Preparation system of ethylene glycol tert-butyl ether acetate

Abstract

The utility model discloses a preparation system of ethylene glycol tert-butyl ether acetate. The preparation system comprises a feeding device, a reaction device, a first rectification device, a second rectification device, a third rectification device and a fourth rectification device, the system adopts strong base as a catalyst to carry out ester exchange on ethylene glycol tert-butyl ether and ethyl acetate, the reaction product ethanol is separated out of the reaction system by utilizing the characteristic that ethyl acetate and ethanol are azeotropic, then ethyl acetate and ethanol are separated through pressure swing distillation, ethyl acetate is recycled, and ethyl acetate is recycled. After refining, not only is an ethylene glycol tert-butyl ether acetate product obtained, but also a byproduct ethanol is obtained; the device disclosed by the utility model avoids the problem that ethylene glycol tert-butyl ether is decomposed when the traditional strong acid is used as a catalyst for esterification, effectively inhibits the generation of side reactions and byproducts, and realizes the preparation of high-purity ethylene glycol tert-butyl ether acetate.

Description

Technical Field

[0001] This utility model relates to the field of ethylene glycol tert-butyl ether acetate preparation technology, and specifically to a preparation system for ethylene glycol tert-butyl ether acetate. Background Technology

[0002] Esterification generally refers to the process by which alcohols or phenols react with oxygen-containing organic or inorganic acids in the presence of a catalyst to form esters and water, i.e., the introduction of an acyl group onto the oxygen atom of the hydroxyl group of the alcohol or phenol. Esterification methods mainly include direct esterification of acids with alcohols or phenols, esterification of acid derivatives with alcohols, transesterification of esters with alcohols (or acids, esters), and esterification of ketones with alcohols. For the esterification of alcohols and carboxylic acids, strong acids are usually used as catalysts, and the produced water is continuously removed during the reaction to achieve a high conversion rate. However, for the preparation of ethylene glycol tert-butyl ether acetate, the reactant ethylene glycol tert-butyl ether has a tert-butyl ether structure, which is unstable in acid and decomposes into isobutylene and the corresponding alcohol under acidic conditions. Therefore, the traditional method of using strong acids as catalysts and esterifying ethylene glycol tert-butyl ether with acetic acid to prepare ethylene glycol tert-butyl ether acetate not only results in a low effective conversion rate but also produces many byproducts, which is detrimental to the subsequent purification process. Utility Model Content

[0003] In view of this, the present invention aims to provide a preparation system for ethylene glycol tert-butyl ether acetate, which can avoid the decomposition of ethylene glycol tert-butyl ether during esterification, achieve a high efficiency conversion rate, and obtain high-purity ethylene glycol tert-butyl ether acetate.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] This invention provides a system for preparing ethylene glycol tert-butyl ether acetate, comprising a feeding device, a reaction device, a first distillation device, a second distillation device, a third distillation device, and a fourth distillation device;

[0006] The feeding device includes a first feed pump, a second feed pump, a first mixing tank, and a first heat exchanger; the reaction device includes a reactor feed pump, a heater, a fixed-bed reactor, a cooler, and a reaction liquid tank; the first distillation device includes a first distillation column feed pump, a first distillation column, a first condenser, a first reflux tank, a first reflux pump, a first top discharge pump, a first reboiler, a first bottom discharge pump, and a second mixing tank; the second distillation device includes a second distillation column feed pump, a second distillation column, a second condenser, a second reflux tank, a second reflux pump, a second top discharge pump, a second reboiler, and a second bottom discharge pump; the third distillation device includes a third distillation column, a third condenser, a third reflux tank, a third reflux pump, a third top discharge pump, a third reboiler, and a third bottom discharge pump; the fourth distillation device includes a fourth distillation column, a fourth condenser, a vacuum pump, a fourth reflux tank, a fourth reflux pump, a fourth top discharge pump, a fourth reboiler, a fourth bottom discharge pump, and a second heat exchanger;

