Titanium dioxide type low-temperature hydrogenolysis catalyst, its preparation method and application
By using a catalyst supported on titanium dioxide to support scandium oxide and tungsten oxide, the problem of decreased catalytic performance of cobalt-molybdenum/alumina catalysts at low temperatures was solved, achieving efficient sulfur recovery tail gas treatment at low temperatures and reducing fuel gas consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2022-11-07
- Publication Date
- 2026-05-29
AI Technical Summary
Existing cobalt-molybdenum/alumina hydrogenation catalysts exhibit decreased catalytic performance at low temperatures, leading to increased fuel gas consumption and failing to meet the requirements for treating tail gas from low-temperature sulfur recovery.
Using titanium dioxide as a carrier and scandium oxide and tungsten oxide as active components, an ultrafine titanium dioxide carrier was prepared by a specific method, which maintained good hydrogenation activity of sulfur dioxide and hydrolysis of organic sulfur at low temperature.
At 210-220℃, the catalyst exhibits excellent sulfur dioxide hydrogenation conversion rate and organic sulfur hydrolysis rate, which are 0.5% and 3% higher than those of traditional catalysts, respectively, and significantly reduce fuel gas consumption.
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Abstract
Description
Technical Field
[0001] This invention relates to a titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst, its preparation method, and its application, belonging to the technical field of hydrogenation hydrolysis catalysts. Background Technology
[0002] Natural gas purification plants, oil refineries, and coal chemical plants typically employ the Claus sulfur recovery process when treating acidic gases containing 20-100% hydrogen sulfide. This technology can recover 90-97% of the sulfides in the acidic gas and convert them into sulfur. The remaining unrecovered sulfides are further treated by a tail gas treatment unit before being incinerated and discharged. Currently, the most mainstream tail gas treatment technology is the hydroreduction process. The core of this process is the hydroreduction reactor. The function of the hydroreduction reactor is to hydrogenate or hydrolyze unconverted sulfur dioxide, carbon disulfide, and unrecovered trace amounts of sulfur in the sulfur recovery tail gas into hydrogen sulfide, which is then subjected to further treatment. The catalyst packed in the hydroreduction reactor is generally a cobalt-molybdenum / alumina hydroreduction catalyst.
[0003] The cobalt-molybdenum / alumina hydrogenation catalyst uses activated alumina as a support and cobalt oxide and molybdenum oxide as active components. Its traditional preparation or production process is as follows: support drying – ammonium molybdate solution preparation – ammonium molybdate impregnation – primary drying and calcination – cobalt nitrate solution preparation – cobalt nitrate impregnation – secondary drying and calcination. The resulting catalyst operates at a temperature of 280-320℃. The Claus tail gas temperature entering the hydrogenation reactor is typically around 130℃. To ensure good catalyst activity, an online combustion furnace is required to raise the Claus tail gas temperature to above 260℃ through high-temperature combustion of fuel gas and air. The fuel gas consumption is approximately 32m³. 3 / ton of sulfur. To reduce combustion gas consumption, a new low-temperature hydrogenation process has been developed, requiring the catalyst operating temperature to be reduced to 210-220℃, thereby reducing fuel gas consumption to approximately 21m³. 3 The efficiency of hydrogenation of sulfur dioxide and hydrolysis of organic sulfur dioxide decreases with decreasing operating temperature. To ensure the performance of the unit, it is necessary to develop a hydrogenation hydrolysis catalyst with excellent catalytic performance under low-temperature conditions to meet production requirements. Summary of the Invention
[0004] To address the aforementioned technical problems, the present invention aims to provide a titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst, its preparation method, and its application. The titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst provided by the present invention exhibits excellent hydrogenation activity for sulfur dioxide and hydrolysis activity for organic sulfur, and can be applied to processes for treating sulfur recovery tail gas at low temperatures of 210-220℃.
[0005] To achieve the above objectives, the first aspect of the present invention provides a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, the catalyst comprising a titanium dioxide support and an active component supported on the titanium dioxide support, the active component comprising scandium oxide and tungsten oxide.
[0006] According to a specific embodiment of the present invention, preferably, based on 100% of the total weight of the titanium dioxide-type low-temperature hydrolysis catalyst, the catalyst comprises: 9-12.5% of the active component and 87.5-91% of the titanium dioxide support. More preferably, based on 100% of the total weight of the titanium dioxide-type low-temperature hydrolysis catalyst, the catalyst comprises: 0.5-1.5% of scandium oxide, 8.5-11% of tungsten oxide, and 87.5-91% of the titanium dioxide support. Particularly preferably, based on 100% of the total weight of the titanium dioxide-type low-temperature hydrolysis catalyst, the catalyst comprises: 1.0-1.5% of scandium oxide, 9.5-11% of tungsten oxide, and 87.5-89.5% of the titanium dioxide support.
[0007] In the above-mentioned titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst, preferably, the water absorption rate of the titanium dioxide support is 40-45%, the particle size of the titanium dioxide support is 200-250 mesh, and the specific surface area of the titanium dioxide support is >180 m². 2 / g, the mechanical strength of the titanium dioxide carrier is >150N / particle. The methods for testing the water absorption rate, particle size, specific surface area, and mechanical strength of the titanium dioxide carrier can all be conventional in the field. The method for testing the water absorption rate is, for example, but not limited to, the following: Take 100g of the carrier, dry it at 120℃ for 2h, and weigh it as 'a' grams; place it in 200g of water for 1h, filter it out, let the carrier stand for 2h, and weigh it as 'b' grams; the formula for calculating the water absorption rate is: (ba) ÷ a × 100%.
[0008] In the above-mentioned titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, preferably, the titanium dioxide support is prepared by the following steps: mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate; drying the titanium hydroxide precipitate to obtain titanium dioxide powder; and molding and calcining the titanium dioxide powder to obtain the titanium dioxide support.
[0009] More preferably, the titanium salt includes one or a combination of several of titanium nitrate, titanium tetrachloride, and titanium oxysulfate. Even more preferably, the titanium salt is titanium nitrate.
[0010] More preferably, the complexing agent includes ethylenediaminetetraacetic acid and ammonia.
