A method for using an ultra-low ruthenium-based catalyst for the fixed-bed acetylene hydrochlorination reaction to produce vinyl chloride

Abstract

The present application relates to a kind of ultra-low content ruthenium-based catalyst for the method for fixed bed acetylene hydrochlorination reaction of vinyl chloride, belong to catalyst preparation technology and application technical field.The present application obtains phosphorus modified activated carbon carrier with P12=triethyl phosphite as phosphorus modifier, obtains ultra-low content ruthenium-based catalyst with phosphorus modified activated carbon as carrier with ruthenium as main active component, water as solvent, and significantly improves the catalytic activity of catalyst.The catalyst has very high activity and vinyl chloride selectivity in the fixed bed acetylene hydrochlorination reaction of vinyl chloride, low cost, no mercury pollution and simple preparation method can be expanded, with greater industrial application value.The loading of ruthenium 0.05% in the reaction gas space velocity 170h ‑1 , V (C2H2) / V (HCl) =1:1.05, reaction temperature is 180 DEG C, acetylene conversion rate can reach 82%, vinyl chloride selectivity is greater than 99%, and activity is basically unchanged in 8h.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology and application, specifically relating to a method for using an ultra-low content ruthenium-based catalyst in a fixed-bed acetylene hydrochlorination reaction to produce vinyl chloride. Background Technology

[0002] Polyvinyl chloride (PVC) is one of the five major general-purpose resins, boasting advantages such as low price, flame retardancy, high strength, weather resistance, and excellent processing performance. It is widely used in building materials, home furnishings, agriculture, and medical devices, among other fields. Vinyl chloride monomer (VCM) is a crucial raw material primarily used in the production of PVC. In 2016, China's VCM production reached 11.84 million tons, accounting for over 30% of global production.

[0003] The calcium carbide process is the main method for producing vinyl chloride monomer in my country, and mercuric chloride is a commonly used catalyst in this process. However, mercury resources are becoming increasingly scarce as they are a non-renewable resource. Furthermore, the high toxicity and volatility of mercuric chloride pose serious threats to environmental safety and human health. On August 16, 2017, the Minamata Convention on Mercury officially came into effect globally. As one of the first signatories to the Convention, China will strictly adhere to its provisions. Therefore, developing mercury-free catalysts has become the most urgent and challenging task for my country's vinyl chloride industry, and is crucial for its green and sustainable development. Currently, mercury-free catalysts reported domestically and internationally are mainly divided into three categories: (1) precious metal catalysts; (2) non-precious metal catalysts; and (3) metal-free catalysts. Among these, precious metal catalysts are considered to have the most promising prospects for industrial application.

[0004] Recent studies have shown that noble metals such as Au, Pt, Pd, and Ru exhibit excellent catalytic performance in the hydrochlorination of acetylene. Hutching et al. discovered a significant positive correlation between the catalytic activity of metal ions and the corresponding standard electrode potential, and predicted that Au would have high catalytic performance. Subsequently, more and more research has focused on Au-based catalysts. The research mainly focuses on improving the catalytic activity and stability of Au-based catalysts by adding metal promoters such as Cu, Li, Ni, Bi, and Sn to promote the dispersion of active components.

[0005] Although gold-based catalysts exhibit good catalytic activity and stability, the scarcity of gold reserves, high cost, and difficulty in recovery pose significant obstacles to their industrial application. Ru-based catalysts, with their low cost and high catalytic activity, have become a new research hotspot in recent years. Zhu et al. compared the reaction energy barriers of HgCl2, AuCl3, and RuCl3 catalyzed acetylene hydrochlorination using DFT calculations, finding that the Ru catalyst had the lowest reaction energy barrier (9.1 kcal / mol), indicating that Ru-based catalysts may be the optimal catalyst for acetylene hydrochlorination. To improve the catalytic activity and stability of ruthenium-based catalysts, modifications are commonly found in literature and patents. For example, patent CN103894195A discloses a Ru-Bi bimetallic catalyst for acetylene hydrochlorination, with a ruthenium loading of 1%, a Ru:Bi molar ratio of 0.5, and an acetylene space velocity (GHSV(C2H2)) of 36 h⁻¹. -1 With a C(C2H2) / HCl ratio of 1:1.15 and a temperature of 140°C, the acetylene conversion rate is 99%, the selectivity for vinyl chloride is greater than 99%, and the acetylene conversion rate remains greater than 95% even after 300 hours of continuous operation. However, the catalyst has a high Ru loading and the acetylene space velocity is too low, making it not very economically viable.

