Preparation method and production system for synthesizing low-odor sulfurized isobutylene by high-pressure method

Abstract

The invention belongs to the technical field of sulfurized isobutylene production. The preparation method comprises the following steps: adding clear water and sulfur, introducing liquid ammonia and hydrogen sulfide, controlling the temperature not to exceed 65 DEG C, and reacting to generate ammonium polysulfide; the method comprises the following steps: mixing ammonium polysulfide and isobutene according to a preset proportion, reacting to generate a crude mixed solution mainly containing sulfurized isobutene, and controlling the temperature to be 150-220 DEG C; the mixed solution is subjected to standing layering, mother liquor obtained after standing layering is used for synthesizing ammonium polysulfide, and an oil layer is washed with water 1-2 times; distilling the washed oil layer to obtain a sulfurized isobutylene crude product; adding the sulfurized isobutylene crude product into a sodium sulfide solution for soda boiling at the temperature of 80-140 DEG C, adding the desulfurization particles in the soda boiling process, stirring to remove sulfur, and then standing for layering; and washing the oil layer with water, and then rectifying and filtering to obtain a sulfurized isobutylene product. The invention also provides a production system for synthesizing the low-odor sulfurized isobutylene by the high-pressure method.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sulfided isobutylene production, and particularly relates to a preparation method and a production system for synthesizing low-odor sulfided isobutylene by a high-pressure method. BACKGROUND

[0002] Sulfided isobutylene is an orange or amber oil-like transparent liquid, has excellent extreme pressure and wear resistance, good oil solubility, low copper corrosion, etc., and can be used as a main extreme pressure and wear resistant agent for preparing gear oil and industrial oil. At present, the synthesis process and research of sulfided isobutylene mainly exist in the following processes.

[0003] 1. Organic amine catalyst method, the organic amine catalysts for preparing sulfided isobutylene mainly include diethylamine, triethylamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, aniline and diphenylamine, etc. However, the basicity of the organic amine catalyst is low, the catalytic activity is low, and 2-butene is easy to polymerize in the process of preparing sulfided isobutylene, thereby resulting in a low yield of the target product.

[0004] 2. Resin catalyst method, the US5786511 patent adopts a PS-DVB resin containing a basic primary amine group as a catalyst to prepare sulfided isobutylene. Organic polysulfides are synthesized by using mercaptan and sulfur as raw materials. In the reaction, the resin catalyst has a highly cross-linked macroporous structure, and has greater catalytic activity than the gel-type resin in the reaction process. The yield of the resin catalyst is high, but the cost of mercaptan is high, and hydrogen sulfide gas is generated in the reaction process. At the same time, since mercaptan is easy to volatilize, a large amount of mercaptan is lost, thereby increasing the amount of mercaptan. The preparation process of the resin catalyst is complex, and the cost is high.

[0005] 3. Alcohol catalyst method, methanol is used as a catalyst, and dichloride sulfur is used to sulfide isobutylene to prepare sulfided isobutylene. However, the preparation process produces a large amount of HCl and H2S strong corrosive gas waste, which is difficult to handle, and the production process is complex, and the environmental protection requirement is relatively harsh.

[0006] 4. New catalyst.

[0007] V. High-Pressure Method: The high-pressure method for preparing isobutylene sulfide uses sulfur and isobutylene as starting materials. Under catalytic conditions, isobutylene sulfide is synthesized in a single step, followed by separation and purification to obtain products of different specifications and applications. The structure of isobutylene sulfide prepared by the high-pressure method differs fundamentally from that prepared by the atmospheric pressure method, resulting in lower viscosity, less odor, better compatibility with other additives and carriers, wider application range, and lower cost, making it the main technical route. Currently, traditional domestic processes for preparing isobutylene sulfide all employ the addition of olefins to sulfur monochloride followed by sodium sulfide dechlorination, resulting in long reaction cycles, high production costs, and severe environmental pollution. Based on environmental protection requirements, a one-step high-pressure method for preparing isobutylene sulfide has been gradually adopted in recent years. This process uses sulfur and isobutylene as raw materials, with an aqueous solution of inorganic or organic bases as a catalyst to directly prepare isobutylene sulfide through a high-pressure reaction. The process is relatively simple, chlorine-free, and has lower production costs. However, this process results in a higher dissolved elemental sulfur content in the isobutylene sulfide. Isobutylene sulfide, as a lubricant, is primarily used to improve wear between metal parts. Metal parts, such as gears, generate high temperatures during high-speed meshing friction, causing elemental sulfur to react with the metal and corrode it. In particular, sulfur reacts with copper, corroding the copper and producing insoluble cuprous sulfides. These precipitates affect lubrication performance, thus reducing the service life of the lubricating oil.

