Catalyst for preparing chlorine by oxidizing hydrogen chloride and preparation method thereof

Abstract

The invention discloses a catalyst for preparing chlorine by oxidizing hydrogen chloride. The catalyst is prepared from an additive modified carrier and an active component, the active component is Ru; the auxiliary agents are Nb, V and W, and the carrier is Al2O3-TiO2; the catalyst comprises, by mass, 0.5%-1.5% of Ru, 0.1%-0.5% of Nb, 2%-6% of V, 1%-5% of W and the balance Al2O3-TiO2 carriers, and the mass ratio of Al2O3 to TiO2 is (0.2-2): 1. Meanwhile, the invention also discloses a preparation method of the catalyst for preparing chlorine by oxidizing hydrogen chloride. According to the invention, the alkylol amine assistant is added in the forming process, so that the uniformity between the carrier and the assistant is improved, the mechanical strength of the carrier is improved, and the pore structure of the carrier is optimized, so that the carrier has more macropores and proper pore size distribution. The catalyst disclosed by the invention is low in metal loading capacity, relatively high in low-temperature activity and high-temperature sintering resistance, and capable of being used at a temperature window of 260-410 DEG C, and the service life of the catalyst can reach more than 2 years.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a high-stability catalyst for preparing chlorine by oxidation of hydrogen chloride and a preparation method thereof. Background Art

[0002] With economic development, the consumption of organic chlorine and inorganic chlorine has gradually increased. Among them, polyvinyl chloride (PVC) is the largest chlorine-consuming product. The production of epichlorohydrin and polyurethane also uses a large amount of chlorine. The chlor-alkali industry has always had the problem of excess hydrogen chloride. Converting hydrogen chloride to produce chlorine can achieve closed-loop recycling of chlorine resources and is the most effective way to treat and recover by-product hydrogen chloride. At present, the main methods for converting hydrogen chloride into chlorine are electrolysis, direct oxidation and catalytic oxidation. Among them, catalytic oxidation is widely used due to its simple process, low energy consumption, safety, no side reactions, and high efficiency.

[0003] The catalytic oxidation reaction of hydrogen chloride is a highly exothermic reaction, and it is inevitable that there will be local high temperatures. In addition, the reaction temperature needs to be continuously increased during the reaction process to ensure the target conversion rate. High temperature will accelerate the sintering and deactivation rate of the catalyst. The key to the catalytic oxidation of hydrogen chloride to produce chlorine is the preparation of the catalyst. The reported catalysts are classified according to the active components, mainly copper, chromium, ruthenium, cerium and vanadium. At present, Japan's Sumitomo ruthenium catalyst is the most mature, which can achieve a high conversion rate of hydrogen chloride at a relatively low temperature and is widely used in industrial production. However, there are also problems such as high Ru metal content, high price, insufficient low-temperature activity, high-temperature sintering and deactivation in the later stage of the reaction, and short life. Summary of the invention

[0004] In view of the problems of high cost and short life of existing industrial Ru-based catalysts, the object of the present invention is to provide a catalyst with high low temperature activity, high stability and low metal content for hydrogen chloride oxidation to produce chlorine and a preparation method thereof. The catalyst prepared by the method can effectively reduce the metal content and save the catalytic cost while ensuring high oxidation activity and stability, and has a good application prospect.

[0005] A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent-modified carrier and an active component; the active component is Ru; the auxiliary agent is Nb, V, W, and the carrier is Al2O3-TiO2; The mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 0.5-1.5%, Nb 0.1-0.5%, V 2-6%, W 1-5%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is (0.2-2):1.

[0006] Preferably, the preparation of the auxiliary agent-modified carrier comprises the following steps: (1) Weigh Nb, V and W precursors and dissolve them in an amine aqueous solution to obtain solution A; (2) Weigh Al and Ti precursors, add a binder, and obtain solid B; (3) Stirring solid B to make it uniformly mixed, then adding solution A and peptizing agent thereto, stirring to make it uniform, to obtain material C; (4) Material C is extruded into strips on an extruder, dried, calcined, and naturally cooled to obtain an additive-modified carrier.

