A method for co-producing vinyl chloride by distilling ammonium chloride

Abstract

The present invention relates to the field of chemical production technology, and in particular to a method for co-producing vinyl chloride by distilling ammonia from ammonium chloride. The catalyst is an organic alkaline solution selected from imidazole organic solvents and / or amide organic solvents. The method for preparing vinyl chloride comprises: 1) reacting an aqueous ammonium chloride solution with a catalyst to decompose the ammonium chloride to produce ammonia gas and hydrogen chloride, wherein the ammonia gas and water vapor are discharged in gaseous form, and the hydrogen chloride reacts with the organic alkaline solution to form an organic alkaline hydrochloride solution; and 2) reacting the hydrogen chloride in the organic alkaline hydrochloride solution with acetylene to produce vinyl chloride. The present invention utilizes an organic alkaline solution to distill ammonia from a soda mother liquor in the ammonia-soda process, producing ammonia gas while retaining hydrogen chloride in the organic alkaline solution. Acetylene gas is then introduced into the organic alkaline hydrochloride solution to react with the hydrogen chloride in the solution, thereby producing a high-value-added vinyl chloride product. The present invention not only solves the environmental issues of existing processes but also achieves efficient utilization of chloride ions.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, in particular to a method for co-producing vinyl chloride by distilling ammonia from ammonium chloride. Background Art

[0002] Almost all of my country's NH4Cl production comes from soda ash production. Soda ash is an important inorganic chemical raw material, widely used in light industry, daily chemicals, chemicals, food, metallurgy, textiles, pharmaceuticals, and other fields. It is a key chemical product with high market demand.

[0003] The ammonia-soda process is one of the main industrial methods for producing soda ash. The raw materials for this process are salt and limestone, with ammonia being recycled within the system. The raw salt undergoes refinement, ammonia absorption, carbonization, crystallization, filtration, and calcination to produce soda ash. The filtered mother liquor is neutralized with lime milk, the ammonia evaporates and is recycled, and the calcium chloride is discharged. The chemical equation is:

[0004] NaCl+NH3+H2O+CO2→NaHCO3+NH4Cl

[0005]

[0006] NH4Cl+Ca(OH)2→NH3+CaCl2

[0007] The ammonia-soda process offers advantages such as abundant raw material resources, a continuous and easily controllable production process, high product quality, and low cost. However, this method has the following disadvantages when producing soda ash: First, the resulting CaCl2 wastewater is difficult to handle, especially in inland areas, creating significant environmental pressure. Second, the utilization rate of NaCl is low, as only the sodium ions are utilized, while all the chloride ions are discarded. Consequently, the promotion of the ammonia-soda process has been limited, and it has gradually been replaced by the Hou-soda process, also known as the combined alkali process.

[0008] The Hou process eliminates the shortcomings of the ammonia-soda process, increasing the utilization rate of NaCl to 96%. It eliminates the generation of difficult-to-treat CaCl2 wastewater, and the byproduct NH4Cl can be used as nitrogen fertilizer. Theoretically, the Hou process produces no waste; all substances, except the products NaHCO3 and NH4Cl, are recycled, making it a green production process. However, the combined soda process requires a supporting ammonia synthesis plant, which is both costly and energy-intensive. Furthermore, with the widespread use of NH4Cl as a fertilizer, it has been found that NH4Cl not only acidifies and compacts soils, but also disrupts the soil microbiome and inhibits microbial growth. These issues have limited its use as a fertilizer. Therefore, finding effective, cost-effective and environmentally friendly ways to process and utilize NH4Cl is crucial to the development of the soda ash industry.

[0009] Invention patent application No. 201910224426.8 discloses a process for preparing ammonium paratungstate from ammonium chloride and tungsten-containing waste. + The invention converts tungstate into ammonium tungstate and chloride ions into low value-added sodium chloride. However, the output of ammonium tungstate as a rare earth industry does not match that of the soda ash industry. Even if the invention technology is promoted, the NH4Cl produced as a by-product of the soda ash industry still cannot be properly handled.

[0010] Invention patent application No. 201110330391.X discloses a method for producing long-lasting, stable, and enhanced-efficiency ammonium chloride fertilizer using a combined alkali process. This method involves adding an ammonium stabilizer and / or synergist to the NH4Cl product during the production and drying process, after the precipitation of soda ash, to produce a long-lasting, stable, or enhanced-efficiency ammonium chloride nitrogen fertilizer. This reduces fertilizer application and extends the effective lifespan. While this invention patent improves the fertilizer efficiency of NH4Cl to a certain extent, it does not fundamentally address the issues of soil acidification and compaction caused by NH4Cl and the damage to the soil microenvironment.

