Method and device for preparing sulfuryl fluoride

Abstract

The invention provides a method and a device for preparing sulfuryl fluoride. The preparation method is carried out in multi-stage tandem reaction kettles and comprises the following steps: filling each stage of reaction kettle with fluoride salt powder, firstly introducing gaseous sulfuryl chloride into the first stage of reaction kettle for reaction, enabling the generated gas to enter the second stage of reaction kettle for reaction with the fluoride salt powder, sequentially carrying out reaction to the last stage of reaction kettle, and collecting the final gas product. Therefore, the sulfuryl fluoride is generated through the gas-solid reaction of the gaseous sulfuryl chloride and the fluoride salt powder, and raw materials such as a solvent and a catalyst are not needed, so that the production cost is reduced. Meanwhile, continuous reaction is realized by adopting series connection of multiple stages of reaction kettles, so that the purity of sulfuryl fluoride is improved.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a method and device for preparing sulfuryl fluoride. Background Art

[0002] Sulfuryl fluoride is one of the important raw materials for producing lithium battery electrolytes, and its preparation process directly affects the cost of lithium battery production. At present, sulfuryl fluoride is mostly prepared by the reaction of sulfuryl chloride and hydrogen fluoride. This method produces a large amount of by-products, such as acidic gases such as hydrogen chloride and sulfur dioxide, and a catalyst needs to be added during the reaction, which has a high production cost. Summary of the invention

[0003] The present application is made in view of the above-mentioned problems, and its purpose is to provide a method and apparatus for preparing sulfuryl fluoride, which avoids the use of hydrogen fluoride, has no by-products such as waste acid, has low equipment requirements, and reduces production costs.

[0004] In order to achieve the above objectives, this application provides the following technical solutions.

[0005] The first aspect of the present application provides a method for preparing sulfuryl fluoride, which is carried out in a multi-stage series reaction kettle, comprising the following steps:

[0006] Each stage of the reactor is filled with fluoride salt powder. First, gaseous sulfuryl chloride is introduced into the first stage reactor for reaction. The generated gas enters the second stage reactor to react with the fluoride salt powder. The reaction is continued to the last stage reactor in sequence, and the final gas product is collected.

[0007] Therefore, the present invention generates sulfuryl fluoride through the gas-solid reaction of gaseous sulfuryl chloride and fluoride salt powder, which does not require raw materials such as solvents and catalysts, thereby reducing production costs. At the same time, a multi-stage reactor is connected in series to achieve continuous reaction, thereby improving the purity of sulfuryl fluoride.

[0008] In any embodiment, the reaction in the first-stage reactor comprises: continuously introducing gaseous sulfuryl chloride into the first-stage reactor at a predetermined rate.

[0009] Continuously introducing gaseous sulfuryl chloride can achieve continuous production of sulfuryl fluoride, while controlling the introduction rate can adjust the purity and yield of the product.

[0010] In any embodiment, the rate of introducing gaseous sulfuryl chloride into the first-stage reactor is 0.4-1.4 kg / h.

[0011] When the introduction rate of sulfuryl chloride is 0.4-1.4 kg / h, a lower number of reaction kettle stages can be used to achieve a higher product purity.

[0012] In any embodiment, the rate of introducing gaseous sulfuryl chloride into the first-stage reactor is 0.4-0.8 kg / h. When the rate of introducing sulfuryl chloride is 0.4-1.4 kg / h, both higher product purity and reaction rate can be taken into account.

[0013] In any embodiment, the reaction temperature in each stage of the reactor is independently 69.1-210°C, preferably 160-210°C.

[0014] When the reaction temperature is 69.1-210°C, the reaction temperature of common fluoride salts and sulfuryl chloride can be reached, and a higher product purity can be obtained.

[0015] In any embodiment, the reaction in each stage of the reactor is carried out under stirring conditions, and the stirring speed is 20 to 30 rpm, preferably 25 to 30 rpm.

[0016] When the stirring speed is between 20 and 30 rpm, the powder and gas can have sufficient contact time, thereby increasing the gas-solid contact area and effectively transferring mass. The powder can also have greater fluidity and improve the gas-solid contact efficiency.

[0017] In any embodiment, the particle size D50 of the fluoride salt powder is 0.1 μm to 50 μm, preferably 0.1 μm to 10 μm.

[0018] When the particle size D50 of the fluoride salt powder is in the range of 0.1 μm to 50 μm, it has a large specific surface area, more complete mass transfer with the gas, and is not prone to agglomeration.