[0007] Preferably, in step (1), the Nb precursor is niobium oxalate; the V precursor is any one of ammonium metavanadate, sodium metavanadate, sodium pyrovanadate, sodium orthovanadate, vanadyl sulfate, and vanadium nitrate; and the W precursor is any one of ammonium tungstate, sodium tungstate, ammonium metatungstate, sodium metatungstate, and potassium tungstate.

[0008] Preferably, in step (2), the Al precursor is pseudo-boehmite or nano-alumina powder, wherein the mass of pseudo-boehmite is calculated as alumina, and the nano-alumina can be any one of γ, θ, α crystal forms or any combination of components in any proportion.

[0009] Preferably, in step (2), the Ti precursor is metatitanic acid or titanium oxide, the mass of metatitanic acid is calculated as titanium oxide; the titanium oxide is anatase titanium oxide, rutile titanium oxide or twinned titanium oxide; the twinned titanium oxide is mixed crystalline titanium oxide or is a mixture of two single crystalline titanium oxides, anatase titanium oxide and rutile titanium oxide, in any proportion.

[0010] Preferably, in step (1), the alcoholamine is any one of ethanolamine, diethanolamine, diisopropanolamine, and methyldiethanolamine; the mass concentration of the alcoholamine is 5-25%; in step (2), the binder is any one of starch, polyvinyl alcohol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and carboxyethyl cellulose, and the binder accounts for 0.5-2% of the weight of solid B; in step (3), the peptizing agent is an aqueous solution of nitric acid, hydrochloric acid, formic acid or acetic acid, and the concentration of the peptizing agent is 1-10 wt %; the mass ratio of solid B, solution A, and peptizing agent is 1: (0.05 -0.3): (0.1-0.4).

[0011] Preferably, the drying conditions in step (4) are: drying at 80-120°C for 6-12h; the roasting conditions are: roasting at 300-400°C for 2-5h, heating to 500-600°C for 2-5h, heating to 700-900°C for 2-12h, and the heating rate is 0.5-3°C / min.

[0012] A method for preparing the catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 1, comprising the following steps: (1) Weighing ruthenium trichloride solid particles, adding concentrated hydrochloric acid and hot water to dissolve, and obtaining a ruthenium trichloride aqueous solution; (2) Weighing the auxiliary agent-modified carrier, impregnating the ruthenium trichloride aqueous solution onto the shaped carrier by an impregnation method, drying, roasting, and naturally cooling to obtain a hydrogen chloride oxidation catalyst for chlorine production.

[0013] Preferably, the mass ratio of the ruthenium trichloride aqueous solution to the auxiliary agent modified carrier is (0.15-0.5):1; the mass ratio of ruthenium trichloride to concentrated hydrochloric acid in step (1) is 1:(0-3); and the solid-liquid ratio of ruthenium trichloride to the hot aqueous solution is 1:(0.15-0.5).

[0014] Preferably, the drying conditions are: drying at 60-120°C for 6-12h; calcining at 200-250°C in air or oxygen atmosphere for 6-18h, with a volume space velocity of 10-50h -1 After roasting, stop ventilation, continue to heat up to 260-310℃, and continue roasting for 3-8h without ventilation.

[0015] Advantages of the present invention: The present invention adopts a conventional kneading method, adds a structural auxiliary agent to extrude a suitable carrier, and then adopts a conventional impregnation method to prepare the catalyst. The process is simple and easy, and an alcohol amine auxiliary agent is added during the molding process to improve the uniformity between the carrier and the auxiliary agent components, improve the mechanical strength of the carrier, and optimize the pore structure of the carrier, so that it has more macropores and a suitable pore size distribution. The addition of auxiliary metal reduces the concentration of surface active species, increases the active metal adsorption sites, reduces the probability of active particle agglomeration, and promotes the active component RuO2 to be highly dispersed in the carrier, and has a strong interaction force with the carrier. The catalyst of the present invention has a low metal loading, high low-temperature activity and high-temperature sintering resistance, can be used in a temperature window of 260-410°C, and has a service life of more than 2 years.

