A ruthenium-based mercury-free catalyst for the production of chloroethylene by the calcium carbide method and methods of making and using the same

Abstract

The application provides a ruthenium-based mercury-free catalyst for calcium carbide method production of chloroethylene and a preparation and use method thereof, and belongs to the technical field of catalysts.The catalyst takes industrial activated carbon as a carrier and takes a ruthenium ion liquid complex as an active component.The catalyst shows good activity and stability in an atmospheric fixed-bed acetylene hydrochlorination reaction.

Description

Technical Field

[0001] This invention proposes a ruthenium-based mercury-free catalyst for the calcium carbide process to produce vinyl chloride, along with its preparation and application methods, belonging to the field of catalyst technology. The catalyst uses industrial activated carbon as a support and a ruthenium ionic liquid complex as the active component. This catalyst exhibits good activity and stability in the atmospheric pressure fixed-bed acetylene hydrochlorination reaction. Background Technology

[0002] Polyvinyl chloride (PVC) is one of the world's five major general-purpose engineering plastics, accounting for more than 16% of the total demand for plastics. According to statistics, PVC is the most complex and versatile polymer material in terms of composition and application range among all plastic materials. Its unique molecular chain gaps make it relatively easy to add various additives, which can be appropriately mixed according to various functional needs. Currently, more than 80% of plastic additives on the market serve the PVC material industry. A huge industrial cluster has emerged around the main and auxiliary materials, modified additives, equipment processing, and other industrial chains surrounding PVC material products.

[0003] PVC resin, as a major consumption pathway for Cl2, a byproduct of the chlor-alkali industry, has long been a pillar industry for the development of the chlor-alkali sector. The PVC industry's disposal of the highly toxic Cl2 has greatly alleviated the pressure on the chlor-alkali industry. PVC products exhibit good acid and alkali resistance, aging resistance, and are easy to color. They also demonstrate excellent electrical insulation and mechanical properties. The CO2 emissions after combustion are far lower than those of similar products, contributing to carbon emission reduction. PVC products, both rigid and flexible, are inexpensive, have a wide range of applications, require short production processes, cause no pollution to the production environment, and have good recyclability, making them advantageous materials with green and environmentally friendly characteristics.

[0004] PVC is mainly polymerized from vinyl chloride (VCM) monomers, and about 80% of VCM comes from the acetylene hydrochlorination process in the coal-based route. However, industrial mercury-based catalysts are volatile and highly toxic, posing a serious threat to environmental safety and human health.

[0005] To find novel, green, and environmentally friendly catalysts to replace mercuric chloride, the development of mercury-free catalysis is imperative. Mercury-free catalysis mainly focuses on two research directions: one is to seek metal catalysts that can replace mercury components, such as Au, Ru, Cu, Pd, and Pt, to alleviate environmental pollution while reducing costs; the other is to abandon the metal active component and construct non-metallic catalyst systems based on activated carbon supports through modification. In the area of ​​precious metal catalysts, ruthenium-based catalysts are characterized by their green and environmentally friendly nature and low cost, exhibiting unique and highly efficient properties as catalysts for the hydrochlorination of acetylene.

[0006] Chinese patent CN107803222A discloses a supported ruthenium complex catalyst, comprising a porous solid support and a ruthenium complex, a metal promoter, and a non-metal promoter supported on the support surface. The ruthenium complex is one or more of the following: polypyridine ruthenium complex, ruthenium-porphyrin ruthenium complex, aromatic ruthenium complex, cyclic metal ruthenium complex, DMSO ruthenium complex, amine ruthenium complex, and imine ruthenium complex. The metal promoter is a salt of one or more metals selected from In, Bi, Ba, Sr, Fe, Mn, Zn, Cs, Ca, and Sn. The non-metal promoter is an ionic liquid. This catalyst exhibits high stability in the acetylene hydrochlorination reaction. While this invention effectively improves the activity of ruthenium-based catalysts, the addition of the metal promoter does not form a stable interaction with the ionic liquid promoter, limiting further improvement in catalyst stability.