[0011] More preferably, the process of mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate specifically includes: mixing titanium salt (preferably titanium nitrate), ethylenediaminetetraacetic acid (EDTA), and ammonia for complexation, stirring for 0.5-1.5 h (more preferably 0.5-1 h), and then letting stand for 2-3 h (more preferably 2 h) to obtain a solution of a complex (the complex is mainly titanium ammonium EDTA) (the solution is a transparent and clear solution); then adding ammonia for precipitation and stirring for 0.5-1.5 h to form titanium hydroxide precipitate; wherein the mass concentration of the ammonia is 2-10% (the concentrations of the ammonia for complexation and the ammonia for precipitation are both within this range), and the mass ratio of titanium salt (preferably titanium nitrate), EDTA, ammonia for complexation, and ammonia for precipitation is (150-280):(50-150):(550-700):(330-420).
[0012] More preferably, the titanium hydroxide precipitate is dried at a temperature of 160-180°C for 2-3 hours. Those skilled in the art should understand that conventional filtration and / or washing steps can be performed before drying the precipitate; this invention does not specifically limit this step, and those skilled in the art can make conventional adjustments.
[0013] More preferably, the average particle size of the titanium dioxide powder is 200-250 mesh.
[0014] More preferably, the molding includes extrusion molding and / or tablet molding; particularly preferably, the carrier obtained by extrusion molding is a cylindrical carrier with a diameter of 3-4 mm and a length of 8-10 mm; the carrier obtained by tablet molding is a disc-shaped carrier with a diameter of 6-8 mm and a height of 2-3 mm.
[0015] More preferably, during the molding process, the titanium dioxide powder is mixed with an appropriate amount of binder and other additives, as well as water, before molding. The binder may be guar gum. The mass ratio of the titanium dioxide powder, binder, and water can be 100:(2-4):(25-30).
[0016] More preferably, the calcination temperature is 500-550℃ and the calcination time is 2-3 hours.
[0017] In the preferred preparation process of the titanium dioxide carrier of the present invention, ammonia water, titanium nitrate, and ethylenediaminetetraacetic acid (EDTA) are first mixed in a specific ratio, and a complex EDTA titanium ammonium is generated after a complexation reaction. The present invention controls the addition of the three raw materials and the complexation reaction time by using approximately 5% excess EDTA, stirring for 0.5-1.5 h (more preferably 0.5-1 h), and then allowing it to stand for 2-3 h (more preferably 2 h), thus ensuring the complexation reaction proceeds fully without decomposing the generated complex. Then, ammonia water is added to convert part of the complex into titanium hydroxide. The present invention controls the amount of ammonia water added for precipitation to ensure the generated titanium hydroxide precipitate has the most suitable particle size. The precipitate is then dried to obtain ultrafine titanium dioxide powder. Finally, the titanium dioxide powder, water, and binder are mixed and extruded or pressed into sheets, then calcined at high temperature to obtain the high water absorption titanium dioxide carrier of the present invention. If the calcination temperature is too low, the binder will not decompose completely, resulting in impurities in the catalyst and affecting its activity. However, if the calcination temperature is too high, the specific surface area of the catalyst will decrease, and its mechanical strength will also be reduced. This invention, by controlling the calcination temperature of the support, enables the catalyst to exhibit superior performance in terms of activity, specific surface area, and mechanical strength.
[0018] According to a specific embodiment of the present invention, preferably, the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst is prepared by the following steps: the titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt and kept for a period of time to load the scandium salt and tungsten salt onto the titanium dioxide support; then the titanium dioxide support loaded with scandium salt and tungsten salt is dried and calcined at least to obtain the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst.
[0019] More preferably, the scandium salt includes scandium nitrate and / or scandium sulfate, etc.; even more preferably, the scandium salt is scandium nitrate.
[0020] More preferably, the tungsten salt includes ammonium tungstate and / or tungsten nitrate, etc.; even more preferably, the tungsten salt is ammonium tungstate.
[0021] More preferably, the concentration of scandium salt in the mixed solution of scandium salt and tungsten salt is 12-35 g / L (calculated as scandium oxide), and the concentration of tungsten salt is 180-240 g / L (calculated as tungsten oxide).
[0022] More preferably, the ratio of the titanium dioxide carrier to the mixed solution of scandium salt and tungsten salt is (20-80) g : (50-150) mL.
[0023] More preferably, the titanium dioxide support is impregnated in a mixed solution of scandium salt and tungsten salt for 2-3 hours. This impregnation process is a static impregnation, and the temperature can be room temperature. If the impregnation time is too short, the active component cannot fully penetrate the center of the support during impregnation, resulting in more active component dispersed on the surface of the support and less in the center, affecting catalyst activity. However, if the impregnation time is too long, the solution will dissolve the support surface, affecting both the appearance of the catalyst and the viscosity of the impregnation solution, affecting reusability. The impregnation time specified in this invention effectively solves these problems, ensuring high catalyst activity without causing surface dissolution of the support or increased viscosity of the impregnation solution.
[0024] More preferably, the above steps further include: filtering the titanium dioxide support loaded with scandium salt and tungsten salt from the mixed solution, allowing it to stand for a period of time, such as 2-3 hours, to allow the liquid to drip dry, and then drying and calcining it.
[0025] More preferably, the temperature for drying the titanium dioxide support loaded with scandium salt and tungsten salt is 100-120°C, and the drying time is 3-5 hours.
[0026] More preferably, the calcination temperature is 480-500℃ and the calcination time is 2-3 hours.
[0027] A second aspect of the present invention provides a method for preparing the above-mentioned titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, comprising the following steps:
[0028] The titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt for a period of time to load the scandium salt and tungsten salt onto the titanium dioxide support; then the titanium dioxide support loaded with scandium salt and tungsten salt is dried and calcined to obtain the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst.
[0029] In the above preparation method, preferably, the titanium dioxide support is prepared by the following steps: mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate; drying the titanium hydroxide precipitate to obtain titanium dioxide powder; and molding and calcining the titanium dioxide powder to obtain the titanium dioxide support.
[0030] More preferably, the titanium salt includes one or a combination of several of titanium nitrate, titanium tetrachloride, and titanium oxysulfate. Even more preferably, the titanium salt is titanium nitrate.
[0031] More preferably, the complexing agent includes ethylenediaminetetraacetic acid and ammonia.
