Separation system for formic acid production and formic acid production system
By introducing a flash evaporation tower into the formic acid production system for first-stage flash separation, the problems of long coexistence time and high energy consumption in the prior art are solved, and the effects of rapid separation and energy saving and consumption reduction are achieved.
Patent Information
- Application Number
- CN202421543598.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-02
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-07-02
AI Technical Summary
In the existing formic acid production technology, methanol and formic acid coexist for a long time, resulting in many side reactions, low conversion rate of methyl ester, and when the hydrolysate enters the distillation tower, feeding it in liquid phase, resulting in high energy consumption.
A separation system for production of formic acid is designed, including a flash evaporation tower and multiple distillation towers. The first-stage flash separation is performed through the flash evaporation tower, and formic acid, water, methyl ester, and methanol are quickly separated, and further separated and recovered through the distillation tower.
The coexistence time of methanol and formic acid is significantly shortened by flash evaporation, the rate of side reactions is reduced, the conversion rate of methyl ester is improved, and by reducing the heating energy consumption of the distillation tower, energy saving and consumption reduction are achieved and production costs are reduced.
Smart Images
Figure CN222900234U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of formic acid production, in particular to a separation system for formic acid production and a formic acid production system. Background Art
[0002] Formic acid is widely used in the production of medicine, rubber, leather, dyes and other industries as a basic organic chemical raw material. It is one of the important chemical raw materials. At present, the separation method of formic acid from water and methyl ester methanol mainly adopts the direct distillation of hydrolyzate for separation and purification. The specific process is that the hydrolyzate directly enters the distillation tower, and the temperature and pressure of the distillation tower are controlled to produce methyl ester and methanol at the top of the tower, and formic acid and water at the bottom of the tower.
[0003] In this method, methanol and formic acid coexist for a long time, many side reactions occur, and the methyl ester conversion rate is not high. In the existing process, the hydrolyzate is directly fed into the distillation tower for separation in liquid form, which has high energy consumption. Utility Model Content
[0004] In order to solve the deficiencies in the prior art, the utility model provides a separation system for formic acid production, comprising a flash tower whose feed end is connected to a discharge end of a hydrolysis tower, the top discharge end of the flash tower is connected to the feed end of a first distillation tower, and the bottom discharge end of the flash tower is connected to the feed end of a second distillation tower. The liquid phase discharge end of the second distillation tower is connected to the feed end of a formic acid distillation system.
[0005] The flash tower comprises: a cylindrical chamber with a wider top and a triangular cone-shaped chamber at the bottom, which are interconnected. An evaporation tube is provided at the bottom of the cylindrical chamber near the top of the triangular cone-shaped chamber. The inlet end of the evaporation tube extends to the outside of the cylindrical chamber as the feed end of the flash tower. An exhaust pipe is provided at the top of the cylindrical chamber. One end of the exhaust pipe extends to the outside of the cylindrical chamber as the top discharge end of the flash tower. The bottom of the triangular cone-shaped chamber is provided with a bottom discharge end of the flash tower at the top of the triangular cone.
[0006] Furthermore, the outer wall of the cylindrical chamber is provided with a lifting lug above the evaporation tube.
[0007] Furthermore, a trumpet-shaped collector is provided on the side of the exhaust pipe facing the evaporation pipe, and a demister covering the cross section of the collector is provided on the collector.
[0008] Furthermore, a control valve for controlling the discharge of materials from the bottom discharge end is provided at the top end of the triangular cone.
[0009] Furthermore, a heating ring is provided on the inner wall of the triangular cone inside the flash tower.
[0010] Furthermore, the gas phase outlet end of the first distillation tower is connected to the methyl ester feedstock end of the hydrolysis tower through a first delivery pipe having a cooling system.
[0011] Furthermore, the liquid phase outlet end of the first distillation tower is connected to a methanol recovery system. The gas phase outlet end of the second distillation tower is connected to a mixture distillation system through a second delivery pipe having a cooling system.
[0012] A second object of the present invention is to provide a formic acid production system, comprising a hydrolysis tower, wherein the discharge end of the hydrolysis tower is connected to the feed end of the flash tower of the separation system for formic acid production through a drainage pipe.
[0013] The hydrolysis tower comprises: a motor fixedly mounted on the top, a linkage rod fixedly mounted on the output end of the motor, the linkage rod penetrates the hydrolysis tower along the axial direction of the hydrolysis tower, and is rotatably connected to the bottom of the hydrolysis tower. The hydrolysis tower is provided with a discharge end near the top, and the discharge end is connected to the drainage pipe. The hydrolysis tower is provided with a feed end near the bottom, and the feed end is connected to the feed pipe.