[0011] Invention patent application number 201811257651.3 describes a process for preparing magnesium chloride using ammonium chloride and magnesium carbonate. This application involves mixing ammonium chloride and magnesium carbonate, heating them, and producing anhydrous magnesium chloride, ammonia, and carbon dioxide. The resulting ammonia and carbon dioxide can be used to prepare soda ash. The NH4Cl produced by soda ash production then reacts with MgCO3. The method for preparing magnesium chloride provided in this application, combined with the process for producing soda ash, essentially achieves zero emissions, meeting environmental protection requirements. However, there are no reports of industrial application of this technology, and the added value of converting the chloride ions in NH4Cl into MgCl2 is low.

[0012] As soda ash production increases, how to transfer and dispose of NH4Cl and how to use it efficiently have become major problems that plague the green and healthy development of the soda ash industry. Summary of the Invention

[0013] In response to the technical defects of the above-mentioned prior art, the present invention provides a method for preparing vinyl chloride by distilling ammonium chloride, which uses an organic alkaline solution instead of lime milk to react with ammonium chloride in the mother liquor of soda ash production to distill ammonia, thereby solving the problems in the prior art.

[0014] The present invention is achieved through the following implementation steps:

[0015] To achieve the above-mentioned and other related purposes, the present invention provides, in a first aspect, a catalyst for the co-production of vinyl chloride from ammonium chloride distillation, wherein the catalyst is an organic alkaline solution selected from imidazole organic solvents and / or amide organic solvents.

[0016] Preferably, the imidazole organic solvent is one or more of imidazole, N-methylimidazole, 1,3-dimethylimidazole, 2-methylimidazole, 2-methylbenzimidazole, 2,4-dimethylimidazole, and 1-ethyl-3-methylimidazole chloride.

[0017] Preferably, the amide organic solvent is one or more of N-methylpyrrolidone, N-ethylpyrrolidone, and 1,3-dimethylimidazolidinone.

[0018] Preferably, the organic base solution is a mixed solution of an imidazole organic solvent and an amide organic solvent.

[0019] Preferably, the molar ratio of the imidazole organic solvent to the amide organic solvent is 1:0 to 6. In some embodiments, the molar ratio of the imidazole organic solvent to the amide organic solvent can be, for example, 1:0 to 1, 1:1 to 2, 1:1 to 3, 1:1 to 4, or 1:4 to 6.

[0020] The second aspect of the present invention provides the use of the above catalyst for the co-production of vinyl chloride from ammonium chloride distillation.

[0021] Preferably, an aqueous ammonium chloride solution is reacted with the catalyst described in the first aspect of the present invention to decompose the ammonium chloride to produce ammonia and hydrogen chloride, the ammonia and water vapor are discharged in gaseous form, the hydrogen chloride reacts with the organic base solution to form an organic base hydrochloride solution, and the hydrogen chloride in the organic base hydrochloride solution reacts with acetylene to obtain vinyl chloride.

[0022] A third aspect of the present invention provides a method for preparing ammonium chloride by distilling ammonia and co-producing vinyl chloride, the method comprising the following steps:

[0023] 1) reacting an aqueous ammonium chloride solution with the catalyst described in the first aspect of the present invention to decompose the ammonium chloride to produce ammonia gas and hydrogen chloride, wherein the ammonia gas and water vapor are discharged in gaseous form, and the hydrogen chloride and the organic base solution form an organic base hydrochloride solution;

[0024] 2) reacting the hydrogen chloride in the organic base hydrochloride solution obtained in step 1) with acetylene to obtain vinyl chloride.

[0025] Preferably, in step 1), an aqueous ammonium chloride solution is added to an organic base solution, mixed uniformly, and heated to decompose the ammonium chloride to produce ammonia gas and hydrogen chloride. The ammonia gas and water vapor are discharged from the gas phase exhaust port 3 at the top of the ammonia distillation column, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution with the organic base. The use of the organic base solution in the present invention not only provides an alkaline environment but also acts as a catalyst.

[0026] Preferably, in step 1), the reaction temperature is 100° C. to 170° C. In specific embodiments, the reaction temperature can be controlled to, for example, 100° C. to 130° C., 130° C. to 150° C., 100° C. to 140° C., 100° C. to 110° C., 110° C. to 120° C., 120° C. to 130° C., 130° C. to 140° C., or 140° C. to 150° C.