[0007] The first feed pump is connected to the first mixing tank, the second feed pump is connected to the first heat exchanger, the first heat exchanger is connected to the first mixing tank, the first mixing tank is connected to the heater via the reactor feed pump, the heater is connected to the fixed-bed reactor, the fixed-bed reactor is connected to the cooler, the cooler is connected to the reaction liquid tank, the reaction liquid tank is connected to the first distillation column via the first distillation column feed pump, the upper end of the first distillation column is connected to the first condenser, the first condenser is connected to the upper end of the first reflux tank, the first reflux tank is connected to the first reflux pump and the first column top discharge pump, the first reflux pump is connected to the upper part of the first distillation column, the first column top discharge pump is connected to the second mixing tank, one end of the first reboiler is connected to the bottom of the first distillation column, and the other end is connected to the bottom pipe of the first distillation column and the first column bottom discharge pump, the first column bottom discharge pump is connected to the first heat exchanger;

[0008] The second mixing tank is connected to the second distillation column via a second distillation column feed pump. The upper end of the second distillation column is connected to the second condenser. The second condenser is connected to the upper end of the second reflux tank. The second reflux tank is connected to the second reflux pump and the second column top discharge pump. The second reflux pump is connected to the upper part of the second distillation column. The second column top discharge pump is connected to the third distillation column. One end of the second reboiler is connected to the bottom of the second distillation column, and the other end is connected to the bottom pipe of the second distillation column and the second column bottom discharge pump. The second column bottom discharge pump is connected to the third reboiler.

[0009] The upper end of the third distillation column is connected to the third condenser, the third condenser is connected to the upper end of the third reflux tank, the third reflux tank is connected to the third reflux pump and the third column top discharge pump, the third reflux pump is connected to the upper part of the third distillation column, the third column top discharge pump is connected to the second mixing tank, one end of the third reboiler is connected to the bottom of the third distillation column, and the other end is connected to the bottom pipe of the third distillation column and the third column bottom discharge pump, and the third reboiler is also connected to the first mixing tank;

[0010] The first heat exchanger is connected to the fourth distillation column, the upper end of the fourth distillation column is connected to the fourth condenser, the fourth condenser is connected to the vacuum pump and the upper end of the fourth reflux tank, the fourth reflux tank is connected to the fourth reflux pump and the fourth column top discharge pump, the fourth reflux pump is connected to the upper part of the fourth distillation column, the fourth column top discharge pump is connected to the second heat exchanger, one end of the fourth reboiler is connected to the bottom of the fourth distillation column, and the other end is connected to the bottom pipe of the fourth distillation column and the fourth column bottom discharge pump, the fourth column bottom discharge pump is connected to the second heat exchanger, and the second heat exchanger is connected to the first mixing tank.

[0011] Furthermore, the fixed-bed reactor is filled with a strong base catalyst.

[0012] The beneficial effects of this utility model are as follows:

[0013] (1) The fixed-bed reactor and distillation column used in this utility model are simple to operate continuously and are suitable for large-scale continuous production.

[0014] (2) This invention performs transesterification under the action of an alkaline catalyst, which avoids the decomposition of ethylene glycol tert-butyl ether during esterification under acidic conditions, effectively suppresses the generation of side reactions and by-products, and is beneficial to the separation process after the reaction, thereby obtaining a high-purity product. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the preparation system of ethylene glycol tert-butyl ether acetate according to the present invention;

[0016] The components include: 1. First feed pump; 2. First mixing tank; 3. Second feed pump; 4. First heat exchanger; 5. Reactor feed pump; 6. Heater; 7. Fixed-bed reactor; 8. Cooler; 9. Reaction liquid tank; 10. First distillation column feed pump; 11. First distillation column; 12. First condenser; 13. First reflux tank; 14. First reflux pump; 15. First column top discharge pump; 16. First reboiler; 17. First column bottom discharge pump; 18. Second mixing tank; 19. Second distillation column feed pump; 20. Second distillation column; 21. Second condenser; 22. Second... Reflux tank; 23. Second reflux pump; 24. Second top discharge pump; 25. Second reboiler; 26. Second bottom discharge pump; 27. Third distillation column; 28. Third condenser; 29. ​​Third reflux tank; 30. Third reflux pump; 31. Third top discharge pump; 32. Third reboiler; 33. Third bottom discharge pump; 34. Fourth distillation column; 35. Fourth condenser; 36. Vacuum pump; 37. Fourth reflux tank; 38. Fourth reflux pump; 39. Fourth top discharge pump; 40. Fourth reboiler; 41. Fourth bottom discharge pump; 42. Second heat exchanger. Detailed Implementation

[0017] To provide a more detailed understanding of the features and technical content of this utility model, the implementation of this utility model will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit this utility model.