[0014] A partition plate is fixedly installed on the inner wall of the hydrolysis tower near the inlet end of the drainage pipe. The partition plate covers the cross section of the hydrolysis tower and is provided with a plurality of through holes penetrating the upper and lower plate surfaces in a matrix arrangement. A linkage rod through hole is provided on the surface of the partition plate for the linkage rod to pass through.
[0015] The linkage rod is fixed with a plurality of spoilers from top to bottom in sequence between the partition plate and the feed end. The spoilers are in the shape of an arc plate protruding upwards, and are provided with a plurality of spoiler grooves on the top plate surface.
[0016] Furthermore, a diverter plate is provided at the bottom of the spoiler at the installation position with the linkage rod.
[0017] Furthermore, the drainage pipe is provided with a flash valve at the discharge end of the hydrolysis tower.
[0018] The beneficial effects of the utility model are:
[0019] (1) The utility model changes the separation process of the four-component mixture of formic acid, water, methyl ester and methanol in the existing formic acid production system. By adding a flash tower to perform primary flash separation, formic acid, water, methyl ester and methanol can be quickly separated, which greatly shortens the coexistence time of methanol and formic acid, reduces the rate of occurrence of side reactions, and improves the methyl ester conversion rate.
[0020] (2) The utility model uses flash evaporation to allow methyl ester and methanol to enter the first distillation tower in the gas phase, thereby significantly reducing the heating energy consumption of the first distillation tower, achieving the purpose of energy saving and consumption reduction, reducing production costs, and increasing product returns. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the structure of the formic acid production system of the utility model;
[0022] Figure 2 It is a front view schematic diagram of the connection structure of the flash tower and the hydrolysis tower of the utility model;
[0023] Figure 3 It is a rear view schematic diagram of the connection mechanism between the flash tower and the hydrolysis tower of the utility model;
[0024] Figure 4 It is a schematic diagram of the front cross-sectional structure of the flash tower and the hydrolysis tower of the utility model;
[0025] Figure 5 for Figure 4 Schematic diagram of the cross-section structure of the middle partition plate;
[0026] Figure 6 for Figure 4 Schematic diagram of the cross-section structure of the middle spoiler.
[0027] In the figure: 1. Flash tower; 2. Flash valve; 3. Lifting ear; 4. Exhaust pipe; 5. Collector; 6. Defoamer; 7. Evaporation tube; 8. Heating ring; 9. Control valve; 10. Diverter plate; 11. Hydrolysis tower; 12. Drainage pipe; 13. Motor; 14. Linkage rod; 15. Partition plate; 16. Spoiler; 17. Feed pipe. DETAILED DESCRIPTION
[0028] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.
[0029] Please note that the terms "above", "below", "left", "right", "top", "top", "bottom", "bottom", etc. used in the present invention to describe the positional relationship do not represent the absolute positional relationship between the modules / components / assemblies / components / parts, but the relative positional relationship between the modules / components / assemblies / components / parts.
[0030] Embodiment 1,
[0031] A separation system for formic acid production, such as Figures 1 to 4 As shown, it includes a flash tower 1 whose feed end is connected to the discharge end of a hydrolysis tower 11, the top discharge end of the flash tower 1 is connected to the feed end of a first distillation tower, and the bottom discharge end of the flash tower 1 is connected to the feed end of a second distillation tower. The liquid phase discharge end of the second distillation tower is connected to the feed end of a formic acid distillation system. The formic acid distillation system is used to distill and separate formic acid and water to obtain formic acid with a desired product concentration.
[0032] The flash tower 1 comprises: a cylindrical chamber with a wider top and a triangular cone-shaped chamber at the bottom, which are interconnected. An evaporation tube 7 is provided at the bottom of the cylindrical chamber near the top of the triangular cone-shaped chamber. The inlet end of the evaporation tube 7 extends to the outside of the cylindrical chamber as the feed end of the flash tower 1. An exhaust pipe 4 is provided at the top of the cylindrical chamber. One end of the exhaust pipe 4 extends to the outside of the cylindrical chamber as the top discharge end of the flash tower 1. The bottom of the triangular cone-shaped chamber is provided with a bottom discharge end of the flash tower 1 at the top of the triangular cone.
[0033] According to one embodiment of the utility model, Figure 4 As shown, the gas phase outlet end of the first distillation tower is connected to the methyl ester feed end of the hydrolysis tower 11 through a first delivery pipe with a cooling system.
[0034] According to one embodiment of the utility model, Figure 4 As shown, the liquid phase outlet end of the first distillation tower is connected to the methanol recovery system. The gas phase outlet end of the second distillation tower is connected to the mixture distillation system through a second delivery pipe with a cooling system.
