Device for removing moisture in organic solvent

Abstract

The invention discloses a device for removing water in an organic solvent, and belongs to the technical field of chemical production devices and rectification water removal. The device is mainly formed by combining a rectifying still, a settler, a rectifying tower, a crude product condenser, an oil-water phase separator A, an oil-water phase separator B, a water-carrying agent metering tank, a qualified product condenser, a qualified product receiving tank, a pressure balance pipe, a wastewater outlet and the like. The device effectively solves the problem of how to remove a small amount of water contained in an organic solvent azeotropic with water, solves the problems of low intermittent azeotropic water removal efficiency and incapability of continuous operation, and solves the problems of low oil-water phase separation speed and incapability of continuous separation; the device for removing the moisture in the organic solvent according to the technical scheme of the invention also has the advantages of reasonable layout, convenience in operation, high production efficiency, stable production process flow and safety and reliability in operation.

Description

Technical Field

[0001] The technical scheme of the present invention belongs to the technical field of pharmaceutical chemical production equipment and distillation purification and water removal, and particularly relates to a device for removing water from an organic solvent. Background Art

[0002] In the production process of pharmaceutical intermediates and fine chemicals, organic solvents that can form azeotropes with water, such as ethanol, are often encountered. In production applications, the purity requirements for anhydrous ethanol and the like are all 99.5% or above, especially the control of water content has more stringent requirements. The presence of a small amount or trace of water will directly affect the normal use of organic solvents and the yield and quality of related products. Take ethanol as an example. Since ethanol and water form an azeotrope with 95.0% ethanol and 5.0% water under normal pressure, and the azeotropic point is 78.1°C, it is not easy to separate it from water. Therefore, it is difficult to obtain ethanol with a water content of less than 0.5% under conventional distillation operating conditions. Using conventional distillation methods to distill ethanol will keep its water content at around 5.0%.

[0003] Intermittent azeotropic distillation is a commonly used method for removing water from organic solvents for purification. In layman's terms, it is a pot-by-pot distillation. Its obvious disadvantages are low output, low yield and efficiency, and relatively high energy consumption. It is only suitable for small enterprises or laboratories and pilot plants to remove water and purify organic solvents. Therefore, it is of great value to design a continuous water removal method that is suitable for more manufacturers and has a simple, efficient and stable process. Summary of the invention

[0004] Based on solving the shortcomings of the existing intermittent distillation water removal device, the technical solution of the present invention discloses a device for removing water from an organic solvent; it introduces and adopts the design of feeding from the upper part of the distillation tower and extracting products from the tower, designs a settler between the bottom of the distillation tower and the distillation kettle, introduces the design of continuous oil-water phase separation, and introduces the design of an inverted U-shaped elbow and a pressure balance pipe; compared with the intermittent azeotropic distillation water removal method, the device for removing water from an organic solvent described in the technical solution of the present invention can effectively prevent gas-liquid entrainment and flooding, can quickly remove water from an organic solvent, and has a relatively high production capacity.

[0005] The energy consumption is relatively low, and it can continuously feed and continuously produce qualified products with a moisture content below 0.5%.

[0006] The device for removing water from an organic solvent described in the technical solution of the present invention comprises: a distillation kettle, a distillation tower, a reboiler, a settler, a fluid distributor, a crude product condenser, a front mixed phase inlet, an oil-water phase separator A, an oil-water phase separator B, a front oil phase outlet, a rear mixed phase inlet, a rear oil phase outlet, a water-containing transfer tank, a water-containing metering tank, a circulation pump, a flow meter, a drainage trough, a qualified product condenser, an online detection sampling point, a non-qualified product control valve, a qualified product control valve, a qualified product receiving tank, a crude product storage tank, a crude product feeding pump, a crude product spray head, an inverted U-shaped bend, a pressure balance pipe, and a wastewater outlet. It is characterized in that a reboiler is arranged in the distillation kettle, the distillation tower is arranged directly above the distillation kettle, a settler is arranged between the bottom of the distillation tower and the distillation kettle, and the top of the distillation tower is connected to the crude product through a pipeline. The condenser is connected to the oil-water phase separator A, the front oil phase outlet at the top of the oil-water phase separator A is connected to the rear mixed phase inlet at the middle of the oil-water phase separator B, the rear oil phase outlet at the top of the oil-water phase separator B is connected to the water-carrying transfer tank, the water-carrying transfer tank is connected to the water-carrying metering tank through a pipeline, the bottom of the water-carrying transfer tank is connected to the top of the distillation tower through a circulation pump, the top of the distillation tower is provided with a fluid distributor, the bottoms of the oil-water phase separator A and the oil-water phase separator B are connected together and connected to the wastewater outlet through a pipeline and an inverted U-shaped bend, the drainage trough is provided in the middle of the distillation tower, the drainage trough is connected to the qualified product condenser through a pipeline, the material outlet front end of the qualified product condenser is provided with an online detection sampling point and a non-qualified product control valve and a qualified product control valve, and the qualified product control valve is connected to the qualified product receiving tank in front. The above-mentioned components are organically combined to achieve the function of effectively removing water from the organic solvent that azeotropes with water.