[0006] Patent CN201910844596.6 describes a method for preparing a ruthenium-based catalyst for the acetylene hydrochlorination reaction modified by combining ammonium oxalate and phosphoric acid. This method involves adding the auxiliary agents ammonium oxalate and phosphoric acid, and then reacting the catalyst at T = 150℃ and GHSV(C2H2) = 552h. -1 Under the conditions of V(C2H2) / V(HCl) = 1:1.15, the catalytic activity of the 0.08% Ru-10% NCO-4% P / A catalyst was tested. The acetylene conversion reached 75.9%, and the selectivity for vinyl chloride production was 99.24%. However, when the ruthenium loading was 0.05%, the acetylene conversion was only 34.6%, and the vinyl chloride selectivity was 99.22%. This catalyst has an extremely low ruthenium content, but the acetylene conversion is low, which does not meet the requirements for industrial production.

[0007] Patent CN114146727A describes the preparation of a highly active ruthenium-based catalyst. This is achieved by modifying an activated carbon support with ammonium polyphosphate, embedding phosphorus into the activated carbon framework, and integrating the CP framework with the noble metal Ru. 3+ A synergistic effect occurs during the reaction, enhancing the catalyst's activity. Furthermore, the addition of PVP, 3-hydroxy-2-pyrrolidone, and 1-butyl-3-methylimidazolium diammonium salt as ligands forms strong bonds with the active components, improving the catalyst's adsorption of HCl and effectively inhibiting Ru... 3+ The reduction. This catalyst (ruthenium chloride content 2%) was used at T = 180℃ and GHSV(C2H2) = 180h. -1V(C2H2) / V(HCl)=

[0008] Catalytic performance tests were conducted under a 1:1.08 ratio, and the conversion rate of acetylene reached 93.5%, with a selectivity of 99.5% for the formation of vinyl chloride. After 300 hours, the conversion rate was 92.1%. This catalyst exhibits high catalytic activity and stability, but its preparation process involving support modification and ligand addition is overly complex, and the high metal loading also limits its industrial application.

[0009] Although some progress has been made in the research of Ru-based catalysts, the reported Ru-based catalysts generally have high loading levels, which significantly reduces their cost advantage compared to gold-based catalysts. Therefore, the development of ultra-low content Ru-based catalysts is of great significance for their industrial application prospects. Summary of the Invention

[0010] The technical problem solved by this invention is to provide a method for the hydrochlorination of acetylene to vinyl chloride using an ultra-low ruthenium-based catalyst. The innovation of this method lies in modifying the activated carbon support with triethyl phosphite as a phosphorus source and optimizing the catalyst synthesis steps to prepare a catalyst with ultra-low ruthenium content, high activity, and good stability. The ruthenium loading is 0.05% at a reaction gas space velocity of 170 h⁻¹. -1 V (C2H2) / V (HCl) With a ratio of 1:1.05 and a reaction temperature of 180℃, the acetylene conversion rate can reach 82%, the vinyl chloride selectivity is greater than 99%, and the activity remains basically unchanged after 8 hours, providing a unique and effective solution for the low-cost and high-efficiency production of vinyl chloride in industry.

[0011] To solve the technical problem of this invention, the proposed technical solution is as follows: a method for using an ultra-low content ruthenium-based catalyst in a fixed-bed acetylene hydrochlorination reaction to produce vinyl chloride, wherein the preparation method of the ultra-low content ruthenium-based catalyst includes the following steps:

[0012] (1) Preparation of precursor solution: Weigh 0.2780g of ruthenium trichloride (RuCl3) solid and dissolve it in 10ml of distilled water. Shake until the RuCl3 is completely dissolved, and then make up to 50ml of brown round bottom flask to obtain RuCl3 stock solution, Ru: 2.7070mg / ml;

[0013] (2) Preparation of phosphorus-modified carbon support: Weigh 3g of activated carbon and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 1.36g of triethyl phosphite (phosphorus source), and 1.5mL of hydrogen peroxide (mass concentration 30%). Add them to the beaker in sequence and stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain phosphorus-modified carbon support.