[0008] Current desulfurization techniques typically involve alkaline boiling of isobutylene sulfide with sodium sulfide, causing elemental sulfur to react with the sodium sulfide to form solid alkali metal polysulfides. However, this reaction can only occur in aqueous solution. During alkaline boiling, the isobutylene sulfide and sodium sulfide solution separate into layers relatively quickly. The sulfur dissolved in the isobutylene is difficult to transfer into the sodium sulfide solution, resulting in a relatively high sulfur content in the isobutylene sulfide and a more pronounced odor. Summary of the Invention

[0009] In view of this, the present invention provides a method for preparing low-odor isobutylene sulfide by high pressure synthesis, so as to reduce the sulfur content in isobutylene sulfide.

[0010] It is also necessary to provide a production system for synthesizing low-odor sulfurized isobutylene using a high-pressure method. A method for preparing low-odor sulfurized isobutylene by high-pressure synthesis includes the following steps: Step S1: Add water and sulfur, then introduce liquid ammonia and hydrogen sulfide, and control the temperature to not exceed 65 degrees Celsius to react and generate ammonium polysulfide; Step S2: Mix ammonium polysulfide and isobutylene in a predetermined ratio to generate a mixture mainly containing crude isobutylene sulfide, and control the temperature at 150~220 degrees Celsius. Step S3: Allow the mixture to stand and separate into layers. The mother liquor after standing and separating into layers is used to synthesize ammonium polysulfides. The oil layer is washed with water 1-2 times. Step S4: Distill the washed oil layer to obtain crude isobutylene sulfide; Step S5: Add crude isobutylene sulfide to sodium sulfide solution for alkaline boiling at a temperature of 80-140 degrees Celsius. During the alkaline boiling process, add desulfurization particles and stir to remove sulfur. Then let it stand to separate into layers. Step S6: Wash the oil layer with water, then distill and filter to obtain the sulfurized isobutylene product.

[0011] Preferably, the method for preparing the desulfurization particles includes the following steps: Step S51: Mix the carbon powder, copper powder, and binder to obtain a mixed mass; Step S52: Granulate the mixed agglomerates in a granulator to obtain mixed granules; Step S53: Carbonize the mixed particles in a carbonization furnace to obtain carbonized particles; Step S54: Activate the carbonized particles in an activation furnace to obtain desulfurization particles with rich pores.

[0012] Preferably, the desulfurization particles consist of 75-85 parts by mass of carbon and 15-25 parts by mass of copper.

[0013] Preferably, the desulfurization particles have a particle size of 5-10 mm.

[0014] A production system for synthesizing low-odor isobutylene by high-pressure method includes an ammonium polysulfide synthesis reactor, a polyamine feeding unit, a pipeline reactor, a receiving reactor, a water washing reactor, a distillation reactor, an alkali boiling and stirring reactor, and a rectification reactor. The ammonium polysulfide synthesis reactor is used to synthesize ammonium polysulfide from sulfur, liquid ammonia, and hydrogen sulfide. The outlet of the ammonium polysulfide synthesis reactor is connected to the inlet of the polyamine feeding unit through a pipeline. The polyamine feeding unit is used to collect ammonium polysulfide and quantitatively feed ammonium polysulfide into the pipeline reactor. The outlet of the polyamine feeding unit is connected to the inlet of the pipeline reactor through a pipeline. The pipeline reactor is used to synthesize isobutylene sulfide from ammonium polysulfide and isobutylene; the outlet of the pipeline reactor is connected to the inlet of the receiving vessel via a pipeline. The receiving vessel is used to receive and store the sulfurized isobutylene mixture; the outlet of the receiving vessel is connected to the inlet of the washing vessel via a pipeline. The washing kettle is used to remove water-soluble impurities such as ammonia and ammonium sulfide from isobutylene sulfide. The oil layer outlet of the washing kettle is connected to the feed inlet of the distillation kettle through a pipeline. The distillation vessel is used to purify and refine sulfide isobutylene; the outlet of the distillation vessel is connected to the inlet of the alkali-cooking stirring vessel via a pipeline. The alkaline boiling stirred tank is used to remove elemental sulfur from isobutylene sulfide, and the outlet of the alkaline boiling stirred tank is connected to the inlet of the distillation tank through a pipeline. The distillation vessel is used to purify isobutylene sulfide, separating it from other organic components.

