Esterification reactor for an mma production plant

Abstract

The utility model relates to methyl methacrylate preparation field, concretely relates to a kind of esterification reactor for MMA production device, the esterification reactor is horizontal structure, and gas phase outlet and liquid phase outlet are provided on shell, and shell is divided into the first cavity, second cavity, third cavity and fourth cavity that communicate, respectively carry out first esterification reaction, secondary esterification reaction, tertiary esterification reaction and four esterification reaction;The first cavity is provided with amide salt inlet and first mixed liquid inlet;The second cavity is provided with first methanol inlet and second mixed liquid inlet;The third cavity is provided with second methanol inlet;The fourth cavity is provided with third methanol inlet;The volume ratio of the first cavity, second cavity, third cavity and fourth cavity is 1-2:1-1.5:1-1.2:1-1.2.The esterification reactor not only realizes multistage esterification reaction, improves esterification reaction rate, also reduces the probability of jam.

Description

Technical Field

[0001] This utility model relates to the field of methyl methacrylate (MMA) preparation, and specifically to an esterification reactor for MMA production equipment. Background Technology

[0002] In the acetone cyanohydrin (ACH) process, during the acylation stage, ACH and sulfuric acid are added in a certain proportion and undergo an acylation reaction to generate an amide salt intermediate. This intermediate then proceeds to the esterification stage to continue reacting and produce methyl methacrylate (MMA). The crude MMA feed solution undergoes an extraction process and is then sent to a refining process, passing through a dehydration tower and an MMA product tower to obtain the final MMA product. The esterification stage typically has 4-7 esterification reactors. The first-stage reactor produces the most methyl methacrylate (MMA) and methacrylic acid (MAA). The gas phase containing MMA and MAA is sent from the top of the reactor to a separation and condensation device. The reaction liquid overflows or is pumped into the next stage reactor, and so on. The reaction liquid from other stages of the reactors also flows into the next stage reactor via overflow or pumping. MMA, MAA, and light components exit from the top gas phase pipes of each stage of the reactor and return to the first-stage reactor. Due to the need for multiple reactors and corresponding transfer pumps, the esterification process requires a relatively large footprint.

[0003] Because MAA and MMA are highly prone to polymerization, the gas phase pipes at the top of each esterification reactor are very susceptible to blockage. On the other hand, due to the acidic corrosive nature of the medium, the esterification reactor, as the main equipment in the MMA unit, is generally made of special materials. Therefore, once the pipe at the top of the reactor is blocked, it is not only difficult to clean, but if damage occurs during cleaning, the maintenance cycle is long and production is affected.

[0004] Therefore, it is very important to take effective measures to reduce the possibility of MMA and MAA polymerization at the top gas phase inlet of the esterification reactor. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing MMA production equipment, such as the large number of esterification reactors, large footprint, easy polymerization of gaseous materials in MMA equipment, and the high probability of polymerization blockage due to the gaseous outlet pipeline of each esterification reactor. This invention provides an esterification reactor for MMA production equipment.

[0006] To achieve the above objectives, this utility model provides an esterification reactor for an MMA production apparatus. The esterification reactor has a horizontal structure with a gas phase outlet and a liquid phase outlet on the shell. The shell is divided into a first chamber, a second chamber, a third chamber, and a fourth chamber that communicate with each other, for carrying out primary esterification, secondary esterification, tertiary esterification, and quaternary esterification reactions, respectively.

[0007] The first cavity is provided with an amide salt inlet and a first mixed liquid inlet; the second cavity is provided with a first methanol inlet and a second mixed liquid inlet; the third cavity is provided with a second methanol inlet; and the fourth cavity is provided with a third methanol inlet.

[0008] The volume ratio of the first cavity, the second cavity, the third cavity, and the fourth cavity is 1-2:1-1.5:1-1.2:1-1.2.

[0009] Through the above technical solution, the esterification reactor provided by this utility model is divided into four interconnected chambers within the same shell. This not only enables multi-stage esterification reactions, which is beneficial for increasing the esterification reaction rate, but also allows the gas phases of the multi-stage esterification reactions to be discharged from the same outlet, reducing the number of gas phase inlets for the esterification reaction and thus reducing the probability of blockage. At the same time, this esterification reactor also has advantages such as compact structure, small footprint, reduced length of connecting pipes between equipment, and reduced consumption of heating steam, making it suitable for the industrial production of methyl methacrylate. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of an esterification reactor structure for an MMA production unit provided by this utility model.

