Trifluoroethanol production device

Abstract

The utility model provides a trifluoroethanol production device. The trifluoroethanol production device comprises an esterification kettle, a crude ester storage tank, a first rectifying tower, a hydrolysis kettle and a crude alcohol storage tank which are sequentially connected in series, the crude ester storage tank is also connected with the first vacuum pump; the crude alcohol storage tank is also connected with the second vacuum pump. According to the device provided by the invention, the crude ester storage tank and the crude alcohol storage tank are respectively connected with the first vacuum pump and the second vacuum pump, and the corresponding storage tanks are pumped into a negative pressure state by the vacuum pumps; after the reaction is finished, heat in the reaction kettle and the pressure difference between the reaction kettle and the corresponding storage tank are utilized to separate an esterification product or a hydrolysis product after the reaction from a reaction base solution in a flash evaporation manner, so that the method has the advantages of rapidness and high efficiency; and an esterification product and a hydrolysis product are separated by adopting a distillation mode, so that energy needs to be additionally consumed, the production time is prolonged, and the yield is influenced.

Description

Technical Field

[0001] The present application relates to the technical field of chemical raw material production, and in particular to a trifluoroethanol production device. Background Art

[0002] Trifluoroethanol is a colorless, non-toxic, non-corrosive liquid with an alcohol odor. It has stable chemical properties and is miscible with water and various organic solvents. At the same time, trifluoroethanol is also an important fluorine-containing fine chemical with a wide range of applications. It is a key intermediate in the synthesis of fluorine-containing medicines and pesticides, a high-grade solvent for some polymer materials, and an excellent thermal working fluid used in waste heat recovery cycles and absorption refrigeration cycles. Trifluoroethanol is a product with a high demand, so it is necessary to develop a device for effectively synthesizing trifluoroethanol.

[0003] The preparation method of trifluoroethanol can be divided into trifluoroacetyl chloride method, trifluoroacetic anhydride method, trifluoroacetic acid method, trifluoroacetaldehyde method, vinylidene fluoride method, trifluoroethane method, trifluorochloroethane method, wherein the trifluorochloroethane method is widely used due to its advantages of short reaction time, high conversion rate and yield, small amount of catalyst, and low price. During its production process, trifluorochloroethane and potassium acetate are pressurized and heated in a reaction solvent to obtain an esterification product, and then the esterification product is hydrolyzed to obtain trifluoroethanol. However, in the existing method of synthesizing trifluoroethanol by the trifluorochloroethane method, when separating the esterification product and the hydrolyzate, the reaction solution is separated by distillation, and this separation method not only requires additional energy consumption but also causes the production time to be prolonged, thereby affecting the production output. Utility Model Content

[0004] The present application provides a trifluoroethanol production device to solve the problem that in the existing method of synthesizing trifluoroethanol by the trifluorochloroethane method, the esterification product and the hydrolysis product are separated by distillation, which requires additional energy consumption and prolongs the production time, thereby affecting the production output.

[0005] The present application provides a trifluoroethanol production device, comprising an esterification kettle, a crude ester storage tank, a first distillation tower, a hydrolysis kettle and a crude alcohol storage tank connected in series in sequence;

[0006] The esterification kettle is connected to the raw material storage tank through a metering pump, and the esterification kettle is also connected to the solvent storage tank;

[0007] The crude ester storage tank is also connected to the first vacuum pump;

[0008] The hydrolysis kettle is also connected to the alkali solution storage tank;

[0009] The crude alcohol storage tank is also connected to a second vacuum pump.

[0010] Optionally, the esterification kettle is also connected to a cooling tank;

[0011] The cooling tank is connected in series with the suction filter, the solvent dehydration device and the solvent storage tank in sequence.

[0012] Optionally, the hydrolysis tank is also connected to a spray dryer;

[0013] The spray dryer is also connected to a potassium acetate storage tank and a distilled water storage tank respectively;

[0014] The distilled water storage tank is also connected to the alkali solution storage tank.

[0015] Optionally, the crude alcohol storage tank is also connected to the second distillation tower and the fine alcohol storage tank in sequence.

[0016] Optionally, the solvent dewatering device includes a shell, and seals arranged at both ends of the shell;

[0017] The head is separated from the shell by a tube sheet;

[0018] A drying pipe is arranged in the shell, and the drying pipe passes through the tube sheets at both ends to connect the heads at both ends of the shell;

[0019] An input port and an output port are respectively provided on the heads at both ends.

