Device and method for continuously synthesizing capryloyl chloride by using scraper film reactor

Abstract

The invention discloses a device and a method for continuously synthesizing capryloyl chloride by using a scraper film reactor. The device comprises a reaction kettle, vacuumizing equipment, a stirrer, a feeding assembly and a discharging assembly, an interlayer is arranged on the inner wall of the reaction kettle and is used for introducing a heat-conducting medium; the vacuumizing equipment is arranged on the reaction kettle and is communicated with the inner cavity of the reaction kettle; the stirrer is mounted in the reaction kettle, a plurality of scrapers are mounted at the output end of the stirrer, and the feeding assembly is mounted at the top of the reaction kettle and communicated with an inner cavity of the reaction kettle; the feeding assembly is used for adding liquid n-caprylic acid and thionyl chloride into the reaction kettle; the discharging assembly is mounted at the bottom of the reaction kettle and is communicated with the inner cavity of the reaction kettle. According to the invention, the principle of scraper type film evaporation is utilized, so that high-purity and high-yield capryloyl chloride products are efficiently synthesized, hydrogen chloride and sulfur dioxide gas generated in the reaction process can be discharged and recycled, the green and environment-friendly process requirements are met, and the purity and yield of the products are improved.

Description

Technical Field

[0001] The invention relates to the technical field of octanoyl chloride synthesis, in particular to a device and method for continuously synthesizing octanoyl chloride using a scraper film reactor. Background Art

[0002] Octanoyl chloride is an important organic synthesis intermediate, which plays a very important role in the fields of medicine, pesticides, chemical industry, etc. At present, the preparation methods of octanoyl chloride are mainly sulfoxide chloride method, phosgene method, diphosgene method, triphosgene method, phosphorus trichloride method, etc.

[0003] There are problems in the preparation of octanoyl chloride by phosgene: phosgene is a highly toxic gas, which is very dangerous during use, transportation and storage, and the cost of phosgene is relatively high. Although diphosgene is more convenient and safer than phosgene in transportation, storage and use, it is still very dangerous in transportation and storage as a highly toxic liquid with a pungent odor. The conditions required for the preparation of octanoyl chloride by triphosgene are mild, the selectivity is high, the yield is high, and it is easy to transport and store. Although triphosgene has a high melting point, low volatility and low toxicity, it is still treated as a general toxic substance in industry. The conditions for preparing octanoyl chloride using thionyl chloride are mild, and the reaction can be carried out at room temperature or slightly heated. The products are all gases except the acyl chloride, which are easy to separate, with high purity and yield. This method uses a large amount of thionyl chloride and serious equipment corrosion.

[0004] The thionyl chloride method is a common industrial route for synthesizing octanoyl chloride. The problem is that the yield and efficiency of the batch reaction are low. At the same time, the by-products of hydrogen chloride and sulfur dioxide are treated by absorption, generating waste liquids such as recycled hydrochloric acid and sodium sulfite solution. The hydrogen chloride and sulfur dioxide in the preparation of octanoyl chloride are difficult to discharge, the product purity and yield are low, and the cost is high.

[0005] To this end, a device and method for continuously synthesizing octanoyl chloride using a scraper film reactor are proposed. Summary of the invention

[0006] The object of the present invention is to provide a device and method for continuously synthesizing octanoyl chloride in a scraped film reactor, aiming to solve or improve at least one of the above-mentioned technical problems.

[0007] To achieve the above object, the present invention provides the following scheme: The present invention provides a device for continuously synthesizing octanoyl chloride using a scraper film reactor, comprising:

[0008] A reactor, wherein the inner wall of the reactor is provided with an interlayer, and the interlayer is used for passing a heat-conducting medium;

[0009] A vacuum pumping device, which is installed on the reactor and communicated with the inner cavity of the reactor;

[0010] A mixer, the mixer is installed in the reactor, and a plurality of scrapers are installed at the output end of the mixer;

[0011] A feeding assembly, which is installed on the top of the reactor and communicated with the inner cavity of the reactor; the feeding assembly is used to add liquid n-octanoic acid and thionyl chloride into the reactor;

[0012] A discharge assembly, which is installed at the bottom of the reactor and communicated with the inner cavity of the reactor;

[0013] Wherein, the distance between the scraper and the inner wall is less than 1 mm.

