Chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur

Abstract

The invention relates to the technical field of chlorosulfonic acid preparation, in particular to a chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur. A gas inlet of a plasma reactor is connected with an inert gas pipeline, and a feeding port of the plasma reactor is connected with a feeding pipeline; a discharge port of the plasma reactor is connected with a feed port of the reaction kettle through a discharge pipeline; a discharge port of the reaction kettle is connected with a feed port of the heat exchanger, a discharge port of the heat exchanger is connected with a feed port of the rectifying tower, and a discharge port of the rectifying tower is connected with the chlorosulfonic acid pipeline. According to the method, the sulfur is pretreated through the plasma, and the surface of the sulfur is bombarded and activated through the low-temperature plasma, so that the reaction activity of the sulfur is effectively improved, the subsequent synthetic reaction with chlorine is more sufficient, and the preparation efficiency and the product purity of chlorosulfonic acid are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of chlorosulfonic acid preparation technology, specifically to a chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur. Background Technology

[0002] Chlorosulfonic acid is an important basic chemical raw material, widely used in the organic synthesis industries of dyes, pharmaceuticals, pesticides, saccharin, and detergents, mainly as a sulfonating agent and chlorosulfonating agent. With the rapid development of the fine chemical industry, the market demand for chlorosulfonic acid continues to grow, while the requirements for its production processes to be green, energy-efficient, and of high quality are becoming increasingly stringent.

[0003] Currently, the mainstream industrial process for preparing chlorosulfonic acid involves the direct combination of hydrogen chloride gas and sulfur trioxide in the liquid or gas phase. Chinese patent CN101100289A discloses a typical mainstream synthesis method that uses liquid sulfur trioxide with a concentration higher than 99% and dry hydrogen chloride in a reaction tower. While this method has the advantage of relatively simple equipment structure, it suffers from significant technical shortcomings: the reaction is strongly exothermic, requiring extremely high precision in temperature control; any temperature fluctuation can easily lead to product decomposition or side reactions. Furthermore, this process heavily relies on high-purity sulfur trioxide and hydrogen chloride raw materials, and the purification and preparation of these raw materials increases the overall production cost, limiting the economic viability of its large-scale application.

[0004] Besides the aforementioned mainstream routes, another important technological path is to directly chlorinate sulfur to prepare sulfur-containing chlorides (such as sulfur monochloride and sulfur dichloride) and use them as the starting reaction for the synthesis of chlorosulfonic acid or its precursors. However, in traditional chlorination reactions using sulfur as a starting material, the sulfur molecule (S8) has a stable cyclic structure and is chemically inert at room temperature, resulting in high kinetic resistance and insufficient reactivity when reacting with chlorine. Existing technologies typically require maintaining the reaction temperature above 200℃ and high pressure conditions to achieve the ideal reaction rate and conversion rate. This high-temperature and high-pressure operation mode not only results in energy consumption of up to 1.5 kWh / kg per unit product, significantly increasing production costs, but also exacerbates the corrosion of reaction equipment and promotes side reactions, affecting product purity. Furthermore, traditional processes have low recovery rates for unreacted chlorine, often employing simple liquid sealing or alkaline absorption methods, which wastes raw materials and easily generates chlorine- and sulfur-containing waste gas emissions, failing to meet increasingly stringent environmental standards.

[0005] In recent years, low-temperature plasma technology, as an efficient method for material surface modification, has been applied to the surface activation treatment of sulfur powder. Related studies have shown that non-thermal plasma treatment of sulfur powder can significantly increase its surface defects and active sites, thereby enhancing its reactivity. However, there are currently no publicly reported applications of this plasma activation technology to the chemical synthesis reactions of chlorosulfonic acid or its precursors, failing to address the core issues of low reactivity and high energy consumption in sulfur production. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A chlorosulfonic acid preparation system based on plasma pretreatment of sulfur includes a plasma reactor, an inert gas pipeline, a drying tower, a chlorine pipeline, a filter, a reaction vessel, a heat exchanger, a distillation column, a chlorosulfonic acid pipeline, a recovery pipe, and a chlorine pump. The inlet of the plasma reactor is connected to the inert gas pipeline, the feed inlet of the plasma reactor is connected to a feed pipeline, and the outlet of the plasma reactor is connected to the feed inlet of the reaction vessel via an outlet pipeline. The inlet of the drying tower is connected to the chlorine pipeline, the outlet of the drying tower is connected to the inlet of the filter, and the outlet of the filter is connected to the inlet of the reaction vessel. The outlet of the reaction vessel is connected to the feed inlet of the heat exchanger, the outlet of the heat exchanger is connected to the feed inlet of the distillation column, the outlet of the distillation column is connected to the chlorosulfonic acid pipeline, the outlet of the distillation column is connected to the input end of the chlorine pump via the recovery pipe, and the output end of the chlorine pump is connected to the inlet of the reaction vessel.