[0015] By adding desulfurization particles and stirring during the alkaline boiling process, the desulfurization particles, with their abundant pores and excellent liquid absorption properties, undergo continuous rising and falling during stirring. This process involves the continuous exchange of isobutylene sulfide and sodium sulfide solution within and outside the desulfurization particles, leading to frequent contact between the isobutylene sulfide and sodium sulfide solution. Consequently, more sulfur in the isobutylene sulfide reacts with the sodium sulfide. Secondly, the settling and floating of desulfurization particles during the stirring process will keep the liquid in a turbulent state, which is more conducive to the mixing of water and oil layers, thereby increasing the contact opportunities between isobutylene sulfide and sodium sulfide. Finally, the desulfurization particles and sodium sulfide solution form a galvanic cell, with carbon in the desulfurization particles as the positive electrode, copper as the negative electrode, and sodium sulfide solution as the electrolyte. Copper will quickly react with elemental sulfur to generate insoluble cuprous sulfide, thereby consuming elemental sulfur in isobutylene sulfide.

[0016] Compared with the prior art, the beneficial effects of this invention are: it can significantly reduce the sulfur content in isobutylene sulfide, resulting in a lower odor in isobutylene sulfide products. Detailed Implementation

[0017] The specific embodiments of this application are described in detail below. However, it should be noted that the scope of protection of this application is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0018] Apart from the embodiments, any specific numerical values ​​(including the endpoints of numerical ranges) disclosed herein are not limited to their exact values, but should be understood to also encompass values ​​close to the exact value, such as all possible values ​​within ±10% of the exact value. Furthermore, with respect to the disclosed numerical ranges, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values ​​themselves; these new numerical ranges should also be considered as specifically disclosed herein.

[0019] Unless otherwise stated, the terms used herein have the same meaning as commonly understood by those skilled in the art, and if a term is defined herein and its definition differs from the common understanding in the art, the definition herein shall prevail.

[0020] The preparation method of low-odor sulfurized isobutylene by high pressure synthesis includes the following steps: Step S1: Add water and sulfur, then introduce liquid ammonia and hydrogen sulfide, and control the temperature to not exceed 65 degrees Celsius to react and generate ammonium polysulfide; The ratio of water, sulfur, liquid ammonia, and hydrogen sulfide is the ratio normally used in the preparation of ammonium polysulfides in the art. For example, in a preferred embodiment, the mass ratio of sulfur, liquid ammonia, and hydrogen sulfide is 5520:492:168.

[0021] Step S2: Mix ammonium polysulfide and isobutylene in a predetermined ratio to generate a mixture mainly containing crude isobutylene sulfide, and control the temperature at 150~220 degrees Celsius. The mixing ratio of ammonium polysulfide and isobutylene is also a common practice in this field, for example, the mass ratio of ammonium polysulfide to isobutylene is 6243:8640.

[0022] Step S3: Allow the mixture to stand and separate into layers. The mother liquor after standing and separating into layers is used to synthesize ammonium polysulfides. The oil layer is washed with water 1-2 times. Step S4: Distill the washed oil layer to obtain crude isobutylene sulfide; Step S5: Add crude isobutylene sulfide to sodium sulfide solution for alkaline boiling at a temperature of 80-140 degrees Celsius. During the alkaline boiling process, add desulfurization particles and stir to remove sulfur. Then let it stand to separate into layers. The purpose of adding sodium sulfide solution is to remove elemental sulfur from isobutylene sulfide. Sodium sulfide solution and isobutylene sulfide are immiscible, making it difficult for elemental sulfur in isobutylene to enter the sodium sulfide solution. During the alkaline boiling process, stratification occurs between the sodium sulfide solution and isobutylene sulfide, with more frequent mass exchange near the interface. Despite the long boiling time, a significant amount of soluble elemental sulfur in isobutylene remains and cannot react with the sodium sulfide. Adding desulfurization particles during the boiling process and stirring the liquid creates localized turbulence with each particle, increasing the contact area between the sodium sulfide solution and isobutylene sulfide.