[0032] More preferably, the process of mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate specifically includes: mixing titanium salt (preferably titanium nitrate), ethylenediaminetetraacetic acid (EDTA), and ammonia for complexation, stirring for 0.5-1.5 h and then letting stand for 2-3 h to obtain a solution of a complex (the complex is mainly titanium ammonium EDTA) (the solution is a transparent and clear solution); then adding ammonia for precipitation and stirring for 0.5-1.5 h to form titanium hydroxide precipitate; wherein, the mass concentration of the ammonia is 2-10% (the concentrations of the ammonia for complexation and the ammonia for precipitation are both within this range), and the mass ratio of titanium salt (preferably titanium nitrate), EDTA, ammonia for complexation, and ammonia for precipitation is (150-280):(50-150):(550-700):(330-420).
[0033] More preferably, the temperature for drying the titanium hydroxide precipitate is 160-180°C, and the drying time is 2-3 hours.
[0034] More preferably, the average particle size of the titanium dioxide powder is 200-250 mesh.
[0035] More preferably, the molding includes extrusion molding and / or tablet molding; particularly preferably, the carrier obtained by extrusion molding is a cylindrical carrier with a diameter of 3-4 mm and a length of 8-10 mm; the carrier obtained by tablet molding is a disc-shaped carrier with a diameter of 6-8 mm and a height of 2-3 mm.
[0036] More preferably, during the molding process, the titanium dioxide powder is mixed with an appropriate amount of binder and other additives, as well as water, before molding. The binder may be guar gum. The mass ratio of the titanium dioxide powder, binder, and water can be 100:(2-4):(25-30).
[0037] More preferably, the calcination temperature is 500-550℃ and the calcination time is 2-3 hours.
[0038] In the above preparation method, preferably, the water absorption rate of the titanium dioxide support is 40-45%, the particle size of the titanium dioxide support is 200-250 mesh, and the specific surface area of the titanium dioxide support is >180 m². 2 / g, the mechanical strength of the titanium dioxide carrier is >150N / particle.
[0039] In the above preparation method, preferably, the scandium salt includes scandium nitrate and / or scandium sulfate, etc.; more preferably, the scandium salt is scandium nitrate.
[0040] In the above preparation method, preferably, the tungsten salt includes ammonium tungstate and / or tungsten nitrate, etc.; more preferably, the tungsten salt is ammonium tungstate.
[0041] In the above preparation method, preferably, the concentration of scandium salt in the mixed solution of scandium salt and tungsten salt is 12-35 g / L (calculated as scandium oxide), and the concentration of tungsten salt is 180-240 g / L (calculated as tungsten oxide).
[0042] In the above preparation method, preferably, the ratio of the amount of titanium dioxide carrier to the mixed solution of scandium salt and tungsten salt is (20-80) g: (50-150) mL.
[0043] In the above preparation method, preferably, the titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt for 2-3 hours. This immersion process is a static immersion, and the temperature can be room temperature.
[0044] According to a specific embodiment of the present invention, preferably, the above preparation method further includes: filtering the titanium dioxide support loaded with scandium salt and tungsten salt from the mixed solution, allowing it to stand for a period of time, for example, 2-3 hours, to allow the liquid to drip dry, and then performing the drying and calcination.
[0045] In the above preparation method, preferably, the temperature for drying the titanium dioxide support loaded with scandium salt and tungsten salt is 100-120℃, and the drying time is 3-5h.
[0046] In the above preparation method, preferably, the calcination temperature is 480-500℃ and the calcination time is 2-3h.
[0047] The third aspect of the present invention provides the application of the above-mentioned titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst as a catalyst in the hydrogenation and / or hydrolysis process of Claus tail gas.
[0048] In the above application, preferably, the hydrogenation and / or hydrolysis process of the Claus tail gas includes: passing the Claus tail gas into a reaction device filled with the titanium dioxide-type low-temperature hydrogenation and hydrolysis catalyst to carry out hydrogenation and / or hydrolysis reactions, obtaining treated tail gas (mainly hydrogen sulfide). The reaction device can be a conventional Claus tail gas hydrogenation reaction device.
[0049] In the above applications, preferably, the reaction temperature of the hydrogenation and / or hydrolysis reaction is 210-220°C.
[0050] In the above applications, preferably, the space velocity of the hydrogenation and / or hydrolysis reaction is 1200-1800 h⁻¹. -1 .
[0051] In the above applications, preferably, the sulfur dioxide hydrogenation conversion rate of the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst is above 99.98%, and the organic sulfur hydrolysis rate is above 98%.
[0052] In the treatment of Claus tail gas, there are two main reasons for the decline in catalyst performance at operating temperatures of 210-220℃. First, traditional catalysts use activated alumina as a support. At low temperatures, activated alumina readily reacts with sulfur dioxide in the Claus tail gas, causing catalyst poisoning and resulting in decreased hydrolysis activity of activated alumina for organic sulfur. Second, the performance of cobalt oxide and molybdenum oxide active components in catalyzing the hydrogenation of sulfur dioxide decreases significantly with decreasing temperature, leading to poorer hydrogenation efficiency at low temperatures.
[0053] The catalyst of this invention uses titanium dioxide as a support, which does not react with sulfur dioxide in Claus tail gas at low temperatures, thus preventing catalyst poisoning and deactivation. Furthermore, the hydrogenation effect of tungsten oxide loaded on the catalyst support at low temperatures is superior to that of cobalt oxide and molybdenum oxide, and the loading of scandium oxide can further enhance the organic sulfur hydrolysis effect of the catalyst at low temperatures. However, ordinary titanium dioxide has poor adhesion, a small specific surface area, low water absorption rate after molding, and a small amount of scandium and tungsten salts loaded, resulting in low catalytic activity at low temperatures. This invention, however, prepares ultrafine titanium dioxide particles through a specific method and raw materials, which, after molding and calcination, yield a titanium dioxide support with excellent water absorption properties. Due to the excellent water absorption properties of this support, the content of scandium oxide and tungsten oxide loaded on it is comparable to that of cobalt oxide and molybdenum oxide on traditional cobalt-molybdenum / alumina catalysts. Due to the synergistic catalytic effect of the titanium dioxide support and the scandium and tungsten oxide active components of this invention, the catalyst of this invention exhibits excellent resistance to sulfur dioxide poisoning and organic sulfur hydrolysis capabilities. Therefore, the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst of the present invention exhibits superior sulfur dioxide hydrogenation activity and organic sulfur hydrolysis activity compared with traditional cobalt-molybdenum / alumina catalysts under operating conditions of 210-220℃. The catalyst also demonstrates excellent sulfur dioxide hydrogenation and organic sulfur hydrolysis effects at low temperatures.