[0027] Preferably, in step 1), the concentration of ammonium chloride in the aqueous ammonium chloride solution is 3 to 25 wt %. In a specific embodiment, the concentration of ammonium chloride in the aqueous ammonium chloride solution can be, for example, 3 to 10 wt %, 10 to 20 wt %, 3 to 5 wt %, 5 to 10 wt %, 10 to 15 wt %, 15 to 20 wt % or 20 to 25 wt %.

[0028] Preferably, in step 1), the molar ratio of ammonium chloride to the organic base solution is controlled to be 1:1 to 10. In specific embodiments, the molar ratio of ammonium chloride to the organic base solution can be controlled to be, for example, 1:1 to 4, 1:4 to 6, 1:6 to 8, 1:8 to 10, 1:1 to 5, or 1:5 to 10.

[0029] Preferably, step 2) is to pump the organic base hydrochloride solution obtained in step 1) into a synthesis tower, and then introduce acetylene into the organic base hydrochloride solution from the bottom of the synthesis tower. Under certain conditions, acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia distillation.

[0030] Preferably, in step 2), the acetylene reaction is carried out in two ways:

[0031] Method 1: An organic base hydrochloride solution absorbs acetylene under pressure at low temperature, and then the temperature is raised to the synthesis reaction temperature in a synthesis tower to obtain vinyl chloride.

[0032] Method 2: An organic base hydrochloride solution is introduced into acetylene while undergoing a synthesis reaction to obtain vinyl chloride.

[0033] Preferably, in step 2), the synthesis reaction temperature is controlled to be 120-200° C. In specific embodiments, the synthesis reaction temperature can be controlled to be, for example, 120-150° C., 150-180° C., 180-200° C., 120-170° C., or 170-200° C.

[0034] Preferably, in step 2), the reaction pressure is controlled to be 0.2-5 MPa. In specific embodiments, the reaction pressure can be controlled to be, for example, 0.2-1 MPa, 1-3 MPa, 3-5 MPa, 0.2-2.5 MPa, or 2.5-5 MPa.

[0035] Preferably, the low temperature in method 1 of step 2) is -30-50°C. In specific embodiments, the low temperature can be, for example, -30--10°C, -10-0°C, 0-10°C, 10-20°C, 20-30°C, or 30-40°C. The pressure of the pressurization is 0-2 MPa. In specific embodiments, the pressure of the pressurization can also be 0-1 MPa, or 1-2 MPa.

[0036] Preferably, the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1 to 2. In a specific embodiment, the molar ratio of acetylene to hydrogen chloride can be controlled to be, for example, 1:1 to 1.5, or 1:1.5 to 2.

[0037] A fourth aspect of the present invention provides an apparatus for co-producing vinyl chloride by distilling ammonia from ammonium chloride, the apparatus comprising an ammonia distillation tower, the ammonia distillation tower comprising an organic alkali solution feed inlet 1, an ammonium chloride feed inlet 2, a gas phase exhaust port 3 and a reaction liquid discharge port 4; the apparatus further comprises a synthesis tower, the synthesis tower comprising a reaction liquid feed inlet 5, an acetylene inlet 6, a synthesis reaction liquid discharge port 7 and a synthesis gas exhaust port 8, the reaction liquid discharge port 4 being connected to the reaction liquid feed inlet 5, and the synthesis reaction liquid discharge port 7 being connected to the organic alkali solution feed inlet 1.

[0038] Preferably, a pump is provided on the connecting pipeline between the reaction liquid discharge port 4 and the reaction liquid feed port 5 .

[0039] Preferably, a pump is provided on the connecting pipeline between the synthesis reaction liquid discharge port 7 and the organic base feed port.

[0040] The working process of the present invention:

[0041] (1) The organic alkali solution and the ammonium chloride solution are introduced into the ammonia still from the organic alkali solution feed port 1 and the ammonium chloride feed port 2 of the ammonia still, respectively.

[0042] (2) Under certain conditions, the ammonium chloride in the ammonia evaporation tower is subjected to ammonia evaporation, and the obtained ammonia gas and water vapor are discharged from the gas phase exhaust port 3 at the top of the ammonia evaporation tower.