[0019] In any embodiment, the pressure during the reaction in each stage of the reactor is controlled at 0.01 MPa to 0.5 MPa, preferably 0.05 MPa to 0.3 MPa.

[0020] When the pressure in the reactor is between 0.01 MPa and 0.5 MPa, preferably between 0.05 MPa and 0.3 MPa, sulfuryl chloride has a suitable flow rate, can fully contact with the fluoride salt powder, and can make the gas product flow effectively into the next reactor, so that the reaction can proceed more smoothly and continuously.

[0021] In any embodiment, the fluoride salt powder includes at least one of ammonium fluoride, sodium fluoride, potassium fluoride, silver fluoride, antimony trifluoride, potassium hydrogen fluoride, and cesium fluoride, preferably at least one of potassium fluoride and sodium fluoride.

[0022] These fluoride salts can all react with gaseous sulfuryl chloride to generate sulfuryl fluoride, among which potassium fluoride and sodium fluoride are easier to obtain fine powder and have low cost.

[0023] In any embodiment, before the reaction in each stage of the reactor, the step of removing water from the reactor is included.

[0024] Water will react with the raw material sulfuryl chloride to generate sulfuric acid and hydrochloric acid, so it needs to be removed. In any embodiment, the method of collecting the final gas product includes: condensation.

[0025] On the one hand, condensation can further improve the purity of the product, and on the other hand, it can also produce a negative pressure effect to promote the continuous progress of reactions at all levels.

[0026] In any embodiment, before the gas generated by each stage of the reactor enters the next stage of the reactor, the process includes: filtering the generated gas to remove dust, which improves the reaction efficiency of the next stage of the reactor on the one hand, and improves the purity of the product on the other hand.

[0027] In any embodiment, the multi-stage series reactor is a four-stage reactor.

[0028] In order to obtain high-purity sulfuryl fluoride, the four-stage reactor can meet the reaction requirements of most fluoride salts, and the equipment cost is low.

[0029] The second aspect of the present application also provides a device for preparing sulfuryl fluoride, comprising:

[0030] Gas storage tanks;

[0031] A multi-stage reactor connected in series, wherein each stage of the reactor is provided with an agitator; an exhaust port is provided at the top of each stage of the reactor, and an air vent is provided at the bottom; the exhaust port of the gas storage tank is connected to the bottom of the first stage of the reactor, and the exhaust port of each stage of the reactor is connected to the air vent of the next stage of the reactor; the exhaust port of the last stage of the reactor is connected to a gas collection device.

[0032] The device can be used for the gas-solid reaction of gaseous sulfuryl chloride and fluoride salt to prepare high-purity sulfuryl fluoride. The specific working principle is: gaseous sulfuryl fluoride is pre-stored in a gas storage tank, and fluoride salt powder is pre-filled in a multi-stage reactor. The gaseous sulfuryl chloride is introduced into the first-stage reactor through the gas storage tank to react. The generated gas enters the second-stage reactor to react with another part of the fluoride salt powder, and then proceeds to the last-stage reactor in turn to collect the final gas product; in this way, the purity and yield of sulfuryl fluoride can be gradually improved through multi-stage continuous reactions. For example, the number of stages of the multi-stage reactor can be controlled so that the volume content of sulfuryl fluoride in the gas product reaches more than 97%. The above device is used to prepare sulfuryl fluoride, and does not require raw materials other than reactants such as solvents and catalysts, which reduces the types of impurities and reduces production costs.

[0033] In any embodiment, it also includes a sulfuryl chloride storage tank and a heat exchanger connected by a pump, and the heat exchanger is connected to the gas storage tank; the outer wall of the gas storage tank is preferably provided with a jacket.

[0034] The jacket can play a role in heat preservation, so that sulfuryl fluoride remains in gaseous state and reduces liquefaction.

[0035] In any embodiment, the stirrer is a ribbon stirrer; the stirrer is preferably a vertical stirrer.

[0036] The ribbon stirrer can bring the powder at the bottom to the upper part, and the powder at the upper part falls from the middle of the ribbon, which can improve the mixing uniformity of the powder and facilitate the reaction. Since the gas flows up and down, the vertical stirrer is used to adapt to its flow direction, which is more conducive to the effective contact between the fluoride salt powder and the sulfuryl chloride.

[0037] In any embodiment, the reactor comprises, from bottom to top, a first cylindrical section, a conical cylindrical section, and a second cylindrical section which are sequentially connected and coaxial, and the diameter of the second cylindrical section is more than twice that of the first cylindrical section.