[0016] Instruction Manual Figure 1 The results of catalyst S1 life test are shown in Figure 2. DETAILED DESCRIPTION

[0017] Example 1 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 1:1; The preparation method of the auxiliary agent modified carrier comprises the following steps: (1) Weigh niobium oxalate, ammonium metavanadate and ammonium tungstate, and dissolve them in a 10% mass concentration ethanolamine aqueous solution to obtain solution A; (2) Weighing pseudo-boehmite and rutile titanium oxide, wherein the mass of pseudo-boehmite is calculated based on the mass of alumina, and adding a binder to obtain solid B; (3) Stirring solid B to make it uniformly mixed, then adding solution A and peptizing agent thereto, stirring to make it uniform, to obtain material C; (4) Material C was extruded into a strip carrier with a diameter of 1.5 mm and a length of 2-6 mm on an extruder. The formed carrier was dried at 100°C for 10 h, heated to 350°C for 3 h, then heated to 550°C for 3 h, and then heated to 800°C for 6 h at a heating rate of 2°C / min. The binder is carboxymethyl cellulose, and the binder accounts for 1% of the solid B; the peptizer is a nitric acid solution with a mass concentration of 5%; the mass ratio of the solid B, solution A, and peptizer is 1:0.1:0.2; A method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride comprises the following steps: (1) taking ruthenium trichloride solid particles, adding concentrated hydrochloric acid and hot water to dissolve them according to the ratio of 1 g Ru / 1 g concentrated hydrochloric acid and the liquid-to-solid ratio of 0.3:1 to obtain a ruthenium trichloride aqueous solution; (2) Take the additive-modified carrier, impregnate the ruthenium trichloride aqueous solution onto the shaped carrier by impregnation, dry it at 100°C for 10 hours, and the volume space velocity is 25h -1 The temperature was raised to 220°C in an air atmosphere and calcined for 8 h. Then, ventilation was stopped and the temperature was continued to rise to 280°C. The catalyst was calcined for 5 h without ventilation. The obtained catalyst was marked as S1.

[0018] Example 2 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 0.5%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 1:1; The V precursor is vanadium nitrate; the W precursor is potassium tungstate; The alcohol amine is diethanolamine; the binder is starch; The other steps were the same as those in Example 1, and the obtained catalyst was denoted as S2.

[0019] Example 3 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1.5%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 1:1; The V precursor is sodium pyrovanadate; the W precursor is sodium tungstate; The Al precursor is θ-crystal nano-alumina; The alcohol amine is diisopropanolamine; the binder is polyvinyl alcohol; The other steps were the same as those in Example 1, and the obtained catalyst was denoted as S3.

[0020] Example 4 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is 100%, and the contents of the components are as follows: Ru 1%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 0.2:1; The V precursor is sodium metavanadate; The other steps were the same as those in Example 1, and the obtained catalyst was denoted as S4.

[0021] Example 5 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 2:1; The W precursor is ammonium metatungstate; The binder is ethyl cellulose; The other steps were the same as those in Example 1, and the obtained catalyst was denoted as S5.

[0022] Example 6 The aluminum source is γ-crystalline nano-alumina powder, and the V precursor is vanadyl sulfate; the rest is the same as in Example 1, and the obtained catalyst is denoted as S6.

[0023] Example 7 The aluminum source is α-crystalline nano-alumina powder, the binder is carboxyethyl cellulose, and the rest is the same as in Example 1. The obtained catalyst is denoted as S7.

[0024] Example 8 The titanium source is metatitanic acid, and its mass is calculated as titanium oxide. Other steps are the same as those in Example 1, and the obtained catalyst is recorded as S8.

[0025] Example 9 The titanium source is anatase titanium oxide, and the rest is the same as in Example 1. The obtained catalyst is denoted as S9.

[0026] Example 10 The titanium source is anatase and rutile mixed titanium oxide, the mass ratio of anatase to rutile is 8:2, and the rest is the same as in Example 1. The obtained catalyst is recorded as S10.

[0027] Embodiment 11 The adhesive is methyl cellulose, the alcohol amine is methyldiethanolamine, and the peptizing agent is hydrochloric acid with a mass concentration of 10%; the rest is the same as in Example 1, and the obtained catalyst is recorded as S11.

[0028] Example 12 The precursor of the additive V is sodium orthovanadate, and the rest is the same as in Example 1. The obtained catalyst is denoted as S12.

[0029] Example 13 The precursor of the auxiliary agent W is sodium metatungstate, and the rest is the same as in Example 1. The obtained catalyst is recorded as S13.