[0043] (3) The reaction solution after ammonia evaporation is discharged from the reaction solution outlet at the bottom of the ammonia evaporation tower and transported to the synthesis tower through the reaction solution feed port 5 at the lower part of the synthesis tower via a pump. At the same time, acetylene gas is introduced into the synthesis tower from the acetylene inlet 6 at the bottom of the synthesis tower. The reaction conditions are controlled so that acetylene reacts with hydrogen chloride in the solution after ammonia evaporation to obtain vinyl chloride, which is discharged from the synthesis gas exhaust port 8 at the top of the synthesis tower.

[0044] (4) The organic alkali solution obtained by the reaction in the synthesis tower is discharged from the synthesis reaction liquid discharge port 7 at the bottom of the synthesis tower and transported to the ammonia distillation tower through a pump to continue to be used for ammonium chloride distillation.

[0045] Compared with the prior art, this application has the following beneficial effects:

[0046] The present invention uses an organic alkaline solution to evaporate ammonia from ammonia-soda process soda ash mother liquor, producing ammonia gas while retaining hydrogen chloride in the organic alkaline solution. Acetylene gas is then introduced into the organic alkaline hydrochloride solution to react with the hydrogen chloride in the solution, yielding a high-value-added vinyl chloride product. Furthermore, the organic alkaline solution obtained by solution regeneration can be recycled and further used in the ammonia evaporation reaction. This invention not only solves the environmental issues existing in existing processes but also achieves efficient utilization of chloride ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Shown is a schematic diagram of the device for co-producing vinyl chloride by distilling ammonium chloride according to the present invention.

[0048] Component numbers in the figure

[0049] 1 Organic alkali solution feed port

[0050] 2 Ammonium chloride feeding port

[0051] 3 Gas phase exhaust port

[0052] 4 Reaction liquid discharge port

[0053] 5 Reaction liquid feed port

[0054] 6 Acetylene inlet

[0055] 7 Synthesis reaction liquid discharge port

[0056] 8 Syngas exhaust port DETAILED DESCRIPTION

[0057] The technical solution of the present invention is described below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships, without substantially changing the technical content, should also be regarded as the scope of the present invention.

[0058] Example 1

[0059] (1) A 3% aqueous solution of ammonium chloride is transported to an ammonia evaporation tower and uniformly mixed with an organic base solution formed by imidazole and N-ethylpyrrolidone, wherein the molar ratio of imidazole to N-ethylpyrrolidone is 1:2; the molar ratio of ammonium chloride to the organic base is controlled to be 1:10, and the ammonia evaporation temperature is 170°C. The ammonium chloride is decomposed to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia evaporation tower by the gas phase component along with the water vapor, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0060] (2) Acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1, the synthesis temperature is 200°C, and the pressure is 5 MPa. Acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0061] Example 2

[0062] (1) A 10% ammonium chloride aqueous solution is transported to an ammonia still and uniformly mixed with an N-methylimidazole organic base solution. The molar ratio of ammonium chloride to the organic base is controlled to be 1:6. The ammonia evaporation temperature is 140°C. The ammonium chloride decomposes to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia still along with the water vapor by the gas phase component, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0063] (2) Acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), and the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1.2. The synthesis temperature is 180° C. and the pressure is 3 MPa. Acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0064] Example 3

[0065] (1) A 15% ammonium chloride aqueous solution is transported to an ammonia still and uniformly mixed with an organic base solution formed by 2-methylbenzimidazole and N-ethylpyrrolidone, wherein the molar ratio of 2-methylbenzimidazole to N-ethylpyrrolidone is 1:3; the molar ratio of ammonium chloride to the organic base is controlled to be 1:4, and the ammonia still temperature is 130°C. The ammonium chloride is decomposed to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia still along with the water vapor from the gas phase component, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0066] (2) Acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), and the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1.5. The synthesis temperature is 170° C. and the pressure is 2.5 MPa. Acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0067] Example 4

[0068] (1) A 20% ammonium chloride aqueous solution is transported to an ammonia still and uniformly mixed with an organic base solution formed by 1-ethyl-3-methylimidazolium chloride and 1,3-dimethylimidazolinone, wherein the molar ratio of 1-ethyl-3-methylimidazolium chloride and 1,3-dimethylimidazolinone is 1:6; the molar ratio of ammonium chloride to the organic base is controlled to be 1:1, and the ammonia still temperature is 100°C. The ammonium chloride decomposes to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia still along with the water vapor from the gas phase component, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0069] (2) Acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), the molar ratio of acetylene to hydrogen chloride is controlled to be 1:2, the synthesis temperature is 120°C, and the pressure is 0.2 MPa. Acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0070] Example 5