[0011] Explanation of reference numerals in the attached figures

[0012] 1. Shell; 1-1. First cavity; 1-2. Second cavity; 1-3. Third cavity; 1-4. Fourth cavity; 2. Amide salt inlet; 3. First mixed liquid inlet; 4. First heat medium inlet; 5. First heat medium outlet; 6. First thermometer port; 7. First upper level gauge port; 8. First lower level gauge port; 9. First manhole; 10. First partition; 11. Second heat medium inlet; 12. Second heat medium outlet; 13. First methanol inlet; 14. Second manhole; 15. Second thermometer port; 16. Second upper level gauge port; 17. Second lower level gauge port; 18. Second partition; 19. Gas phase outlet; 20. Second methanol inlet; 21. Third heat medium inlet; 22. Third heat medium outlet; 23. Third manhole; 24. Third thermometer port; 25. Third upper level gauge port; 26. 27. Third lower level gauge port; 28. Third partition plate; 29. ​​Fourth heat medium inlet; 20. Fourth heat medium outlet; 31. Third methanol inlet; 32. Fourth manhole; 33. Liquid phase outlet; 34. Fourth thermometer port; 35. Fourth upper level gauge port; 36. Fourth lower level gauge port; 37. First drain port; 38. Second drain port; 39. Third drain port; 40. Saddle; 41. First socket tube; 42. Second socket tube; 43. Third socket tube; 44. Fourth socket tube; 45. Fifth socket tube; 46. Sixth socket tube; 47. First stirrer; 48. Second stirrer; 49. Third stirrer; 50. Fourth stirrer; 51. First inner coil; 52. Second inner coil; 53. Third inner coil; 54. Fourth inner coil; 55. Second mixed liquid inlet. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] In this utility model, unless otherwise specified, "first", "second", "third" and "fourth" do not indicate a sequence or limit the various materials or steps, but are only used to distinguish or indicate that they are not the same material or step. For example, "first", "second", "third" and "fourth" in the first cavity, second cavity, third cavity and fourth cavity are only used to indicate that they are not the same cavity.

[0015] In this utility model, unless otherwise specified, the "top" of the shell refers to 0-10% of the shell from top to bottom; the "upper part" of the shell refers to 10-40% of the shell from top to bottom; the "middle part" of the shell refers to 40-60% of the shell from top to bottom; the "lower part" of the shell refers to 60-90% of the shell from top to bottom; and the "bottom" of the shell refers to 90-100% of the shell from top to bottom.

[0016] This utility model provides a schematic diagram of an esterification reactor for an MMA production unit, as shown below. Figure 1 As shown, the esterification reactor has a horizontal structure, with a gas phase outlet 19 and a liquid phase outlet 32 ​​on the shell 1. The shell 1 is divided into a first cavity 1-1, a second cavity 1-2, a third cavity 1-3 and a fourth cavity 1-4 that are in communication, for primary esterification reaction, secondary esterification reaction, tertiary esterification reaction and quaternary esterification reaction, respectively.

[0017] The first cavity 1-1 is provided with an amide salt inlet 2 and a first mixed liquid inlet 3; the second cavity 1-2 is provided with a first methanol inlet 13 and a second mixed liquid inlet 55; the third cavity 1-3 is provided with a second methanol inlet 20; and the fourth cavity 1-4 is provided with a third methanol inlet 30.

[0018] The volume ratio of the first cavity 1-1, the second cavity 1-2, the third cavity 1-3 and the fourth cavity 1-4 is 1-2:1-1.5:1-1.2:1-1.2.

[0019] In this invention, the volume ratio of the first cavity 1-1, the second cavity 1-2, the third cavity 1-3, and the fourth cavity 1-4 is 1-2:1-1.5:1-1.2:1-1.2, including but not limited to 1:1:1:1, 1:1.5:1.2:1.2, 2:1:1:1, etc. Controlling the volume ratio of each cavity within the above-mentioned preferred range not only allows for better control of the esterification reactor system temperature and improves the esterification reaction effect of methyl methacrylate, but also more effectively increases the reaction rate of methyl methacrylate.

[0020] The esterification reactor provided by this utility model not only has the advantages of fewer equipment and smaller footprint while meeting the process requirements of each stage of esterification reaction, but also reduces the number of gas phase inlets for esterification reaction, thereby reducing the probability of blockage.