[0038] When the diameter ratio of the upper and lower cylindrical areas is greater than 2, the fluoride salt powder can fall more easily, thereby preventing the powder from being stationary in a dead corner and being unable to effectively contact and react with gaseous sulfuryl chloride.

[0039] In any embodiment, the aspect ratio of the first cylindrical section is 1.5-6, preferably 3-5.

[0040] The first cylindrical section is the main reaction zone. The slender structure with a length-to-diameter ratio of 1.5 to 6 can extend the contact path between the gas and the powder, thereby making the reaction more complete.

[0041] In any embodiment, the gas collection device comprises a condenser.

[0042] The condenser can utilize the differences in condensation points of different gases to purify the product.

[0043] In any embodiment, a negative pressure fan is connected to the end of the condenser opposite to the reactor.

[0044] The negative pressure fan can promote the airflow from the first-stage reactor to the tail end, so that the reaction can proceed smoothly and continuously.

[0045] In any embodiment, the exhaust port of each stage of the reactor is provided with a dust filter, which can remove dust in the produced gas, thereby improving the reaction efficiency of the next stage of the reactor and improving the purity of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the structure of a device for preparing sulfuryl fluoride in one embodiment of the present application;

[0047] Figure 2 It is a schematic diagram of the structure of a reactor in one embodiment of the present application.

[0048] Reference numerals:

[0049] 1-Sulfuryl chloride storage tank, 2-Pump, 3-Heat exchanger, 4-Gas storage tank, 5-Reactor, 6-Gas collection device,

[0050] Reactor No. 51-1, Reactor No. 52-2, Reactor No. 53-3, Reactor No. 54-4,

[0051] 501-first cylindrical section, 502-agitator, 503-conical cylinder section, 504-second cylindrical section. DETAILED DESCRIPTION

[0052] Hereinafter, the embodiments of the method and apparatus for preparing sulfuryl fluoride of the present application are specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0053] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0054] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0055] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0056] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0057] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0058] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0059] In the process of preparing sulfuryl fluoride using a fluorination agent and sulfuryl chloride, since the fluorination agent is solid and sulfuryl chloride is liquid under normal conditions, and the two are immiscible, a catalyst needs to be added to promote effective contact between the two and promote the effective chemical reaction. However, the catalyst needs to be replaced regularly due to deactivation problems, making it difficult to achieve continuous production.

[0060] To this end, the present application proposes a method for preparing sulfuryl fluoride, which is carried out in a multi-stage series reactor, comprising the following steps:

[0061] Each stage of the reactor is filled with fluoride salt powder. First, gaseous sulfuryl chloride is introduced into the first stage reactor for reaction. The generated gas enters the second stage reactor to react with the fluoride salt powder. The reaction is continued to the last stage reactor in sequence, and the final gas product is collected.

[0062] Therefore, the present invention generates sulfuryl fluoride through the gas-solid reaction of gaseous sulfuryl chloride and fluoride salt powder, which does not require raw materials such as solvents and catalysts, thereby reducing production costs. At the same time, a multi-stage reactor is connected in series to achieve continuous reaction, thereby improving the purity of sulfuryl fluoride.

[0063] In addition, when the gaseous sulfuryl chloride is introduced into the present invention, the fluoride salt powder will be continuously flying, so that the gas-solid two phases can fully contact and transfer mass, and an effective chemical reaction can occur.

[0064] In this application, the chemical reactions occurring in each stage of the reactor include the following:

[0065] SO2Cl2+M1F→SO2FCl+M1Cl;

[0066] SO2FCl+M2F→SO2F2+M2Cl.

[0067] The overall reaction formula is:

[0068] SO2Cl2+2MF→SO2F2+2MCl

[0069] Wherein, M1F and M2F in the above formula can be the same fluoride salt or different fluoride salts, can be metal fluoride salts or non-metal fluoride salts, and M1 and M2 refer to cations combined with fluoride ions.

[0070] The SO2FCl gas generated by the reaction of each stage of the reactor will enter the next stage of the reactor to continue to react with the fluoride salt to generate SO2F2. Therefore, with the continuous generation of each stage of the reaction, the purity of sulfuryl fluoride in the product will increase step by step. Therefore, the volume content of sulfuryl fluoride in the gas product can be controlled by controlling the number of stages of the multi-stage reactor to meet the predetermined requirements, such as the common requirement of more than 97% pure product, or more than 98%, or more than 99%. The percentage here refers to the volume percentage. It should be noted that in order to improve the purity, controlling the number of stages is not the only means, and it can also be combined with the reaction conditions in each reactor.