[0035] Compared with the prior art, the utility model first separates the four-component mixture of formic acid, water, methyl ester and methanol produced by the hydrolysis tower 11 through a flash tower 1, and controls the temperature and pressure in the flash tower 1 so that methyl ester and methanol are mainly discharged as gaseous components and transported from the top of the flash tower 1 to the first distillation tower. Formic acid and water are discharged as liquid components and transported from the bottom of the flash tower 1 to the second distillation tower. In this way, on the one hand, a rapid preliminary separation of methanol and formic acid is achieved, and methyl ester is produced by long-term contact between methanol and formic acid, thereby reducing the formic acid productivity. On the other hand, methyl ester and methanol enter the first distillation tower as high-temperature gaseous components, which can reduce the heat consumption of the first distillation tower in distilling and separating methyl ester and methanol, thereby achieving the purpose of energy saving and consumption reduction, reducing production costs, and increasing product revenue.
[0036] In addition, the methyl ester obtained after the first distillation tower distills the methyl ester and methanol can be directly returned to the methyl ester raw material end of the hydrolysis tower 11 if it meets the production needs, thereby reducing the consumption of the methyl ester raw material and further reducing the production cost. The first distillation tower of the utility model is not limited to performing only one distillation, and can also perform multiple distillations as needed, so that the separated methyl ester and methanol meet the purity requirements.
[0037] According to an embodiment of the utility model, the outer wall of the cylindrical chamber is provided with a lifting lug 3 above the evaporation tube 7. Since the flash tower body is generally a hollow barrel structure, the installation of the lifting lug 3 is convenient for hoisting the flash tower to the installation position on the one hand, and also convenient for fixing and installing the flash tower on the other hand.
[0038] Example 2
[0039] Based on the separation system for formic acid production described in Example 1, Figure 4 As shown, a trumpet-shaped collector 5 is provided on the side of the exhaust pipe 4 facing the evaporation pipe 7, and a demister 6 covering the collector cross section is provided on the collector 5. Since the utility model needs to collect the gas phase components after flash evaporation as much as possible and transport them to the next mechanism, the trumpet-shaped collector 5 can be added to increase the collection surface of the gas phase components and improve the collection efficiency.
[0040] According to one embodiment of the utility model, a control valve 9 for controlling the discharge of the bottom discharge end is provided at the top of the triangular cone. The gas phase components after flash evaporation can be discharged in real time, and the discharge of the liquid phase components can be controlled as needed through the installed control valve 9, so that the liquid phase components can be discharged after a certain collection and buffering, so that the gas phase components in the phase can be further emitted during the buffering period.
[0041] According to one embodiment of the utility model, a heating ring 8 is provided on the inner wall of the triangular cone inside the flash tower 1. This arrangement can maintain the necessary temperature environment inside the flash tower 1, and can also maintain the temperature of the liquid phase components to promote the volatilization of methyl ester and methanol.
[0042] Example 3
[0043] A formic acid production system, such as Figures 1 to 6 As shown, it includes a hydrolysis tower 11, and the discharge end of the hydrolysis tower 11 is connected to the feed end of the flash tower 1 of the separation system for formic acid production through a drainage pipe 12.
[0044] like Figure 4 As shown, the hydrolysis tower 11 includes: a motor 13 fixedly installed at the top, a linkage rod 14 fixedly installed at the output end of the motor 13, the linkage rod 14 penetrates the hydrolysis tower 11 along the axial direction of the hydrolysis tower 11, and is rotatably connected to the bottom of the hydrolysis tower 11. The hydrolysis tower 11 is provided with a discharge end near the top, and the discharge end is connected to the drainage pipe 12. The hydrolysis tower 11 is provided with a feed end near the bottom, and the feed end is connected to the feed pipe 17.
[0045] A partition plate 15 is fixedly mounted on the inner wall of the hydrolysis tower 11 near the inlet end of the drainage pipe 12. The partition plate 15 covers the cross section of the hydrolysis tower 11, and is provided with a plurality of through holes penetrating the upper and lower plate surfaces in a matrix arrangement. A linkage rod through hole is provided on the plate surface of the partition plate 15 for the linkage rod 14 to pass through.
[0046] The linkage rod 14 is fixedly mounted with a plurality of spoilers 16 from top to bottom between the partition plate 15 and the feed end. The spoilers 16 are in the shape of an arc-shaped plate protruding upward, and a plurality of spoiler grooves are arranged on the top plate surface.
[0047] The traditional hydrolysis tower 11 is a cylindrical hollow structure, which controls the ratio of methyl ester to water and the temperature in the hydrolysis tower, so that methyl ester is hydrolyzed into formic acid and methanol, and the mixture of methyl ester, water, formic acid and methanol is output and separated. The utility model improves the hydrolysis tower 11, and the motor 13 is installed to continuously or intermittently drive the linkage rod 14 to rotate, thereby further driving the spoiler 16 to rotate, and the mixture is stirred to accelerate the hydrolysis reaction. Since the present invention accelerates the hydrolysis reaction by adding a turbulent effect, it is necessary to install a partition plate 15 at the discharge end, so as to stabilize the mixed flow mixture into a mixture that is continuously and stably output, so as to avoid unstable feed affecting the flash evaporation effect of the flash tower 1.
