Flash evaporator and methanol carbonylation acetic acid synthesis system comprising same

Abstract

The utility model relates to a flash evaporator and a methanol carbonylation acetic acid synthesis system comprising the same. The flash evaporator comprises a tank body, a feeding pipe, a vertical demister and a partition plate, the partition plates are respectively arranged at two ends of the vertical demister and are connected with the inner wall of the tank body, so that the internal space of the tank body is divided into a gas-phase chamber and a liquid-phase chamber, and the feeding pipe is connected with the liquid-phase chamber. The methanol carbonylation acetic acid synthesis system comprises a reaction kettle, a flash evaporator, a light component removal tower and a heavy component removal tower which are connected in sequence, wherein the reaction kettle comprises a reaction kettle body, and a liquid phase ejector and a gas phase ejector which are arranged at the bottom of the reaction kettle body; a gas phase outlet of the gas phase chamber is formed in the top of the flash evaporator and is communicated with a feeding hole of the light component removal tower; a liquid phase outlet of the liquid phase chamber is formed in the bottom of the flash evaporator and is communicated with a liquid phase ejector at the bottom of the reaction kettle. Compared with the prior art, the flash evaporator disclosed by the utility model has the advantages of small volume, good flash evaporation effect, high defoaming efficiency and the like, and the acetic acid separation efficiency of a methanol carbonylation acetic acid synthesis system is higher.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of organic synthesis, and relates to a flash evaporator and a methanol carbonylation synthesis acetic acid system comprising the flash evaporator. BACKGROUND

[0002] Acetic acid, a key organic chemical raw material, plays a pivotal role in many fields such as fiber manufacturing, plasticizer, coating, adhesive and copolymer resin, and its production capacity has increased rapidly in recent years. The dominant technologies for global acetic acid production include acetaldehyde oxidation process, butane and light oil oxidation process and methanol carbonylation synthesis process. In particular, the methanol carbonylation synthesis process accounts for more than 70% of the total acetic acid production in the world.

[0003] The existing flash evaporator in the methanol carbonylation synthesis reaction is large in size, and there is incomplete defoaming, resulting in low acetic acid separation efficiency. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a methanol carbonylation synthesis acetic acid system to solve the problems of low acetic acid separation efficiency and high equipment investment in traditional methanol carbonylation synthesis reaction.

[0005] The purpose of the utility model can be achieved by the following technical solutions:

[0006] The utility model discloses a flash evaporator, including tank body, feed pipe, vertical defoamer and partition, the partition is respectively arranged in the both ends of vertical defoamer and is connected with the inner wall of tank body, so as to separate the internal space of tank body into gas phase chamber and liquid phase chamber.

[0007] The flash evaporator of the utility model has small size, which is 50% of the traditional flash evaporator, has good flash evaporation effect, the top of the column is provided with an efficient vertical defoamer, has high defoaming efficiency, solves the problems of large size, high investment and low separation efficiency of the traditional defoamer, and the flash evaporator can be used in combination with a catalyst trap, further reducing the number of equipment and equipment investment.

[0008] Further, the tank body is provided with guide vanes in the opening direction of the feed pipe, and the guide vanes are V-shaped with the opening pointing to the feed pipe.

[0009] Further, the first vertical defoamer and the second vertical defoamer are connected in parallel in the tank body, and the partition plates are connected to the top end of the first vertical defoamer and the bottom end of the second vertical defoamer.

[0010] Further, the tank body is provided with a sprayer pointing to the liquid phase side of the vertical defoamer.

[0011] In some specific embodiments, the sprayer adopts a high-efficiency atomizing nozzle to spray dilute acetic acid on the demister to accelerate the demisting effect and the washing effect.

[0012] Further, a catalyst washing spray tray is arranged in the gas phase chamber to further capture catalyst and reduce catalyst loss.

[0013] Further, the flash evaporator further comprises a reboiler connected with the liquid phase chamber to perform secondary flash evaporation.

[0014] In some specific embodiments, the vertical demister has a liquid flow guide pipe to collect and guide the captured liquid droplets to the liquid phase in the tower kettle, thereby reducing secondary entrainment.