[0071] (1) A 15% ammonium chloride aqueous solution is transported to an ammonia still and uniformly mixed with an organic base solution of 1-ethyl-3-methylimidazolium chloride. The molar ratio of ammonium chloride to the organic base is controlled to be 1:3. The ammonia still temperature is 103°C. The ammonium chloride decomposes to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia still along with the water vapor from the gas phase component, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0072] (2) acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), the acetylene absorption temperature is controlled to be -30°C, the pressure is controlled to be 0 MPa, the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1, the reaction temperature of the synthesis tower is controlled to be 140°C, and the pressure is controlled to be 0.35 MPa. The acetylene reacts with the hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0073] Example 6

[0074] (1) A 20% ammonium chloride aqueous solution is transported to an ammonia still and uniformly mixed with an organic base solution formed by N-methylimidazole and N-methylpyrrolidone, wherein the molar ratio of N-methylimidazole to N-methylpyrrolidone is 1:6; the molar ratio of ammonium chloride to the organic base is controlled to be 1:5, and the ammonia still temperature is 120°C. The ammonium chloride is decomposed to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia still along with the water vapor from the gas phase component, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0075] (2) acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), the acetylene absorption temperature is controlled to be -20°C, the pressure is 1.0 MPa, the molar ratio of acetylene to hydrogen chloride is 1:1.1, the reaction temperature of the synthesis tower is 130°C, and the pressure is 1.0 MPa. Acetylene reacts with hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0076] Example 7

[0077] (1) A 25% ammonium chloride aqueous solution is transported to an ammonia evaporation tower and uniformly mixed with an organic base solution formed by imidazole and 1,3-dimethylimidazolidinone, wherein the molar ratio of imidazole to 1,3-dimethylimidazolidinone is 1:2; the molar ratio of ammonium chloride to the organic base is controlled to be 1:1, and the ammonia evaporation temperature is 150°C. The ammonium chloride is decomposed to produce ammonia gas and hydrogen chloride. The ammonia gas is carried out of the ammonia evaporation tower by the gas phase component along with the water vapor, and the hydrogen chloride remains in the organic base solution to form an organic base hydrochloride solution.

[0078] (2) acetylene is introduced into the organic base hydrochloride solution obtained after ammonia evaporation in step 1), the acetylene absorption temperature is controlled to be 50°C, the pressure is controlled to be 2.0 MPa, the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1.5, the reaction temperature of the synthesis tower is controlled to be 150°C, and the pressure is controlled to be 2.0 MPa. The acetylene reacts with the hydrogen chloride in the solution to obtain vinyl chloride. After the reaction is completed, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by solution regeneration is returned to step 1) to continue ammonia evaporation.

[0079] Comparative Example 1

[0080] (1) A 15% ammonium chloride aqueous solution is transported to the center of an ammonia evaporation tower and uniformly mixed with an organic base solution formed by triphenylbenzimidazole and N-methylpyrrolidone, wherein the molar ratio of triphenylbenzimidazole to N-methylpyrrolidone is 1:3; the molar ratio of ammonium chloride to the organic base is controlled to be 1:5, the ammonia evaporation temperature is 150°C, and there is no ammonia in the gas phase components at the top of the ammonia evaporation tower.

[0081] (2) Acetylene was introduced into the solution of step 1), and the molar ratio of acetylene to hydrogen chloride was controlled to be 1:1.5. The reaction temperature of the synthesis tower was 160° C. and the pressure was 3 MPa. No vinyl chloride gas was detected in the gaseous components discharged from the top of the synthesis tower.

[0082] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A catalyst for the co-production of vinyl chloride from ammonium chloride, characterized in that: The catalyst is an organic alkaline solution, which is selected from imidazole organic solvents and / or amide organic solvents. The imidazole organic solvent is one or more of imidazole, N-methylimidazole, 1,3-dimethylimidazole, 2-methylimidazole, 2-methylbenzimidazole, 2,4-dimethylimidazole, and 1-ethyl-3-methylimidazole chloride; the amide organic solvent is one or more of N-methylpyrrolidone, N-ethylpyrrolidone, and 1,3-dimethylimidazolidinone.