[0007] Patent application number 201711294495.3 discloses a ruthenium complex catalyst for the hydrochlorination of acetylene and its preparation method. The catalyst is characterized by using activated carbon as a catalyst support, loading RuCl3 and an organic ligand; the molar ratio of RuCl3 to the organic ligand is 1:1 to 1:6, and Ru accounts for 0.1 to 5.0 wt.% of the total catalyst weight; the organic ligand is one or more of triphenylphosphine, pyridine, 2,2'-bipyridine, acetylacetone, dichlorophenylphosphine, chlorobenzene, cyclopentadiene, 4-methylisopropylbenzene, and 1,5-cyclooctadiene. Although the catalyst preparation process is simple, the loading of the added metal is too high, and its catalytic activity and stability under the same conditions need to be improved.

[0008] Currently, the main challenges of ruthenium-based acetylene hydrochlorination catalysts include high cost due to high loading, the need to improve catalyst stability, and difficulties in industrial-scale production. Against this backdrop, this application discloses a mercury-free acetylene hydrochlorination catalyst using activated carbon as a support, a ruthenium ionic liquid complex as the active component, and nitrogen-containing ionic liquids to enhance activity and stability. This method is environmentally friendly, cost-effective, and shows promising prospects for industrialization. Summary of the Invention

[0009] To address the shortcomings of the disclosed technologies, this invention proposes a ruthenium-based mercury-free catalyst for the calcium carbide process to produce vinyl chloride, as well as its preparation and application methods.

[0010] The specific technical solution adopted in this invention is as follows: a method for preparing a ruthenium-based mercury-free catalyst for the calcium carbide process to produce vinyl chloride, characterized by comprising the following preparation steps:

[0011] (1) Under stirring at room temperature, N-methylimidazolium was added to disubstituted alkanes of different carbon chain lengths, with a molar ratio of imidazolium to disubstituted alkane of 1–4:1. The mixture was then refluxed at 100–130 °C for 6–18 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain a nitrogen-containing diimidazolium cyclic ionic liquid. The disubstituted alkanes of different carbon chain lengths were one or more of 1,2-dichloroethane, 1,5-dichloropentane, 1,8-dichlorooctane, 1,10-dichlorodecane, and 1,4-dichlorobenzyl.

[0012] or:

[0013] Morpholine compounds were added to 1,4-dibromobutane under stirring at room temperature, with a molar ratio of morpholine compounds to 1,4-dibromobutane of 1–4:1. The mixture was then stirred at 60–100 °C for 6–18 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain a nitrogen-containing bismorpholine ring ionic liquid. The morpholine compounds were one or more of morpholine, N-methylmorpholine, and N-ethylmorpholine.

[0014] (2) Place the nitrogen-containing bisimidazole ring ionic liquid or nitrogen-containing bismorpholine ring ionic liquid, solvent and ruthenium salt into a hydrothermal reactor, seal it and react it at 80–140 °C for 6–12 h. Then, the obtained product is rotary evaporated, washed and dried to obtain the ruthenium ionic liquid complex.

[0015] (3) Dissolve the ruthenium ionic liquid complex in a solvent, then impregnate it into the activated carbon support by an equal volume impregnation method, let it stand at room temperature for 1 h, and then dry it at 100 °C to obtain the desired catalyst.

[0016] Preferably, the ruthenium salt is one or both of ruthenium chloride and ruthenium acetylacetonate.

[0017] Preferably, the molar ratio of the nitrogen-containing diimidazolium ring ionic liquid or nitrogen-containing dimorpholine ring ionic liquid, the solvent, and the ruthenium salt is 0.5–6:80–100:1.

[0018] Preferably, the solvent is one or more of ethanol, acetone, acetonitrile, isobutanol, and deionized water.

[0019] Preferably, the mass ratio of ruthenium ionic liquid complex to activated carbon support is 1%–5%.

[0020] The catalyst was prepared by a method for preparing ruthenium-based mercury-free catalysts for the calcium carbide process to produce vinyl chloride.