[0014] According to a device for continuously synthesizing octanoyl chloride in a scraper film reactor provided by the present invention, the stirrer includes a motor and a stirring paddle, the motor is mounted on the top wall of the reactor, the output shaft of the motor extends into the inner cavity of the reactor, and the output shaft of the motor is mounted with a rotating shaft through a coupling, a plurality of stirring paddles are mounted on the side walls of the rotating shaft, and a plurality of the scrapers are respectively mounted on the plurality of the stirring paddles.

[0015] According to a device for continuously synthesizing octanoyl chloride using a scraper film reactor provided by the present invention, the vacuum pumping equipment comprises a condenser, a buffer tank, a vacuum pump and an absorber which are sequentially connected through an air pipe;

[0016] An air outlet is provided at the center of the top wall of the reactor, and one end of the air pipe close to the condenser is fixedly connected to and communicated with the air outlet; three first valves are installed on the air pipe, and the three first valves are respectively located between the condenser and the reactor, between the condenser and the buffer tank, and between the buffer tank and the vacuum pump.

[0017] According to a device for continuously synthesizing octanoyl chloride using a scraper film reactor provided by the present invention, the feeding assembly comprises a first feeding tank and a second feeding tank, the first feeding tank stores n-octanoic acid, the second feeding tank stores thionyl chloride, the first feeding tank and the second feeding tank are respectively connected to the top of the inner cavity of the reactor through a feeding pipe, and feeding ports are respectively arranged on both sides of the top of the reactor, and the two feeding pipes are respectively connected to the two feeding ports;

[0018] A discharge port is provided at the bottom center of the reactor, and the discharge assembly comprises a discharge pipe installed on the discharge port, a receiving tank is installed at one end of the discharge pipe away from the discharge port, and a discharge valve is installed on the discharge pipe.

[0019] According to a device for continuously synthesizing octanoyl chloride using a scraper film reactor provided by the present invention, the scraper and the stirring paddle are arranged vertically;

[0020] The number of the scrapers is 3 to 6;

[0021] The distance between the scraper located at the top and the top wall of the reactor is 4 cm to 6 cm, and the distance between the scraper located at the bottom and the bottom wall of the reactor is 4 cm to 6 cm.

[0022] According to a device for continuously synthesizing octanoyl chloride in a scraper film reactor provided by the present invention, the outer wall of the reactor is provided with an oil outlet installed on the top of one side and an oil inlet installed on the bottom of the other side, and the oil outlet and the oil inlet are both connected to the interlayer.

[0023] The present invention also provides a method for continuously synthesizing octanoyl chloride using a scraper film reactor, comprising the following steps:

[0024] Step 1: Evacuate the reactor and introduce a heat-conducting medium into the interlayer to raise the temperature in the reactor to 60°C to 100°C;

[0025] Step 2: adding liquid octanoic acid and thionyl chloride to the top of the inner cavity of the reactor, the liquid octanoic acid and thionyl chloride flow along the inner wall of the reactor respectively, the scraper driven by the stirrer performs a thin film reaction, and the temperature in the reactor is 60° C. to 100° C.;

[0026] Step 3: discharge and collect the gas generated by the reaction, and the product after the reaction is discharged through the discharge component. The reaction is continued until no octanoic acid remains, and the production of octanoyl chloride is completed.

[0027] According to a method for continuously synthesizing octanoyl chloride in a scraper film reactor provided by the present invention, in the step 1, vacuuming is performed by a vacuuming device, and the vacuum degree is -0.06MPa to -0.1Mpa;

[0028] In the step 1, the heat transfer medium is heat transfer oil, and the temperature of the heat transfer oil is 60°C to 100°C.

[0029] According to a method for continuously synthesizing octanoyl chloride using a scraper film reactor provided by the present invention, in the step 2, the rotation speed of the stirrer is 200 rpm to 1000 rpm;

[0030] In the step 2, the flow rate of adding n-octanoic acid is controlled to be 6.4 mL / min to 8.9 mL / min, and the flow rate of adding thionyl chloride is controlled to be 2.5 mL / min to 4.0 mL / min.

[0031] According to a method for continuously synthesizing octanoyl chloride in a scraper film reactor provided by the present invention, in the step 3, the specific operation of discharging and collecting the gas generated by the reaction is: the gas generated by the reaction is extracted from the reactor by a vacuum pump, and is collected and recycled after condensation and buffering;

[0032] In the step 3, the method for determining whether the reaction is completed until no octanoic acid remains is: performing gas chromatography detection on the product generated in the discharge component every 30 minutes.