[0015] The second aspect of the utility model provides a kind of methanol carbonylation synthesis acetic acid system, comprising: reaction kettle, flash evaporator, light removal column and heavy removal column connected in sequence;

[0016] The reaction kettle includes a reaction kettle body, a liquid phase injector and a gas phase injector arranged at the bottom of the reaction kettle body;

[0017] The gas phase outlet of the gas phase chamber is arranged at the top of the flash evaporator and is in communication with the feed inlet of the light removal column; the liquid phase outlet of the liquid phase chamber is arranged at the bottom of the flash evaporator and is in communication with the liquid phase injector at the bottom of the reaction kettle.

[0018] The reaction kettle of the utility model adopts a jet type liquid stirring reaction kettle without mechanical stirrer, and the liquid phase injector and the gas phase injector form jet flow in the reaction kettle through corresponding nozzles, which solves the leakage problem of traditional mechanical stirring seal, fully utilizes the kinetic energy of gas phase and liquid phase feed, makes the reaction liquid form rotation and disperse gas, makes the reaction more sufficient, and achieves the stirring effect of mechanical stirrer. Further, a circulating liquid feed pipe extending inward is arranged at the top of the reaction kettle body, a reflux pipe is arranged between the circulating liquid feed pipe and the liquid outlet, and a heat exchanger is arranged on the reflux pipe.

[0019] Further, a filter is arranged between the gas phase outlet of the flash evaporator and the feed inlet of the light removal column to serve as a catalyst collector.

[0020] Further, a drying tower is further arranged between the light removal column and the heavy removal column.

[0021] Further, the reaction kettle further comprises a plurality of flow guide plates arranged on the inner wall of the reaction kettle body and a gas-liquid separator arranged outside the inlet of the gas outlet pipe. The demisting device at the gas phase outlet at the top of the reaction kettle, i.e. the gas-liquid separator, reduces the entrainment of liquid droplets in the gas phase.

[0022] Further, the flow guide plates are sieve hole plates.

[0023] Further, the guide plate is arranged in a circumferential direction of the reaction kettle body.

[0024] Further, a liquid stabilizing plate is arranged in the reaction kettle body to divide the internal space of the reaction kettle body, the gas-liquid separator and the guide plate are arranged on two sides of the liquid stabilizing plate respectively, and the gas-phase ejector penetrates the liquid stabilizing plate.

[0025] Compared with the prior art, the reaction kettle has the following beneficial effects:

[0026] The reaction kettle of the utility model adopts the jet type liquid stirring reaction kettle without mechanical stirrer, the liquid-phase ejector and the gas-phase ejector form jet flow in the reaction kettle through corresponding nozzles respectively, the situation that the traditional mechanical stirring seal is easy to leak is solved, kinetic energy of gas-phase and liquid-phase feed is fully utilized, the reaction liquid forms rotation, gas is dispersed, the reaction is more sufficient, and the stirring effect of the mechanical stirrer is reached.

[0027] The flash evaporator has the advantages of small volume, 50% of the traditional flash evaporator, good flash evaporation effect, high-efficiency vertical demister on the top of the tower, high demisting efficiency, solves the problems of large size, high investment and low separation efficiency of the traditional demister, and simultaneously, the flash evaporator can be used in combination with the catalyst trap, further reduces the equipment quantity and the equipment investment. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a process flow diagram of a system for synthesizing acetic acid by methanol carbonylation in embodiment 1;

[0029] Figure 2 It is a structure schematic view of the reaction kettle in embodiment 1;

[0030] Figure 3 It is a structure schematic view of the flash evaporator in embodiment 1;

[0031] Figure 4 It is a structure schematic view of the reaction kettle in embodiment 4;

[0032] Figure 5 It is a structure schematic view of the flash evaporator in embodiment 5;

[0033] Figure 6 It is a structure schematic view of the flash evaporator in embodiment 6;

[0034] Figure 7 It is a structure schematic view of the flash evaporator in embodiment 7;

[0035] Figure 8 It is a process flow diagram of a system for synthesizing acetic acid by methanol carbonylation in embodiment 9;