[0014] (3) Catalyst preparation by impregnation method: Take 1.2g of phosphorus-modified carbon support obtained in step (2) and spread it evenly in a mortar; take 222ul of ruthenium precursor solution obtained in step (1), add it to pure water to prepare 2.4ml solution, and uniformly drop it onto the phosphorus-modified carbon support, so that the final ratio of phosphorus-modified carbon support / g: solution / ml is 1:2. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth. The mass ratio of ruthenium to support in the catalyst is 0.05:99.95.

[0015] (4) Place the ground catalyst in a forced-air drying oven and dry for 12-24 hours.

[0016] (5) The prepared ruthenium-based catalyst was used in the fixed-bed acetylene hydrochlorination reaction to produce vinyl chloride.

[0017] Preferably, in step (1), distilled water is used as the solvent. An appropriate amount of ruthenium trichloride (RuCl3) solid is dissolved in distilled water at room temperature, shaken for 10 min using a mixer, and then sonicated for 30 min to prepare a RuCl3 stock solution of 2.7070 mg / ml. The solution is then sealed and stored at low temperature in the dark.

[0018] Preferably, the activated carbon in step (2) is one or more of the following: untreated 200-mesh wood-based activated carbon, coconut shell activated carbon, and coal-based activated carbon.

[0019] Preferably, the activated carbon in step (2) is in the form of columnar, powdered, or flake-shaped particles with a particle size of 200 mesh and a specific surface area of ​​1000-1200 m². 2 / g.

[0020] Preferably, the mass ratio of the modifier to activated carbon in step (2) is 1wt%-10wt%, and the theoretical phosphorus loading is 4wt%.

[0021] Preferably, the catalyst after grinding in step (3) should have a smooth surface and then be dried in a 90°C forced-air drying oven.

[0022] Preferably, the specific steps are as follows:

[0023] (1) Filling the catalyst: Place a layer of quartz wool with a thickness of 10 mm in the middle of a quartz reaction tube with a diameter of 10 mm, add the catalyst into the reaction tube and ensure that the catalyst is flat, and then place another layer of quartz wool with a thickness of 10 mm.

[0024] (2) Before the reaction: The entire pipeline was purged with N2 at a flow rate of 20 mL / min for 60 min to remove air and moisture from the system. At the same time, the temperature was controlled, increased to 150℃ at 5℃ / min and held for 30 min, and then increased to 180℃ at 5℃ / min. Then, HCl was introduced at a flow rate of V = 20 mL / min and held for 30 min. Subsequently, the reaction gas was introduced at a flow rate of V(C2H2) = 16 mL / min and V(HCl) = 16.8 mL / min and held for 10 min to ensure that the catalyst was in a gaseous atmosphere of acetylene and hydrogen chloride. Then, the reaction gas flow rate was reduced to a ratio of V(C2H2) / V(HCl) = 1:1.05 and held at the reaction flow rate for 10 minutes before online monitoring began.

[0025] (3) After the reaction: The gaseous product is first passed through an absorption bottle containing NaOH solution to remove excess HCl, and then analyzed online by gas chromatography to evaluate the acetylene conversion rate and selectivity to vinyl chloride.

[0026] Beneficial effects:

[0027] This invention provides a method for preparing an ultra-low content ruthenium-based catalyst. Compared with other methods, this method significantly reduces preparation costs, simplifies operation, and is scalable. The technical solution adopted in this invention involves modifying the support with one or more of the following activated carbon surface modifiers: P1 = 1,4-bis(diphenylphosphine)butane, P2 = hydroxyethylidene diphosphonic acid, P3 = triphenylphosphine, P4 = phosphoric acid, P5 = diammonium hydrogen phosphate, P6 = tetraphenylphosphine bromide, P7 = diphenylphosphonic acid, P8 = ethylenediaminetetramethylenephosphonic acid, P9 = phenylphosphonic acid, P10 = nitrilotrimethylenephosphonic acid, P11 = triphenyl phosphonate, and P12 = triethyl phosphonite. Water is chosen as the solvent, and the Ru content in the catalyst is significantly reduced, thus preparing an ultra-low content ruthenium-based catalyst with phosphorus-modified carbon as the support. This effectively saves production costs. The catalyst prepared by this invention exhibits excellent catalytic performance for the hydrochlorination of acetylene and is suitable for industrial production.