[0071] In summary, compared with the industrial preparation of sulfuryl fluoride, the present application avoids the use of hazardous materials such as hydrogen fluoride and does not involve the deactivation of the catalyst, thereby enabling continuous production. The reaction has low production costs, and only sulfuryl chloride and fluoride salts are used as raw materials, and the byproduct produced is chloride salt.

[0072] In some embodiments, the reaction in the first-stage reactor comprises: continuously introducing gaseous sulfuryl chloride into the first-stage reactor at a predetermined rate.

[0073] Continuously introducing gaseous sulfuryl chloride can achieve continuous production of sulfuryl fluoride, while controlling the introduction rate can adjust the purity and yield of the product.

[0074] In some embodiments, the rate of introducing gaseous sulfuryl chloride into the first-stage reactor is 0.4-1.4 kg / h.

[0075] When the rate of introduction of sulfuryl chloride is 0.4-1.4 kg / h, a higher product purity can be achieved with fewer reactor stages. If the rate is too slow, the viscosity of the solid phase powder is large and the fluidity is poor, which is not conducive to the expansion of the mass transfer area; if the rate is too slow, the contact time of the gas-solid two phases is too short, which is not conducive to the full reaction. Therefore, controlling the appropriate ventilation rate can take into account both higher product purity and reaction rate. For example, the rate of introduction of sulfuryl chloride can be any value in the range of 0.4-1.4 kg / h, including but not limited to 0.4 kg / h, 0.5 kg / h, 0.6 kg / h, 0.8 kg / h, 1.0 kg / h, 1.1 kg / h, 1.2 kg / h, 1.3 kg / h, 1.4 kg / h, etc.

[0076] In some embodiments, the rate of introducing gaseous sulfuryl chloride into the first-stage reactor is 0.4-0.8 kg / h.

[0077] In some embodiments, the reaction temperature in each stage of the reactor is independently 69.1-210°C.

[0078] When the reaction temperature is 69.1-210°C, the reaction temperature of the commonly used fluoride salt and sulfuryl chloride can be reached, and a higher product purity can be obtained. For example, for potassium fluoride, the reaction temperature can be any value within 160-210°C, including but not limited to 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, etc. For sodium fluoride or ammonium fluoride, the reaction temperature can be any value within 69.1-100°C, including but not limited to 90°C, 100°C, etc.

[0079] In some embodiments, the reaction in each stage of the reactor is carried out under stirring conditions, and the stirring speed is 20 to 30 rpm, preferably 25 to 30 rpm.

[0080] When the stirring speed is 20 to 30 rpm, the powder can have sufficient contact time with the gas, increase the gas-solid contact area, effectively transfer mass, and make the powder have greater fluidity, thereby improving the gas-solid contact efficiency. If the stirring is too slow, the powder itself has a large viscosity and poor fluidity, and the reaction is not sufficient; if the stirring is too fast, the contact time between some powders and sulfuryl chloride is too short, and the reaction is also insufficient. For example, the stirring speed can be any value within the range of 20 to 30 rpm, including but not limited to 20 rpm, 22 rpm, 25 rpm, 27 rpm, 29 rpm, 30 rpm, etc., or any value within the range of 25 to 30 rpm.

[0081] In some embodiments, the particle size D50 of the fluoride salt powder is 0.1 μm to 50 μm, preferably 0.1 μm to 10 μm.

[0082] When the particle size D50 of the fluoride salt powder is in the range of 0.1 μm to 50 μm, it has a large specific surface area, more sufficient mass transfer with the gas, and is not easy to agglomerate. For example, it can be any value in the range of 0.1 μm to 50 μm, including but not limited to 0.1 μm, 0.5 μm, 0.7 μm, 1 μm, 3 μm, 5 μm, 10 μm, 13 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 50 μm, etc., or any value in the range of 0.1 μm to 10 μm.

[0083] In the present application, D50 refers to the particle size corresponding to when the cumulative particle size distribution percentage of the powder reaches 50%.

[0084] In some embodiments, the pressure during the reaction in the reactor is controlled at 0.01 MPa to 0.5 MPa, preferably 0.05 MPa to 0.3 MPa.

[0085] When the pressure in the reactor is between 0.01MPa and 0.5MPa, the gas can be more effectively brought into contact with the solid, thereby extending the gas residence time and improving the product conversion rate.