[0021] In this utility model, such as Figure 1 As shown, preferably, the ratio of the length L and the inner diameter D of the housing 1 is 1.5-5:1, for example, 1.5:1, 2:1, 16:7, 3:1, 4:1, 5:1, and any value within the range of any two values.

[0022] In this utility model, such as Figure 1 As shown, the first chamber 1-1 is used to perform a primary esterification reaction on a mixture of amide salt and low-boiling-point substances to obtain a first esterified gas phase and a first esterified liquid phase; the second chamber 1-2 is used to perform a secondary esterification reaction on a mixture of the first esterified liquid phase, a high-boiling-point substance, and first methanol to obtain a second esterified gas phase and a second esterified liquid phase; the third chamber 1-3 is used to perform a tertiary esterification reaction on a mixture of the second esterified liquid phase and second methanol to obtain a third esterified gas phase and a third esterified liquid phase; the fourth chamber 1-4 is used to perform a quaternary esterification reaction on a mixture of the third esterified liquid phase and third methanol to obtain a fourth esterified gas phase and a fourth esterified liquid phase; wherein, the first esterified gas phase, the second esterified gas phase, the third esterified gas phase, and the fourth esterified gas phase are all discharged through the gas phase outlet 19; the fourth esterified liquid phase is discharged through the liquid phase outlet 32.

[0023] In this invention, the first esterification gas phase, the second esterification gas phase, the third esterification gas phase, and the fourth esterification gas phase are all discharged through the gas phase outlet 19, reducing the number of gas phase outlets for the esterification reaction and thus reducing the probability of blockage; the fourth esterification liquid phase is discharged through the liquid phase outlet 32.

[0024] In this invention, the first cavity, second cavity, third cavity, and fourth cavity are independent and do not interfere with each other. This invention does not have any particular limitations on how to obtain each independent region; conventional techniques in the field can be used.

[0025] In this utility model, such as Figure 1 As shown, preferably, the housing 1 is further provided with a first partition 10, a second partition 18, and a third partition 27. Each of the first partition 10, second partition 18, and third partition 27 is independently connected to the bottom of the housing 1 and not connected to the top of the housing 1. This arrangement ensures that the esterified liquid phase from each cavity overflows into the next cavity for esterification, and also allows the esterified gas phase from each cavity to collect and be discharged through the gas phase outlet 19, reducing the number of gas phase pipes.

[0026] In this utility model, such as Figure 1 As shown, preferably, the heights of the first partition 10, the second partition 18, and the third partition 27 are the same or different, preferably the same.

[0027] In this utility model, such as Figure 1 As shown, preferably, the ratio of the height of the first partition 10, the second partition 18 and the third partition 27 to the inner diameter D of the housing 1 is independently 0.5-0.9:1, for example, 0.5:1, 0.6:1, 0.8:1, 0.9:1, and any value within the range of any two values.

[0028] In this invention, the first chamber 1-1 is used to perform a primary esterification reaction on a mixture of amide salt material and low-boiling-point substance to obtain a first esterified gas phase and a first esterified liquid phase. The amide salt material originates from the upstream amidation process; the low-boiling-point substance mixture is selected from methanol, an aqueous phase from the extraction process, or a mixture containing methanol and MMA from the distillation process.

[0029] In this invention, preferably, in the first cavity 1-1, the methanol feed accounts for 75-90 wt% of the total methanol feed.

[0030] In this utility model, such as Figure 1 As shown, preferably, the amide salt inlet 2 and the first mixed liquid inlet 3 are each independently internally extended structures; more preferably, the amide salt inlet 2 and the first mixed liquid inlet 3 extend into the first cavity 1-1 through the first socket tube 41 and the second socket tube 42, respectively. This arrangement ensures that the amide salt-containing material and the low-boiling-point mixture are mixed uniformly, improving the mass transfer rate, thereby enabling the amide salt-containing material to cool and hydrolyze rapidly, and subsequently undergo a primary esterification reaction with methanol.

[0031] In this utility model, such as Figure 1 As shown, more preferably, the first socket tube 41 and the second socket tube 42 have the same or different lengths; wherein the vertical distance from the first socket tube 41 and the second socket tube 42 to the bottom of the housing 1 is 150-300mm, for example, 150mm, 200mm, 250mm, 300mm, or any value within the range of any two values. By adjusting the above vertical distance, it is more beneficial to improve the esterification effect of the primary esterification reaction.