[0009] Furthermore, the feed pipe is equipped with a feeding device, and the discharge pipe is equipped with a discharge device.

[0010] Furthermore, the plasma reactor is connected to a power supply system.

[0011] Furthermore, the reactor is equipped with a stirring device, and the stirring blades of the stirring device are of an anchor type, a paddle type, or a propeller type.

[0012] Furthermore, the drying tower is filled with a desiccant, which is one of anhydrous calcium chloride, silica gel, or molecular sieve.

[0013] Furthermore, the inert gas transported by the inert gas pipeline is one or more mixed gases selected from nitrogen, argon, or helium.

[0014] This invention also includes the following technical solutions:

[0015] A method for preparing chlorosulfonic acid from sulfur based on plasma pretreatment using the above system includes the following steps:

[0016] Step 1, Plasma Pretreatment: Sulfur powder is placed in a plasma reactor, and inert gas is introduced through an inert gas pipeline. The power supply system supplies power to the plasma reactor to generate low-temperature plasma, which bombards and activates the sulfur surface to obtain pretreated sulfur. The inert gas flow rate for plasma pretreatment is 100-300 mL / min, the pressure is 0.1-0.3 MPa, the plasma power is 50-150 W, the treatment time is 10-30 minutes, and the temperature is 40-60℃.

[0017] Step 2, Synthesis Reaction: The pretreated sulfur obtained in Step 1 is transported to the reactor through the discharge pipe and discharge device. Chlorine gas is dried in a drying tower through a chlorine gas pipeline, then purified by a filter. The purified chlorine gas is then introduced into the reactor, and the pretreated sulfur and chlorine gas are mixed in the reactor at a molar ratio of 1:1.02-1.08. The reaction is carried out by stirring with a stirring device. The reaction temperature in the reactor is 180-220℃, and the reaction pressure is 0.3-0.5MPa.

[0018] Step 3, Condensation and Recovery: The product vapor generated by the reaction is transported from the outlet of the reactor to the heat exchanger for cooling. The cooled material enters the distillation column for separation. The finished chlorosulfonic acid is collected through the chlorosulfonic acid pipeline. The unreacted chlorine gas is transported to the chlorine pump through the outlet of the distillation column and the recovery pipe. After being pressurized by the chlorine pump, it is circulated back to the reactor. The temperature of the heat exchanger is -10℃ to 0℃.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] This invention provides a chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur. By pretreating sulfur with plasma, the surface of the sulfur is bombarded and activated using low-temperature plasma, effectively enhancing the reactivity of sulfur and allowing for a more complete subsequent synthesis reaction with chlorine, significantly improving the preparation efficiency and product purity of chlorosulfonic acid. The combination of a drying tower and a filter in the system achieves deep drying and purification of chlorine, avoiding the adverse effects of impurities on the reaction. Simultaneously, the chlorine recovery and circulation system, through a distillation tower, recovery pipe, and chlorine pump, reintroduces unreacted chlorine into the reactor, significantly reducing raw material consumption and production costs, thus possessing both environmental and economic value. The overall system structure is rationally designed, with smooth coordination among components. Precise control of key process parameters ensures the stability and reliability of the preparation process, making it suitable for large-scale industrial production. Attached Figure Description

[0021] The embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein:

[0022] Figure 1 A schematic diagram of an embodiment of a chlorosulfonic acid preparation system based on plasma pretreatment of sulfur is shown;