[0086] In some embodiments, the fluoride salt powder includes at least one of ammonium fluoride, sodium fluoride, potassium fluoride, silver fluoride, antimony trifluoride, potassium bifluoride, and cesium fluoride, preferably at least one of potassium fluoride and sodium fluoride.

[0087] These fluoride salts can all react with gaseous sulfuryl chloride to generate sulfuryl fluoride, among which potassium fluoride and sodium fluoride are easier to obtain fine powder and have low cost.

[0088] In some embodiments, before the reaction in each stage of the reactor, the process includes: removing water from the reactor.

[0089] Water will react with the raw material sulfuryl chloride to generate sulfuric acid and hydrochloric acid, so it needs to be removed. The removal means can be heating and drying, and / or passing non-reactive gas (gas that does not chemically react with the reactants) to replace it.

[0090] In some embodiments, the method of collecting the final gas product comprises: condensation.

[0091] On the one hand, condensation can further improve the purity of the product, and on the other hand, it can also produce a negative pressure effect to promote the continuous progress of reactions at all levels.

[0092] Dust removal can be performed before condensation, and alkali solution washing, drying, etc. can be performed after condensation.

[0093] In some embodiments, before the gas generated by each stage of the reactor enters the next stage of the reactor, the generated gas is filtered to remove dust, which improves the reaction efficiency of the next stage of the reactor on the one hand and improves the purity of the product on the other hand.

[0094] The number of stages of the reactor in the present application can be two-stage, three-stage, four-stage, five-stage, six-stage, etc.

[0095] In some embodiments, the multi-stage series reactor is a four-stage reactor.

[0096] In order to obtain high-purity sulfuryl fluoride, the four-stage reactor can meet the reaction requirements of most fluoride salts, and the equipment cost is low.

[0097] In some embodiments, in order to fully convert sulfuryl chloride into sulfuryl fluoride, the fluoride salt added to each stage of the reaction kettle is excessive, which can be more than 2 times, 3 times, 4 times, etc., the total molar amount of sulfuryl chloride added in terms of fluoride ion content.

[0098] At the same time, the present application also provides a device for preparing sulfuryl fluoride, such as Figure 1 As shown, it includes:

[0099] Gas storage tank 4;

[0100] A multi-stage reactor 5 is connected in series, and an agitator is provided in each stage of the reactor 5; an exhaust port is provided on the top of each stage of the reactor 5, and an air vent is provided on the bottom; the exhaust port of the gas storage tank 4 is connected to the bottom of the first stage reactor 5, and the exhaust port of each stage of the reactor 5 is connected to the air vent of the next stage reactor 5; the exhaust port of the last stage reactor 5 is connected to the gas collection device 6.

[0101] The device can be used for the gas-solid reaction of gaseous sulfuryl chloride and fluoride salt to prepare high-purity sulfuryl fluoride. The specific working principle is: gaseous sulfuryl fluoride is stored in advance, fluoride salt powder is pre-filled in the multi-stage reactor 5, gaseous sulfuryl chloride is introduced into the first-stage reactor 5 through the gas storage tank 4, and the reaction is carried out. The generated gas enters the second-stage reactor 5 and reacts with another part of the fluoride salt powder, and then proceeds to the last-stage reactor 5 in sequence to collect the final gas product; in this way, the purity and yield of sulfuryl fluoride can be gradually improved through multi-stage continuous reactions. For example, the number of stages of the multi-stage reactor 5 can be controlled so that the volume content of sulfuryl fluoride in the gas product reaches more than 97%. The above device is used to prepare sulfuryl fluoride, without the need for raw materials other than reactants such as solvents and catalysts, reducing the type of impurities and reducing production costs. It can be seen that the device provided in this application can match the sulfuryl fluoride preparation method described above and has the same technical effect.

[0102] Although Figure 1 Four stages of reactors are shown, namely, reactor No. 1 51, reactor No. 2 52, reactor No. 3 53, and reactor No. 4 54, but the number of stages is not limited to the present invention, and can be two, three, four, five, six, etc.

[0103] In some embodiments, in combination Figure 1 , may also include a sulfuryl chloride storage tank 1 and a heat exchanger 3 connected by a pump 2, and the heat exchanger 3 is connected to a gas storage tank 4. The sulfuryl chloride storage tank 1 is used to pre-store liquid sulfuryl chloride, which is transported to the heat exchanger 3 by the pump 2 and heated into a gas state, and the gaseous sulfuryl chloride is stored in the gas storage tank 4 for standby use. The outer wall of the gas storage tank 4 may also be provided with a jacket (not shown in the figure). The jacket can have a heat preservation effect, so that the sulfuryl fluoride remains in a gaseous state and reduces the liquefaction phenomenon.