[0028] (1) The catalyst uses phosphorus-modified activated carbon as a support, ruthenium as the main active component, and water as a solvent. By rationally controlling the optimal ratio of phosphorus-modified carbon support to solvent: support / g: solution / ml = 0.5, the synthesis steps were improved to enhance the efficiency of the catalyst.

[0029] (2) The support used in this invention: One or more of the following are selected as the phosphorus source modified activated carbon: 1,4-bis(diphenylphosphine)butane, hydroxyethylidene diphosphonic acid, triphenylphosphine, phosphoric acid, diammonium hydrogen phosphate, tetraphenylphosphine bromide, diphenylphosphonic acid, ethylenediaminetetramethylenephosphonic acid, phenylphosphonic acid, nitrotrimethylphosphonic acid, triphenyl phosphonate, and triethyl phosphonite. Under the same conditions, phosphorus-modified carbon support can stabilize the active center, improve catalytic activity, and reduce the deactivation rate by changing the electronic environment of activated carbon. Through numerous experiments, triethyl phosphonite is preferred as the support used in this invention. The ruthenium loading is 0.05% at a reaction gas space velocity of 170 h⁻¹. -1 V (C2H2) / V (HCl) With a ratio of 1:1.05 and a reaction temperature of 180℃, the acetylene conversion rate can reach 82%, the vinyl chloride selectivity is greater than 99%, and the activity remains basically unchanged after 8 hours, providing a unique and effective solution for the low-cost and high-efficiency production of vinyl chloride in industry.

[0030] Compared with existing technologies: First, the modifier selected in this invention is non-toxic, harmless, and inexpensive; second, the amount of modifier used in this invention is small, and the utilization rate is high, thus the modification cost is lower than other technologies. In summary, the method of this invention significantly improves the catalytic activity and stability of the catalyst by improving the phosphorus modification process of the support. Compared with unmodified activated carbon, the synthesis method in this technology can exhibit excellent catalytic activity and can be used for industrial applications.

[0031] (3) In step (2) of the present invention, the nitrogen flow rate is kept at 50 mL / min, and the temperature is raised to 900℃ for calcination at a rate of 5℃ / min for 1 h to obtain phosphorus-modified carbon support.

[0032] (4) In step (3) of the present invention, the catalyst is ground until smooth in a clockwise direction within 10 minutes, and then placed in a 90°C forced-air drying oven for drying. Grinding to smoothness in a short time can reduce the contact between the catalyst and air at room temperature and improve the loading rate and dispersion of the active components.

[0033] (5) Among them, 0.05% Ru / P12AC catalyzes the reaction at an acetylene space velocity of 170 h⁻¹. -1 At T=180℃, the conversion rate of acetylene is 82%, the selectivity of vinyl chloride is 99%, and the activity remains basically unchanged within 8 hours. Attached Figure Description

[0034] The present invention will be further described below with reference to the accompanying drawings.

[0035] Figure 1 — Relationship between acetylene conversion and reaction time for different phosphine-modified carbon-supported catalysts

[0036] Figure 2 —Selectivity-reaction time relationship of different phosphine-modified carbon-supported catalysts Detailed Implementation

[0037] Example 1 Catalyst Preparation

[0038] (1) Preparation of precursor solution: Weigh 0.2780g of ruthenium trichloride (RuCl3) solid and dissolve it in 10ml of distilled water. Shake and sonicate, and then make up to 50ml in a brown round-bottom flask to obtain RuCl3 stock solution, Ru: 2.7070mg / ml;

[0039] (2) Preparation of catalyst by impregnation method: Take 1.2g of coconut shell powdered activated carbon (AC>200 mesh, specific surface area about 1200) and spread it evenly in a mortar; take 222ul of the ruthenium precursor solution obtained in step (1), add it to pure water to make a 2.4ml solution, and evenly drop it onto the activated carbon support (AC). Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0040] The catalyst is named 0.05%Ru / AC*.

[0041] The steps for using a low-content ruthenium-based catalyst in the fixed-bed hydrochlorination of acetylene to vinyl chloride are as follows:

[0042] 1. Catalyst loading: Place a 10mm thick layer of quartz wool in the middle of a 10mm diameter quartz reaction tube, add 1.00g of catalyst into the reaction tube and ensure that the catalyst is level, and then place another 10mm thick layer of quartz wool.