[0023] Attached diagram labels: 1-Plasma reactor, 2-Power supply system, 3-Inert gas pipeline, 4-Feeding device, 5-Drying tower, 5a-Chlorine pipeline, 6-Filter, 7-Reaction vessel, 8-Discharge device, 9-Heat exchanger, 10-Distillation tower, 10a-Chlorosulfonic acid pipeline, 10b-Recovery pipe, 11-Chlorine pump. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Reference Appendix Figure 1 A chlorosulfonic acid preparation system based on plasma pretreatment of sulfur includes a plasma reactor 1, an inert gas pipeline 3, a drying tower 5, a chlorine pipeline 5a, a filter 6, a reaction vessel 7, a heat exchanger 9, a distillation column 10, a chlorosulfonic acid pipeline 10a, a recovery pipe 10b, and a chlorine pump 11. The inlet of the plasma reactor 1 is connected to the inert gas pipeline 3, the feed inlet of the plasma reactor 1 is connected to the feed pipeline, and the outlet of the plasma reactor 1 is connected to the feed inlet of the reaction vessel 7 through the outlet pipeline. The inlet of the drying tower 5 is connected to the chlorine pipeline 5a, the outlet of the drying tower 5 is connected to the inlet of the filter 6, and the outlet of the filter 6 is connected to the inlet of the reactor 7. The outlet of the reactor 7 is connected to the inlet of the heat exchanger 9, the outlet of the heat exchanger 9 is connected to the inlet of the distillation tower 10, the outlet of the distillation tower 10 is connected to the chlorosulfonic acid pipeline 10a, the outlet of the distillation tower 10 is connected to the input end of the chlorine pump 11 through the recovery pipe 10b, and the output end of the chlorine pump 11 is connected to the inlet of the reactor 7.

[0026] In one embodiment of the present invention, a feeding device 4 is provided on the feeding pipe and a discharging device 8 is provided on the discharging pipe.

[0027] In one embodiment of the present invention, the plasma reactor 1 is connected to the power supply system 2.

[0028] In one embodiment of the present invention, the reaction vessel 7 is provided with a stirring device, and the stirring blades of the stirring device are of an anchor type, a paddle type or a propeller type.

[0029] In one embodiment of the present invention, the drying tower 5 is filled with a desiccant, which is one of anhydrous calcium chloride, silica gel or molecular sieve.

[0030] In one embodiment of the present invention, the inert gas transported by the inert gas pipeline 3 is one or more mixed gases selected from nitrogen, argon or helium.

[0031] A method for preparing chlorosulfonic acid from sulfur based on plasma pretreatment using the above system includes the following steps:

[0032] Step 1, Plasma Pretreatment: Sulfur powder is placed in plasma reactor 1, and inert gas is introduced through inert gas pipe 3. The power supply system 2 supplies power to plasma reactor 1 to generate low-temperature plasma, which bombards and activates the sulfur surface to obtain pretreated sulfur. The inert gas flow rate for plasma pretreatment is 100-300 mL / min, the pressure is 0.1-0.3 MPa, the plasma power is 50-150 W, the treatment time is 10-30 minutes, and the temperature is 40-60℃.

[0033] Step 2, Synthesis Reaction: The pretreated sulfur obtained in Step 1 is transported to the reactor 7 through the discharge pipe and discharge device 8. Chlorine gas is introduced into the drying tower 5 through the chlorine gas pipe 5a for drying, and then purified by the filter 6. The purified chlorine gas is then introduced into the reactor 7, so that the pretreated sulfur and chlorine gas are mixed in the reactor 7 at a molar ratio of 1:1.02-1.08. The reaction is carried out by stirring with a stirring device. The reaction temperature in the reactor 7 is 180-220℃, and the reaction pressure is 0.3-0.5MPa.

[0034] Step 3, Condensation and Recovery: The product vapor generated by the reaction is transported from the outlet of the reactor 7 to the heat exchanger 9 for cooling. The cooled material enters the distillation column 10 for separation. The finished chlorosulfonic acid is collected through the chlorosulfonic acid pipeline 10a. The unreacted chlorine gas is transported to the chlorine pump 11 through the gas outlet of the distillation column 10 and the recovery pipe 10b. After being pressurized by the chlorine pump 11, it is circulated back to the reactor 7. The temperature of the heat exchanger 9 is -10℃ to 0℃.

[0035] Example 1

[0036] A method for preparing chlorosulfonic acid based on plasma pretreatment of sulfur includes the following steps:

[0037] Step 1, Plasma Pretreatment: Sulfur powder is placed in plasma reactor 1, and inert gas is introduced through inert gas pipe 3. The power supply system 2 supplies power to plasma reactor 1 to generate low-temperature plasma, which bombards and activates the sulfur surface to obtain pretreated sulfur. The inert gas flow rate for plasma pretreatment is 100 mL / min, the pressure is 0.1 MPa, the plasma power is 50 W, the treatment time is 10 minutes, and the temperature is 40 °C.