[0032] In this utility model, unless otherwise specified, the vertical distance refers to the vertical distance from the bottom of the component (e.g., the bottom of the socket tube, or the bottom of the stirrer) to the bottom of the shell 1.

[0033] In this utility model, such as Figure 1 As shown, preferably, a first inner coil 51 is provided inside the first cavity 1-1, and the two ends of the first inner coil 51 are respectively connected to a first heat medium inlet 4 and a first heat medium outlet 5 provided on the first cavity 1-1.

[0034] In this invention, the temperature of the primary esterification reaction is controlled by adjusting the inlet and outlet temperatures of the first heat medium; the first heat medium includes, but is not limited to, steam, circulating water, etc.

[0035] In this utility model, such as Figure 1 As shown, more preferably, the diameter of the first inner coil 51 is 15-40mm, and the spacing between adjacent coils is 300-700mm.

[0036] In this utility model, such as Figure 1 As shown, preferably, a first stirrer 47 is provided inside the first cavity 1-1 to make the primary esterification reaction more uniform. More preferably, the first stirrer 47 is located at the center of the first cavity 1-1.

[0037] In this utility model, such as Figure 1 As shown, preferably, the first cavity 1-1 is also provided with a first thermometer port 6 for monitoring the temperature of the primary esterification reaction; more preferably, the first thermometer port 6 is located below the first stirrer 47.

[0038] In this utility model, such as Figure 1 As shown, preferably, the first cavity 1-1 is also provided with a first upper liquid level gauge 7 and a first lower liquid level gauge 8 for observing the liquid level of the internal reaction liquid; the first cavity 1-1 is also provided with a first drain port 36 for draining the internal reaction liquid when the first cavity 1-1 is not in use.

[0039] In this utility model, such as Figure 1 As shown, a first partition 10 is provided between the first cavity 1-1 and the second cavity 1-2, so that the first esterified liquid phase in the first cavity 1-1 overflows into the second cavity 1-2 along the top of the first partition 10.

[0040] In this invention, the second chamber 1-2 is used to perform a secondary esterification reaction on the first esterified liquid phase, the high-boiling mixture, and the first methanol to obtain a second esterified gas phase and a second esterified liquid phase. The high-boiling mixture is selected from a mixture containing methyl α-hydroxyisobutyrate derived from a distillation process.

[0041] In this invention, preferably, in the second cavity 1-2, the methanol feed accounts for 9-15 wt% of the total methanol feed.

[0042] In this utility model, such as Figure 1 As shown, preferably, the first methanol inlet 13 and the second mixture inlet 55 are each independently internally extended structures; more preferably, the first methanol inlet 13 and the second mixture inlet 55 extend into the second cavity 1-2 through the third socket tube 43 and the fourth socket tube 44, respectively. This arrangement ensures that the first esterification liquid phase, the first methanol, and the high-boiling-point mixture are mixed uniformly, improving the mass transfer rate and thus increasing the efficiency of the secondary esterification reaction.

[0043] In this utility model, such as Figure 1As shown, more preferably, the third socket tube 43 and the fourth socket tube 44 have the same or different lengths; wherein, the vertical distance from each of the third socket tube 43 and the fourth socket tube 44 to the bottom of the shell 1 is 150-300 mm, for example, 150 mm, 200 mm, 250 mm, 300 mm, or any value within a range of any two values. By adjusting the above vertical distance, it is more beneficial to improve the esterification effect of the secondary esterification reaction.

[0044] In this utility model, such as Figure 1 As shown, preferably, a second inner coil 52 is provided inside the second cavity 1-2, and the two ends of the second inner coil 52 are respectively connected to the second heat medium inlet 11 and the second heat medium outlet 12 provided on the second cavity 1-2.

[0045] In this invention, the temperature of the secondary esterification reaction is controlled by adjusting the inlet and outlet temperatures of the second heat medium; the second heat medium includes, but is not limited to, steam, circulating water, etc.

[0046] In this utility model, such as Figure 1 As shown, more preferably, the diameter of the second inner coil 52 is 15-40mm, and the spacing between adjacent coils is 300-700mm.

[0047] In this utility model, such as Figure 1 As shown, preferably, a second stirrer 48 is provided inside the second cavity 1-2 to make the secondary esterification reaction more uniform. More preferably, the second stirrer 48 is located at the center of the second cavity 1-2.