[0021] The specific steps for preparing vinyl chloride using a catalyst are as follows:

[0022] (1) The catalyst is loaded into the isothermal zone of the atmospheric pressure fixed bed reactor, and quartz sand is loaded on the top layer of the catalyst as a preheating layer. The temperature is raised to 160–180 °C under flowing nitrogen and maintained for at least 1 h.

[0023] (2) Turn off the nitrogen gas, introduce hydrogen chloride gas and continue to maintain this for at least 1 hour;

[0024] (3) Introduce acetylene gas and adjust the volume ratio of hydrogen chloride to acetylene to 1.2:1. The volume hourly space velocity of acetylene gas is 40–320 h⁻¹. –1 The reaction begins;

[0025] (4) The reaction products were analyzed using a gas chromatograph equipped with a TCD detector.

[0026] The advantages and positive effects of this invention are: the ruthenium ionic liquid complex prepared can have stronger interaction under the action of coordination bonds, effectively inhibiting the reduction of metal active components; by synthesizing a novel bicyclic ionic liquid, the conjugated organic framework structure plays a stronger role in anchoring metals and reducing the loss of metal active components.

[0027] The innovation of this invention compared with the prior art lies in:

[0028] (1) Using nitrogen-containing bi-heterocyclic ionic liquid as a promoter, based on the coordination of a single nitrogen-containing heterocyclic compound, the number of nitrogen-containing heterocycles is increased by grafting through organic synthesis, enriching nitrogen-containing active sites, enhancing the interaction between metal active species and nitrogen-containing bi-heterocyclic promoter, stabilizing the high oxidation state of ruthenium, and improving catalyst stability.

[0029] (2) Synthesize nitrogen-containing bi-heterocyclic ionic liquids for functional ionization modification. With the excellent properties of ionic liquids such as good solubility, good electron conduction, strong fluidity and wide liquid range, adding them to ruthenium-based catalysts can improve the adsorption and enrichment of acetylene and hydrogen chloride, which helps to better disperse ruthenium active species, thereby further improving the activity and stability of ruthenium-based catalysts.

[0030] (3) In-situ synthesis of metal-nitrogen-containing bi-heterocyclic ionic liquid catalysts: Ruthenium salts are directly introduced during the synthesis of nitrogen-containing bi-heterocyclic ionic liquids to enhance the coordination interaction between the active species of ruthenium metal and the nitrogen-containing bi-heterocyclic ionic liquid. The electronic effect and ionization function modification play a promoting role at the same time, increasing the content of trivalent ruthenium ions in the catalyst and preventing the ruthenium ions from being reduced and deactivated during the reaction. At the same time, the addition of these ligands can significantly reduce the content of elemental ruthenium in the catalyst, effectively reducing the deactivation and carbon deposition of the catalyst in the acetylene hydrochlorination reaction, thereby improving the stability of the catalyst. Attached Figure Description

[0031] Figure 1High-resolution transmission electron microscopy image of the catalyst prepared in Example 1. Implementation

[0032] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0033] This invention discloses a method for preparing a ruthenium-based mercury-free catalyst for the calcium carbide process to produce vinyl chloride. The active species of the catalyst is a ruthenium ionic liquid complex. Compared with traditional ionic liquids, the novel bicyclic ionic liquid has an additional imidazole or morpholine ring, which enhances the anchoring effect on the metal active species. The interaction between ruthenium metal and ionic liquid improves the stability of the ruthenium-based catalyst in the hydrochlorination of acetylene. This method can overcome the problems of easy reduction of the metal valence state, poor dispersion of active components, and easy carbon deposition on the catalyst surface in traditional catalysts.

[0034] Specifically, a novel nitrogen-containing bi-heterocyclic ionic liquid was synthesized through organic synthesis. Then, the interaction between ruthenium salt and the novel ionic liquid was enhanced by hydrothermal method to construct a ruthenium ionic liquid complex. This strengthened the anchoring effect of the nitrogen-containing bi-heterocyclic structure on the active metal species. Through subsequent impregnation and atmosphere treatment steps, a ruthenium-based mercury-free catalyst for the calcium carbide method of producing vinyl chloride can be prepared, with the ruthenium ionic liquid complex as the active component.