[0023] Simultaneously, the pores of the desulfurization particles themselves also absorb liquid, as substances can spontaneously diffuse from high concentration to low concentration. When the desulfurization particles are in isobutylene sulfide, they absorb isobutylene sulfide and release their own sodium sulfide solution; when the desulfurization particles are in sodium sulfide solution, they absorb sodium sulfide solution and release their own isobutylene sulfide. In this way, the exchange between sodium sulfide solution and isobutylene sulfide becomes more frequent, thereby helping to remove elemental sulfur from isobutylene sulfide.

[0024] To achieve good mixing results, the desulfurization particles are preferably mixed from top to bottom.

[0025] Step S6: Wash the oil layer with water, then distill and filter to obtain the sulfurized isobutylene product.

[0026] Preferably, the method for preparing the desulfurization particles includes the following steps: Step S51: Mix the carbon powder, copper powder, and binder to obtain a mixed mass; In a preferred embodiment, the carbon powder is coal powder or graphite powder.

[0027] In a preferred embodiment, the binder is an organic binder such as asphalt or coal tar. Thus, during subsequent carbonization and activation processes, the binder dehydrates into carbon, and simultaneously forms pores due to dehydration. The carbon remaining after dehydration also becomes part of the particle skeleton.

[0028] Step S52: Granulate the mixed agglomerates in a granulator to obtain mixed granules; Step S53: Carbonize the mixed particles in a carbonization furnace to obtain carbonized particles; Carbonization is carried out in an oxygen-free environment. The carbonization process causes thermal decomposition of the binder and allows moisture and some organic matter to evaporate, resulting in the formation of initial pores in the particles. In a preferred embodiment, the carbonization temperature is 500–600 degrees Celsius.

[0029] Step S54: Activate the carbonized particles in an activation furnace to obtain desulfurization particles with rich pores.

[0030] The activation process involves the burning off of carbon particles, requiring the addition of carbon dioxide and water vapor to further decarbonize the carbonized particles, thereby enriching the porosity. During this process, the remaining carbon and copper form the framework of the desulfurization particles. The abundant porosity facilitates liquid absorption. Simultaneously, the copper and carbon in the desulfurization particles form a galvanic cell upon encountering sodium sulfide solution. When copper encounters elemental sulfur in isobutylene sulfide, an electrochemical reaction occurs, with copper reacting with sulfur to form cuprous sulfide, thus consuming the elemental sulfur in the isobutylene sulfide.

[0031] In a preferred embodiment, when using steam for activation, the activation temperature is 800-950 degrees Celsius.

[0032] Under natural conditions, elemental sulfur hardly reacts with copper. Even at temperatures between 120 and 140 degrees Celsius, the reaction is very slow, especially when the amount of isobutylene sulfide is very large, making it difficult to completely remove sulfur. Generally, a small amount of isobutylene sulfide and copper flakes are only used to react when testing the elemental sulfur content of isobutylene sulfide, and this reaction takes at least 3 hours. Furthermore, copper powder has a very high density; even with continuous stirring, copper powder that sinks to the bottom rarely floats back to the surface. If copper powder is directly poured into isobutylene sulfide, the desulfurization effect will be far from ideal. When copper powder and carbon are combined to form desulfurization granules, due to their lower density, the time the desulfurization granules remain in the liquid during stirring is greatly extended. This increases the contact time between copper and isobutylene sulfide, and combined with the electrochemical reaction, the time required for copper to remove elemental sulfur is significantly reduced.

[0033] In a preferred embodiment, the desulfurization particles comprise 75-85 parts by mass of carbon and 15-25 parts by mass of copper. Excessive carbon content will cause some copper powder to be encapsulated within the carbon, preventing it from contacting the external environment and thus hindering its reaction with elemental sulfur. Conversely, excessive copper powder content will result in a higher density of the desulfurization particles, hindering their retention and increasing production costs. Furthermore, the desulfurization particles will have low porosity and be relatively loose, lacking sufficient support strength.

[0034] In a preferred embodiment, the particle size of the carbon powder is 100-300 mesh, and the particle size of the copper powder is 50-100 mesh.

[0035] In a preferred embodiment, the desulfurization particles have a particle size of 5-10 mm. If the particle size is too large, the copper powder inside will have difficulty contacting the external liquid; if the particle size is too small, the disturbance effect will be weak, and the turbulence effect will be poor.

[0036] The desulfurization granules mentioned above can be reused; only periodic testing of the sulfur content is required. When the sulfur content reaches a predetermined value, it indicates that the copper in the desulfurization granules is no longer effectively absorbing elemental sulfur as expected. Afterward, the desulfurization granules are retrieved, dried, and the isobutylene sulfide is recovered through condensation.