[0048] In this utility model, such as Figure 1 As shown, preferably, the second cavity 1-2 is further provided with a second thermometer port 15 for monitoring the temperature of the secondary esterification reaction; more preferably, the second thermometer port 15 is located below the second stirrer 48.

[0049] In this utility model, such as Figure 1 As shown, preferably, the second cavity 1-2 is also provided with a second upper liquid level gauge port 17 and a second lower liquid level gauge port 18 for observing the liquid level of the internal reaction liquid; the second cavity 1-2 is also provided with a second drain port 37 for draining the internal reaction liquid when the second cavity 1-2 is not in use.

[0050] In this utility model, such as Figure 1 As shown, a second partition 18 is provided between the second cavity 1-2 and the third cavity 1-3, so that the second esterified liquid phase in the second cavity 1-2 overflows into the third cavity 1-3 along the top of the second partition 18.

[0051] In this invention, the third chamber 1-3 is used to perform a tertiary esterification reaction on the second esterified liquid phase and the second methanol to obtain a third esterified gas phase and a third esterified liquid phase.

[0052] In this invention, preferably, the methanol feed in the third chamber 1-3 accounts for 0.5-7.5 wt% of the total methanol feed.

[0053] In this utility model, such as Figure 1 As shown, preferably, the second methanol inlet 20 is an internally extending structure; more preferably, the second methanol inlet 20 extends into the third cavity 1-3 through the fifth socket tube 45. This configuration ensures that the second esterification liquid phase and the second methanol are mixed uniformly, improving the mass transfer rate and thus increasing the efficiency of the tertiary esterification reaction.

[0054] In this utility model, such as Figure 1 As shown, more preferably, the vertical distance from the fifth socket tube 45 to the bottom of the shell 1 is 150-300 mm, for example, 150 mm, 200 mm, 250 mm, 300 mm, or any value within a range of any two values. Adjusting this vertical distance is more conducive to improving the esterification effect of the tertiary esterification reaction.

[0055] In this utility model, such as Figure 1 As shown, preferably, a third inner coil 53 is provided inside the third cavity 1-3, and the two ends of the third inner coil 53 are respectively connected to the third heat medium inlet 21 and the third heat medium outlet 22 provided on the third cavity 1-3.

[0056] In this invention, the temperature of the tertiary esterification reaction is controlled by adjusting the inlet and outlet temperatures of the third heat medium; the third heat medium includes, but is not limited to, steam, circulating water, etc.

[0057] In this utility model, such as Figure 1 As shown, more preferably, the diameter of the third inner coil 53 is 15-40mm, and the spacing between adjacent coils is 300-700mm.

[0058] In this utility model, such as Figure 1 As shown, preferably, a third stirrer 49 is provided in the third cavity 1-3 to make the tertiary esterification reaction more uniform. More preferably, the third stirrer 49 is located at the center of the third cavity 1-3.

[0059] In this utility model, such as Figure 1As shown, preferably, the third chamber 1-3 is also provided with a third thermometer port 24 for monitoring the temperature of the tertiary esterification reaction; more preferably, the third thermometer port 24 is located below the third stirrer 49.

[0060] In this utility model, such as Figure 1 As shown, preferably, the third chamber 1-3 is further provided with a third upper liquid level gauge 25 and a third lower liquid level gauge 26 for observing the liquid level of the internal reaction liquid; the third chamber 1-3 is also provided with a third drain port 38 for draining the internal reaction liquid when the third chamber 1-3 is not in use.

[0061] In this utility model, such as Figure 1 As shown, a third partition 27 is provided between the third cavity 1-3 and the fourth cavity 1-4, so that the third esterified liquid phase in the third cavity 1-3 overflows into the fourth cavity 1-4 along the top of the third partition 27.

[0062] In this invention, the fourth chamber 1-4 is used to carry out a tertiary esterification reaction between the third esterification liquid phase and the third methanol to obtain the third esterification gas phase and the third esterification liquid phase.

[0063] In this invention, preferably, the methanol feed in the fourth chamber 1-4 accounts for 0.5-2.5 wt% of the total methanol feed.

[0064] In this utility model, such as Figure 1 As shown, preferably, the third methanol inlet 30 is an internally extending structure; more preferably, the third methanol inlet 30 extends into the fourth cavity 1-4 through the sixth socket tube 46. This arrangement ensures that the third esterification liquid phase and the third methanol are mixed uniformly, improving the mass transfer rate and thus increasing the efficiency of the fourth-stage esterification reaction.