[0035] The specific preparation process can be carried out according to the following steps:

[0036] Step 1: Under stirring at room temperature, N-methylimidazolium was added to disubstituted alkanes with different carbon chain lengths. The molar ratio of imidazolium to disubstituted alkane was 1–4:1. The mixture was then refluxed at 100–130 °C for 6–18 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain a nitrogen-containing bisimidazole cyclic ionic liquid.

[0037] The disubstituted alkanes with different carbon chain lengths are one or more of 1,2-dichloroethane, 1,5-dichloropentane, 1,8-dichlorooctane, 1,10-dichlorodecane, and 1,4-dichlorobenzyl.

[0038] or:

[0039] Morpholine compounds were added to 1,4-dibromobutane under stirring at room temperature, with a molar ratio of morpholine compounds to 1,4-dibromobutane of 1–4:1. The mixture was then stirred at 60–100 °C for 6–18 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain a nitrogen-containing bismorpholine ring ionic liquid.

[0040] Among them, morpholine compounds are one or more of morpholine, N-methylmorpholine, and N-ethylmorpholine;

[0041] Step 2: Place the nitrogen-containing bisimidazole ring ionic liquid or nitrogen-containing bismorpholine ring ionic liquid, solvent and ruthenium salt into a hydrothermal reactor, seal it and react at 80–150 °C for 4–16 h. Then, the obtained product is rotary evaporated, washed and dried to obtain the ruthenium ionic liquid complex.

[0042] Step 3: Dissolve the ruthenium ionic liquid complex in a solvent, then impregnate it onto the activated carbon support using an equal-volume impregnation method. After standing at room temperature for 1 hour, dry it at 100 °C to obtain the desired catalyst.

[0043] The ruthenium salt is one or both of ruthenium chloride and ruthenium acetylacetonate; the molar ratio of nitrogen-containing diimidazolium ring ionic liquid or nitrogen-containing bismorpholine ring ionic liquid, solvent and ruthenium salt is 0.5–6:80–100:1; the solvent is one or more of ethanol, acetone, acetonitrile, isobutanol and deionized water; the mass ratio of ruthenium ionic liquid complex to activated carbon support is 1%–5%.

[0044] The following description, in conjunction with the accompanying drawings, illustrates this solution. Experimental methods not specifically described are performed according to the corresponding product instructions. Unless otherwise specified, the instruments, reagents, and consumables used in the embodiments can be purchased from commercial companies. The following embodiments are provided to enable those skilled in the art to gain a more detailed understanding of the invention, or to allow for non-essential improvements and adjustments based on the content of the invention. However, the scope of the invention is not limited to these embodiments. Example

[0045] (1) N-methylimidazolium was added to 1,2-dichloroethane under stirring at room temperature. The molar ratio of imidazolium to 1,2-dichloroethane was 1:1. The mixture was then refluxed at 100 °C for 6 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain the nitrogen-containing diimidazolium ring ionic liquid ethylenediimidazolium chloride.

[0046] (2) Ethylene imidazole chloride, ethanol and ruthenium chloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1, sealed and reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium ion liquid complex.

[0047] (3) The ruthenium ionic liquid complex was dissolved in deionized water at a mass ratio of 1% to 1% of the activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-1. Example

[0048] The preparation steps of Example 2 are the same as those of Example 1, except that the molar ratio of imidazole to 1,2-dichloroethane in step (1) is changed to 4:1, and the resulting catalyst is numbered CAT-2. Example

[0049] The preparation steps of Example 3 are the same as those of Example 1, except that the reflux temperature in step (1) is changed to 130 °C, and the resulting catalyst is numbered CAT-3. Example

[0050] The preparation steps of Example 4 are the same as those of Example 1, except that the reflux time in step (1) is changed to 18 h, and the resulting catalyst is numbered CAT-4. Example

[0051] The preparation steps of Example 5 are the same as those of Example 1, except that ruthenium chloride in step (2) is replaced with ruthenium acetylacetonate, and the resulting catalyst is numbered CAT-5. Example