[0104] The gas storage tank 4 may be a pressure tank, and the heating method of the heat exchanger 3 may be steam heating or oil heating.

[0105] In some embodiments, in combination Figure 1 As shown, the stirrer in the reactor 5 is a ribbon stirrer. The ribbon stirrer can bring the bottom powder to the upper part, and the upper powder falls from the middle of the ribbon, which can improve the mixing uniformity of the powder and is conducive to the reaction.

[0106] In some embodiments, Figure 1 As shown, the stirrer is a vertical stirrer. Since the gas is in an up-and-down flow state, a vertical stirrer is used to adapt to its flow direction, which is more conducive to the effective contact between the fluoride salt powder and the sulfuryl chloride.

[0107] In some embodiments, Figure 2 As shown, the reactor 5 includes a first cylindrical section, a conical cylindrical section and a second cylindrical section which are connected in sequence and are coaxial from bottom to top, and the diameter D2 of the second cylindrical section is more than twice the diameter D1 of the first cylindrical section.

[0108] Under the action of gas flow and / or stirring, the fluoride salt powder will fly. When the diameter ratio of the upper and lower cylindrical areas is greater than 2, the fluoride salt powder can fall more easily and avoid the powder from being stationary in a dead corner.

[0109] In some embodiments, the aspect ratio of the first cylindrical section is 1.5 to 6. The aspect ratio refers to Figure 2 The ratio of the height H1 of the first cylindrical section to its diameter D1, that is, H1 / D1.

[0110] The first cylindrical section of the reactor 5 is the main reaction zone. The slender structure with an aspect ratio of 1.5 to 6 can extend the contact path between the gas and the powder, thereby making the reaction more complete, wherein 3 to 5 is preferred.

[0111] The present application has no special requirements on the bottom shape of the reactor 5, which can be Figure 2 The cone shown is to facilitate the rapid introduction of gas to slow down after entering the reactor 5, thereby increasing the contact time with the powder.

[0112] The volumes of the reactors 5 at each stage may be the same or different.

[0113] In some embodiments, the gas collecting device 6 includes a condenser (not shown).

[0114] The condenser can utilize the differences in condensation points of different gases to purify the product.

[0115] In some embodiments, a negative pressure fan is connected to the end of the condenser opposite to the reaction kettle 5 .

[0116] The negative pressure fan can promote the airflow from the first-stage reactor 5 to the tail end, so that the reaction can proceed smoothly and continuously.

[0117] In some embodiments, a dust filter is provided at the exhaust port of each stage of the reactor 5. The dust filter can remove dust in the produced gas, which can improve the reaction efficiency of the next stage of the reactor 5 on the one hand, and improve the purity of the product on the other hand. The dust filter can be a filter cotton or a filter plate, for example, a filter plate can be installed at the exhaust port of each reactor 5.

[0118] In some embodiments, a sampling port and a flow meter are provided on the pipelines connecting the reaction kettles 5 .

[0119] Example

[0120] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0121] Example 1

[0122] exist Figure 1 and 2 Sulfuryl fluoride is produced in the device shown. Among them, the capacity of the gas storage tank 4 is 5L. The four-stage reactors are all spiral ribbon stirring reactors. The diameter of each reactor is 14 cm, the total height is 84 cm, and the filling height of the fluoride salt powder is flush with the height of the uppermost blade of the stirrer. The aspect ratio of the first cylindrical section 501 is 3, D2 / D1=2, and each reactor is equipped with a filter plate for filtering dust at the exhaust port. The specific production process is as follows.

[0123] Reactor No. 1 51, Reactor No. 2 52, Reactor No. 3 53, Reactor No. 4 54 are respectively loaded with 5 kg of anhydrous potassium fluoride (powder particle size D50 is 10 μm), and stirred and heated to 160°C. Then 3 kg of sulfuryl chloride is loaded into sulfuryl chloride storage tank 1, and heat exchanger 3 and gas storage tank 4 are preheated. After preparation, sulfuryl chloride is transported into heat exchanger 3 through peristaltic pump 2 via mass flow meter, and the flow rate of sulfuryl chloride liquid is controlled at 0.8 kg / h. The temperature of heat exchanger 3 and gas storage tank 4 is controlled at 105±15°C. Vaporized sulfuryl chloride enters gas storage tank 4, and sulfuryl chloride gas passes through the storage tank and enters reactor No. 1, No. 2, No. 3, and No. 4 in turn. A gas sampling port is set at the gas outlet of each reactor, and sampling is performed every hour to detect the tail gas composition of each reactor, as shown in Table 1. During the reaction, the pressure in the last reactor is 0.1 MPa, while the pressure in the first reactor may be 0.15 MPa, the second reactor is 0.13 MPa, and the third reactor is about 0.11 MPa (the pressure of the first to fourth reactors decreases, which is usually achieved by controlling the pressure of the last reactor, and the pressure drop of each stage is maintained at about 10% to 15%, and the same applies to the following embodiments). The gas component values ​​in Table 1 are the average values ​​of sulfuryl chloride samples taken every hour from the beginning to the end of feeding. The tail gas of Reactor No. 4 is collected after condensation and compression.