[0018] like Figure 1 As shown in the figure, an embodiment of the present invention provides a preparation system for ethylene glycol tert-butyl ether acetate, which includes a feeding device, a reaction device, a first distillation device, a second distillation device, a third distillation device, and a fourth distillation device.

[0019] The feeding device includes a first raw material pump 1, a second raw material pump 3, a first mixing tank 2, and a first heat exchanger 4.

[0020] The reaction apparatus includes a reactor feed pump 5, a heater 6, a fixed-bed reactor 7, a cooler 8, and a reaction liquid tank 9.

[0021] The first distillation apparatus includes a first distillation column feed pump 10, a first distillation column 11, a first condenser 12, a first reflux tank 13, a first reflux pump 14, a first column top discharge pump 15, a first reboiler 16, a first column bottom discharge pump 17, and a second mixing tank 18.

[0022] The second distillation apparatus includes a second distillation column feed pump 19, a second distillation column 20, a second condenser 21, a second reflux tank 22, a second reflux pump 23, a second column top discharge pump 24, a second reboiler 25, and a second column bottom discharge pump 26.

[0023] The third distillation unit includes a third distillation column 27, a third condenser 28, a third reflux tank 29, a third reflux pump 30, a third top discharge pump 31, a third reboiler 32, and a third bottom discharge pump 33.

[0024] The fourth distillation unit includes a fourth distillation column 34, a fourth condenser 35, a vacuum pump 36, a fourth reflux tank 37, a fourth reflux pump 38, a fourth column top discharge pump 39, a fourth reboiler 40, a fourth column bottom discharge pump 41, and a second heat exchanger 42.

[0025] The first feed pump 1 and the second feed pump 3 are respectively connected to external ethyl acetate feed and ethylene glycol tert-butyl ether feed. The first feed pump 1 is connected to the first mixing tank 2, and the second feed pump 3 is connected to the first heat exchanger 4. The first heat exchanger 4 is connected to the first mixing tank 2. The first mixing tank 2 is connected to the heater 6 via the reactor feed pump 5. The heater 6 is connected to the fixed-bed reactor 7. The fixed-bed reactor 7 is connected to the cooler 8. The cooler 8 is connected to the reaction liquid tank 9. The reaction liquid tank 9 is connected to the first distillation column 1 via the first distillation column feed pump 10. 1. Connection: The upper end of the first distillation column 11 is connected to the first condenser 12. The first condenser 12 is connected to the upper end of the first reflux tank 13. The first reflux tank 13 is connected to the first reflux pump 14 and the first top discharge pump 15. The first reflux pump 14 is connected to the upper part of the first distillation column 11. The first top discharge pump 15 is connected to the second mixing tank 18. One end of the first reboiler 16 is connected to the bottom of the first distillation column 11, and the other end is connected to the bottom pipe of the first distillation column 11 and the first bottom discharge pump 17. The first bottom discharge pump 17 is connected to the first heat exchanger 4.

[0026] The second mixing tank 18 is connected to the second distillation column 20 via the second distillation column feed pump 19. The upper end of the second distillation column 20 is connected to the second condenser 21. The second condenser 21 is connected to the upper end of the second reflux tank 22. The second reflux tank 22 is connected to the second reflux pump 23 and the second column top discharge pump 24. The second reflux pump 23 is connected to the upper part of the second distillation column 20. The second column top discharge pump 24 is connected to the third distillation column 27. One end of the second reboiler 25 is connected to the bottom of the second distillation column 20, and the other end is connected to the bottom pipe of the second distillation column 20 and the second column bottom discharge pump 26. The second column bottom discharge pump 26 is connected to the third reboiler 32.

[0027] The upper end of the third distillation column 27 is connected to the third condenser 28, the third condenser 28 is connected to the upper end of the third reflux tank 29, the third reflux tank 29 is connected to the third reflux pump 30 and the third column top discharge pump 31 respectively, the third reflux pump 30 is connected to the upper part of the third distillation column 27, the third column top discharge pump 31 is connected to the second mixing tank 18, one end of the third reboiler 32 is connected to the bottom of the third distillation column 27, and the other end is connected to the bottom pipe of the third distillation column 27 and the third column bottom discharge pump 33 respectively, and the third reboiler 32 is also connected to the first mixing tank 2.