[0052] The preparation steps of Example 6 are the same as those of Example 1, except that the molar ratio of ethylenediimidazole chloride, ethanol and ruthenium chloride in step (2) is changed to 6:80:1, and the resulting catalyst is numbered CAT-6. Example

[0053] The preparation steps of Example 7 are the same as those of Example 1, except that the solvent in step (2) is changed to acetonitrile, and the resulting catalyst is numbered CAT-7. Example

[0054] The preparation steps of Example 8 are the same as those of Example 1, except that the temperature condition in step (2) is changed to 150 °C, and the resulting catalyst is numbered CAT-8. Example

[0055] The preparation steps of Example 9 are the same as those of Example 1, except that the reaction time in step (2) is changed to 12 h, and the resulting catalyst is numbered CAT-9. Example

[0056] The preparation steps of Example 10 are the same as those of Example 1, except that 1,2-dichloroethane in step (1) is replaced with 1,5-dichloropentane, and the resulting catalyst is numbered CAT-10. Example

[0057] The preparation steps of Example 11 are the same as those of Example 1, except that 1,2-dichloroethane in step (1) is replaced with 1,8-dichlorooctane, and the resulting catalyst is numbered CAT-11. Example

[0058] The preparation steps of Example 12 are the same as those of Example 1, except that 1,2-dichloroethane in step (1) is replaced with 1,10-dichlorodecane, and the resulting catalyst is numbered CAT-12. Example

[0059] The preparation steps of Example 13 are the same as those of Example 1, except that 1,2-dichloroethane in step (1) is replaced with 1,4-dichlorobenzyl, and the resulting catalyst is numbered CAT-13. Example

[0060] (1) Morpholine was added to 1,4-dibromobutane under stirring at room temperature. The molar ratio of morpholine to 1,4-dibromobutane was 1:1. The mixture was then stirred at 60 °C for 6 h. After the reaction was stopped, the mixture was washed and dried under vacuum to obtain the nitrogen-containing bismorpholine ring ionic liquid bismorpholine bromide.

[0061] (2) Nitrogen-containing bismorpholine ring ionic liquid dimorpholine bromide, ethanol and ruthenium trichloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1, sealed and reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium ionic liquid complex.

[0062] (3) The ruthenium ionic liquid complex was dissolved in a solvent at a mass ratio of 1% to 1% of the activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-14. Example

[0063] The preparation steps of Example 15 are the same as those of Example 14, except that the molar ratio of morpholine compound to 1,4-dibromobutane in step (1) is changed to 4:1, and the resulting catalyst is numbered CAT-15. Example

[0064] The preparation steps of Example 16 are the same as those of Example 14, except that the reflux temperature in step (1) is changed to 100 °C, and the resulting catalyst is numbered CAT-16. Example

[0065] The preparation steps of Example 17 are the same as those of Example 14, except that the temperature condition in step (1) is changed to 18 h, and the resulting catalyst is numbered CAT-17. Example

[0066] The preparation steps of Example 18 are the same as those of Example 14, except that the temperature condition in step (2) is changed to 150 °C, and the resulting catalyst is numbered CAT-18. Example

[0067] The preparation steps of Example 19 are the same as those of Example 14, except that the reaction time in step (2) is changed to 18 h, and the resulting catalyst is numbered CAT-19. Example

[0068] The preparation steps of Example 20 are the same as those of Example 14, except that the molar ratio of dimorpholine bromide, ethanol and ruthenium chloride in step (2) is changed to 6:80:1, and the resulting catalyst is numbered CAT-20. Example

[0069] The preparation steps of Example 21 are the same as those of Example 14, except that the solvent in step (2) is changed to acetonitrile, and the resulting catalyst is numbered CAT-21. Example

[0070] The preparation steps of Example 22 are the same as those of Example 14, except that ruthenium chloride in step (2) is replaced with ruthenium acetylacetonate, and the resulting catalyst is numbered CAT-22. Example

[0071] The preparation steps of Example 23 are the same as those of Example 14, except that the morpholine in step (1) is replaced with N-methylmorpholine, and the resulting catalyst is numbered CAT-23. Example

[0072] The preparation steps of Example 24 are the same as those of Example 14, except that the morpholine in step (1) is replaced with N-ethylmorpholine, and the resulting catalyst is numbered CAT-24.