[0030] Embodiment 14 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 1:1; The preparation method of the auxiliary agent modified carrier is the same as that of Example 1; A method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride comprises the following steps: (1) Take ruthenium trichloride solid particles, add concentrated hydrochloric acid and hot water according to 1g Ru / 0g concentrated hydrochloric acid and a liquid-to-solid ratio of 0.5:1 to dissolve; (2) Take the additive-modified carrier, impregnate the ruthenium trichloride aqueous solution onto the shaped carrier by impregnation, dry it at 100°C for 10 hours, and the volume space velocity is 25h -1 The temperature was raised to 220°C in an air atmosphere and calcined for 8 h. Then, ventilation was stopped and the temperature was continued to rise to 280°C. The catalyst was calcined for 5 h without ventilation. The obtained catalyst was marked as S14.

[0031] Embodiment 15 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1%, Nb 0.3%, V 4%, W 3%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 1:1; The preparation method of the auxiliary agent modified carrier comprises the following steps: (1) Weigh niobium oxalate, ammonium metavanadate and ammonium tungstate, and dissolve them in a 25% mass concentration ethanolamine aqueous solution to obtain solution A; (2) Weighing pseudo-boehmite and rutile titanium oxide, wherein the mass of pseudo-boehmite is calculated based on the mass of alumina, and adding a binder to obtain solid B; (3) Stirring solid B to make it uniformly mixed, then adding solution A and peptizing agent thereto, stirring to make it uniform, to obtain material C; (4) Material C was extruded into a strip carrier with a diameter of 1.5 mm and a length of 2-6 mm on an extruder. The formed carrier was dried at 100°C for 10 h, heated to 350°C for 3 h, then heated to 550°C for 3 h, and then heated to 800°C for 6 h at a heating rate of 2°C / min. The binder is carboxyethyl cellulose, and the binder accounts for 0.5 of the solid B; the peptizer is an acetic acid solution with a mass concentration of 1%; the mass ratio of the solid B, solution A, and peptizer is 1:0.1:0.2; A method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride comprises the following steps: (1) taking ruthenium trichloride solid particles, adding concentrated hydrochloric acid and hot water to dissolve them according to the ratio of 1 g Ru / 1 g concentrated hydrochloric acid and the liquid-to-solid ratio of 0.3:1 to obtain a ruthenium trichloride aqueous solution; (2) Take the additive-modified carrier, impregnate the ruthenium trichloride aqueous solution onto the shaped carrier by impregnation, dry it at 120°C for 8h, and the volume space velocity is 50h -1 The temperature was raised to 250°C in an air atmosphere and calcined for 8 h. Then, ventilation was stopped and the temperature was continued to rise to 300°C. The catalyst was calcined for 6 h without ventilation. The obtained catalyst was marked as S15.

[0032] Example 16 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst is composed of an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the content of each component is as follows: Ru 1%, Nb 0.1%, V 2%, W 1%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 0.2:1. The catalyst preparation method comprises the following steps: The preparation method of the auxiliary agent modified carrier comprises the following steps: (1) Weigh niobium oxalate, ammonium metavanadate and ammonium tungstate, and dissolve them in a 5% by mass concentration ethanolamine aqueous solution to obtain solution A; (2) Weigh pseudo-boehmite and rutile titanium oxide, where the mass of pseudo-boehmite is calculated as the mass of alumina, and add a certain amount of binder, which is regarded as solid B; (3) Stir solid B in a mixer until uniformly mixed, pour solution A and peptizing agent into the mixture and continue stirring until uniformly mixed, to obtain material C; (4) Material C is extruded into a strip carrier with a diameter of 3 mm and a length of 2-6 mm on an extruder. The formed carrier is dried at 80°C for 10 h, heated to 300°C for 5 h, then heated to 500°C for 5 h, and then heated to 700°C for 12 h, with a heating rate of 2°C / min. The adhesive is carboxymethyl cellulose, the peptizing agent is a formic acid solution with a mass concentration of 10%, and the mass ratio of the solid B, solution A, and peptizing agent is 1:0.05:0.1; A method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride comprises the following steps: (1) Weighing ruthenium trichloride solid particles, adding concentrated hydrochloric acid and water at a ratio of 1 g Ru / 0 g concentrated hydrochloric acid and a liquid-to-solid ratio of 0.15:1 to dissolve the particles, thereby obtaining a ruthenium trichloride aqueous solution; (2) Take the modified support and impregnate the ruthenium trichloride aqueous solution onto the shaped support by dropwise impregnation. Dry it at 60°C for 12h and the volume space velocity is 10h. -1 The temperature was raised to 200°C in an air atmosphere and calcined for 18 h. Then, ventilation was stopped and the temperature was continued to rise to 260°C. The catalyst was calcined for 8 h without ventilation. The obtained catalyst was marked as S16.