[0043] 2. Before the reaction: The entire pipeline was filled with 20 mL / min. -1 The system was purged with N2 for 60 min to remove air and moisture. Simultaneously, the temperature was controlled, increasing to 150℃ at 5℃ / min and holding for 30 min, then increasing to 180℃ at 5℃ / min. Hydrogen chloride was then introduced at a flow rate of V = 20 mL / min and held for 30 min. Subsequently, the reaction gas was introduced at a flow rate of V(C2H2) = 16 mL / min and V(HCl) = 16.8 mL / min and held for 10 min, ensuring the catalyst was in an atmosphere of acetylene and hydrogen chloride. The reaction gas flow rate was then reduced to V(C2H2) = 4 mL / min and the ratio of V(C2H2) / V(HCl) = 1:1.05. After maintaining this flow rate for ten minutes, detection began.

[0044] 3. After the reaction: The gaseous product is first passed through an absorption bottle containing NaOH solution to remove excess HCl, and then analyzed online by gas chromatography to evaluate the acetylene conversion rate and selectivity for VCM.

[0045] Example 2 Catalyst Preparation

[0046] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area of ​​about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 1.14g of P1 = 1,4-bis(diphenylphosphine)butane and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P1AC*.

[0047] (2) Preparation of catalyst by impregnation method: Take 1.2g of P1AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0048] The catalyst was named 0.05% Ru / P1AC.

[0049] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0050] Example 3 Catalyst Preparation

[0051] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 0.86g of P2=hydroxyethylidene diphosphonic acid (HEDP), and 1.5mL of hydrogen peroxide (30%). Add them to the beaker in sequence and stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P2AC*.

[0052] (2) Preparation of catalyst by impregnation method: Take 1.2g of P2AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0053] The catalyst was named 0.05% Ru / P2AC.

[0054] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0055] Example 4 Catalyst Preparation

[0056] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 1.5g of P3=triphenylphosphine and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P3AC*.

[0057] (2) Preparation of catalyst by impregnation method: Take 1.2g of P3AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0058] The catalyst was named 0.05% Ru / P3AC*.

[0059] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0060] Example 5 Catalyst Preparation

[0061] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area of ​​about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 0.435g of P4=phosphoric acid and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P4AC*.

[0062] (2) Preparation of catalyst by impregnation method: Take 1.2g of P4AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0063] The catalyst was named 0.05% Ru / P4AC*.

[0064] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0065] Example 6 Catalyst Preparation

[0066] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 0.660g of P5=diammonium hydrogen phosphate and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, keep the nitrogen flow rate at 50mL / min and heat to 900℃ for 1h at a heating rate of 5℃ / min to obtain P5AC*.

[0067] (2) Preparation of catalyst by impregnation method: Take 1.2g of P5AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0068] The catalyst was named 0.05% Ru / P5AC*.

[0069] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0070] Example 7 Catalyst Preparation

[0071] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. Add 1.5mL of glacial acetic acid while stirring at room temperature for 30min. Measure 25mL of deionized water, weigh 3.53g of P6=tetraphenylphosphine bromide and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P6AC*.

[0072] (2) Preparation of catalyst by impregnation method: Take 1.2g of P6AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0073] The catalyst was named 0.05% Ru / P6AC*.

[0074] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0075] Example 8 Catalyst Preparation

[0076] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. Add 1.5mL of glacial acetic acid while stirring at room temperature for 30min. Measure 25mL of deionized water, weigh 0.880g of P7=diphenylphosphine acid and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P7AC*.

[0077] (2) Preparation of catalyst by impregnation method: Take 1.2g of P7AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and evenly drop it onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0078] The catalyst was named 0.05% Ru / P7AC*.

[0079] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0080] Example 9 Catalyst Preparation

[0081] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. Add 1.5mL of glacial acetic acid while stirring at room temperature for 30min. Measure 25mL of deionized water, weigh 0.440g of P8=ethylenediaminetetramethylenephosphonic acid, and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P8AC*.

[0082] (2) Preparation of catalyst by impregnation method: Take 1.2g of P8AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0083] The catalyst was named 0.05% Ru / P8AC*.