[0007] Preferably, the device for removing water from an organic solvent described in the technical solution of the present invention is characterized in that the shape of the settler disposed between the bottom of the distillation tower and the distillation kettle is a sphere, an ellipsoid or a cylinder, and the diameter of the settler is 1.5-2.5 times the diameter of the distillation tower. The purpose of this design is to prevent gas-liquid entrainment or flooding caused by overheating during the distillation process, and to ensure product purity and process safety.

[0008] Preferably, the device for removing water from an organic solvent described in the technical solution of the present invention is characterized in that the crude product condenser consists of 2-4 sets of heat exchange areas of 100m 2 The spiral plate condenser is connected in parallel, or 2-4 tube-in-tube condensers are connected in parallel, with a heat exchange area of ​​200-400m2. The purpose of this design is to ensure that the mixed gas coming out of the distillation tower is condensed quickly to avoid the backward migration of organic solvent gas, which will cause material waste and safety risks.

[0009] Preferably, the device for removing water from an organic solvent described in the technical solution of the present invention is characterized in that the oil-water phase separator A and the oil-water phase separator B are connected in series in parallel through a pipeline, and the internal structures of the two are the same, and the heights of the corresponding components are also the same. The purpose of this design is to allow the mixed phase to be quickly separated in two stages, avoiding or minimizing the return of the water phase to the distillation tower.

[0010] Preferably, the device for removing water from an organic solvent described in the technical solution of the present invention is characterized in that the middle position of the oil-water phase separator A and the middle position of the oil-water phase separator B are provided with the same fluid disperser, the middle upper part is provided with a wave blocking plate, and the middle lower part is provided with a sedimentation plate. The purpose of such a design is also to avoid fluctuations during the oil-water separation process, promote the oil phase to rise, the water phase to sink, and achieve rapid separation of the oil and water phases.

[0011] Preferably, the device for removing water from an organic solvent described in the technical solution of the present invention is characterized in that the top height of the inverted U-shaped bend pipe is the same as the oil phase outlet at the top of the oil-water phase separator A and the oil phase outlet at the top of the oil-water phase separator B. The purpose of this design is to prevent the oil phase liquid level from being lower than the oil phase outlet height, thereby promoting the improvement of separation efficiency.

[0012] Preferably, the device for removing moisture from an organic solvent described in the technical solution of the present invention is characterized in that the top of the reverse U-shaped bend is connected to a pressure balance pipe, and the pressure balance pipe is connected to the atmosphere. The purpose of this design is to break the siphon effect of the reverse U-shaped bend and avoid discharging all the liquid in the oil-water phase separator due to the siphon effect.

[0013] The device for removing water from an organic solvent described in the technical solution of the present invention has four significant beneficial effects: (1) the design of the settler can effectively avoid gas-liquid entrainment or flooding during the distillation process, which is very beneficial to product purity and process safety; (2) the use of a crude product condenser with a larger heat exchange area can quickly condense the mixed gas, thereby effectively avoiding material loss and safety risks; (3) the combination of an oil-water phase separator A and an oil-water phase separator B can promote rapid and complete separation of the oil phase and the water phase; (4) the combination of an inverted U-bend pipe and a pressure balance pipe can effectively prevent material loss, thereby achieving production process safety and orderly and controllable production technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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 or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and a person skilled in the art can also obtain other drawings based on these drawings.