[0033] Embodiment 17 A catalyst for preparing chlorine by oxidation of hydrogen chloride, the catalyst comprising an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agents are Nb, V, and W, and the carrier is Al2O3-TiO2; the mass of the catalyst is calculated as 100%, and the contents of the components are as follows: Ru 1%, Nb 0.5%, V 6%, W 5%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is 2:1; The preparation method of the auxiliary agent modified carrier comprises the following steps: (1) Weigh niobium oxalate, ammonium metavanadate and ammonium tungstate, and dissolve them in a 15% mass concentration ethanolamine aqueous solution to obtain solution A; (2) Weigh pseudo-boehmite and rutile titanium oxide, where the mass of pseudo-boehmite is calculated as the mass of alumina, and add a certain amount of binder, which is regarded as solid B; (3) Stir solid B in a mixer until uniformly mixed, pour solution A and peptizing agent into the mixture and continue stirring until uniformly mixed, to obtain material C; (4) Material C was extruded into a strip carrier with a diameter of 1.5 mm and a length of 2-6 mm on an extruder. The formed carrier was dried at 120°C for 6 h, programmed to be calcined at 400°C for 2 h, then calcined at 600°C for 2 h, and then calcined at 900°C for 2 h, with a heating rate of 2°C / min; The adhesive is carboxymethyl cellulose, the peptizing agent is a hydrochloric acid solution with a mass concentration of 5%, and the mass ratio of the solid B, solution A, and peptizing agent is 1:0.3:0.3; A method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride comprises the following steps: (1) Weighing ruthenium trichloride solid particles, adding concentrated hydrochloric acid and water at a ratio of 1 g Ru / 3 g concentrated hydrochloric acid and a liquid-to-solid ratio of 0.5:1 to dissolve the particles, thereby obtaining a ruthenium trichloride aqueous solution; (2) Take the additive-modified carrier and impregnate the ruthenium trichloride aqueous solution onto the shaped carrier by dropwise impregnation. Dry it at 120°C for 6 hours at a volume space velocity of 50 h. -1 The temperature was raised to 250°C in an air atmosphere and calcined for 6 h. Then, ventilation was stopped and the temperature was continued to be raised to 310°C. The catalyst was calcined for 3 h without ventilation. The obtained catalyst was marked as S17.

[0034] Comparative Example 1 The auxiliary agent does not include W, and the other parts are the same as in Example 1. The obtained catalyst is marked as D1.

[0035] Comparative Example 2 No alcohol amine was added to the auxiliary agent-modified carrier, and the other steps were the same as in Example 1. The obtained catalyst was marked as D2.

[0036] Comparative Example 3 The catalyst was prepared by the method of Example 1 in patent CN103285855A, and the obtained catalyst was marked as D3.

[0037] Comparative Example 4 The catalyst was prepared by the method of Example 1 in patent CN102216207A, and the obtained catalyst was marked as D4.

[0038] Catalyst activity evaluation: 10g of catalyst was loaded into the constant temperature section of a nickel reaction tube with an inner diameter of 18mm. After the flow rates of two dry experimental gases (HCl and O2) were controlled by flow controllers, they were mixed as needed and entered the reactor. The tail gas was absorbed by an alkali barrel and then discharged. Sampling ports were set at the inlet and outlet of the reactor. After absorption with potassium iodide absorption liquid, the HCl conversion rate was determined by titration.

[0039] The conversion results of the catalyst at different temperatures are shown in Table 1.

[0040] The results of catalyst S1 life test are shown in Figure 1 As shown in the figure, the catalyst was operated continuously for 720 days while ensuring a hydrogen chloride conversion rate of more than 85%, and the reaction temperature was controlled at 350°C, showing good catalyst stability.