[0054] The titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst provided by this invention is suitable for treating tail gas in sulfur recovery processes in the fields of natural gas, refinery gas, and coal chemical gas processing under low-temperature conditions (210-220℃), converting sulfur dioxide, sulfur, carbon disulfide, etc., into hydrogen sulfide through hydrogenation or hydrolysis. The operating temperature for Claus tail gas treatment is significantly lower than that of existing conventional catalysts; the catalytic activity, especially the hydrolysis performance of organic sulfur, is greatly improved; it solves many problems existing in the low-temperature operation of existing catalysts and saves fuel gas consumption.
[0055] Therefore, the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, its preparation method, and its application provided by this invention have at least the following beneficial technical effects:
[0056] 1. The titanium dioxide support prepared by this invention has a water absorption rate of 40-45%, which is at least 10-15% higher than that of titanium dioxide supports prepared by conventional methods such as the metatitanic acid method. The catalyst prepared by impregnating cobalt and molybdenum with titanium dioxide prepared by conventional methods has a cobalt oxide content of about 0.5-1% (w) and a molybdenum oxide content of about 6-7% (w). However, due to its excellent water absorption performance, the titanium dioxide support prepared by this invention can achieve a scandium oxide content of 0.5-1.5% (w) and a tungsten oxide content of 8.5-11% (w) in the catalyst after loading scandium oxide and tungsten oxide by impregnation. This solves the problem that traditional titanium dioxide supports are not suitable for impregnating active components, thereby ensuring sufficient loading of scandium oxide and tungsten oxide on the catalyst and giving full play to the synergistic catalytic effect of scandium, tungsten and titanium dioxide.
[0057] 2. Traditional cobalt-molybdenum catalysts use activated alumina as a support. These catalysts perform well under high-temperature conditions of 280-320℃, but their sulfur dioxide hydrogenation conversion rate decreases and organic sulfur hydrolysis rate drops significantly under low-temperature conditions of 210-220℃. Specifically, the sulfur dioxide hydrogenation conversion rate is approximately 99.50%, and the organic sulfur hydrolysis rate is approximately 95%. In contrast, the catalyst of this invention first prepares ultrafine titanium dioxide, then shapes and calcines it to prepare a support, and then loads scandium oxide and tungsten oxide active components. This ensures good performance under low-temperature conditions of 210-220℃, improving the catalyst's sulfur dioxide hydrogenation and organic sulfur hydrolysis performance. Specifically, the sulfur dioxide hydrogenation conversion rate is greater than 99.98%, and the organic sulfur hydrolysis rate is greater than 98%. Compared to traditional cobalt-molybdenum / alumina catalysts, the catalyst of this invention improves the sulfur dioxide hydrogenation conversion rate by approximately 0.5% and the organic sulfur hydrolysis rate by approximately 3%, which is a significant improvement in the field of hydrogenation / hydrolysis catalytic treatment of Claus tail gas.
[0058] 3. Because the catalyst of the present invention has excellent catalytic performance under low temperature operating conditions, it saves fuel gas consumption. Attached Figure Description
[0059] Figure 1 The flowchart illustrates the preparation process of a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to a specific embodiment of the present invention. Detailed Implementation
[0060] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.
[0061] According to a specific embodiment of the present invention, preferably, the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst of the present invention can be prepared by the following steps, such as... Figure 1As shown:
[0062] 550-700g of 5% ammonia solution was placed in a 2L beaker, and 150-280g of titanium nitrate (purity >99%) and 50-150g of ethylenediaminetetraacetic acid (purity >99.5%) were added. The mixture was stirred for 0.5-1.5h (more preferably 1h) and then allowed to stand for 2-3h (more preferably 2h) to obtain a solution of a complex (the complex is mainly titanium ammonium ethylenediaminetetraacetate) (this solution is a transparent and clear solution). Then, 330-420g of 5% ammonia solution was added, and the mixture was stirred for 0.5-1.5h (more preferably 1h). A large amount of white precipitate appeared in the beaker, which is titanium hydroxide precipitate. The precipitate was filtered out using medium-speed filter paper (pore size 40 micrometers). The precipitate was then heated at 160-100°C. Titanium dioxide powder with an average particle size of 200-250 mesh was obtained by drying at 80℃ for 2-3 hours. 100g of titanium dioxide powder was weighed, and 25-30g of water and 2-4g of guar gum (purity >99%) were added. After mixing, the mixture was extruded or pressed into sheets. The extruded carrier was a cylindrical carrier with a diameter of 3-4mm and a length of 8-10mm. The pressed carrier was a disc-shaped carrier with a diameter of 6-8mm and a height of 2-3mm. The cylindrical or disc-shaped carrier was calcined at 500-550℃ for 2-3 hours (preferably 2 hours) to obtain a titanium dioxide carrier. The water absorption rate of this titanium dioxide carrier was found to be 40-45%, and the specific surface area was >180m². 2 / g, mechanical strength >150N / particle;
[0063] Place 20-60g of scandium nitrate (purity >99%) and 200-260g of ammonium tungstate (purity >99%) into a 1L beaker, add water to a total volume of 1L, and stir for 0.5-1.5h to obtain a bright yellow clear solution, which is the mixed solution of scandium nitrate and ammonium tungstate; test the concentration of scandium salt (calculated as scandium oxide) in the solution to be 12-35g / L, and the concentration of tungstate salt (calculated as tungsten oxide) to be 180-240g / L; add 100mL of the above solution to a 500mL beaker. The mixed solution was weighed, and 50g of cylindrical or disc-shaped support was poured into a 500mL beaker for static impregnation for 2-3 hours at room temperature to obtain a titanium dioxide support loaded with scandium and tungsten salts. The titanium dioxide support loaded with scandium and tungsten salts was filtered out and allowed to stand for 2-3 hours, then dried at 100-120℃ for 3-5 hours, and then calcined at 480-500℃ for 2-3 hours to obtain the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst.