[0065] In this utility model, such as Figure 1 As shown, more preferably, the vertical distance from the sixth socket tube 46 to the bottom of the shell 1 is 150-300 mm, for example, 150 mm, 200 mm, 250 mm, 300 mm, or any value within a range of any two values. By adjusting the above vertical distance, it is more beneficial to improve the esterification effect of the fourth-stage esterification reaction.

[0066] In this utility model, such as Figure 1 As shown, preferably, a fourth inner coil 54 is provided inside the fourth cavity 1-4, and the two ends of the fourth inner coil 54 are respectively connected to the fourth heat medium inlet 28 and the fourth heat medium outlet 29 provided on the fourth cavity 1-4.

[0067] In this invention, the temperature of the fourth-stage esterification reaction is controlled by adjusting the inlet and outlet temperatures of the fourth heat medium; the fourth heat medium includes, but is not limited to, steam, circulating water, etc.

[0068] In this utility model, such as Figure 1 As shown, more preferably, the diameter of the fourth inner coil 54 is 15-40mm, and the spacing between adjacent coils is 300-700mm.

[0069] In this utility model, such as Figure 1 As shown, preferably, a fourth stirrer 50 is provided in the fourth cavity 1-4 to make the four-stage esterification reaction more uniform. More preferably, the fourth stirrer 50 is located at the center of the fourth cavity 1-4.

[0070] In this utility model, such as Figure 1 As shown, preferably, the fourth chamber 1-4 is further provided with a fourth thermometer port 33 for monitoring the temperature of the fourth-stage esterification reaction; more preferably, the fourth thermometer port 33 is located below the fourth stirrer 50.

[0071] In this utility model, such as Figure 1 As shown, preferably, the fourth chamber 1-4 is also provided with a fourth upper liquid level gauge 34 and a fourth lower liquid level gauge 35 for observing the liquid level of the internal reaction liquid; the fourth chamber 1-4 is also provided with a fourth drain port 39 for draining the internal reaction liquid when the fourth chamber 1-4 is not in use.

[0072] In this utility model, such as Figure 1 As shown, the gas phase outlet 19 is located at the top center of the housing 1 and is used to discharge the esterified gas phase generated by the esterification reaction in each chamber.

[0073] In this utility model, such as Figure 1 As shown, a saddle 40 is provided at the bottom of the shell 1 for supporting the esterification reactor; the first cavity 1-1 is provided with a first manhole 9, the second cavity 1-2 is provided with a second manhole 14, the third cavity 1-3 is provided with a third manhole 23, and the fourth cavity 1-4 is provided with a fourth manhole for subsequent inspection and maintenance of each cavity.

[0074] The present invention will be described in detail below through embodiments.

[0075] Example 1

[0076] like Figure 1As shown, the esterification reactor has a horizontal structure. The inner diameter D of the shell 1 is 3.5m and the length L is 8m. The shell 1 is equipped with a first partition 10, a second partition 18 and a third partition 27, which are divided into a first cavity 1-1, a second cavity 1-2, a third cavity 1-3 and a fourth cavity 1-4 with a volume ratio of 1:1:1:1.

[0077] The heights of the first partition 10, the second partition 18, and the third partition 27 are all 2.1m;

[0078] The top of the first cavity 1-1 is provided with an amide salt inlet 2 generated from the amidation process, which extends into the cavity through the first socket tube 41. A mixture of methanol, aqueous phase from the extraction process, and low-boiling liquid containing methanol and MMA from the distillation process is provided with a first mixture inlet 3, which extends into the cavity through the second socket tube 42. The ends of the first socket tube 41 and the second socket tube 42 are on the same plane, and the vertical distance from the first socket tube 41 and the second socket tube 42 to the bottom of the shell 1 is 200mm, which allows the 130℃ amide salt to be rapidly cooled, hydrolyzed, and reacted with methanol to obtain the first esterified gas phase and the first esterified liquid phase.

[0079] The first chamber 1-1 is equipped with a first inner coil 51 with a coil diameter of 25 mm and a coil spacing of 500 mm. Steam is introduced to control the reaction temperature. The first thermometer 6 is used to maintain the primary esterification reaction temperature at 90°C. The vertical distance from the first stirrer 47 to the bottom of the shell 1 is 250 mm. The first upper liquid level gauge 7 and the first lower liquid level gauge 8 are used to observe the liquid level inside the chamber.