[0038] Step 2, Synthesis Reaction: The pretreated sulfur obtained in Step 1 is transported to the reactor 7 through the discharge pipe and discharge device 8. Chlorine gas is introduced into the drying tower 5 through the chlorine gas pipe 5a for drying, and then purified by the filter 6. The purified chlorine gas is then introduced into the reactor 7, so that the pretreated sulfur and chlorine gas are mixed in the reactor 7 at a molar ratio of 1:1.02. The reaction is carried out by stirring with a stirring device. The reaction temperature in the reactor 7 is 180℃, and the reaction pressure is 0.3MPa.

[0039] Step 3, Condensation and Recovery: The product vapor generated by the reaction is transported from the outlet of the reactor 7 to the heat exchanger 9 for cooling. The cooled material enters the distillation column 10 for separation. The finished chlorosulfonic acid is collected through the chlorosulfonic acid pipeline 10a. The unreacted chlorine gas is transported to the chlorine pump 11 through the gas outlet of the distillation column 10 and the recovery pipe 10b. After being pressurized by the chlorine pump 11, it is circulated back to the reactor 7. The temperature of the heat exchanger 9 is -10℃.

[0040] Example 2

[0041] A method for preparing chlorosulfonic acid based on plasma pretreatment of sulfur includes the following steps:

[0042] Step 1, Plasma Pretreatment: Sulfur powder is placed in plasma reactor 1, and inert gas is introduced through inert gas pipe 3. The power supply system 2 supplies power to plasma reactor 1 to generate low-temperature plasma, which bombards and activates the sulfur surface to obtain pretreated sulfur. The inert gas flow rate for plasma pretreatment is 300 mL / min, the pressure is 0.3 MPa, the plasma power is 150 W, the treatment time is 30 minutes, and the temperature is 60℃.

[0043] Step 2, Synthesis Reaction: The pretreated sulfur obtained in Step 1 is transported to the reactor 7 through the discharge pipe and discharge device 8. Chlorine gas is introduced into the drying tower 5 through the chlorine gas pipe 5a for drying, and then purified by the filter 6. The purified chlorine gas is then introduced into the reactor 7, so that the pretreated sulfur and chlorine gas are mixed in the reactor 7 at a molar ratio of 1:1.08. The reaction is carried out by stirring with a stirring device. The reaction temperature in the reactor 7 is 220℃, and the reaction pressure is 0.5MPa.

[0044] Step 3, Condensation and Recovery: The product vapor generated by the reaction is transported from the outlet of the reactor 7 to the heat exchanger 9 for cooling. The cooled material enters the distillation column 10 for separation. The finished chlorosulfonic acid is collected through the chlorosulfonic acid pipeline 10a. The unreacted chlorine gas is transported to the chlorine pump 11 through the gas outlet of the distillation column 10 and the recovery pipe 10b. After being pressurized by the chlorine pump 11, it is circulated back to the reactor 7. The temperature of the heat exchanger 9 is 0℃.

[0045] This invention provides a chlorosulfonic acid preparation system and method based on plasma pretreatment of sulfur. By pretreating sulfur with plasma, the surface of the sulfur is bombarded and activated using low-temperature plasma, effectively enhancing the reactivity of sulfur and allowing for a more complete subsequent synthesis reaction with chlorine, significantly improving the preparation efficiency and product purity of chlorosulfonic acid. The combination of a drying tower and a filter in the system achieves deep drying and purification of chlorine, avoiding the adverse effects of impurities on the reaction. Simultaneously, the chlorine recovery and circulation system, through a distillation tower, recovery pipe, and chlorine pump, reintroduces unreacted chlorine into the reactor, significantly reducing raw material consumption and production costs, thus possessing both environmental and economic value. The overall system structure is rationally designed, with smooth coordination among components. Precise control of key process parameters ensures the stability and reliability of the preparation process, making it suitable for large-scale industrial production.

[0046] The foregoing descriptions have outlined some exemplary embodiments of the present invention. It is understood that these embodiments are merely illustrative and do not constitute a limitation on the scope of protection of the present invention. Features in these embodiments can be rearranged in suitable ways, and the resulting solutions remain within the scope of protection claimed by the present invention. All other embodiments obtained by those skilled in the art based on the foregoing embodiments without inventive effort, i.e., all modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, fall within the scope of protection claimed by the present invention.