[0033] The present invention discloses the following technical effects:

[0034] The thionyl chloride process adopted by the present invention adopts a scraper film reactor to continuously synthesize octanoyl chloride. The raw materials of n-octanoic acid and thionyl chloride are fed in liquid form through a feeding component and introduced into the top wall of the inner cavity of a reactor. The scraper is driven to rotate by a stirrer, so that a film reaction is carried out on the inner wall of the reactor by utilizing the principle of scraper film evaporation. During the reaction process, hydrogen chloride and sulfur dioxide are easy to escape from the film layer, which effectively improves the reaction efficiency and the product purity. No filler is required, and the reaction temperature is reduced, thereby avoiding the deterioration of octanoyl chloride in a high temperature environment. The raw materials react more fully, the residual reactants are greatly reduced, and the yield of octanoyl chloride is improved.

[0035] In the present invention, the gas (hydrogen chloride and sulfur dioxide) generated during the reaction of liquid n-octanoic acid and thionyl chloride is extracted from the top of the reactor by a vacuum pump, collected and then separated, and the recovered gas can be used as a raw material when the company produces other products, thereby achieving high-efficiency synthesis of high-purity and high-yield octanoyl chloride products, achieving green and environmentally friendly process requirements, and saving costs;

[0036] The invention solves the problems of difficulty in discharging hydrogen chloride and sulfur dioxide, low product purity and yield, high cost, etc. in the existing preparation of octanoyl chloride. The method of the invention has simple process, high product purity, high yield, direct reaction of raw materials, no participation of solvent and catalyst, which saves cost and simplifies operation, and is suitable for large-scale industrial production.

[0037] The raw materials of the invention are n-octanoic acid and thionyl chloride, which are in a liquid state at room temperature. No water or other solvents are involved in the reaction process, so the product quality is better, the product storage stability is good and the yield is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a structural schematic diagram of the present invention;

[0040] Figure 2 It is a schematic diagram of the opening of the feed port and the gas outlet in the present invention.

[0041] Among them, 1. reactor; 2. first feeding tank; 3. second feeding tank; 4. oil inlet; 5. oil outlet; 6. mixer; 61. motor; 62. stirring paddle; 7. receiving tank; 8. condenser; 9. buffer tank; 10. vacuum pump; 11. absorber; 12. inner wall; 13. feeding port; 14. air outlet; 15. discharge port; 16. scraper. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] The reaction mechanism of thionyl chloride method: C7H 15 COOH+SOC l2=C7H 15 COCl+SO2+HCl

[0045]

[0046] Reference Figure 1-Figure 2 The present invention provides a device for continuously synthesizing octanoyl chloride using a scraper film reactor, comprising:

[0047] A reactor 1, wherein the inner wall 12 of the reactor 1 is provided with an interlayer, and the interlayer is used for passing a heat-conducting medium;

[0048] A vacuum pumping device, which is installed on the reactor 1 and communicated with the inner cavity of the reactor 1;

[0049] A stirrer 6 is installed in the reactor 1. A plurality of scrapers 16 are installed at the output end of the stirrer 6. The width of the scrapers 16 is 2.5 cm to 3.5 cm.

[0050] A feeding assembly is installed on the top of the reactor 1 and is connected to the inner cavity of the reactor 1; the feeding assembly is used to add liquid n-octanoic acid and thionyl chloride into the reactor 1;

[0051] A discharge assembly, which is installed at the bottom of the reactor 1 and communicated with the inner cavity of the reactor 1;

[0052] Wherein, the distance between the scraper 16 and the inner wall 12 is less than 1 mm;

[0053] With such a configuration, the thionyl chloride process route adopted by the present invention adopts a scraper film reactor to continuously synthesize octanoyl chloride, and the raw materials of n-octanoic acid and thionyl chloride are fed in liquid form through a feeding assembly and introduced into the top wall of the inner cavity of the reactor 1, and the scraper 16 is driven to rotate by the stirrer 6, so that a film reaction is carried out on the inner wall of the reactor 1 by utilizing the principle of scraper film evaporation, and hydrogen chloride and sulfur dioxide are easy to escape from the film layer during the reaction process, thereby effectively improving the reaction efficiency and the product purity; no filler is required, and the reaction temperature is also reduced, thereby avoiding the deterioration of octanoyl chloride in a high temperature environment, the raw materials react more fully, the residual reactants are greatly reduced, and the yield of octanoyl chloride is improved;