[0064] Analysis revealed that the scandium oxide content of the titanium dioxide-type low-temperature hydrolysis catalyst was 0.5-1.5% (w) and the tungsten oxide content was 8.5-11% (w). More preferably, based on 100% of the total weight of the titanium dioxide-type low-temperature hydrolysis catalyst, the catalyst comprises: 1.0-1.5% scandium oxide, 9.5-11% tungsten oxide, and 87.5-89.5% titanium dioxide support.
[0065] In the following examples and comparative examples, the catalyst performance evaluation experiment may include the following steps: crushing the catalyst and loading it into a catalyst activity evaluation device; introducing a mixture of hydrogen sulfide, sulfur dioxide, hydrogen, carbon disulfide, water vapor and nitrogen, and carrying out a catalytic reaction at a reaction temperature of 210-220°C; analyzing the concentrations of hydrogen sulfide, sulfur dioxide and carbon disulfide in the inlet and outlet gases of the device, and calculating the sulfur dioxide hydrogenation conversion rate and organic sulfur (carbon disulfide) hydrolysis rate of the catalyst based on the analysis results. The catalyst performance evaluation experiment may specifically include the following steps: Weigh 20g of catalyst, crush it to a particle size of 1-1.5mm, and load it into a catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1-1.5%), sulfur dioxide (volume concentration 0.5-0.8%), hydrogen (volume concentration 3-4%), carbon disulfide (volume concentration 0.1-0.2%), water vapor (volume concentration 25-30%), and the remainder nitrogen, controlling the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 210-220℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device, and calculate the sulfur dioxide hydrogenation conversion rate and organic sulfur (carbon disulfide) hydrolysis rate of the catalyst based on the analysis results. The catalyst activity evaluation device used can be a conventional Claus tail gas hydrogenation reactor.
[0066] Example 1
[0067] This embodiment provides a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0068] 650g of 5% ammonia solution was weighed and placed in a 2L beaker. 170g of titanium nitrate (purity >99%) and 57g of ethylenediaminetetraacetic acid (purity >99.5%) were added. After stirring for 1 hour, the mixture was allowed to stand for 2 hours to obtain a clear, transparent solution. Then, 355g of 5% ammonia solution was added, and after stirring for 1 hour, a large amount of white precipitate appeared in the beaker. The precipitate was filtered out using medium-speed filter paper (40 micrometer pore size) and dried at 168℃ for 2 hours to obtain white titanium dioxide powder. The average particle size of the powder was measured to be 210 mesh using laser particle size analysis. 100g of the powder was weighed, and 27g of water and 3.5g of guar gum (purity >99%) were added. After mixing, the mixture was extruded into cylindrical strips. The formed cylindrical strips were calcined at 520℃ for 2 hours to obtain a titanium dioxide carrier. The carrier was cylindrical with a diameter of 3.2mm and a length of 9.3mm. The carrier's water absorption rate was tested to be 44.3%, and its specific surface area was >180m². 2 / g, mechanical strength >150N / particle;
[0069] 34g of scandium nitrate (purity >99%) and 241g of ammonium tungstate (purity >99%) were placed in a 1L beaker, and water was added to bring the total volume to 1L. After stirring for 1 hour, a bright yellow clear solution was obtained. The concentration of scandium salt (calculated as scandium oxide) in the solution was 23.7g / L, and the concentration of tungsten salt (calculated as tungsten oxide) was 217.3g / L. 100mL of the solution was added to a 500mL beaker, and 50g of cylindrical titanium dioxide support was weighed. The support was poured into the 500mL beaker and allowed to stand for 2.5 hours for impregnation, resulting in a titanium dioxide support loaded with scandium and tungsten salts. The titanium dioxide support loaded with scandium and tungsten salts was filtered out and allowed to stand for 2 hours. Then it was dried at 110℃ for 4 hours and calcined at 500℃ for 2 hours to obtain the catalyst product.
[0070] The analysis showed that the scandium oxide content of the catalyst product was 1.05% (w) and the tungsten oxide content was 10.2% (w).
[0071] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.2%), sulfur dioxide (volume concentration 0.6%), hydrogen (volume concentration 3.5%), carbon disulfide (volume concentration 0.13%), water vapor (volume concentration 25%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 218℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0072] Based on the analysis results, the hydrogenation conversion rate of sulfur dioxide of the catalyst in this embodiment is calculated to be 99.985%, and the hydrolysis rate of organic sulfur (carbon disulfide) is 98.4%.
[0073] Example 2
[0074] This embodiment provides a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0075] 580g of 5% ammonia solution was weighed and placed in a 2L beaker. 163g of titanium nitrate (purity >99%) and 55g of ethylenediaminetetraacetic acid (purity >99.5%) were added. After stirring for 1 hour, the mixture was allowed to stand for 2 hours to obtain a clear, transparent solution. Then, 338g of 5% ammonia solution was added, and after stirring for 1 hour, a large amount of white precipitate appeared in the beaker. The precipitate was filtered out using medium-speed filter paper (40 micrometer pore size) and dried at 173℃ for 2 hours to obtain white titanium dioxide powder. The average particle size of the powder was measured to be 218 mesh using laser particle size analysis. 100g of the powder was weighed, and 28g of water and 3.6g of guar gum (purity >99%) were added. After mixing, the mixture was compressed into tablets. The resulting circular tablets were calcined at 530℃ for 2 hours to obtain a titanium dioxide carrier. The carrier was circular, with a diameter of 6.5mm and a height of 2.7mm. The carrier's water absorption rate was tested to be 43.9%, and its specific surface area was >180m². 2 / g, mechanical strength >150N / particle;
[0076] 54g of scandium nitrate (purity >99%) and 235g of ammonium tungstate (purity >99%) were placed in a 1L beaker, and water was added to bring the total volume to 1L. After stirring for 1 hour, a bright yellow clear solution was obtained. The concentration of scandium salt (calculated as scandium oxide) in the solution was 31.1g / L, and the concentration of tungsten salt (calculated as tungsten oxide) was 211.3g / L. 100mL of the solution was added to a 500mL beaker, and 50g of disc-shaped titanium dioxide support was weighed. The support was poured into the 500mL beaker and allowed to stand for 2 hours to impregnate, resulting in a titanium dioxide support loaded with scandium and tungsten salts. The titanium dioxide support loaded with scandium and tungsten salts was filtered out and allowed to stand for 2 hours. Then it was dried at 115℃ for 4 hours and calcined at 495℃ for 2 hours to obtain the catalyst product.