2. Use of the catalyst according to claim 1 in the co-production of vinyl chloride from ammonium chloride distillation, characterized in that: The organic base solution is a mixed solution of an imidazole organic solvent and an amide organic solvent; the molar ratio of the imidazole organic solvent to the amide organic solvent is 1:1-6.

3. The use according to claim 1, characterized in that The ammonium chloride aqueous solution is reacted with the catalyst to decompose the ammonium chloride to obtain ammonia and hydrogen chloride, the ammonia and water vapor are discharged in gaseous form, the hydrogen chloride reacts with the organic alkali solution to form an organic alkali hydrochloride solution, and the hydrogen chloride in the organic alkali hydrochloride solution reacts with acetylene to obtain vinyl chloride.

4. A method for preparing vinyl chloride by distilling ammonium chloride, characterized in that: The preparation method comprises the following steps: 1) reacting an aqueous ammonium chloride solution with a catalyst, wherein the catalyst is an organic alkaline solution selected from an imidazole organic solvent and / or an amide organic solvent, to decompose the ammonium chloride to produce ammonia gas and hydrogen chloride, wherein the ammonia gas and water vapor are discharged in gaseous form, and the hydrogen chloride reacts with the organic alkaline solution to form an organic alkaline hydrochloride solution; Wherein, the imidazole organic solvent is one or more of imidazole, N-methylimidazole, 1,3-dimethylimidazole, 2-methylimidazole, 2-methylbenzimidazole, 2,4-dimethylimidazole, and 1-ethyl-3-methylimidazole chloride; the amide organic solvent is one or more of N-methylpyrrolidone, N-ethylpyrrolidone, and 1,3-dimethylimidazolidinone; 2) reacting the hydrogen chloride in the organic base hydrochloride solution obtained in step 1) with acetylene to obtain vinyl chloride.

5. The preparation method according to claim 4, wherein The organic base solution is a mixed solution of an imidazole organic solvent and an amide organic solvent; the molar ratio of the imidazole organic solvent to the amide organic solvent is 1:1-6.

6. The preparation method according to claim 4, wherein It also includes one or more of the following technical features: A1) In step 1), the reaction temperature is 100°C to 170°C; A2) In step 1), the concentration of ammonium chloride in the aqueous ammonium chloride solution is 3-25 wt%; A3) In step 1), the molar ratio of ammonium chloride to the organic base solution is controlled to be 1:1-10; A4) Step 2) is to pump the organic base hydrochloride solution obtained in step 1) into a synthesis tower, then introduce acetylene into the organic base hydrochloride solution from the bottom of the synthesis tower. Under certain conditions, the acetylene reacts with the hydrogen chloride in the solution to produce vinyl chloride. After the reaction is complete, the vinyl chloride is discharged from the top of the tower, and the organic base solution obtained by regeneration is returned to step 1) to continue ammonia distillation.

7. The preparation method according to claim 6, wherein In step 2), there are two ways to pass acetylene into the reaction: Method 1: An organic base hydrochloride solution absorbs acetylene under pressure at low temperature, and then the temperature is raised to the synthesis reaction temperature in a synthesis tower to obtain vinyl chloride; Alternatively, in method 2, an organic base hydrochloride solution is introduced into acetylene while undergoing a synthesis reaction to obtain vinyl chloride.

8. The preparation method according to claim 7, wherein The low temperature is -30-50℃; the pressure is 0~2Mpa.

9. The preparation method according to claim 6 or 7, wherein: In step 2), one or more of the following technical features are also included: B1) In step 2), the synthesis reaction temperature is controlled to be 120-200°C; B2) In step 2), the reaction pressure is controlled to be 0.2-5 MPa; B3) In step 2), the molar ratio of acetylene to hydrogen chloride is controlled to be 1:1-2.

10. A device for co-producing vinyl chloride by distilling ammonium chloride according to the method of any one of claims 4 to 9, the device comprising an ammonia distillation tower, the ammonia distillation tower comprising an organic alkali solution feed inlet (1), an ammonium chloride feed inlet (2), a gas phase exhaust port (3) and a reaction liquid discharge port (4); the device further comprising a synthesis tower, the synthesis tower comprising a reaction liquid feed inlet (5), an acetylene gas inlet (6), a synthesis reaction liquid discharge port (7) and a synthesis gas exhaust port (8), the reaction liquid discharge port (4) being in communication with the reaction liquid feed inlet (5), and the synthesis reaction liquid discharge port (7) being in communication with the organic alkali solution feed inlet (1).

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