[0020] Optionally, a color-changing silica gel layer is filled in the sealing head near the output port.

[0021] Optionally, the drying tube includes a tube body and tube covers arranged at both ends of the tube body, and the tube covers are detachably connected to the tube body;

[0022] The top plate of the tube cover is a hollow mesh structure.

[0023] The trifluoroethanol production device provided in the present application connects a first vacuum pump and a second vacuum pump to a crude ester storage tank and a crude alcohol storage tank respectively, and uses the vacuum pumps to evacuate the corresponding storage tanks into a negative pressure state. After the reaction is completed, the heat in the reactor (esterification reactor and hydrolysis reactor) and the pressure difference between the reactor and the corresponding storage tanks are used to separate the esterification product or hydrolysis product after the reaction from the reaction bottom liquid by flash evaporation. The device has the advantages of being fast and efficient, and overcomes the disadvantages of using distillation to separate the esterification product and the hydrolysis product in the existing method of synthesizing trifluoroethanol by the trifluorochloroethane method, which requires additional energy consumption and prolongs the production time, thereby affecting the production output. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a trifluoroethanol production device provided in one embodiment of the present application;

[0026] Figure 2 A schematic diagram of a trifluoroethanol production device provided in another embodiment of the present application;

[0027] Figure 3 A schematic diagram of a trifluoroethanol production device provided in another embodiment of the present application;

[0028] Figure 4 A schematic diagram of a trifluoroethanol production device provided in yet another embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of a solvent drying device provided in one embodiment of the present application;

[0030] Figure 6 A schematic structural diagram of a solvent drying device provided in another embodiment of the present application;

[0031] Figure 7 A schematic diagram of the structure of a drying tube provided in one embodiment of the present application.

[0032] Description of reference numerals:

[0033] 1. Esterification kettle; 2. Crude ester storage tank; 3. First distillation tower; 4. Hydrolysis kettle; 5. Crude alcohol storage tank; 6. Cooling tank; 7. Spray dryer; 8. Second distillation tower; 11. Metering pump; 12. Raw material storage tank; 13. Solvent storage tank; 21. First vacuum pump; 41. Alkali liquid storage tank; 51. Second vacuum pump; 61. Filter; 62. Solvent dehydration device; 71. Potassium acetate storage tank; 72. Fractionated water storage tank; 81. Fine product storage tank; 601. Input port; 602. Output port; 621. Shell; 622. Head; 623. Tube sheet; 624. Drying tube; 625. Color-changing silica gel layer; 6241. Tube body; 6242. Tube cover. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0035] like Figure 1 As shown, the present application provides a trifluoroethanol production device, comprising an esterification kettle 1, a crude ester storage tank 2, a first distillation tower 3, a hydrolysis kettle 4 and a crude alcohol storage tank 5 connected in series in sequence;

[0036] The esterification kettle 1 is connected to the raw material storage tank 12 via a metering pump 11, and the esterification kettle 1 is also connected to the solvent storage tank 13;

[0037] The crude ester storage tank 2 is also connected to the first vacuum pump 21;

[0038] The hydrolysis kettle 4 is also connected to the alkali solution storage tank 41;

[0039] The crude alcohol storage tank 5 is also connected to a second vacuum pump 51 .

[0040] When in use, first dry the esterification kettle 1 (for example, dry at 200°C for 2h), then add an appropriate proportion of potassium acetate (potassium acetate can come from potassium acetate recovered from the hydrolysis kettle 4), then add an appropriate proportion of solvent (N-methyl-2-pyrrolidone in this application) through the solvent storage tank 13, close the esterification kettle 1, and start stirring and heating at the same time, raise the temperature to a preset temperature, and then continuously add the reaction raw material in the raw material storage tank 12 (R133a, i.e., 1,1,1-trifluoro-2-chloroethane in this application) to the esterification kettle 1 through the metering pump 11, the feeding speed is adjusted according to the pressure increase speed and the pressure does not exceed 0.8MPa, the reaction temperature is controlled at 190-220°C, and the reaction pressure is controlled below 1.0Mpa. After R133a is added, keep the reaction warm for 2-5 hours, during which the gas phase at the top of the reactor is sampled and analyzed. After keeping the reaction warm for 5 hours, cool to 150°C. First, the crude ester storage tank 2 is pumped into a negative pressure state (for example, -0.09 to -0.08 MPa) by using the first vacuum pump 21, and then the material output end on the esterification kettle 1 is opened to flash the gas phase product (i.e., crude trifluoroethyl acetate) into the crude ester storage tank 2.