[0084] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0085] Implementation of 10 catalyst preparation

[0086] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 0.637g of P9=diphenylphosphonic acid and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P9AC*.

[0087] (2) Preparation of catalyst by impregnation method: Take 1.2g of P9AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0088] The catalyst was named 0.05% Ru / P9AC*.

[0089] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0090] Example 11 Catalyst Preparation

[0091] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area of ​​about 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 0.402g of P10=trimethylammonium phosphonic acid, and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 25mL-50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P10AC*.

[0092] (2) Preparation of catalyst by impregnation method: Take 1.2g of P10AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0093] The catalyst was named 0.05% Ru / P10AC*.

[0094] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0095] Example 12 Catalyst Preparation

[0096] (1) Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area about 1200) and place it in a beaker containing 25mL of deionized water. Add 1.5mL of glacial acetic acid while stirring at room temperature for 30min. Measure 25mL of deionized water, weigh 3.63g of P11=triphenyl phosphonate, and 1.5mL of hydrogen peroxide (30%), and add them to the beaker in sequence. Stir continuously at room temperature in the dark for 24h. Filter and dry in an oven at 90℃ for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a heating rate of 5℃ / min to 900℃ for 1h to obtain P11AC*.

[0097] (2) Preparation of catalyst by impregnation method: Take 1.2g of P11AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to make 2.4ml solution, and add it evenly dropwise onto the phosphine-modified carbon support. Grind the catalyst thoroughly in a clockwise direction until the surface is smooth, then transfer it to a petri dish and dry it in a 90℃ forced-air drying oven for 12h. After drying, seal and store.

[0098] The catalyst was named 0.05% Ru / P11AC*.

[0099] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0100] Example 13 Catalyst Preparation

[0101] (1) Preparation of precursor solution: Weigh 0.2780g of ruthenium trichloride (RuCl3) solid and dissolve it in 10ml of distilled water. Shake until the RuCl3 is completely dissolved, and then make up to 50ml of brown round bottom flask to obtain RuCl3 stock solution, Ru: 2.7070mg / ml;

[0102] Weigh 3g of coconut shell powdered activated carbon (>200 mesh, specific surface area approximately 1200) and place it in a beaker containing 25mL of deionized water. While stirring at room temperature, add 1.5mL of glacial acetic acid for 30min. Measure 25mL of deionized water, weigh 1.36g of P12=triethyl phosphite, and 1.5mL of hydrogen peroxide (30%), and add them sequentially to the above beaker. Stir continuously at room temperature in the dark for 24h. Filter and dry in a 90℃ oven for 12-24h. In a tube furnace, maintain a nitrogen flow rate of 50mL / min and calcine at a rate of 5℃ / min to 900℃ for 1h to obtain P12AC*.

[0103] (2) Catalyst preparation by impregnation method: Take 1.2g of P12AC* obtained in step (1) and spread it evenly in a mortar; weigh 222ul of ruthenium precursor solution, add it to pure water to prepare a 2.4ml solution, and evenly drop it onto the phosphine-modified carbon support. Grind the catalyst in a clockwise direction until smooth within 10min, and then place it in a 90℃ forced-air drying oven to dry. Grinding to smoothness in a short time can reduce the contact between the catalyst and air at room temperature and improve the loading rate and dispersion of the active components. Then transfer it to a petri dish and place it in a 90℃ forced-air drying oven to dry for 12h. After drying, seal and store.

[0104] The catalyst was named 0.05% Ru / P12AC*.

[0105] The steps for using a low-content ruthenium-based catalyst in the fixed-bed acetylene hydrochlorination to produce vinyl chloride are the same as in Example 1 and will not be repeated here.

[0106] Table 1. Acetylene hydrochlorination reactivity test

[0107]

[0108]

[0109] With 0.05% Ru / P12AC catalysis, at an acetylene space velocity of 170 h⁻¹, -1 At T=180℃, the conversion rate of acetylene is 82%, the selectivity of vinyl chloride is 99%, and the activity remains basically unchanged within 8 hours.