[0077] The analysis showed that the scandium oxide content of the catalyst product was 1.36% (w) and the tungsten oxide content was 9.8% (w).
[0078] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.2%), sulfur dioxide (volume concentration 0.6%), hydrogen (volume concentration 3.5%), carbon disulfide (volume concentration 0.13%), water vapor (volume concentration 25%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 218℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0079] Based on the analysis results, the sulfur dioxide hydrogenation conversion rate of the catalyst in this embodiment is calculated to be 99.983%, and the organic sulfur (carbon disulfide) hydrolysis rate is 98.1%.
[0080] Example 3
[0081] This embodiment provides a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0082] 550g of 5% ammonia solution was weighed and placed in a 2L beaker. 150g of titanium nitrate (purity >99%) and 50g of ethylenediaminetetraacetic acid (purity >99.5%) were added. After stirring for 1 hour, the mixture was allowed to stand for 2 hours to obtain a clear, transparent solution. Then, 330g of 5% ammonia solution was added, and after stirring for 1 hour, a large amount of white precipitate appeared in the beaker. The precipitate was filtered out using medium-speed filter paper (40 micrometer pore size) and dried at 180℃ for 2 hours to obtain white titanium dioxide powder. The average particle size of the powder was measured to be 245 mesh using laser particle size analysis. 100g of the powder was weighed, and 30g of water and 4.0g of guar gum (purity >99%) were added. After mixing, the mixture was extruded into cylindrical strips. The formed cylindrical strips were calcined at 500℃ for 2 hours to obtain a titanium dioxide carrier. The carrier was cylindrical with a diameter of 3.3mm and a length of 9.2mm. The carrier's water absorption rate was tested to be 45.0%, and its specific surface area was >180m². 2 / g, mechanical strength >150N / particle;
[0083] 59.0 g of scandium nitrate (purity >99%) and 257.5 g of ammonium tungstate (purity >99%) were placed in a 1 L beaker, and water was added to a total volume of 1 L. After stirring for 1 h, a bright yellow clear solution was obtained. The concentration of scandium salt (calculated as scandium oxide) in the solution was 34.3 g / L, and the concentration of tungsten salt (calculated as tungsten oxide) was 238.7 g / L. 100 mL of the solution was added to a 500 mL beaker, and 50 g of cylindrical titanium dioxide support was weighed. The support was poured into the 500 mL beaker and allowed to stand for 3 h for impregnation to obtain a titanium dioxide support loaded with scandium and tungsten salts. The titanium dioxide support loaded with scandium and tungsten salts was filtered out and allowed to stand for 2 h. Then it was dried at 120 °C for 4 h and calcined at 500 °C for 2 h to obtain the catalyst product.
[0084] The catalyst product was found to contain 1.49% (w) scandium oxide and 10.8% (w) tungsten oxide.
[0085] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.4%), sulfur dioxide (volume concentration 0.7%), hydrogen (volume concentration 3.9%), carbon disulfide (volume concentration 0.2%), water vapor (volume concentration 28%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 228℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0086] Based on the analysis results, the hydrogenation conversion rate of sulfur dioxide of the catalyst in this embodiment is calculated to be 99.985%, and the hydrolysis rate of organic sulfur (carbon disulfide) is 98.7%.
[0087] Comparative Example 1
[0088] This comparative example provides a hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0089] Titanium dioxide support was prepared using the metatitanic acid method: 100g metatitanic acid powder, 2-3g guar gum powder, and 30-35g nitric acid aqueous solution (10% by weight) were mixed and extruded into a column using an extruder. After being placed for 24-48 hours, the support was dried at 120℃ for 2-3 hours and then calcined at 460-480℃ for 5-8 hours to obtain the titanium dioxide support. The support was cylindrical with a diameter of 4.0mm and a length of 8.7mm. The water absorption rate of the support was tested to be 12.9%.
[0090] Weigh 310g of ammonium molybdate with a purity of 98.0%, place it in a 5L beaker, add 600g of distilled water to dissolve it, and continue adding distilled water until the total volume of the solution reaches 1L; the concentration of molybdenum salt (calculated as molybdenum oxide) in the solution is 263g / L; measure 100mL of ammonium molybdate solution into another 1L beaker, weigh 50g of titanium dioxide support, immerse it in 100mL of ammonium molybdate solution, soak for 3h, filter it out, dry it at 120℃ for 4h, and then calcine it at 485℃ for 2h;
[0091] Weigh 138g of cobalt nitrate with a purity of 96.5%, place it in a 5L beaker, add 600g of distilled water to dissolve it, and continue adding distilled water until the total volume of the solution reaches 1L; the concentration of cobalt salt in the solution (calculated as cobalt oxide) is 34.2g / L; measure 100mL of cobalt nitrate solution into another 1L beaker, weigh 50g of the above-prepared molybdenum oxide-supported carrier, immerse it in 100mL of cobalt nitrate solution, soak for 3h, filter it out, dry it at 110℃ for 4h, and then calcine it at 508℃ for 2h to obtain the catalyst product.
[0092] The catalyst product was found to contain 0.73% (w) cobalt oxide and 6.8% (w) molybdenum oxide.
[0093] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.2%), sulfur dioxide (volume concentration 0.6%), hydrogen (volume concentration 3.5%), carbon disulfide (volume concentration 0.13%), water vapor (volume concentration 25%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 218℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0094] Based on the analysis results, the hydrogenation conversion rate of sulfur dioxide of the catalyst in this comparative example was calculated to be 88.5%, and the hydrolysis rate of organic sulfur (carbon disulfide) was 95.2%.
[0095] Comparative Example 2
[0096] This comparative example provides a hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0097] The activated alumina carrier is used. This carrier is spherical with a diameter of 5.5 mm and a specific surface area of 283 g / m². 2 The water absorption rate is 45%. Weigh 310g of ammonium molybdate with a purity of 98.0%, put it into a 5L beaker, add 600g of distilled water to dissolve it, and continue to add distilled water until the total volume of the solution reaches 1L. The concentration of molybdenum salt in the solution (calculated as molybdenum oxide) is 263g / L. Measure 100mL of ammonium molybdate solution into another 1L beaker, weigh 50g of activated alumina carrier, immerse it in 100mL of ammonium molybdate solution, soak for 3h, filter it out, dry at 120℃ for 4h, and then calcine at 485℃ for 2h.