[0073] Comparative Example 1

[0074] The purpose of using N-methylimidazole alone as a promoter for ruthenium-based catalysts is to compare the catalyst activity with that after the addition of bicyclic ionic liquids, in order to illustrate the effect of the addition of bicyclic ionic liquids on the catalyst.

[0075] (1) N-methylimidazole, ethanol and ruthenium chloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1, sealed and reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium-imidazole complex.

[0076] (2) The ruthenium imidazole complex was dissolved in deionized water at a mass ratio of 1% to 1% of the activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-25.

[0077] Comparative Example 2

[0078] The purpose of using N-methylmorpholine alone as a promoter for ruthenium-based catalysts is to compare the catalyst activity with that after the addition of a bicyclic ionic liquid, in order to illustrate the effect of the addition of a bicyclic ionic liquid on the catalyst.

[0079] (1) N-methylmorpholine, ethanol and ruthenium chloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1, sealed and reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium morpholine complex.

[0080] (2) The ruthenium morpholine complex was dissolved in deionized water at a mass ratio of 1% to 1% of the activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-26.

[0081] Comparative Example 3

[0082] The purpose of using 1-methyl-3-ethylimidazolium bromide alone as an additive to ruthenium-based catalysts is to compare the catalytic performance of the catalysts with that of those with imidazolium bicyclic ionic liquids, in order to illustrate the difference in the effect of adding bicyclic and monocyclic ionic liquids on the catalyst.

[0083] (1) 1-methyl-3-ethylimidazolium bromide, ethanol and ruthenium chloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1, sealed and reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium ionic liquid complex.

[0084] (2) The ruthenium imidazole complex was dissolved in deionized water at a mass ratio of 1% to 1% of the ruthenium ionic liquid complex and activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-27.

[0085] Comparative Example 4

[0086] The purpose of using N-methylbutylmorpholine chloride alone as an additive to ruthenium-based catalysts is to compare the catalytic performance of the catalysts with that of catalysts with added morpholine bicyclic ionic liquids, in order to illustrate the difference in the effect of adding bicyclic and monocyclic ionic liquids on the catalyst.

[0087] (1) N-methylbutylmorpholine chloride, ethanol and ruthenium chloride were placed in a hydrothermal reactor at a molar ratio of 0.5:100:1. After sealing, the mixture was reacted at 80 °C for 6 h. The resulting product was then rotary evaporated, washed and dried to obtain the ruthenium ionic liquid complex.

[0088] (2) The ruthenium imidazole complex was dissolved in deionized water at a mass ratio of 1% to 1% of the ruthenium ionic liquid complex and activated carbon support. Then, it was impregnated into the activated carbon support by an equal volume impregnation method. After standing at room temperature for 1 h, it was dried at 100 °C to obtain the desired catalyst, which was numbered CAT-28.

[0089] Methods and conditions for testing catalyst activity:

[0090] (1) The catalyst was loaded into the isothermal zone of the atmospheric pressure fixed bed reactor, and quartz sand was loaded on the top layer of the catalyst as a preheating layer. The temperature was raised to 180 °C under flowing nitrogen and held for 1 h.

[0091] (2) Turn off the nitrogen gas, introduce hydrogen chloride gas and continue to maintain this for 1 hour;

[0092] (3) Introduce acetylene gas and adjust the volume ratio of hydrogen chloride to acetylene to 1.2:1, with the acetylene gas volume hourly space velocity (VHSV) being 160 h⁻¹. –1 The reaction begins;

[0093] (4) The reaction products were analyzed using a gas chromatograph equipped with a TCD detector.

[0094] Table 1 shows the activity evaluation results of CAT-1 to CAT-28 catalysts after 10 hours of reaction.