[0124] Example 2

[0125] Except that the intake rate of sulfuryl chloride is adjusted to 0.4 kg / h, the other steps of Example 2 are the same as those of Example 1.

[0126] Example 3

[0127] Except that the intake rate of sulfuryl chloride is adjusted to 1.4 kg / h, the other steps of Example 3 are the same as those of Example 1.

[0128] Example 4

[0129] Except that the temperature of reaction kettles No. 1, No. 2, No. 3 and No. 4 was adjusted to 120° C., the other steps of Example 4 were the same as those of Example 1.

[0130] Example 5

[0131] Except that the temperature of reaction kettles No. 1, No. 2, No. 3 and No. 4 was adjusted to 210° C., the other steps of Example 5 were the same as those of Example 1.

[0132] Example 6

[0133] The other steps of Example 6 are the same as those of Example 1, except that the fluoride salt in reactor No. 1 is replaced with 3.3 kg of ammonium fluoride and the reactor temperature is controlled at 50°C, and the fluoride salt in reactors No. 2 and 3 is replaced with 3.1 kg of sodium fluoride and the reactor temperatures are controlled at 170°C.

[0134] Example 7

[0135] The other steps of Example 7 are the same as those of Example 1, except that the fluoride salt in the No. 1, No. 2, No. 3, and No. 4 reaction kettles are all replaced with 3.1 kg of sodium fluoride and the kettle temperatures are all controlled at 170°C.

[0136] Example 8

[0137] Except that the fluoride salt in the No. 1, No. 2 and No. 3 reaction kettles were replaced with 3.3 kg of ammonium fluoride and the kettle temperatures were all controlled at 50° C., the other steps of Example 8 were the same as those of Example 1.

[0138] Example 9

[0139] During the reaction process, the pressure in the last stage reactor was controlled at about 0.2 MPa, and the remaining steps were the same as in Example 1.

[0140] Example 10

[0141] During the reaction, the pressure in the last stage reactor was controlled at about 0.05 MPa, and the remaining steps were the same as in Example 1.

[0142] Embodiment 11

[0143] During the reaction, the pressure in the last stage reactor was controlled at about 0.3 MPa, and the remaining steps were the same as in Example 1.

[0144] Comparative Example

[0145] Add 550g potassium fluoride to 10L deionized water to dissolve, add 1600g columnar activated carbon after dissolution, and let the potassium fluoride aqueous solution completely soak the activated carbon for 24 hours. Then take out the activated carbon and slowly dry it. After drying, put it into a vacuum drying oven at 150℃ for vacuum drying. Fill the dried activated carbon into the shell-and-tube reactor and heat it to 200℃. Then, chlorine, sulfur dioxide and hydrogen fluoride (where hydrogen fluoride enters the storage tank after being heated and vaporized) in a molar ratio of 1:1.1:3.5 are introduced into the storage tank, and the storage tank is equipped with a heating jacket for heating so that the gas temperature in the storage tank is 150-180° C. After the gas in the storage tank is evenly mixed, it is slowly introduced into a tubular reactor equipped with an activated carbon catalyst for reaction, and the reaction temperature is controlled at 190-240° C. and the pressure is 3-5 kg. The mixed gas coming out of the tail pipe is dedusted by a bag, then alkali washed, condensed, dried and collected to obtain sulfuryl fluoride, and the purity of sulfuryl fluoride can reach 99%. On average, 1 kg of activated carbon-loaded potassium fluoride catalyst can prepare 10 kg of sulfuryl fluoride gas, and the raw material unit consumption is as follows: chlorine: sulfur dioxide: hydrogen fluoride is about 1.55:1.57:0.98.