[0037] The following examples and comparative examples will be used to verify the effectiveness of the present invention.

[0038] Specifically, crude isobutylene sulfide is prepared first by following steps S1 to S4.

[0039] Example 1 Crude isobutylene sulfide was added to a sodium sulfide solution and boiled at 120 degrees Celsius. During the boiling process, desulfurization particles were added and stirred to remove sulfur for 30 minutes, after which the mixture was allowed to stand and separate into layers.

[0040] Comparative Example 1 The crude isobutylene sulfide was added to a sodium sulfide solution of the same concentration as in Example 1 and boiled in an alkaline solution at 120 degrees Celsius for 30 minutes, after which it was allowed to stand and separate into layers.

[0041] Comparative Example 2 The crude isobutylene sulfide was added to a sodium sulfide solution of the same concentration as in Example 1 and boiled with stirring at 120 degrees Celsius for 30 minutes, after which it was allowed to stand and separate into layers.

[0042] Comparative Example 3 The temperature of crude isobutylene sulfide was raised to 120 degrees Celsius, copper powder was added and stirred for 30 minutes, and then allowed to stand to separate into layers.

[0043] 20 ml samples of liquid from the oil layers of Examples 1, 1, 2, and 3 were heated to 140°C. 5 g of copper powder was added to each of the four samples, and the mixture was shaken and mixed for 2 hours. After standing for 20 minutes, the samples were filtered, and the filter residue was dried and then analyzed. The results are shown in Table 1. Table 1: Filter Cake Weight Measurement Table Copper powder (mg) Filter residue (mg) Weight gain (mg) Example 1 5022.1 5028.6 6.5 Comparative Example 1 5018.3 5225.4 207.1 Comparative Example 2 5016.9 5187.7 170.8 Comparative Example 3 5010.8 5494.3 483.5 The mass of the filter residue minus the copper powder is the mass gain. This is because the copper powder reacts with the elemental sulfur in isobutylene sulfide to form cuprous sulfide. Therefore, the mass gain is the mass of sulfur. As can be seen from Table 1, the oil layer after desulfurization in Example 1 has a lower sulfur content, and therefore, the mass of cuprous sulfide formed when reacting with copper powder is also lower. Similarly, the sulfur content in the oil layer in Comparative Example 2 is lower than that in Comparative Example 1; the sulfur content in the oil layer in Comparative Example 1 is lower than that in Comparative Example 3. This shows that, compared to alkaline boiling desulfurization with sodium sulfide solution, the present invention, by adding desulfurization particles and stirring desulfurization simultaneously with sodium sulfide solution, can significantly reduce the sulfur content in isobutylene sulfide.

[0044] In a preferred embodiment, the production system used in the high-pressure synthesis method for low-odor isobutylene sulfide of the present invention includes an ammonium polysulfide synthesis reactor, a polyamine feeding unit, a pipeline reactor, a receiving reactor, a water washing reactor, a distillation reactor, an alkali boiling and stirring reactor, and a rectification reactor. The ammonium polysulfide synthesis reactor is used to synthesize ammonium polysulfide from sulfur, liquid ammonia, and hydrogen sulfide. The outlet of the ammonium polysulfide synthesis reactor is connected to the inlet of the polyamine feeding unit through a pipeline. The polyamine feeding unit is used to collect ammonium polysulfide and quantitatively feed ammonium polysulfide into the pipeline reactor. The outlet of the polyamine feeding unit is connected to the inlet of the pipeline reactor through a pipeline. The pipeline reactor is used to synthesize isobutylene sulfide from ammonium polysulfide and isobutylene; the outlet of the pipeline reactor is connected to the inlet of the receiving vessel via a pipeline. The receiving vessel is used to receive and store the sulfurized isobutylene mixture; the outlet of the receiving vessel is connected to the inlet of the washing vessel via a pipeline. The washing kettle is used to remove water-soluble impurities such as ammonia and ammonium sulfide from isobutylene sulfide. The oil layer outlet of the washing kettle is connected to the feed inlet of the distillation kettle through a pipeline. The distillation vessel is used to purify and refine sulfide isobutylene; the outlet of the distillation vessel is connected to the inlet of the alkali-cooking stirring vessel via a pipeline. The alkaline boiling stirred tank is used to remove elemental sulfur from isobutylene sulfide, and the outlet of the alkaline boiling stirred tank is connected to the inlet of the distillation tank through a pipeline. The distillation vessel is used to purify isobutylene sulfide, separating it from other organic components.

