. The catalyst for hydrocarbon removal in a chlorine-containing environment according to claim 1, characterized in that, The molar ratio of vanadium to tungsten in the active ingredient is (2.5-3.5):1, the molar ratio of cerium to manganese is 1:(1.5-2.5), and the molar ratio of tungsten to cerium is 1:

1.

5. A method for preparing a catalyst for hydrocarbon removal in a chlorine-containing environment according to any one of claims 1-4, characterized in that, Comprising the following steps: S1. Prepare a carrier with a large number of mesopores on the surface; S2. Immerse the carrier in a noble metal solution, evaporate under vacuum, then dry and calcine to distribute noble metal ions in the mesopores of the carrier to obtain a semi-finished product; S3. Immerse the semi-finished product in a mixed solution of vanadium and tungsten, dry and calcine; then immerse it in a mixed solution of manganese and cerium, dry and calcine to obtain the finished catalyst.

6. The method according to claim 5, wherein Step S1 comprises the following steps: S11. Dissolve a zirconium salt solution, a magnesium nitrate solution, an iron nitrate solution, and cetyltrimethylammonium bromide in ethanol and stir evenly; S12. Add ammonia water to adjust the pH value to 8-10, then raise the temperature to 40-60°C and add ethylene glycol, and carry out a hydrolysis reaction for 2-4 h to obtain a wet gel; S13. Age the wet gel at room temperature for 24-48 h, then wash it and vacuum dry it at 80-100°C for 12-24 h; S14. Calcine at 300-400°C for 2-4 h, then raise the temperature to 550-700°C and calcine for 4-6 h.

7. The method according to claim 5, characterized in that In step S2, the noble metal solution comprises at least three of a rhodium solution, a ruthenium solution, a platinum solution, a palladium solution, and a gold solution. Evaporate under vacuum for 4 h, vacuum dry for more than 24 h, and calcine at 600°C for 5 h in a nitrogen atmosphere.

8. The method according to claim 5, wherein In step S3, the immersion is at room temperature; the drying temperature is 80-100°C and the time is more than 8 h; the calcination temperature is 600°C and the time is 5 h in a nitrogen atmosphere.

9. Use of a catalyst for dehydrocarbonation in a chlorine-containing environment as described in any one of claims 1-4 or a catalyst prepared by the method as described in any one of claims 5-8 in removing chlorine-containing organic compounds and organic compounds.

10. The application according to claim 9, wherein The chlorine-containing organic compounds comprise at least one of epichlorohydrin and methyl chloride, and the organic compounds comprise at least one of acrolein and ethylene oxide.

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