[0054] In the present invention, the gas (hydrogen chloride and sulfur dioxide) generated during the reaction of liquid n-octanoic acid and thionyl chloride is extracted from the top of the reactor 1 by a vacuum pump, collected and then separated, and the recovered gas can be used as a raw material when the company produces other products, thereby achieving high-efficiency synthesis of high-purity and high-yield octanoyl chloride products, achieving green and environmentally friendly process requirements, and saving costs;

[0055] The invention solves the problems of difficulty in discharging hydrogen chloride and sulfur dioxide, low product purity and yield, high cost, etc. in the existing preparation of octanoyl chloride. The method of the invention has simple process, high product purity, high yield, direct reaction of raw materials, no participation of solvent and catalyst, which saves cost and simplifies operation, and is suitable for large-scale industrial production.

[0056] The raw materials of the invention are n-octanoic acid and thionyl chloride, which are in a liquid state at room temperature. No water or other solvents are involved in the reaction process, so the product quality is better, the product storage stability is good, and the yield is high. The obtained product has a purity of more than 99.5% and a yield of more than 96%.

[0057] Further optimized, the mixer 6 includes a motor 61 and a stirring paddle 62, the motor 61 is mounted on the top wall of the reactor 1, the output shaft of the motor 61 extends into the inner cavity of the reactor 1, and the output shaft of the motor 61 is mounted with a rotating shaft through a coupling, a plurality of stirring paddles 62 are mounted on the side wall of the rotating shaft, and a plurality of scrapers 16 are respectively mounted on the plurality of stirring paddles 62;

[0058] When the motor 61 is started, it drives the rotating shaft and the stirring paddle 62 to rotate, and then the scraper 16 rotates close to the inner wall 12 of the reactor 1. This movement of the scraper 16 not only stirs the reactants, but also helps to form an extremely thin reactant film on the inner wall, so that the raw materials are fully mixed and reacted, thereby promoting the efficient progress of the reaction.

[0059] Further optimizing the scheme, the vacuum pumping equipment includes a condenser 8, a buffer tank 9, a vacuum pump 10 and an absorber 11 which are sequentially connected through an air pipe;

[0060] An air outlet 14 is provided at the center of the top wall of the reactor 1, and one end of the air pipe close to the condenser 8 is fixedly connected to and communicated with the air outlet 14; three first valves are installed on the air pipe, and the three first valves are respectively located between the condenser 8 and the reactor 1, between the condenser 8 and the buffer tank 9, and between the buffer tank 9 and the vacuum pump 10;

[0061] In the present invention, the gas generated by the reaction is extracted from the reactor 1 through the gas outlet 14 by the vacuum pump 10, and then enters the buffer tank 9 under the condensation effect of the condenser 8, and then enters the absorber 11 through the vacuum pump 10, so that the collection is completed; the by-product hydrogen chloride and sulfur dioxide are separated by dry low-temperature distillation, the hydrogen chloride is recycled as a raw material for synthesizing trichlorosilane, and the sulfur dioxide is returned to the thionyl chloride manufacturer as a raw material, so that the high-efficiency synthesis of high-purity and high-yield octanoyl chloride products is achieved, and the green and environmentally friendly process requirements are achieved.

[0062] Further optimizing the scheme, the feeding assembly includes a first feeding tank 2 and a second feeding tank 3, the first feeding tank 2 stores n-octanoic acid, the second feeding tank 3 stores thionyl chloride, the first feeding tank 2 and the second feeding tank 3 are connected to the top of the inner cavity of the reactor 1 through feeding pipes, and the raw materials flow in sequentially along the top of the inner wall of the reactor 1, which is helpful to form a uniform initial reaction mixture; feeding ports 13 are respectively provided on both sides of the top of the reactor 1, and two feeding pipes are respectively connected to the two feeding ports 13; the diameter of the feeding port 13 is 1.5 cm to 2.5 cm; the distance from the center of the feeding port 13 to the adjacent inner wall 12 of the reactor 1 is 3 cm to 4 cm;

[0063] A discharge port 15 is provided at the bottom center of the reactor 1. The discharge assembly includes a discharge pipe installed on the discharge port 15. A receiving tank 7 is installed at one end of the discharge pipe away from the discharge port 15. A discharge valve is installed on the discharge pipe.