Claims

1. A chlorosulfonic acid preparation system based on plasma pretreatment of sulfur, characterized in that, The system includes a plasma reactor (1), an inert gas pipeline (3), a drying tower (5), a chlorine pipeline (5a), a filter (6), a reactor (7), a heat exchanger (9), a distillation tower (10), a chlorosulfonic acid pipeline (10a), a recovery pipe (10b), and a chlorine pump (11). The inlet of the plasma reactor (1) is connected to the inert gas pipeline (3), the feed inlet of the plasma reactor (1) is connected to the feed pipeline, and the outlet of the plasma reactor (1) is connected to the feed inlet of the reactor (7) via the outlet pipeline. The inlet of the drying tower (5) is connected to the chlorine pipeline (5a). 5a) The outlet of the drying tower (5) is connected to the inlet of the filter (6), and the outlet of the filter (6) is connected to the inlet of the reactor (7); the outlet of the reactor (7) is connected to the inlet of the heat exchanger (9), the outlet of the heat exchanger (9) is connected to the inlet of the distillation tower (10), the outlet of the distillation tower (10) is connected to the chlorosulfonic acid pipeline (10a), the outlet of the distillation tower (10) is connected to the input end of the chlorine pump (11) through the recovery pipe (10b), and the output end of the chlorine pump (11) is connected to the inlet of the reactor (7).

2. The chlorosulfonic acid preparation system based on plasma pretreatment of sulfur according to claim 1, characterized in that, The feed pipe is equipped with a feed device (4), and the discharge pipe is equipped with a discharge device (8).

3. The chlorosulfonic acid preparation system based on plasma pretreatment of sulfur according to claim 1, characterized in that, The plasma reactor (1) is connected to the power supply system (2).

4. The chlorosulfonic acid preparation system based on plasma pretreatment of sulfur according to claim 1, characterized in that, The reactor (7) is equipped with a stirring device, and the stirring blades of the stirring device are anchor type, paddle type or propeller type.

5. The chlorosulfonic acid preparation system based on plasma pretreatment of sulfur according to claim 1, characterized in that, The drying tower (5) is filled with a desiccant, which is one of anhydrous calcium chloride, silica gel or molecular sieve.

6. The chlorosulfonic acid preparation system based on plasma pretreatment of sulfur according to claim 1, characterized in that, The inert gas transported by the inert gas pipeline (3) is one or more mixed gases of nitrogen, argon or helium.

7. A method for preparing chlorosulfonic acid from sulfur based on plasma pretreatment using the system described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1, Plasma pretreatment: Sulfur powder is placed in plasma reactor (1), and inert gas is introduced through inert gas pipe (3). The power supply system (2) supplies power to plasma reactor (1) to generate low-temperature plasma, which bombards and activates the sulfur surface to obtain pretreated sulfur. The inert gas flow rate for plasma pretreatment is 100-300 mL / min, the pressure is 0.1-0.3 MPa, the plasma power is 50-150 W, the treatment time is 10-30 minutes, and the temperature is 40-60℃. Step 2, Synthesis Reaction: The pretreated sulfur obtained in Step 1 is transported to the reactor (7) through the discharge pipe and discharge device (8). Chlorine gas is introduced into the drying tower (5) through the chlorine gas pipe (5a) for drying, and then purified by the filter (6). The purified chlorine gas is introduced into the reactor (7) so that the pretreated sulfur and chlorine gas are mixed in the reactor (7) at a molar ratio of 1:1.02-1.

08. The reaction is carried out by stirring with a stirring device. The reaction temperature in the reactor (7) is 180-220℃ and the reaction pressure is 0.3-0.5MPa. Step 3, condensation and recovery: The product vapor generated by the reaction is transported from the outlet of the reactor (7) to the heat exchanger (9) for cooling. The cooled material enters the distillation column (10) for separation. The finished chlorosulfonic acid is collected through the chlorosulfonic acid pipeline (10a). The unreacted chlorine gas is transported to the chlorine pump (11) through the outlet of the distillation column (10) and the recovery pipe (10b). After being pressurized by the chlorine pump (11), it is circulated back to the reactor (7). The temperature of the heat exchanger (9) is -10℃ to 0℃.

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