[0036] Figure 9 ,Figure 10 This is a schematic diagram of the liquid stabilizing plate in Example 4;

[0037] Explanation of markings in the diagram:

[0038] 1- 101-Reaction vessel body, 102-Liquid phase ejector, 103-Gas outlet pipe, 104-Gas phase ejector, 105-Guide plate, 106-Gas-liquid separator, 107-Stabilizing plate, 2-Flash evaporator, 201-Tank body, 202-Feed pipe, 203-First vertical demister, 204-Second vertical demister, 205-Sprayer, 206-Catalyst washing spray plate, 207-Reboiler, 3-Light weight removal tower, 4-Heavy weight removal tower, 5-Heat exchanger, 6-Catalyst collector, 7-Drying tower. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are based on the above-described technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0042] Example 1:

[0043] like Figure 1 The methanol carbonylation synthesis system for acetic acid shown includes: a reaction vessel 1, a flash evaporator 2, a light component removal tower 3, and a heavy component removal tower 4 connected in sequence; wherein the reaction vessel 1, as shown... Figure 2 As shown, it includes a reactor body 101, a liquid phase ejector 102 and a gas phase ejector 108 disposed at the bottom of the reactor body 101, a circulating liquid feed pipe 104 disposed at the top of the reactor body 101 and extending inward, and a liquid outlet disposed on the side of the reactor body 101.

[0044] The liquid outlet is connected to the feed inlet of flash evaporator 2 and gas phase ejector 104 respectively; the gas phase outlet of flash evaporator 2 is connected to the feed inlet of light dust removal tower 3, and the liquid phase outlet is connected to liquid phase ejector pipe 102.

[0045] The reaction kettle of the embodiment adopts a jet type liquid stirring reaction kettle without mechanical stirrer. The liquid jet and the gas jet form jet flow in the reaction kettle through corresponding nozzles to mix, solve the leakage problem of traditional mechanical stirring seal, make full use of kinetic energy of gas and liquid feed, make the reaction liquid form rotation, disperse gas, and make the reaction more sufficient to achieve the stirring effect of mechanical stirrer.

[0046] As shown in Figure 1 , a reflux pipe is further arranged between the gas phase jet of the circulating liquid feed pipe and the gas outlet pipe, and a heat exchanger 5 is arranged on the reflux pipe. A filter is arranged between the gas phase outlet of the flash evaporator 2 and the feed inlet of the light component removal tower 3 to serve as a catalyst trap 6.

[0047] As shown in Figure 2 , the reaction kettle 1 further comprises a plurality of guide plates 105 arranged on the inner wall of the reaction kettle body 101, and a gas-liquid separator 106 arranged outside the inlet of the gas outlet pipe 103. The gas-liquid separator 106 is specifically a defoaming device, which reduces liquid droplets entrained in the gas phase through the defoaming device at the gas phase outlet of the top of the reaction kettle.

[0048] As shown in Figure 3 , the flash evaporator 2 comprises a tank body 201, a feed pipe 202, vertical defoamers, and a partition plate. The partition plate is arranged at both ends of the vertical defoamer and connected to the inner wall of the tank body 201 to divide the internal space of the tank body 201 into a gas phase chamber and a liquid phase chamber. The feed pipe 202 is connected to the liquid phase chamber and a liquid outlet. The gas phase outlet of the gas phase chamber is connected to the feed inlet of the light component removal tower 3, and the liquid phase outlet of the liquid phase chamber is connected to the liquid phase jet 102.

[0049] More specifically, the first vertical defoamer 203 and the second vertical defoamer 204 are connected side by side in the tank body 201. The partition plate is connected to the top end of the first vertical defoamer 203 and the bottom end of the second vertical defoamer 204, respectively.