[0098] Weigh 138g of cobalt nitrate with a purity of 96.5%, place it in a 5L beaker, add 600g of distilled water to dissolve it, and continue adding distilled water until the total volume of the solution reaches 1L; the concentration of cobalt salt in the solution (calculated as cobalt oxide) is 34.2g / L; measure 100mL of cobalt nitrate solution into another 1L beaker, weigh 50g of the above-prepared molybdenum oxide-supported carrier, immerse it in 100mL of cobalt nitrate solution, soak for 3h, filter it out, dry it at 110℃ for 4h, and then calcine it at 508℃ for 2h to obtain the catalyst product.
[0099] The catalyst product was found to contain 1.66% (w) cobalt oxide and 9.74% (w) molybdenum oxide.
[0100] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.2%), sulfur dioxide (volume concentration 0.6%), hydrogen (volume concentration 3.5%), carbon disulfide (volume concentration 0.13%), water vapor (volume concentration 25%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 218℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0101] Based on the analysis results, the hydrogenation conversion rate of sulfur dioxide of the catalyst in this comparative example was calculated to be 99.502%, and the hydrolysis rate of organic sulfur (carbon disulfide) was 94.8%.
[0102] Comparative Example 3
[0103] This comparative example provides a hydrogenation hydrolysis catalyst, which is prepared through the following steps:
[0104] 650g of 5% ammonia solution was weighed and placed in a 2L beaker. 170g of titanium nitrate (purity >99%) and 57g of ethylenediaminetetraacetic acid (purity >99.5%) were added. After stirring for 1 hour, the mixture was allowed to stand for 2 hours to obtain a clear, transparent solution. Then, 355g of 5% ammonia solution was added, and after stirring for 1 hour, a large amount of white precipitate appeared in the beaker. The precipitate was filtered out using medium-speed filter paper (40 micrometer pore size) and dried at 168℃ for 2 hours to obtain white titanium dioxide powder. The average particle size of the powder was measured to be 210 mesh using laser particle size analysis. 100g of the powder was weighed, and 27g of water and 3.5g of guar gum (purity >99%) were added. After mixing, the mixture was extruded into cylindrical strips. The formed cylindrical strips were calcined at 520℃ for 2 hours to obtain a titanium dioxide carrier. The carrier was cylindrical with a diameter of 3.2mm and a length of 9.3mm. The carrier's water absorption rate was tested to be 44.3%, and its specific surface area was >180m². 2 / g, mechanical strength >150N / particle;
[0105] 241g of ammonium tungstate (purity >99%) was placed in a 1L beaker, and water was added to a total volume of 1L. After stirring for 1 hour, a bright yellow clear solution was obtained. The concentration of tungsten salt in the solution (calculated as tungsten oxide) was 217.3g / L. 100mL of the solution was added to a 500mL beaker, and 50g of cylindrical titanium dioxide support was weighed. The support was poured into the 500mL beaker and allowed to stand for 2.5 hours for impregnation, resulting in titanium dioxide support loaded with tungsten salt. The titanium dioxide support loaded with tungsten salt was filtered out and allowed to stand for 2 hours. Then it was dried at 110℃ for 4 hours and calcined at 500℃ for 2 hours to obtain the catalyst product.
[0106] The tungsten oxide content of the catalyst product was analyzed to be 10.2% (w).
[0107] Weigh 20g of catalyst product, crush it to a particle size of 1-1.5mm and load it into the catalyst activity evaluation device; introduce a mixture of hydrogen sulfide (volume concentration 1.2%), sulfur dioxide (volume concentration 0.6%), hydrogen (volume concentration 3.5%), carbon disulfide (volume concentration 0.13%), water vapor (volume concentration 25%), and the remainder nitrogen; control the total gas flow rate at 1500mL / min (under standard conditions) and the reaction temperature at 218℃ to carry out the catalytic reaction; analyze the concentrations of hydrogen sulfide, sulfur dioxide, and carbon disulfide in the inlet and outlet gases of the device.
[0108] Based on the analysis results, the hydrogenation conversion rate of sulfur dioxide of the catalyst in this comparative example was calculated to be 64.5%, and the hydrolysis rate of organic sulfur (carbon disulfide) was 83.5%.
Claims
1. A titanium dioxide-based low-temperature hydrogenation hydrolysis catalyst, the catalyst comprising a titanium dioxide support and an active component supported on the titanium dioxide support, wherein the active component is scandium oxide and tungsten oxide; in, Based on the total weight of the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst as 100%, the catalyst consists of 9-12.5% of the active component and 87.5-91% of the titanium dioxide support.
2. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 1, wherein, Based on the total weight of the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst as 100%, the catalyst is composed of 0.5-1.5% scandium oxide, 8.5-11% tungsten oxide, and 87.5-91% titanium dioxide support.
3. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 1 or 2, wherein, The titanium dioxide carrier has a water absorption rate of 40-45%, a particle size of 200-250 mesh, and a specific surface area >180 m². 2 / g, the mechanical strength of the titanium dioxide carrier is >150N / particle.
4. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 1, wherein, The titanium dioxide carrier is prepared by the following steps: mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate; drying the titanium hydroxide precipitate to obtain titanium dioxide powder; and molding and calcining the titanium dioxide powder to obtain the titanium dioxide carrier.
5. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The titanium salt includes one or a combination of titanium nitrate, titanium tetrachloride, and titanium oxysulfate.
6. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The complexing agent includes ethylenediaminetetraacetic acid and ammonia.
7. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The specific steps of mixing titanium salt with a complexing agent and reacting to form titanium hydroxide precipitate include: mixing titanium salt, ethylenediaminetetraacetic acid (EDTA), and ammonia for complexation, stirring for 0.5-1.5 h and then letting stand for 2-3 h to obtain a solution of the complex; then adding ammonia for precipitation and stirring for 0.5-1.5 h to form titanium hydroxide precipitate; wherein the mass concentration of the ammonia is 2-10%, and the mass ratio of titanium salt, EDTA, ammonia for complexation, and ammonia for precipitation is (150-280):(50-150):(550-700):(330-420).
8. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The titanium hydroxide precipitate is dried at a temperature of 160-180℃ for 2-3 hours.
9. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The average particle size of the titanium dioxide powder is 200-250 mesh.
10. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The molding process includes extrusion molding and / or tablet molding; the carrier obtained by extrusion molding is a cylindrical carrier with a diameter of 3-4 mm and a length of 8-10 mm; the carrier obtained by tablet molding is a disc-shaped carrier with a diameter of 6-8 mm and a height of 2-3 mm.
11. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, During the molding process, the titanium dioxide powder is mixed with binder and water and then molded; the mass ratio of the titanium dioxide powder, binder and water is 100:(2-4):(25-30).
12. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 4, wherein, The roasting temperature is 500-550℃, and the roasting time is 2-3 hours.
13. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 1, wherein, The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst is prepared by the following steps: the titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt and kept for a period of time to load the scandium salt and tungsten salt onto the titanium dioxide support; then the titanium dioxide support loaded with scandium salt and tungsten salt is dried and calcined at least to obtain the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst.
14. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The scandium salts include scandium nitrate and / or scandium sulfate.
15. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The tungsten salt includes ammonium tungstate and / or tungsten nitrate.
16. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The concentration of scandium salt in the mixed solution of scandium and tungsten salt is 12-35 g / L (calculated as scandium oxide), and the concentration of tungsten salt is 180-240 g / L (calculated as tungsten oxide).
17. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt for 2-3 hours.
18. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The titanium dioxide support loaded with scandium salt and tungsten salt was dried at a temperature of 100-120℃ for 3-5 hours.
19. The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to claim 13, wherein, The roasting temperature is 480-500℃, and the roasting time is 2-3 hours.
20. A method for preparing a titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to any one of claims 1-19, comprising the following steps: The titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt for a period of time to load the scandium salt and tungsten salt onto the titanium dioxide support; then the titanium dioxide support loaded with scandium salt and tungsten salt is dried and calcined to obtain the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst.
21. The preparation method according to claim 20, wherein, The titanium dioxide carrier is prepared by the following steps: mixing and reacting titanium salt with a complexing agent to form titanium hydroxide precipitate; drying the titanium hydroxide precipitate to obtain titanium dioxide powder; and molding and calcining the titanium dioxide powder to obtain the titanium dioxide carrier.
22. The preparation method according to claim 21, wherein, The titanium salt includes one or a combination of titanium nitrate, titanium tetrachloride, and titanium oxysulfate.
23. The preparation method according to claim 21, wherein, The complexing agent includes ethylenediaminetetraacetic acid and ammonia.
24. The preparation method according to claim 21, wherein, The specific steps of mixing titanium salt with a complexing agent and reacting to form titanium hydroxide precipitate include: mixing titanium salt, ethylenediaminetetraacetic acid (EDTA), and ammonia for complexation, stirring for 0.5-1.5 h and then letting stand for 2-3 h to obtain a solution of the complex; then adding ammonia for precipitation and stirring for 0.5-1.5 h to form titanium hydroxide precipitate; wherein the mass concentration of the ammonia is 2-10%, and the mass ratio of titanium salt, EDTA, ammonia for complexation, and ammonia for precipitation is (150-280):(50-150):(550-700):(330-420).
25. The preparation method according to claim 21, wherein, The titanium hydroxide precipitate is dried at a temperature of 160-180℃ for 2-3 hours.
26. The preparation method according to claim 21, wherein, The average particle size of the titanium dioxide powder is 200-250 mesh.
27. The preparation method according to claim 21, wherein, The molding process includes extrusion molding and / or tablet molding; the carrier obtained by extrusion molding is a cylindrical carrier with a diameter of 3-4 mm and a length of 8-10 mm; the carrier obtained by tablet molding is a disc-shaped carrier with a diameter of 6-8 mm and a height of 2-3 mm.
28. The preparation method according to claim 21, wherein, During the molding process, the titanium dioxide powder is mixed with binder and water and then molded; the mass ratio of the titanium dioxide powder, binder and water is 100:(2-4):(25-30).
29. The preparation method according to claim 21, wherein, The roasting temperature is 500-550℃, and the roasting time is 2-3 hours.
30. The preparation method according to claim 20, wherein, The scandium salts include scandium nitrate and / or scandium sulfate.
31. The preparation method according to claim 20, wherein, The tungsten salt includes ammonium tungstate and / or tungsten nitrate.
32. The preparation method according to claim 20, wherein, The concentration of scandium salt in the mixed solution of scandium and tungsten salt is 12-35 g / L (calculated as scandium oxide), and the concentration of tungsten salt is 180-240 g / L (calculated as tungsten oxide).
33. The preparation method according to claim 20, wherein, The titanium dioxide support is immersed in a mixed solution of scandium salt and tungsten salt for 2-3 hours.
34. The preparation method according to claim 20, wherein, The titanium dioxide support loaded with scandium salt and tungsten salt was dried at a temperature of 100-120℃ for 3-5 hours.
35. The preparation method according to claim 20, wherein, The roasting temperature is 480-500℃, and the roasting time is 2-3 hours.
36. The application of the titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst according to any one of claims 1-19 as a catalyst in the hydrogenation and / or hydrolysis process of Claus tail gas.
37. The application according to claim 36, wherein, The hydrogenation and / or hydrolysis process of the Claus tail gas includes: passing the Claus tail gas into a reaction device filled with the titanium dioxide-type low-temperature hydrogenation and hydrolysis catalyst to carry out hydrogenation and / or hydrolysis reactions to obtain the treated tail gas.
38. The application according to claim 37, wherein, The reaction temperature for the hydrogenation and / or hydrolysis reaction is 210-220℃.
39. The application according to claim 37, wherein, The space velocity of the hydrogenation and / or hydrolysis reaction is 1200-1800 h⁻¹. -1 .
40. The application according to claim 37, wherein, The titanium dioxide-type low-temperature hydrogenation hydrolysis catalyst has a sulfur dioxide hydrogenation conversion rate of over 99.98% and an organic sulfur hydrolysis rate of over 98%.