[0080] The second cavity 1-2 is provided with a first methanol inlet 13 at the top, which extends into the cavity through a third socket tube 43; and a high-boiling mixture containing methyl α-hydroxyisobutyrate from the distillation process is provided with a second mixture inlet 55, which extends into the cavity through a fourth socket tube 44; the ends of the third socket tube 43 and the fourth socket tube 44 are on the same plane, and the vertical distance from the third socket tube 43 and the fourth socket tube 44 to the bottom of the shell 1 is 200mm respectively;

[0081] The second chamber 1-2 is equipped with a second inner coil 52 with a coil diameter of 25 mm and a coil spacing of 500 mm. Steam is introduced to control the reaction temperature. The second thermometer 15 is used to maintain the secondary esterification reaction temperature at 100°C. The vertical distance from the second stirrer 48 to the bottom of the shell 1 is 250 mm. The second upper liquid level gauge 16 and the second lower liquid level gauge 17 are used to observe the liquid level inside the chamber.

[0082] The third chamber 1-3 is equipped with a second methanol inlet 20 at the top, which extends into the chamber through a fifth socket tube 45; inside is a third inner coil 53 with a diameter of 25 mm and a coil spacing of 500 mm. Steam is introduced to control the reaction temperature. The third thermometer 24 is used to maintain the tertiary esterification reaction temperature at 110°C. The vertical distance from the third stirrer 49 to the bottom of the shell 1 is 250 mm. The third upper liquid level gauge 25 and the third lower liquid level gauge 26 are used to observe the liquid level inside the chamber.

[0083] The fourth chamber 1-4 is equipped with a third methanol inlet 30 at the top, which extends into the chamber through a sixth socket tube 46; inside is a fourth inner coil 54 with a coil diameter of 25 mm and a coil spacing of 500 mm. Steam is introduced to control the reaction temperature. The fourth-stage esterification reaction temperature is maintained at 120°C by a third thermometer 33. The vertical distance from the fourth stirrer 50 to the bottom of the shell 1 is 250 mm. The fourth upper liquid level gauge 34 and the fourth lower liquid level gauge 35 are used to observe the liquid level inside the chamber.

[0084] In the four chambers mentioned above, the mass ratio of methanol feed is 80:15:3:2. The esterified gas phase generated in the four chambers is discharged through the gas phase outlet 19, and the fourth esterified liquid phase obtained in the fourth chamber is discharged through the liquid phase outlet 32.

[0085] Compared to the multi-stage esterification reactors used in traditional esterification processes, the esterification reactor provided by this invention can reduce the floor space by 7m². 2 The number of gas phase pipelines was reduced by more than 3, with a length of 10m, and the probability of blockage at the gas phase pipeline inlet was reduced by 25%-35%.

[0086] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed by this utility model and are all within the protection scope of this utility model.

Claims

1. An esterification reactor for an MMA production unit, characterized in that, The esterification reactor is a horizontal structure with a gas phase outlet (19) and a liquid phase outlet (32) on the shell (1). The shell (1) is divided into a first cavity (1-1), a second cavity (1-2), a third cavity (1-3) and a fourth cavity (1-4) that are connected to each other, and respectively carry out first-stage esterification reaction, second-stage esterification reaction, third-stage esterification reaction and fourth-stage esterification reaction. The first chamber (1-1) is provided with an amide salt inlet (2) and a first mixed liquid inlet (3); the second chamber (1-2) is provided with a first methanol inlet (13) and a second mixed liquid inlet (55); the third chamber (1-3) is provided with a second methanol inlet (20); and the fourth chamber (1-4) is provided with a third methanol inlet (30). The volume ratio of the first cavity (1-1), the second cavity (1-2), the third cavity (1-3), and the fourth cavity (1-4) is 1-2:1-1.5:1-1.2:1-1.

2.

2. The esterification reactor according to claim 1, characterized in that, The ratio of the length L to the inner diameter D of the shell (1) is 1.5-5:1; The first chamber (1-1) is used to carry out a primary esterification reaction of the mixture containing amide salt and low-boiling substances to obtain a first esterified gas phase and a first esterified liquid phase; The second chamber (1-2) is used to carry out a secondary esterification reaction of the first esterified liquid phase, the high-boiling mixture and the first methanol to obtain the second esterified gas phase and the second esterified liquid phase; The third chamber (1-3) is used to carry out a tertiary esterification reaction of the second esterified liquid phase and the second methanol to obtain a third esterified gas phase and a third esterified liquid phase; The fourth chamber (1-4) is used to carry out a fourth-stage esterification reaction between the third esterification liquid phase and the third methanol to obtain a fourth esterification gas phase and a fourth esterification liquid phase; The first esterification gas phase, the second esterification gas phase, the third esterification gas phase and the fourth esterification gas phase are all discharged through the gas phase outlet (19); the fourth esterification liquid phase is discharged through the liquid phase outlet (32).