[0041] The crude ester in the crude ester storage tank 2 is transferred to the first distillation tower 3 for distillation, and the distilled trifluoroethyl acetate is extracted from the top of the tower (cooled by the top condenser) and transferred to the hydrolysis kettle 4. The prepared alkali solution (such as a saturated aqueous solution of potassium hydroxide) is added to the hydrolysis kettle 4 in proportion, and stirring and heating are turned on. The reaction temperature is controlled at 80-100°C, the normal reaction pressure is about 0.20MPa, and the reaction is kept warm for 4-6 hours. First, the crude alcohol storage tank 5 is pumped to a negative pressure state (such as -0.09-0.08MPa) by the second vacuum pump 51, and then the material output end at the top of the hydrolysis kettle 4 is opened, and the gas phase product after hydrolysis (mainly crude trifluoroethanol) is flashed into the crude alcohol storage tank 5 to be refined in the subsequent refining process.

[0042] The trifluoroethanol production device provided in the present application connects the first vacuum pump 21 and the second vacuum pump 51 to the crude ester storage tank 2 and the crude alcohol storage tank 5 respectively, and uses the vacuum pump to evacuate the corresponding storage tanks into a negative pressure state. After the reaction is completed, the heat in the reactor (esterification reactor 1 and hydrolysis reactor 4) and the pressure difference between the reactor and the corresponding storage tank are used to separate the esterification product or hydrolysis product from the reaction bottom liquid by flash evaporation. It has the advantages of being fast and efficient, and overcomes the disadvantages of the existing method of synthesizing trifluoroethanol by trifluorochloroethane method, that is, the esterification product and hydrolysis product are separated by distillation, which requires additional energy consumption and prolongs the production time, thereby affecting the production output.

[0043] like Figure 2 As shown, optionally, the esterification kettle 1 is also connected to a cooling tank 6;

[0044] The cooling tank 6 is connected in series with the suction filter 61 , the solvent dehydration device 62 and the solvent storage tank 13 in sequence.

[0045] In the present application, when in use, after the flash evaporation of the esterification kettle 1 is completed, the reaction byproducts, excess solvent and other esterification bottom liquid are discharged from the bottom of the esterification kettle 1 into the cooling tank 6, cooled to room temperature, and then the cooled esterification bottom liquid is transferred to the suction filter 61 for suction filtration, and the filter cake is collected and sold as a by-product after drying and refining. The filtrate is transferred to the solvent dehydration device 62 for drying, and then recovered to the solvent storage tank 13 for recycling.

[0046] like Figure 3 As shown, optionally, the hydrolysis tank 4 is also connected to the spray dryer 7;

[0047] The spray dryer 7 is also connected to a potassium acetate storage tank 71 and a distilled water storage tank 72 respectively;

[0048] The distilled water storage tank 72 is also connected to the alkali solution storage tank 41 .

[0049] In the present application, after the flash evaporation of the hydrolysis kettle 4 is completed, the hydrolysis bottom liquid such as the excess hydrolysis fractionation water of the reaction byproduct (potassium acetate) in the hydrolysis kettle is passed into the spray dryer 7 for drying and then cooling and separation. The water discharged during the drying process will be collected in the fractionation water storage tank 72, which can be used to prepare the alkali solution in the alkali solution storage tank 41. The potassium acetate byproduct after drying treatment by the spray dryer 7 can be recycled for esterification reaction.

[0050] like Figure 4 As shown, optionally, the crude alcohol storage tank 5 is also connected to the second distillation tower 8 and the fine alcohol storage tank 81 in sequence.

[0051] In the present application, when in use, the crude trifluoroethanol in the crude alcohol storage tank 5 is transferred to the second distillation tower 8 for distillation, and the pure trifluoroethanol obtained by distillation is transferred to the fine product storage tank 81 for temporary storage.

[0052] like Figure 5 As shown, optionally, the solvent dewatering device 62 includes a shell 621 and seals 622 disposed at both ends of the shell 621;

[0053] The head 622 is separated from the shell 621 by a tube sheet 623;

[0054] A drying pipe 624 is provided in the shell 621, and the drying pipe 624 passes through the tube sheets 623 at both ends to connect the heads 622 at both ends of the shell 621;

[0055] An input port 601 and an output port 602 are respectively provided on the sealing heads 622 at both ends.