[0028] The first heat exchanger 4 is connected to the fourth distillation column 34. The upper end of the fourth distillation column 34 is connected to the fourth condenser 35. The fourth condenser 35 is connected to the upper end of the vacuum pump 36 and the fourth reflux tank 37. The fourth reflux tank 37 is connected to the fourth reflux pump 38 and the fourth column top discharge pump 39. The fourth reflux pump 38 is connected to the upper part of the fourth distillation column 34. The fourth column top discharge pump 39 is connected to the second heat exchanger 42. One end of the fourth reboiler 40 is connected to the bottom of the fourth distillation column 34, and the other end is connected to the bottom pipe of the fourth distillation column 34 and the fourth column bottom discharge pump 41. The fourth column bottom discharge pump 41 is connected to the second heat exchanger 42. The second heat exchanger 42 is also connected to the first mixing tank 2.

[0029] The fixed-bed reactor 7 is filled with a strong base catalyst.

[0030] The specific working principle of this utility model is as follows:

[0031] Ethyl acetate feedstock is fed into the first mixing tank 2 via the first feedstock pump 1. Ethyl glycol tert-butyl ether feedstock is fed into the first heat exchanger 4 via the second feedstock pump 3, where it is preheated by exchanging heat with the material from the first bottom discharge pump 17 before entering the first mixing tank 2. Additionally, the first mixing tank 2 has two recycled materials: one from the material from the second bottom discharge pump 26 after being cooled by the third reboiler 32, and the other from the material from the fourth bottom discharge pump 41 after being preheated by the second heat exchanger 42. These four materials are mixed in the first mixing tank 2 and then fed into the heater 6 via the reactor feed pump 5. After heating, ethyl acetate and ethylene glycol tert-butyl ether undergo transesterification in a fixed-bed reactor 7 packed with a strong base catalyst, reacting to produce ethanol and ethylene glycol tert-butyl ether acetate. The resulting reaction solution is cooled by the cooler 8 before entering the reaction solution tank 9.

[0032] The reaction liquid in reaction tank 9 is fed into the first distillation column 11 by the first distillation column feed pump 10, where it undergoes distillation. The first distillation column 11 operates at atmospheric pressure. The vaporous mixture of ethanol and ethyl acetate at the top of the column is condensed by the first condenser 12 and enters the first reflux tank 13. Then, part of it is returned to the first distillation column 11 as reflux liquid by the first reflux pump 14, and the remaining part is sent to the second mixing tank 18 by the first column top discharge pump 15. Part of the liquid mixture of ethylene glycol tert-butyl ether and ethylene glycol tert-butyl ether acetate at the bottom of the column is heated and vaporized by the first reboiler 16 and returned to the first distillation column 11. The remaining part is sent to the first heat exchanger 4 by the first column bottom discharge pump 17, where it is cooled by heat exchange with the second feed pump 3 and then enters the fourth distillation column 34.

[0033] The ethanol and ethyl acetate mixture in the second mixing tank 18 is mixed with the material from the bottom discharge pump 33 of the third column, and then fed into the second distillation column 20 by the second distillation column feed pump 19, where it undergoes distillation. The second distillation column 20 is pressurized. The vaporous ethanol and ethyl acetate azeotrope at the top of the column is condensed by the second condenser 21 and enters the second reflux tank 22. Part of it is then returned to the second distillation column 20 as reflux liquid by the second reflux pump 23, and the remainder is sent to the third distillation column 27 by the top discharge pump 24. The liquid ethyl acetate at the bottom of the column is heated and vaporized by the second reboiler 25 and returned to the second distillation column 20. The remainder is sent to the third reboiler 32 by the second bottom discharge pump 26 to exchange heat with the material at the bottom of the third distillation column 27 and be cooled, and then returned to the first mixing tank 2.