[0064] In a further optimized solution, the scraper 16 and the stirring paddle 62 are arranged vertically;

[0065] The number of scrapers 16 is 3 to 6;

[0066] The distance between the scraper 16 at the top and the top wall of the reactor 1 is 4 cm to 6 cm, and the distance between the scraper 16 at the bottom and the bottom wall of the reactor 1 is 4 cm to 6 cm.

[0067] To further optimize the solution, the outer wall of the reactor 1 is provided with an oil outlet 5 installed on the top of one side and an oil inlet 4 installed on the bottom of the other side, and the oil outlet 5 and the oil inlet 4 are both connected to the interlayer; by introducing a heat transfer medium (such as heat transfer oil) into the interlayer, the temperature in the reactor 1 can be controlled, thereby ensuring that the reaction is carried out within the optimal temperature range. This temperature control method not only improves the reaction efficiency and yield.

[0068] The present invention also provides a method for continuously synthesizing octanoyl chloride using a scraper film reactor, comprising the following steps:

[0069] Step 1: Evacuate the reactor 1, introduce a heat-conducting medium into the interlayer, and raise the temperature of the reactor 1 to 60° C. to 100° C.;

[0070] Step 2: adding liquid octanoic acid and thionyl chloride to the top of the inner cavity of the reactor 1, the liquid octanoic acid and thionyl chloride flow in along the inner wall 12 of the reactor 1 respectively, the scraper 16 driven by the stirrer 6 performs a thin film reaction, and the temperature in the reactor 1 is 60° C. to 100° C.;

[0071] Step 3: discharge and collect the gas generated by the reaction, and the product after the reaction is discharged through the discharge component. The reaction is continued until no octanoic acid remains, and the production of octanoyl chloride is completed.

[0072] Further optimizing the scheme, in step 1, vacuuming is performed by vacuuming equipment, and the vacuum degree is -0.06MPa~-0.1Mpa;

[0073] In step 1, the heat transfer medium is heat transfer oil, and the temperature of the heat transfer oil is 60°C to 100°C; in this embodiment, the temperature of the heat transfer oil is preferably 60°C.

[0074] Further optimizing the scheme, in step 2, the rotation speed of the stirrer 6 is 200 rpm to 1000 rpm; in this embodiment, the rotation speed of the stirrer 6 is preferably 600 rpm;

[0075] In step 2, the flow rate of adding n-octanoic acid is controlled to be 6.4 mL / min to 8.9 mL / min, and in this embodiment, it is preferably 6.9 mL / min;

[0076] The flow rate of adding thionyl chloride is 2.5 mL / min to 4.0 mL / min, and in this embodiment, preferably 3.4 mL / min.

[0077] To further optimize the scheme, in step 3, the specific operation of discharging and collecting the gas generated by the reaction is as follows: the gas generated by the reaction is extracted from the reactor 1 by a vacuum pump, and is collected and recycled after condensation and buffering;

[0078] In step 3, the method for determining whether the reaction is completed until no octanoic acid remains is as follows: every 30 minutes, the product generated in the discharge component is tested by gas chromatography.

[0079] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0080] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technical users in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A device for continuously synthesizing octanoyl chloride using a scraped film reactor, characterized in that: include: A reaction kettle (1), wherein the inner wall (12) of the reaction kettle (1) is provided with an interlayer, and the interlayer is used to pass a heat-conducting medium; A vacuum pumping device, the vacuum pumping device is installed on the reaction kettle (1) and is connected to the inner cavity of the reaction kettle (1); A stirrer (6), the stirrer (6) being installed in the reaction kettle (1), and a plurality of scrapers (16) being installed at the output end of the stirrer (6); A feeding component, the feeding component is installed on the top of the reactor (1) and is in communication with the inner cavity of the reactor (1); the feeding component is used to add liquid n-octanoic acid and thionyl chloride into the reactor (1); A discharge assembly, the discharge assembly being installed at the bottom of the reaction kettle (1) and being in communication with the inner cavity of the reaction kettle (1); Wherein, the distance between the scraper (16) and the inner wall (12) is less than 1 mm.

2. The device for continuous synthesis of octanoyl chloride by scraper film reactor according to claim 1, characterized in that: The stirrer (6) comprises a motor (61) and a stirring paddle (62), wherein the motor (61) is mounted on the top wall of the reactor (1), the output shaft of the motor (61) extends into the inner cavity of the reactor (1), and the output shaft of the motor (61) is mounted with a rotating shaft via a coupling, a plurality of stirring paddles (62) are mounted on the side wall of the rotating shaft, and a plurality of scrapers (16) are respectively mounted on the plurality of stirring paddles (62).