[0056] In the present application, when the filtrate is dried in the solvent dehydration device 62, the filtrate enters the cap 622 at one end from the input port 601, and then flows into the drying tube 624, contacts with the desiccant (such as silica gel or molecular sieve) filled in the drying tube 624 to absorb and remove the moisture in the solvent, and the dried solvent enters the cap 622 at the other end, and then is discharged from the output port 602 to the solvent storage tank 13.

[0057] In the present application, in one feasible manner, a heat exchange medium inlet and a heat exchange medium outlet are also provided on the shell 621, and the output port 602 is also connected to the nitrogen pipeline through a valve. When the desiccant in the drying tube 624 is deactivated and needs to be regenerated, a heating medium can be introduced into the shell side of the shell 621 to heat the drying tube 624 to a preset regeneration temperature, and the valve is opened to allow the nitrogen in the nitrogen pipeline to be introduced into the solvent dehydration device 62 to back-blow and dry the desiccant in the drying tube 624. The waste gas discharged during the drying process can be discharged into the corresponding waste gas treatment section for treatment.

[0058] like Figure 6 As shown, optionally, a color-changing silicone layer 625 is filled in the sealing head near the output port 602 .

[0059] In the present application, a color-changing silica gel layer 625 is provided to indicate whether the desiccant in the drying tube 624 is inactivated. When the color-changing silica gel in the color-changing silica gel layer 625 in the end cap near the output port 602 changes color (in the present application, the color-changing silica gel is added with cobalt chloride, which turns blue after absorbing water), it indicates that the desiccant in the drying tube 624 has been inactivated, and the desiccant in the drying tube 624 can be regenerated at this time. Accordingly, a window can be provided on the end cap 622 provided with the color-changing silica gel layer 625 for easy observation by the operator.

[0060] like Figure 7 As shown, optionally, the drying tube 624 includes a tube body 6241 and tube covers 6242 disposed at both ends of the tube body 6241, and the tube covers 6242 are detachably connected to the tube body 6241;

[0061] The top plate of the tube cover 6242 is a hollow mesh structure.

[0062] In the present application, the tube cover 6242 is provided to prevent the desiccant in the tube body 6241 from leaking out, and the top plate on the tube cover 6242 is a hollow mesh structure to ensure the passage of the solvent. In one achievable manner, a filter screen can be provided inside the tube cover 6242 as an inner lining to prevent the desiccant from leaking out during use.

[0063] A trifluoroethanol production device, the use process of which is as follows:

[0064] When in use, first dry the esterification kettle 1 (for example, dry at 200°C for 2h), then add an appropriate proportion of potassium acetate (potassium acetate can come from potassium acetate recovered from the hydrolysis kettle), then add an appropriate proportion of solvent (N-methyl-2-pyrrolidone in this application) through the solvent storage tank 13, close the esterification kettle 1, and start stirring and heating at the same time, raise the temperature to a preset temperature, and then continuously add the reaction raw material in the raw material storage tank 12 (R133a, i.e., 1,1,1-trifluoro-2-chloroethane in this application) to the esterification kettle 1 through the metering pump 11, the feeding speed is adjusted according to the pressure increase speed and the pressure does not exceed 0.8MPa, the reaction temperature is controlled at 190-220°C, and the reaction pressure is controlled below 1.0Mpa. After R133a is added, keep the reaction warm for 2-5 hours, during which the gas phase at the top of the reactor is sampled and analyzed. After keeping the reaction warm for 5 hours, cool to 150°C. First, the crude ester storage tank 2 is pumped into a negative pressure state (for example, -0.09 to -0.08 MPa) by using the first vacuum pump 21, and then the material output end on the esterification kettle 1 is opened to flash the gas phase product (i.e., crude trifluoroethyl acetate) into the crude ester storage tank 2.

[0065] After the flash evaporation of the esterification kettle 1 is completed, the reaction by-products, excess solvent and other esterification bottom liquid are discharged from the bottom of the esterification kettle 1 into the cooling tank 6, cooled to room temperature, and then the cooled esterification bottom liquid is transferred to the suction filter 61 for suction filtration, and the filter cake is collected and sold as a by-product after drying and refining. The filtrate is transferred to the solvent dehydration device 62 for drying, and then recovered to the solvent storage tank 13 for recycling.