[0050] In the embodiment, the reaction liquid from the reaction kettle 1 enters the flash evaporator 2. The flash evaporator 2 has a feed pipe 202, and the opening direction of the feed pipe 202 is provided with guide vanes. The guide vanes are in V shape, and the opening direction points to the feed pipe 202 to enhance the gas-liquid separation efficiency and reduce the vibration generated by the feed. The upper part of the feed has a high-efficiency vertical defoamer. The defoamer is a high-efficiency blade type defoamer or a high-efficiency blade plus wire mesh defoamer. The use of the device can greatly reduce the volume of the traditional flash evaporator, and the reduction can reach more than 50%. At the same time, for the high-priced defoamer made of Hastelloy B or zirconium material, the use of the new flash evaporator can reduce the equipment investment by more than 50%, greatly reducing the investment cost of the new acetic acid device.

[0051] Embodiment 2

[0052] A system for synthesizing acetic acid by methanol carbonylation, which is different from example 1 only in that the flow guide plate 105 is a sieve plate. The reaction kettle of this example cancels mechanical stirring, and the gas-liquid enters the reaction kettle at a certain angle under the action of the nozzle and the flow guide plate 105, and the gas-liquid pushes the liquid in the reaction kettle to rotate, and the gas-liquid reaction is continuously carried out in the process. In the process of gas-liquid rising, the bubbles are broken on the flow guide plate with a sieve plate, the liquid is guided, the bubbles are finer, and the stirring effect is beneficial to improve the gas-liquid contact area; improve the conversion rate and reduce the temperature difference between the top and bottom of the reaction kettle.

[0053] Example 3

[0054] A system for synthesizing acetic acid by methanol carbonylation, which is different from example 1 only in that the flow guide plate 105 is arranged along the circumference of the reaction kettle body 101.

[0055] Example 4

[0056] A system for synthesizing acetic acid by methanol carbonylation, which is different from example 1 only in that:

[0057] As shown in Figure 4 , a liquid stabilizing plate 107 is also arranged in the reaction kettle body 101, and the internal space of the reaction kettle body 101 is divided, the gas-liquid separator 106 and the flow guide plate 105 are arranged on the two sides of the liquid stabilizing plate 107, and the gas phase injector 104 penetrates the liquid stabilizing plate 107. The liquid stabilizing plate 107 is used to stabilize the liquid level and increase the effective liquid level height.

[0058] As shown in Figure 9 , Figure 10 , the liquid stabilizing plate 10 is in the shape of an inverted V, and three liquid stabilizing plates 10 are arranged in a staggered manner, forming a liquid stabilizing plate combination. One end of the liquid stabilizing plate 10 is welded to the inner wall of the shell, and the other end extends to the center of the gas-liquid mixing reactor. The three liquid stabilizing plates can be arranged in a triangular shape as shown in Figure 3 , or in a diagonal one-dimensional shape. Taking the triangular arrangement in Figure 3 as an example, the size and spacing parameters of the liquid stabilizing plate combination are preferably set as follows: a is 300mm-900mm, b is 150mm-450mm, c is 300mm-900mm, d is 150mm-450mm, e is 50mm-300mm, and f is 50mm-500mm.

[0059] Example 5

[0060] A system for synthesizing acetic acid by methanol carbonylation, which is different from example 1 only in that, as shown in Figure 5 , the tank body 201 of the flash evaporator 2 is also provided with a sprayer 205 directed to the liquid side of the vertical demister. The sprayer 205 can use a high-efficiency atomizing nozzle to spray dilute acetic acid on the demister, accelerating the demisting effect and washing effect.

[0061] Example 6

[0062] A system for synthesizing acetic acid by carbonylation of methanol, which differs from Example 4 only in that, as shown in Figure 6 A catalyst washing spray tray 206 is arranged in the gas phase chamber to further capture catalyst and reduce catalyst loss.

[0063] Example 7

[0064] A system for synthesizing acetic acid by carbonylation of methanol, which differs from Example 5 only in that, as shown in Figure 7 The flasher 2 further comprises a reboiler 107 connected in circulation with the liquid phase chamber to perform secondary flashing.

[0065] Example 8

[0066] A system for synthesizing acetic acid by carbonylation of methanol, which differs from Example 1 only in that the vertical demister has a liquid flow guide pipe to collect and guide the captured liquid droplets into the liquid phase in the column kettle, reducing secondary entrainment.