[0048] According to an embodiment of the utility model, a diverter plate 10 is provided at the bottom of the spoiler 16 at the installation position of the linkage rod 14. This arrangement can prevent the mixed liquid from converging at the installation position of the bottom of the spoiler 16 and the linkage rod 14.
[0049] According to one embodiment of the utility model, the draft pipe 12 is provided with a flash valve 2 at the discharge end of the hydrolysis tower 11. The flash valve 2 is used to preliminarily flash the mixture, which can further improve the flash separation effect of the flash tower.
[0050] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A separation system for formic acid production, characterized in that: It comprises a flash tower (1) whose feed end is connected to the discharge end of a hydrolysis tower (11), the top discharge end of the flash tower (1) is connected to the feed end of a first distillation tower, and the bottom discharge end of the flash tower (1) is connected to the feed end of a second distillation tower; the liquid phase discharge end of the second distillation tower is connected to the feed end of a formic acid distillation system; The flash tower (1) comprises: a cylindrical chamber with a wider top and a triangular cone-shaped chamber at the bottom, which are interconnected; an evaporation tube (7) is provided at the bottom of the cylindrical chamber near the top of the triangular cone-shaped chamber; the inlet end of the evaporation tube (7) extends to the outside of the cylindrical chamber and serves as the feed end of the flash tower (1); an exhaust pipe (4) is provided at the top of the cylindrical chamber; one end of the exhaust pipe (4) extends to the outside of the cylindrical chamber and serves as the top discharge end of the flash tower (1); and the bottom discharge end of the flash tower (1) is provided at the top of the triangular cone-shaped chamber.
2. The separation system for formic acid production according to claim 1, characterized in that: The outer wall of the cylindrical chamber is provided with a lifting lug (3) above the evaporation tube (7).
3. The separation system for formic acid production according to claim 1, characterized in that: A trumpet-shaped collector (5) is provided on the side of the exhaust pipe (4) facing the evaporation pipe (7), and a defoamer (6) covering the cross section of the collector is provided on the collector (5).
4. The separation system for formic acid production according to claim 1, characterized in that: A control valve (9) for controlling the discharge of materials from the bottom discharge end is provided at the top end of the triangular cone.
5. The separation system for formic acid production according to claim 1, characterized in that: Inside the flash tower (1), a heating ring (8) is arranged on the inner wall of the triangular cone.
6. The separation system for formic acid production according to claim 1, characterized in that: The gas phase outlet end of the first distillation tower is connected to the methyl ester raw material end of the hydrolysis tower (11) through a first delivery pipe with a cooling system.
7. The separation system for formic acid production according to claim 1, characterized in that: The liquid phase outlet end of the first distillation tower is connected to the methanol recovery system; the gas phase outlet end of the second distillation tower is connected to the mixture distillation system through a second delivery pipe with a cooling system.
8. A formic acid production system, comprising a hydrolysis tower (11), characterized in that: The discharge end of the hydrolysis tower (11) is connected to the feed end of the flash tower (1) of the separation system for formic acid production according to any one of claims 1 to 7 through a drainage pipe (12); The hydrolysis tower (11) comprises: a motor (13) fixedly mounted on the top, a linkage rod (14) fixedly mounted on the output end of the motor (13), the linkage rod (14) penetrating the hydrolysis tower (11) along the axial direction of the hydrolysis tower (11) and being rotatably connected to the bottom of the hydrolysis tower (11); the hydrolysis tower (11) is provided with a discharge end near the top, the discharge end being communicated with a drainage pipe (12); the hydrolysis tower (11) is provided with a feed end near the bottom, the feed end being communicated with a feed pipe (17); A partition plate (15) is fixedly mounted on the inner wall of the hydrolysis tower (11) near the inlet end of the drainage pipe (12); the partition plate (15) covers the cross section of the hydrolysis tower (11) and is provided with a plurality of through holes penetrating the upper and lower plate surfaces in a matrix arrangement; a linkage rod through hole is provided on the plate surface of the partition plate (15) for the linkage rod (14) to pass through; On the linkage rod (14) between the partition plate (15) and the feed end, a plurality of spoilers (16) are fixedly installed in sequence from top to bottom; the spoiler (16) is in the shape of an arc-shaped plate protruding upward, and a plurality of spoiler grooves are provided on the top plate surface.
9. The formic acid production system according to claim 8, characterized in that: A splitter plate (10) is provided at the bottom of the spoiler (16) at the installation position with the linkage rod (14).
10. The formic acid production system according to claim 8, characterized in that: The draft pipe (12) is provided with a flash valve (2) at the discharge end of the hydrolysis tower (11).