[0066] When the filtrate is dried in the solvent dehydration device 62, the filtrate enters the end cap 622 at one end from the input port 601, and then flows into the drying tube 624, contacts with the desiccant (such as silica gel or molecular sieve) filled in the drying tube 624 to absorb and remove the moisture in the solvent, and the dried solvent enters the end cap 622 at the other end, and then is discharged from the output port 602 to the solvent storage tank 13. When the color-changing silica gel in the color-changing silica gel layer 625 in the end cap near the output port 602 changes color (in this application, the color-changing silica gel with cobalt chloride added, which turns blue after absorbing water), it indicates that the desiccant in the drying tube 624 has been deactivated, and the desiccant in the drying tube 624 can be regenerated at this time.

[0067] The crude ester in the crude ester storage tank 2 is transferred to the first distillation tower 3 for distillation, and the trifluoroethyl acetate after distillation is extracted from the top of the tower (cooled by the top condenser) and transferred to the hydrolysis kettle 4. The prepared alkali solution (such as a saturated aqueous solution of potassium hydroxide) is added to the hydrolysis kettle 4 in proportion, and stirring and heating are turned on. The reaction temperature is controlled at 80-100°C, and the normal reaction pressure is about 0.20MPa. The reaction is kept warm for 4-6 hours. First, the crude alcohol storage tank 5 is pumped to a negative pressure state (such as -0.09 to -0.08MPa) by the second vacuum pump 51, and then the material output end at the top of the hydrolysis kettle 4 is opened, and the gas phase product after hydrolysis (mainly crude trifluoroethanol) is flashed into the crude alcohol storage tank 5.

[0068] After the flash evaporation of the hydrolysis kettle 4 is completed, the hydrolysis bottom liquid such as the excess hydrolysis fractionation water of the reaction byproduct (potassium acetate) in the hydrolysis kettle 4 is passed into the spray dryer 7 for drying and cooling and separation. The water discharged during the drying process will be collected in the fractionation water storage tank 72, which can be used to prepare the alkali solution in the alkali solution storage tank 41. The potassium acetate byproduct after drying treatment in the spray dryer 7 can be recovered for esterification reaction.

[0069] The crude trifluoroethanol in the crude alcohol storage tank 5 is transferred to the second distillation tower 8 for distillation, and the pure trifluoroethanol obtained by distillation is transferred to the fine product storage tank 81 for temporary storage.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A trifluoroethanol production device, characterized in that, It comprises an esterification kettle (1), a crude ester storage tank (2), a first distillation tower (3), a hydrolysis kettle (4) and a crude alcohol storage tank (5) which are connected in series in sequence; The esterification kettle (1) is connected to a raw material storage tank (12) via a metering pump (11), and the esterification kettle (1) is also connected to a solvent storage tank (13); The crude ester storage tank (2) is also connected to a first vacuum pump (21); The hydrolysis kettle (4) is also connected to an alkali solution storage tank (41); The crude alcohol storage tank (5) is also connected to a second vacuum pump (51).

2. The trifluoroethanol production device according to claim 1, characterized in that: The esterification kettle (1) is also connected to a cooling tank (6); The cooling tank (6) is connected in series with the suction filter (61), the solvent dewatering device (62) and the solvent storage tank (13).

3. The trifluoroethanol production device according to claim 1, characterized in that: The hydrolysis kettle (4) is also connected to a spray dryer (7); The spray dryer (7) is also connected to a potassium acetate storage tank (71) and a distilled water storage tank (72) respectively; The distilled water storage tank (72) is also connected to the alkali solution storage tank (41).

4. The trifluoroethanol production device according to any one of claims 1 to 3, characterized in that: The crude alcohol storage tank (5) is also connected to the second distillation tower (8) and the fine alcohol storage tank (81) in sequence.

5. The trifluoroethanol production device according to claim 2, characterized in that: The solvent dewatering device (62) comprises a shell (621) and sealing heads (622) arranged at both ends of the shell (621); The head (622) is separated from the shell (621) by a tube sheet (623); A drying tube (624) is arranged in the shell (621), and the drying tube (624) passes through the tube sheets (623) at both ends to connect the seal heads (622) at both ends of the shell (621); The sealing heads (622) at both ends are respectively provided with an input port (601) and an output port (602).

6. The trifluoroethanol production device according to claim 5, characterized in that: A color-changing silica gel layer (625) is filled in the sealing head near the output port (602).

7. The trifluoroethanol production device according to claim 5 or 6, characterized in that: The drying tube (624) comprises a tube body (6241) and tube covers (6242) arranged at both ends of the tube body (6241), and the tube covers (6242) are detachably connected to the tube body (6241); The top plate of the tube cover (6242) is a hollow mesh structure.

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