[0045] The above-mentioned production system is similar to the existing sulfurized isobutylene production system, except that the alkaline boiling stirred tank contains desulfurization particles.

[0046] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing low-odor sulfurized isobutylene by high-pressure synthesis, characterized in that: Includes the following steps: Step S1: Add water and sulfur, then introduce liquid ammonia and hydrogen sulfide, and control the temperature to not exceed 65 degrees Celsius to react and generate ammonium polysulfide; Step S2: Mix ammonium polysulfide and isobutylene in a predetermined ratio to generate a mixture mainly containing crude isobutylene sulfide, and control the temperature at 150~220 degrees Celsius. Step S3: Allow the mixture to stand and separate into layers. The mother liquor after standing and separating into layers is used to synthesize ammonium polysulfides. The oil layer is washed with water 1-2 times. Step S4: Distill the washed oil layer to obtain crude isobutylene sulfide; Step S5: Add crude isobutylene sulfide to sodium sulfide solution for alkaline boiling at a temperature of 80-140 degrees Celsius. During the alkaline boiling process, add desulfurization particles and stir to remove sulfur. Then let it stand to separate into layers. Step S6: Wash the oil layer with water, then distill and filter to obtain the sulfurized isobutylene product.

2. The method for preparing low-odor sulfurized isobutylene by high-pressure synthesis as described in claim 1, characterized in that: The method for preparing the desulfurization particles includes the following steps: Step S51: Mix the carbon powder, copper powder, and binder to obtain a mixed mass; Step S52: Granulate the mixed agglomerates in a granulator to obtain mixed granules; Step S53: Carbonize the mixed particles in a carbonization furnace to obtain carbonized particles; Step S54: Activate the carbonized particles in an activation furnace to obtain desulfurization particles with rich pores.

3. The method for preparing low-odor sulfurized isobutylene by high-pressure synthesis as described in claim 2, characterized in that: The desulfurization particles consist of 75-85 parts by mass of carbon and 15-25 parts by mass of copper.

4. The method for preparing low-odor sulfurized isobutylene by high-pressure synthesis as described in claim 2, characterized in that: The desulfurization particles have a particle size of 5~10mm.

5. The method for preparing low-odor sulfurized isobutylene by high-pressure synthesis as described in claim 2, characterized in that: The particle size of the carbon powder is 100~300 mesh, and the particle size of the copper powder is 50~100 mesh.

6. A production system for synthesizing low-odor sulfurized isobutylene using a high-pressure method, characterized in that: It includes an ammonium polysulfide synthesis reactor, a polyamine feeding unit, a pipeline reactor, a receiving reactor, a water washing reactor, a distillation reactor, an alkali boiling and stirring reactor, and a rectification reactor; The ammonium polysulfide synthesis reactor is used to synthesize ammonium polysulfide from sulfur, liquid ammonia, and hydrogen sulfide. The outlet of the ammonium polysulfide synthesis reactor is connected to the inlet of the polyamine feeding unit through a pipeline. The polyamine feeding unit is used to collect ammonium polysulfide and quantitatively feed ammonium polysulfide into the pipeline reactor. The outlet of the polyamine feeding unit is connected to the inlet of the pipeline reactor through a pipeline. The pipeline reactor is used to synthesize isobutylene sulfide from ammonium polysulfide and isobutylene; the outlet of the pipeline reactor is connected to the inlet of the receiving vessel via a pipeline. The receiving vessel is used to receive and store the sulfurized isobutylene mixture; the outlet of the receiving vessel is connected to the inlet of the washing vessel via a pipeline. The washing kettle is used to remove water-soluble impurities such as ammonia and ammonium sulfide from isobutylene sulfide. The oil layer outlet of the washing kettle is connected to the feed inlet of the distillation kettle through a pipeline. The distillation vessel is used to purify and refine sulfide isobutylene; the outlet of the distillation vessel is connected to the inlet of the alkali-cooking stirring vessel via a pipeline. The alkaline boiling stirred tank is used to remove elemental sulfur from isobutylene sulfide, and the outlet of the alkaline boiling stirred tank is connected to the inlet of the distillation tank through a pipeline. The distillation vessel is used to purify isobutylene sulfide, separating it from other organic components.