3. The device for continuous synthesis of octanoyl chloride by scraper film reactor according to claim 1, characterized in that: The vacuum pumping equipment comprises a condenser (8), a buffer tank (9), a vacuum pump (10) and an absorber (11) which are sequentially connected through an air pipe; An air outlet (14) is provided at the center of the top wall of the reactor (1), and one end of the air pipe close to the condenser (8) is fixedly connected to and communicated with the air outlet (14); three first valves are installed on the air pipe, and the three first valves are respectively located between the condenser (8) and the reactor (1), between the condenser (8) and the buffer tank (9), and between the buffer tank (9) and the vacuum pump (10).

4. The device for continuous synthesis of octanoyl chloride by scraper film reactor according to claim 1, characterized in that: The feeding assembly comprises a first feeding tank (2) and a second feeding tank (3), wherein n-octanoic acid is stored in the first feeding tank (2), and thionyl chloride is stored in the second feeding tank (3), wherein the first feeding tank (2) and the second feeding tank (3) are respectively connected to the top of the inner cavity of the reactor (1) through feeding pipes, and feeding ports (13) are respectively provided on both sides of the top of the reactor (1), and the two feeding pipes are respectively connected to the two feeding ports (13); A discharge port (15) is provided at the center of the bottom of the reactor (1), and the discharge assembly comprises a discharge pipe installed on the discharge port (15), a receiving tank (7) is installed at one end of the discharge pipe away from the discharge port (15), and a discharge valve is installed on the discharge pipe.

5. The device for continuous synthesis of octanoyl chloride by scraper film reactor according to claim 2, characterized in that: The scraper (16) and the stirring paddle (62) are arranged vertically; The number of the scrapers (16) is 3 to 6; The distance between the scraper (16) located at the top and the top wall of the reactor (1) is 4 cm to 6 cm, and the distance between the scraper (16) located at the bottom and the bottom wall of the reactor (1) is 4 cm to 6 cm.

6. The device for continuous synthesis of octanoyl chloride by scraper film reactor according to claim 1, characterized in that: The outer wall of the reactor (1) is provided with an oil outlet (5) installed on the top of one side and an oil inlet (4) installed on the bottom of the other side, and the oil outlet (5) and the oil inlet (4) are both connected to the interlayer.

7. A method for continuously synthesizing octanoyl chloride using a scraper film reactor, based on the device for continuously synthesizing octanoyl chloride using a scraper film reactor according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: evacuate the reactor (1) and introduce a heat-conducting medium into the interlayer to raise the temperature of the reactor (1) to 60° C. to 100° C.; Step 2: adding liquid octanoic acid and thionyl chloride to the top of the inner cavity of the reactor (1); the liquid octanoic acid and thionyl chloride flow in along the inner wall (12) of the reactor (1); the stirrer (6) drives the scraper (16) to perform a thin film reaction; the temperature in the reactor (1) is 60° C. to 100° C.; Step 3: discharge and collect the gas generated by the reaction, and the product after the reaction is discharged through the discharge component. The reaction is continued until no octanoic acid remains, and the production of octanoyl chloride is completed.

8. The method for continuously synthesizing octanoyl chloride by a scraper film reactor according to claim 7, characterized in that: In the step 1, vacuum is drawn by a vacuum pump, and the vacuum degree is -0.06MPa to -0.1Mpa; In the step 1, the heat transfer medium is heat transfer oil, and the temperature of the heat transfer oil is 60°C to 100°C.

9. The method for continuously synthesizing octanoyl chloride by a scraper film reactor according to claim 7, characterized in that: In the step 2, the rotation speed of the stirrer (6) is 200 rpm to 1000 rpm; In the step 2, the flow rate of adding n-octanoic acid is controlled to be 6.4 mL / min to 8.9 mL / min, and the flow rate of adding thionyl chloride is controlled to be 2.5 mL / min to 4.0 mL / min.

10. The method for continuously synthesizing octanoyl chloride by a scraper film reactor according to claim 7, characterized in that: In the step 3, the specific operation of discharging and collecting the gas generated by the reaction is as follows: the gas generated by the reaction is extracted from the reaction kettle (1) by a vacuum pump, and is collected and recycled after condensation and buffering; In the step 3, the method for determining whether the reaction is completed until no octanoic acid remains is: performing gas chromatography detection on the product generated in the discharge component every 30 minutes.

Images