[0146] In the production process of the above comparative example, the product mixed gas mainly comprises sulfuryl fluoride and unreacted sulfur dioxide and hydrogen fluoride.

[0147] Table 1 Process conditions and production results of each embodiment

[0148]

[0149]

[0150]

[0151] Note: Potassium fluoride, sodium fluoride and ammonium fluoride in the table all refer to anhydrous potassium fluoride, sodium fluoride and ammonium fluoride. The total yield of sulfuryl fluoride is calculated based on the amount of sulfuryl chloride introduced.

[0152] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, within the scope of the subject matter of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing sulfuryl fluoride, characterized in that: The method is carried out in a multi-stage series reactor and comprises the following steps: Each stage of the reactor is filled with fluoride salt powder. First, gaseous sulfuryl chloride is introduced into the first stage reactor for reaction. The generated gas enters the second stage reactor to react with the fluoride salt powder. The reaction is continued to the last stage reactor in sequence, and the final gas product is collected.

2. The method according to claim 1, characterized in that The reaction in the first-stage reactor includes: continuously introducing gaseous sulfuryl chloride into the first-stage reactor at a predetermined rate.

3. The method according to claim 2, characterized in that The rate of introducing gaseous sulfuryl chloride into the first-stage reaction kettle is 0.4-1.4 kg / h, preferably 0.4-0.8 kg / h.

4. The method according to any one of claims 1 to 3, characterized in that: The reaction temperature in each stage of the reactor is independently 69.1-210°C, preferably 160-210°C.

5. The method according to any one of claims 1 to 4, characterized in that: The reaction in each stage of the reactor is carried out under stirring conditions, with a stirring speed of 20 to 30 rpm, preferably 25 to 30 rpm.

6. The method according to any one of claims 1 to 5, characterized in that: The particle size D50 of the fluoride salt powder is 0.1 μm to 50 μm, preferably 0.1 μm to 10 μm.

7. The method according to any one of claims 1 to 6, characterized in that: The pressure during the reaction in each stage of the reactor is controlled at 0.01MPa to 0.5MPa, preferably 0.05MPa to 0.3MPa.

8. The method according to any one of claims 1 to 7, characterized in that: The fluoride salt powder includes at least one of ammonium fluoride, sodium fluoride, potassium fluoride, silver fluoride, antimony trifluoride, potassium hydrogen fluoride, and cesium fluoride, preferably at least one of potassium fluoride and sodium fluoride.

9. The method according to any one of claims 1 to 8, characterized in that: Before the reaction in each stage of the reactor, the following steps are performed: removing the water in the reactor.

10. The method according to any one of claims 1 to 9, characterized in that: The method for collecting the final gas product includes: condensation.

11. The method according to any one of claims 1 to 10, characterized in that: Before the gas generated by each stage of the reactor enters the next stage of the reactor, the following steps are performed: filtering the generated gas and removing dust.

12. The method according to any one of claims 1 to 11, characterized in that: The multi-stage series reactor is a four-stage reactor.

13. A device for preparing sulfuryl fluoride, characterized in that: include: Gas storage tanks; A multi-stage reactor connected in series, wherein each stage of the reactor is provided with an agitator; an exhaust port is provided at the top of each stage of the reactor, and an air vent is provided at the bottom; the exhaust port of the gas storage tank is connected to the bottom of the first stage of the reactor, and the exhaust port of each stage of the reactor is connected to the air vent of the next stage of the reactor; the exhaust port of the last stage of the reactor is connected to a gas collection device.

14. The device according to claim 13, characterized in that It also includes a sulfuryl chloride storage tank and a heat exchanger connected by a pump, wherein the heat exchanger is connected to the gas storage tank; and the outer wall of the gas storage tank is preferably provided with a jacket.

15. The device according to claim 13, characterized in that The stirrer is a ribbon stirrer; the stirrer is preferably a vertical stirrer.

16. The device according to claim 13, characterized in that The reactor comprises, from bottom to top, a first cylindrical section, a conical cylindrical section and a second cylindrical section which are connected in sequence and are coaxial, and the diameter of the second cylindrical section is more than twice that of the first cylindrical section.

17. The device according to claim 16, characterized in that The aspect ratio of the first cylindrical section is 1.5-6, preferably 3-5.

18. The device according to any one of claims 13 to 17, characterized in that: The gas collection device includes a condenser; Preferably, a negative pressure fan is connected to the end of the condenser opposite to the reactor.

19. The device according to any one of claims 13 to 18, characterized in that: The exhaust port of each reactor is equipped with a dust filter.

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