[0015] Figure 1 It is a planar structure and flow diagram of a device for removing water from an organic solvent as described in the technical solution of the present invention.

[0016] Figure 1 Middle: distillation kettle 01, distillation tower 02, reboiler 03, settler 04, crude product condenser 05, front mixed phase inlet 06, oil-water phase separator A07, oil-water phase separator B08, front oil phase outlet 09, rear mixed phase inlet 10, rear oil phase outlet 11, water-containing transfer tank 12, water-containing metering tank 13, circulation pump 14, flow meter 15, drainage trough 16, qualified product condenser 17, online detection sampling point 18, Reject product control valve 191, qualified product control valve 192, qualified product receiving tank 19, crude product storage tank 20, crude product feeding pump 21, crude product spray head 22, steam inlet 23, steam trap 24, reverse U-shaped bend 25, pressure balance pipe 26, wastewater outlet 27, fluid distributor 28, material inlet 51 and 171, material outlet 52 and 172, cooling water inlet 53 and 173, cooling water outlet 54 and 174. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following Figure 1 This specific implementation example is further described.

[0018] The device for removing water from an organic solvent described in the embodiment of the present specific implementation method comprises: a distillation kettle 01, a distillation tower 02, a reboiler 03, a settler 04, a crude product condenser 05, a front mixed phase inlet 06, an oil-water phase separator A07, an oil-water phase separator B08, a front oil phase outlet 09, a rear mixed phase inlet 10, a rear oil phase outlet 11, a water-containing transfer tank 12, a water-containing metering tank 13, a circulating pump 14, a flow meter 15, a drainage trough 16, and a qualified product cooler. Condenser 17, online detection sampling point 18, unqualified product control valve 191, qualified product control valve 192, qualified product receiving tank 19, crude product storage tank 20, crude product feeding pump 21, crude product spray head 22, steam inlet 23, steam trap 24, reverse U-shaped elbow 25, pressure balance pipe 26, wastewater outlet 27, fluid distributor 28, material inlet 51 and 171, material outlet 52 and 172, cooling water inlet 53 and 173, cooling water outlet 54 and 174. The above-mentioned components are organically combined to effectively remove part of the water in the organic solvent that is azeotropic with water.

[0019] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation method is characterized in that a reboiler 03 is provided in the distillation kettle 01, the distillation tower 02 is arranged directly above the distillation kettle 01, a settler 04 is provided between the bottom of the distillation tower 02 and the distillation kettle 01, the top of the distillation tower 02 is connected to the oil-water phase separator A07 through a pipeline and a crude product condenser 05, the front oil phase outlet 09 at the top of the oil-water phase separator A07 is connected to the rear mixed phase inlet 10 in the middle of the oil-water phase separator B08, the rear oil phase outlet 11 at the top of the oil-water phase separator B08 is connected to the water-carrying agent transfer tank 12, and the water-carrying agent transfer tank 12 is connected to the oil-carrying agent transfer tank 12 through a pipeline. The water-containing transfer tank 12 is connected to the top of the distillation tower 02 through the circulating pump 14, and the top of the distillation tower 02 is provided with a fluid distributor 28. The oil-water phase separator A07 and the oil-water phase separator B08 are connected together at the bottom and connected to the wastewater outlet 27 through a pipeline and an inverted U-shaped elbow 25. The drainage trough 16 is arranged in the middle of the distillation tower 02, and the drainage trough 16 is connected to the qualified product condenser 17 through a pipeline. The front end of the material outlet 172 of the qualified product condenser 17 is provided with an online detection sampling point 18 and a non-qualified product control valve 191 and a qualified product control valve 192, and the qualified product control valve 192 is connected to the qualified product receiving tank 19 in front. The above-mentioned components are organically combined to achieve the function of effectively removing water from the organic solvent that azeotropes with water.

[0020] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation is characterized in that the shape of the settler disposed between the bottom of the distillation tower and the distillation kettle is a sphere, an ellipsoid or a cylinder, and the diameter of the settler is 1.5-2.5 times the diameter of the distillation tower. The purpose of this design is to prevent gas-liquid entrainment or flooding caused by overheating during the distillation process, and to ensure product purity and process safety.