Claims

1. A process for the use of an ultra-low content ruthenium-based catalyst for the fixed-bed acetylene hydrochlorination to vinyl chloride reaction, characterized in that The method for preparing a ruthenium-based catalyst with an ultra-low content comprises the following steps: (1) preparing a precursor solution: first, 0.2780 g of ruthenium trichloride (RuCl3) solid is weighed and dissolved in 10 ml of distilled water, and after the RuCl3 is completely dissolved, the solution is diluted to 50 ml in a brown round-bottom flask to obtain a RuCl3 mother liquor, with Ru: 2.7070 mg / ml; (2) preparing a phosphorus-modified carbon carrier: 3 g of activated carbon is weighed and placed in a beaker containing 25 ml of deionized water, and 1.5 ml of glacial acetic acid is added while stirring at room temperature for 30 min; 25 ml of deionized water is measured, and 1.36 g of phosphorus source triethyl phosphite and 1.5 ml of 30% hydrogen peroxide are weighed and added to the above beaker in sequence, and the mixture is continuously stirred for 24 h under room temperature and light-proof conditions; filtration is performed, and the mixture is dried in a 90°C oven for 12-24 h; in a tube furnace, the nitrogen flow rate is maintained at 50 ml / min, the temperature is raised to 900°C at a rate of 5°C / min, and calcination is performed for 1 h to obtain a phosphorus-modified carbon carrier; (3) preparing the catalyst by impregnation: 1.2 g of the phosphorus-modified carbon carrier prepared in step (2) is taken and laid flat in a mortar; 222 ul of the ruthenium precursor solution prepared in step (1) is taken and added to pure water to prepare a 2.4 ml solution, which is uniformly added to the phosphorus-modified carbon carrier, with the final phosphorus-modified carbon carrier / g: solution / ml = 1:2; the catalyst is thoroughly ground in a clockwise direction until the surface is smooth, and the mass ratio of ruthenium to carrier in the catalyst is 0.05:99.95; (4) the ground catalyst is placed in a forced air drying oven for 12-24 h; (5) the prepared ruthenium-based catalyst is used for the fixed-bed acetylene hydrochlorination reaction to prepare vinyl chloride.

2. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized by: In step (1), distilled water is used as the solvent, and an appropriate amount of ruthenium trichloride (RuCl3) solid is dissolved in distilled water at room temperature, stirred for 10 min using a mixing instrument, and then ultrasonically treated for 30 min to prepare a RuCl3 mother liquor with a concentration of 2.7070 mg / ml, which is sealed, stored in the dark, and stored at low temperature.

3. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized in that In step (2), the activated carbon is one or more of 200 mesh wood-based activated carbon, coconut shell activated carbon, and coal-based activated carbon without pretreatment.

4. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized in that The shape of the activated carbon in step (2) is cylindrical, powdered or flaky, the particle size is 200 mesh, and the specific surface area is 1000-1200 m 2 / g.

5. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized in that In step (2), the phosphorus loading is 4 wt%.

6. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized in that In step (3), the ground catalyst should be smooth on the surface before being placed in a 90°C forced air drying oven.

7. Process for the use of the ultra-low ruthenium-based catalyst according to claim 1 for the production of vinyl chloride by the fixed-bed acetylene hydrochlorination reaction, characterized by: The specific steps are as follows: (1) loading the catalyst: a layer of quartz wool with a thickness of 10 mm is laid in the middle position of a quartz reaction tube with a diameter of 10 mm, the catalyst is added to the reaction tube and ensured to be flat, and then another layer of quartz wool with a thickness of 10 mm is laid; (2) Before reaction: the whole pipeline was purged with N2 at a flow rate of 20 mL / min for 60 min to remove air and moisture in the system, at the same time, the temperature was controlled to increase to 150°C at a rate of 5°C / min and keep for 30 min, then to increase to 180°C at a rate of 5°C / min, then HCl was introduced at a flow rate of V=20 mL / min and kept for 30 min, then the reaction gas was introduced at a flow rate of V(C2H2)=16 mL / min, V(HCl)=16.8 mL / min and kept for 10 min to ensure that the catalyst was in the gas atmosphere of acetylene and hydrogen chloride, then the flow rate of the reaction gas was reduced at a ratio of V(C2H2) / V(HCl)=1:1.05, after keeping for ten minutes at the reaction flow rate, online detection was started; (3) After reaction: the gas phase product was first passed through an absorption bottle containing NaOH solution to remove excess HCl, then online analysis was carried out by gas chromatography to evaluate the acetylene conversion rate and the selectivity to vinylidene chloride.

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