[0067] Example 9

[0068] A system for synthesizing acetic acid by carbonylation of methanol, which differs from Example 1 only in that, as shown in Figure 8

[0069] No reflux pipe and heat exchanger 5 are arranged between the gas phase sparger 104 and the gas outlet pipe 103;

[0070] No catalyst trap 6 is arranged between the gas phase outlet of the flasher 2 and the feed inlet of the light-removing column 3;

[0071] A drying column 7 is further arranged between the light-removing column 3 and the heavy-removing column 4.

[0072] The rest is the same as Example 1.

[0073] The above description of the embodiments is to facilitate those of ordinary skill in the art to understand and use the utility model. Those skilled in the art can obviously make various modifications to these embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the utility model is not limited to the above embodiments, and those skilled in the art can make improvements and modifications within the scope of the utility model without departing from the scope of the utility model.​

Claims

1. A flash evaporator characterized by, The application relates to a flash evaporator, which comprises a tank body (201), a feed pipe (202), vertical demisters and a partition plate; the partition plate is arranged at the two ends of the vertical demisters and connected to the inner wall of the tank body (201) to divide the inner space of the tank body (201) into a gas phase chamber and a liquid phase chamber, and the feed pipe (202) is connected to the liquid phase chamber.

2. The flash evaporator of claim 1, wherein, The tank body (201) is provided with guide vanes in the direction of the opening of the feed pipe (202), the guide vanes are V-shaped, and the opening is directed to the feed pipe (202).

3. The flash evaporator of claim 1, wherein, The first vertical demister (203) and the second vertical demister (204) are connected to the top end of the first vertical demister (203) and the bottom end of the second vertical demister (204) in the tank body (201) in parallel.

4. The flash evaporator of claim 1, wherein, The tank body (201) is provided with a sprayer (205) directed to the liquid phase side of the vertical demister.

5. The flash evaporator of claim 1, wherein, The gas phase chamber is provided with a catalyst washing spray tray (206).

6. The flash evaporator of claim 1, wherein, The flash evaporator (2) further comprises a reboiler (207) connected to the liquid phase chamber.

7. A methanol carbonylation system for the synthesis of acetic acid comprising a flasher according to any one of claims 1 to 6, characterized in that, The application further relates to a reaction system comprising the flash evaporator. The reaction system comprises a reaction kettle, the flash evaporator, a light component removal tower and a heavy component removal tower connected in sequence. The reaction kettle (1) comprises a reaction kettle body (101), a liquid phase sprayer (102) and a gas phase sprayer (108) arranged at the bottom of the reaction kettle body (101). The gas phase outlet of the gas phase chamber is arranged at the top of the flash evaporator (2) and is communicated with the feed inlet of the light component removal tower (3); the liquid phase outlet of the liquid phase chamber is arranged at the bottom of the flash evaporator (2) and is communicated with the liquid phase sprayer (102) at the bottom of the reaction kettle.

8. The methanol carbonylation system for acetic acid synthesis of claim 7, wherein, The top of the reaction kettle body (101) is provided with a circulating liquid feed pipe (104) extending inwardly, a reflux pipe is arranged between the circulating liquid feed pipe (104) and the liquid outlet at the side of the reaction kettle body (101), and a heat exchanger (5) is arranged on the reflux pipe. And / or, a catalyst catcher (6) is arranged between the gas phase outlet of the flash evaporator (2) and the feed inlet of the light component removal tower (3). And / or, a drying tower (7) is further arranged between the light component removal tower (3) and the heavy component removal tower (4).

9. The methanol carbonylation system for synthesizing acetic acid of claim 7, wherein, The reaction kettle (1) further comprises a plurality of guide plates (105) arranged on the inner wall of the reaction kettle body (101) and a gas-liquid separator (106) arranged on the gas outlet pipe (103). The guide plates (105) are sieve plates. And / or, the guide plates (105) are arranged in a circumferential direction of the reaction kettle body (101).

10. The methanol carbonylation system for acetic acid synthesis of claim 7, wherein, The reaction kettle body (101) is provided with a liquid stabilizing plate (107).

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