[0021] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation is characterized in that the crude product condenser is composed of 2-4 spiral plate condensers with a heat exchange area of ​​100m2 in parallel, or 2-4 shell-and-tube condensers in parallel, with a heat exchange area of ​​200-400m2. The purpose of this design is to ensure that the mixed gas coming out of the distillation tower is quickly condensed to avoid the organic solvent gas from moving backward, thereby causing material waste and safety risks.

[0022] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation is characterized in that the oil-water phase separator A and the oil-water phase separator B are connected in parallel in series through a pipeline, and the internal structures of the two are the same, and the heights of the corresponding components are also the same. The purpose of this design is to allow the mixed phase to be quickly separated in two stages, avoiding or minimizing the return of the water phase to the distillation tower.

[0023] Furthermore, the device for removing water from an organic solvent described in the embodiment of this specific implementation is characterized in that the middle position of the oil-water phase separator A and the middle position of the oil-water phase separator B are provided with the same fluid disperser, the middle upper part is provided with a wave blocking plate, and the middle lower part is provided with a sedimentation plate. The purpose of such a design is also to avoid fluctuations during the oil-water separation process, promote the oil phase to rise, the water phase to sink, and achieve rapid separation of the oil and water phases.

[0024] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation is characterized in that the top height of the inverted U-shaped bend pipe is the same as the oil phase outlet at the top of the oil-water phase separator A and the oil phase outlet at the top of the oil-water phase separator B. The purpose of this design is to prevent the oil phase liquid level from being lower than the oil phase outlet height, thereby promoting the improvement of separation efficiency.

[0025] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation is characterized in that the top of the reverse U-shaped bend is connected to a pressure balance pipe, and the pressure balance pipe is connected to the atmosphere. The purpose of this design is to break the siphon effect of the reverse U-shaped bend, thereby avoiding the discharge of all the liquid in the oil-water phase separator due to the siphon effect.

[0026] Furthermore, the device for removing water from an organic solvent described in the embodiment of the present specific implementation method has a simple operation process as follows: first, check the closed state of the corresponding pipelines and valves of the distillation system, inject the organic solvent-water mixture into the distillation kettle 01, start the reboiler 03, and when the tower top temperature rises to the azeotropic point, start the circulation pump 14 according to the process regulations, so that the water-carrying agent is transported from the water-carrying agent transfer tank 12 to the tower top through the flow meter 15, and is evenly sprayed from top to bottom through the fluid distributor 28 at the tower top; A certain flow of water-carrying agent enters the distillation tower 02 to form a mixed phase of "organic solvent-water-water-carrying agent". The three-phase mixture enters the oil-water phase separator A07 and the oil-water phase separator B08 through the top outlet of the tower and the crude product condenser 05 for orderly oil-water phase separation; the oil phase composed of "water-carrying agent + organic solvent" enters the water-carrying agent transfer tank 12, and then is transferred and transported to the fluid distributor 28 at the top of the tower by the circulating pump 14 to flow downward, and the cycle repeats; the wastewater separated from the oil-water phase separators A and B Under the combined action of the reverse U-shaped bend 25 and the pressure balance pipe 26, the mixed phase inflow and the oil phase and water phase outflow are always balanced in the entire oil-water phase separation process; when the prompt information that the water content is ≤0.5% and the content of the organic solvent to be purified is ≥99.5% is seen from the online detection port 18, the qualified product receiving control valve 192 is opened, and the unqualified product control valve 191 is closed, so that the organic solvent in a state close to anhydrous state is condensed and cooled by the qualified product condenser 17 and then collected into the qualified product The product receiving tank 19 is placed in the product receiving tank 19; the replenishment dripping speed of the pure product with water is controlled in the operation process to maintain the balance between the loss amount and the replenishment amount; the separated waste water is discharged through the lower part of the oil-water separator A and the oil-water phase separator B through the reverse U-shaped bend pipe 25; in this way, the crude organic solvent is continuously fed, the qualified organic solvent is continuously extracted, and the waste water flows out at a constant rate, thus forming a continuous azeotropic distillation water removal mode, which can continuously obtain high-quality organic solvents with a moisture content of ≤0.5% and a main content of ≥99.5%.