[0095] Catalyst number Acetylene conversion rate (%) Vinyl chloride selectivity (%) CAT-1 46.2 99.6 CAT-2 47.5 99.5 CAT-3 46.4 99.5 CAT-4 47.3 99.9 CAT-5 46.2 99.7 CAT-6 47.5 99.8 CAT-7 46.1 99.6 CAT-8 45.3 99.6 CAT-9 46.6 99.7 CAT-10 81.6 99.6 CAT-11 86.3 99.6 CAT-12 93.4 99.5 CAT-13 57.6 99.5 CAT-14 91.5 99.9 CAT-15 92.8 99.7 CAT-16 93.1 99.8 CAT-17 93.9 99.6 CAT-18 94.2 99.6 CAT-19 92.1 99.8 CAT-20 94.9 99.6 CAT-21 96.0 99.6 CAT-22 93.6 99.5 CAT-23 88.8 99.5 CAT-24 89.1 99.9 CAT-25 74.3 99.7 CAT-26 75.1 99.8 CAT-27 79.6 99.6 CAT-28 73.1 99.6

Claims

1. A process for the preparation of a ruthenium-based mercury-free catalyst for the production of chloroethylene by the calcium carbide method, characterized in that The preparation method comprises the following steps: (1) stirring N-methyl imidazole into a double-substituted alkane with different carbon chain lengths at room temperature, the molar ratio of imidazole to double-substituted alkane being 1-4:1, then refluxing at 100-130 ℃ for 6-18 h, washing and vacuum drying after stopping the reaction to obtain a nitrogen-containing double-imidazole ring ionic liquid; wherein the double-substituted alkane with different carbon chain lengths is one or more of 1,5-dichloropentane, 1,8-dichlorooctane, 1,10-dichlorodecane and 1,4-dichlorobenzene; Or: stirring a morpholine compound into 1,4-dibromobutane at room temperature, the molar ratio of the morpholine compound to 1,4-dibromobutane being 1-4:1, then stirring at 60-100 ℃ for 6-18 h, washing and vacuum drying after stopping the reaction to obtain a nitrogen-containing double-morpholine ring ionic liquid; wherein the morpholine compound is one or more of morpholine, N-methyl morpholine and N-ethyl morpholine; (2) placing the nitrogen-containing double-imidazole ring ionic liquid or the nitrogen-containing double-morpholine ring ionic liquid, a solvent and a ruthenium salt into an autoclave, reacting at 80-150 ℃ for 6-12 h after sealing, then performing rotary evaporation, washing and drying on the obtained product to obtain a ruthenium ionic liquid complex; (3) dissolving the ruthenium ionic liquid complex in a solvent, then immersing it into an activated carbon carrier by using an equal-volume immersion method, standing at room temperature for 1 h, then drying at 100 ℃ to obtain a required catalyst.

2. The method of claim 1, wherein: The ruthenium salt is one or both of ruthenium chloride and ruthenium acetylacetonate.

3. The method of claim 1, wherein: The molar ratio of the nitrogen-containing double-imidazole ring ionic liquid or the nitrogen-containing double-morpholine ring ionic liquid, the solvent and the ruthenium salt is 0.5-6:80-100:

1.

4. The method of claim 1, wherein: The solvent is one or more of ethanol, acetone, acetonitrile, isobutanol and deionized water.

5. The method of claim 1, wherein: The mass ratio of the ruthenium ionic liquid complex to the activated carbon carrier in step (3) is 1%-5%.

6. A ruthenium-based mercury-free catalyst for the production of chloroethylene by the calcium carbide method, characterized in that The preparation method is prepared by using any one of the preparation methods in claims 1-5.

7. A method of using the catalyst of claim 6, wherein The specific steps are as follows: (1) loading the catalyst into a constant-temperature interval of a normal-pressure fixed-bed reactor, loading quartz sand as a preheating layer on the upper layer of the catalyst, and heating to 160-180 ℃ under flowing nitrogen and keeping for at least 1 h; (2) closing the nitrogen, and introducing hydrogen chloride gas and continuing to keep for at least 1 h; (3) ethyne gas was introduced and the volume ratio of hydrogen chloride and ethyne was adjusted to 1.2:1, and the volume space velocity of ethyne gas was 40-320 h –1 , the reaction was started; (4) analyzing the reaction product by using a gas chromatograph equipped with a TCD detector.

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