Claims

1. A catalyst for preparing chlorine by oxidation of hydrogen chloride, characterized in that The catalyst is composed of an auxiliary agent modified carrier and an active component; the active component is Ru; the auxiliary agent is Nb, V, W, and the carrier is Al2O3-TiO2; The mass of the catalyst is calculated as 100%, and the content of each component is as follows: Ru 0.5-1.5%, Nb 0.1-0.5%, V 2-6%, W1-5%, and the balance is Al2O3-TiO2 carrier, wherein the mass ratio of Al2O3:TiO2 is (0.2-2):

1.

2. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 1, characterized in that The preparation of the auxiliary agent modified carrier comprises the following steps: (1) Weigh Nb, V and W precursors and dissolve them in an amine aqueous solution to obtain solution A; (2) Weigh Al and Ti precursors, add a binder, and obtain solid B; (3) Stirring solid B to make it uniformly mixed, then adding solution A and peptizing agent thereto, stirring to make it uniform, to obtain material C; (4) Material C is extruded into strips on an extruder, dried, calcined, and naturally cooled to obtain an additive-modified carrier.

3. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 2, characterized in that: In the step (1), the Nb precursor is niobium oxalate; the V precursor is any one of ammonium metavanadate, sodium metavanadate, sodium pyrovanadate, sodium orthovanadate, vanadyl sulfate, and vanadium nitrate; and the W precursor is any one of ammonium tungstate, sodium tungstate, ammonium metatungstate, sodium metatungstate, and potassium tungstate.

4. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 2, characterized in that In the step (2), the Al precursor is pseudo-boehmite or nano-alumina powder, wherein the mass of pseudo-boehmite is calculated as alumina, and the nano-alumina can be any one of γ, θ, and α crystal forms or any multiple components mixed in any proportion.

5. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 2, characterized in that: In the step (2), the Ti precursor is titanic acid or titanium oxide, and the mass of the titanic acid is calculated based on titanium oxide; the titanium oxide is anatase titanium oxide, rutile titanium oxide or twinned titanium oxide; the twinned titanium oxide is a mixed crystalline titanium oxide or a mixture of two single crystalline titanium oxides, anatase titanium oxide and rutile titanium oxide, in any proportion.

6. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 2, characterized in that: In step (1), the alcoholamine is any one of ethanolamine, diethanolamine, diisopropanolamine, and methyldiethanolamine; the mass concentration of the alcoholamine is 5-25%; in step (2), the binder is any one of starch, polyvinyl alcohol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and carboxyethyl cellulose, and the binder accounts for 0.5-2% of the weight of solid B; in step (3), the peptizing agent is an aqueous solution of nitric acid, hydrochloric acid, formic acid, or acetic acid, and the concentration of the peptizing agent is 1-10 wt %; the mass ratio of solid B, solution A, and peptizing agent is 1: (0.05 -0.3): (0.1-0.4).

7. The catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 2, characterized in that: The drying conditions in step (4) are: drying at 80-120°C for 6-12h; the roasting conditions are: roasting at 300-400°C for 2-5h, heating to 500-600°C for 2-5h, heating to 700-900°C for 2-12h, and the heating rate is 0.5-3°C / min.

8. A method for preparing the catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 1, characterized in that: The following steps are involved: (1) Weighing ruthenium trichloride solid particles, adding concentrated hydrochloric acid and hot water to dissolve, and obtaining a ruthenium trichloride aqueous solution; (2) Weighing the auxiliary agent-modified carrier, impregnating the ruthenium trichloride aqueous solution onto the shaped carrier by an impregnation method, drying, calcining, and naturally cooling to obtain a hydrogen chloride oxidation catalyst for chlorine production.

9. The method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 8, wherein: The mass ratio of the ruthenium trichloride aqueous solution to the auxiliary agent modified carrier is (0.15-0.5):1; the mass ratio of ruthenium trichloride to concentrated hydrochloric acid in step (1) is 1:(0-3); and the solid-liquid ratio of ruthenium trichloride to the hot aqueous solution is 1:(0.15-0.5).

10. The method for preparing a catalyst for preparing chlorine by oxidation of hydrogen chloride according to claim 8, characterized in that: The drying conditions are: drying at 60-120°C for 6-12h; calcining at 200-250°C in air or oxygen atmosphere for 6-18h, with a volume space velocity of 10-50h -1 After roasting, stop ventilation, continue to heat up to 260-310℃, and continue roasting for 3-8h without ventilation.

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