[0027] Such a device, a device for removing water from an organic solvent as described in the technical solution of the present invention, has obvious beneficial effects including four aspects: (1) the design of the settler can effectively avoid gas-liquid entrainment or liquid overflow during the distillation process, which is very beneficial to product purity and process safety; (2) the use of a crude product condenser with a larger heat exchange area can quickly condense the mixed gas, thereby effectively avoiding material loss and safety risks; (3) the use of a combination of oil-water phase separator A and oil-water phase separator B can promote the rapid and complete separation of oil phase and water phase; (4) the combination of the reverse U-bend pipe and the pressure balance pipe can effectively prevent material loss, thereby achieving production process safety and orderly and controllable process.

[0028] Such a device, a device for removing moisture from an organic solvent as described in the technical solution of the present invention, also has the advantages of reasonable layout, convenient operation, high production efficiency, stable production process, and safe and reliable operation.

[0029] Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The protection scope of the present invention is to conform to the widest scope consistent with the principles and novel features described herein.

Claims

1. A device for removing water from an organic solvent, comprising: Rectification kettle, rectification tower, reboiler, settler, fluid distributor, crude product condenser, front mixed phase inlet, oil-water phase separator A, oil-water phase separator B, front oil phase outlet, rear mixed phase inlet, rear oil phase outlet, water-containing transfer tank, water-containing metering tank, circulation pump, flow meter, drainage trough, qualified product condenser, online detection sampling point, unqualified product control valve, qualified product control valve, qualified product receiving tank, crude product storage tank, crude product feeding pump, crude product spray head, reverse U-shaped elbow, pressure balance pipe, wastewater outlet, characterized in that a reboiler is arranged in the rectification kettle, the rectification tower is arranged just above the rectification kettle, a settler is arranged between the bottom of the rectification tower and the rectification kettle, and the top of the rectification tower is connected to the oil-water phase separator A through a pipeline and the crude product condenser, The front oil phase outlet at the top of the oil-water phase separator A is connected to the rear mixed phase inlet at the middle of the oil-water phase separator B, the rear oil phase outlet at the top of the oil-water phase separator B is connected to the water-containing agent transfer tank, the water-containing agent transfer tank is connected to the water-containing agent metering tank through a pipeline, the bottom of the water-containing agent transfer tank is connected to the top of the distillation tower through a circulation pump, and a fluid distributor is arranged on the top of the distillation tower. The bottoms of the oil-water phase separator A and the oil-water phase separator B are connected together and connected to the wastewater outlet through a pipeline and an inverted U-shaped elbow. The drainage trough is arranged in the middle of the distillation tower, and the drainage trough is connected to the qualified product condenser through a pipeline. The front end of the material outlet of the qualified product condenser is provided with an online detection sampling point and a non-qualified product control valve and a qualified product control valve, and the qualified product control valve is connected to the qualified product receiving tank forward.

2. The device for removing water from an organic solvent according to claim 1, characterized in that: The settler disposed between the bottom of the distillation tower and the distillation kettle has a spherical, ellipsoidal or cylindrical shape, and the diameter of the settler is 1.5-2.5 times the diameter of the distillation tower.

3. The device for removing water from an organic solvent according to claim 1, characterized in that: The crude product condenser is composed of 2-4 units with a heat exchange area of ​​100m 2 The spiral plate condensers are connected in parallel, or 2-4 shell and tube condensers are connected in parallel, and the heat exchange area reaches 200-400m2.

4. The device for removing water from an organic solvent according to claim 1, characterized in that: The oil-water phase separator A and the oil-water phase separator B are connected in parallel in a serial pipeline manner, and the internal structures of the two are the same, and the heights of the corresponding components are the same.

5. The device for removing water from an organic solvent according to claim 1, characterized in that: The oil-water phase separator A and the oil-water phase separator B are provided with the same fluid disperser in the middle, a wave-blocking plate in the upper middle, and a settling plate in the lower middle.

6. The device for removing water from an organic solvent according to claim 1, characterized in that: The top height of the reverse U-shaped bend pipe is the same as the front oil phase outlet of the upper part of the oil-water phase separator A and the rear oil phase outlet of the upper part of the oil-water phase separator B.

7. The device for removing water from an organic solvent according to claim 1, characterized in that: The top of the reverse U-shaped bend pipe is connected to a pressure balance pipe, and the pressure balance pipe is connected to the atmosphere.

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