3. The esterification reactor according to claim 1, characterized in that, The housing (1) is further provided with a first partition (10), a second partition (18) and a third partition (27). The first partition (10), the second partition (18) and the third partition (27) are each independently connected to the bottom of the housing (1) and are not connected to the top of the housing (1). The ratio of the height of the first partition (10), the second partition (18) and the third partition (27) to the inner diameter D of the shell (1) is independently 0.5-0.9:

1.

4. The esterification reactor according to claim 1, characterized in that, The amide salt inlet (2) and the first mixed liquid inlet (3) are each independently an internal extension structure; The first methanol inlet (13) and the second mixture inlet (55) are each independently an internal structure; The second methanol inlet (20) has an internal extension structure; The third methanol inlet (30) is an internal structure.

5. The esterification reactor according to claim 4, characterized in that, The amide salt inlet (2) and the first mixed liquid inlet (3) extend into the first cavity (1-1) through the first socket tube (41) and the second socket tube (42), respectively; The first methanol inlet (13) and the second mixture inlet (55) extend into the second cavity (1-2) through the third socket tube (43) and the fourth socket tube (44), respectively; The second methanol inlet (20) extends into the third cavity (1-3) through the fifth socket tube (45); The third methanol inlet (30) extends into the fourth cavity (1-4) through the sixth socket tube (46).

6. The esterification reactor according to claim 5, characterized in that, The vertical distances from the first socket (41), the second socket (42), the third socket (43), the fourth socket (44), the fifth socket (45) and the sixth socket (46) to the bottom of the housing (1) are each 150-300 mm.

7. The esterification reactor according to claim 1, characterized in that, The first cavity (1-1) is provided with a first inner coil (51), and the two ends of the first inner coil (51) are respectively connected to the first heat medium inlet (4) and the first heat medium outlet (5) provided on the first cavity (1-1). The second cavity (1-2) is provided with a second inner coil (52), and the two ends of the second inner coil (52) are respectively connected to the second heat medium inlet (11) and the second heat medium outlet (12) provided on the second cavity (1-2). The third cavity (1-3) is provided with a third inner coil (53), and the two ends of the third inner coil (53) are respectively connected to the third heat medium inlet (21) and the third heat medium outlet (22) provided on the third cavity (1-3). The fourth cavity (1-4) is provided with a fourth inner coil (54), and the two ends of the fourth inner coil (54) are respectively connected to the fourth heat medium inlet (28) and the fourth heat medium outlet (29) provided on the fourth cavity (1-4).

8. The esterification reactor according to claim 1, characterized in that, A first stirrer (47) is provided inside the first cavity (1-1); A second stirrer (48) is provided inside the second cavity (1-2); A third stirrer (49) is provided inside the third cavity (1-3). The fourth chamber (1-4) is equipped with a fourth stirrer (50). The vertical distance from the first stirrer (47), the second stirrer (48), the third stirrer (49) and the fourth stirrer (50) to the bottom of the shell is 200-300mm.

9. The esterification reactor according to claim 8, characterized in that, The first cavity (1-1) is also provided with a first thermometer port (6), a first upper liquid level port (7), a first lower liquid level port (8) and a first drain port (36); wherein, the first thermometer port (6) is located below the first stirrer (47); The second cavity (1-2) is also provided with a second thermometer port (15), a second upper liquid level port (16), a second lower liquid level port (17) and a second drain port (37); wherein, the second thermometer port (15) is located below the second stirrer (48); The third cavity (1-3) is also provided with a third thermometer port (24), a third upper liquid level port (25), a third lower liquid level port (26) and a third drain port (38); wherein, the third thermometer port (24) is located below the third stirrer (49); The fourth chamber (1-4) is also provided with a fourth thermometer port (33), a fourth upper liquid level port (34), a fourth lower liquid level port (35) and a fourth drain port (39); wherein the fourth thermometer port (33) is located below the fourth stirrer (50).

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