[0034] The material from the second column top discharge pump 24 is fed into the third distillation column 27, where it undergoes distillation. The third distillation column 27 operates at atmospheric pressure. The vaporous ethanol and ethyl acetate azeotrope at the top of the column is condensed by the third condenser 28 and enters the third reflux tank 29. Part of it is then returned to the third distillation column 27 as reflux liquid by the third reflux pump 30, while the remaining part is returned to the second mixing tank 18 by the third column top discharge pump 31. The liquid ethanol at the bottom of the column exchanges heat with the material from the second column bottom discharge pump 26 in the third reboiler 32, is heated and vaporized, and then returns to the third distillation column 27. The remaining part is sent out of the system as an ethanol byproduct by the third column bottom discharge pump 33.

[0035] The mixture of ethylene glycol tert-butyl ether and ethylene glycol tert-butyl ether acetate from the first bottom discharge pump 17 exchanges heat with ethylene glycol tert-butyl ether from the second feed pump 3 in the first heat exchanger 4. After being cooled, the mixture enters the fourth distillation column 34 for distillation. The fourth distillation column 34 operates under reduced pressure, with negative pressure provided by vacuum pump 36. The vaporous mixture of ethylene glycol tert-butyl ether and ethylene glycol tert-butyl ether acetate at the top of the column is condensed by the fourth condenser 35 and enters the fourth reflux tank 37. Part of it is then returned to the fourth distillation column 34 as reflux liquid by the fourth reflux pump 38, while the remaining part is sent to the second heat exchanger 42 by the fourth column top discharge pump 39. In the second heat exchanger 42, it is preheated by exchanging heat with the hot material from the fourth column bottom discharge pump 41 and then returned to the first mixing tank 2. Part of the liquid ethylene glycol tert-butyl ether acetate at the bottom of the column is heated and vaporized by the fourth reboiler 40 and returned to the fourth distillation column 34. The remaining part is sent to the second heat exchanger 42 by the fourth column bottom discharge pump 41 and is cooled by exchanging heat with the cold material from the fourth column top discharge pump 39. Finally, it is sent out of the system as the ethylene glycol tert-butyl ether acetate product.

[0036] The fixed-bed reactor and distillation column used in this invention are simple to operate continuously and are suitable for large-scale continuous production. Furthermore, this invention performs transesterification under the action of an alkaline catalyst, which avoids the decomposition of ethylene glycol tert-butyl ether during esterification under acidic conditions, effectively suppresses the generation of side reactions and byproducts, and facilitates the separation process after the reaction, thereby obtaining a high-purity product.

[0037] Here, the specific models of the devices mentioned above are not limited or described in detail, and the in-depth connection methods of the devices mentioned above are not described in detail, as they are common knowledge and can be understood by those skilled in the art.

[0038] This utility model embodiment is merely an illustration of its specific implementation and is not intended to limit its scope of protection. Those skilled in the art can make certain modifications based on this embodiment; therefore, all equivalent changes or modifications made in accordance with the scope of this utility model patent claim fall within the scope of this utility model patent claim.

Claims

1. A system for preparing ethylene glycol tert-butyl ether acetate, characterized in that, It includes a feeding device, a reaction device, a first distillation unit, a second distillation unit, a third distillation unit, and a fourth distillation unit; The feeding device includes a first feed pump, a second feed pump, a first mixing tank, and a first heat exchanger; the reaction device includes a reactor feed pump, a heater, a fixed-bed reactor, a cooler, and a reaction liquid tank; the first distillation device includes a first distillation column feed pump, a first distillation column, a first condenser, a first reflux tank, a first reflux pump, a first top discharge pump, a first reboiler, a first bottom discharge pump, and a second mixing tank; the second distillation device includes a second distillation column feed pump, a second distillation column, a second condenser, a second reflux tank, a second reflux pump, a second top discharge pump, a second reboiler, and a second bottom discharge pump; the third distillation device includes a third distillation column, a third condenser, a third reflux tank, a third reflux pump, a third top discharge pump, a third reboiler, and a third bottom discharge pump; the fourth distillation device includes a fourth distillation column, a fourth condenser, a vacuum pump, a fourth reflux tank, a fourth reflux pump, a fourth top discharge pump, a fourth reboiler, a fourth bottom discharge pump, and a second heat exchanger; The first feed pump is connected to the first mixing tank, the second feed pump is connected to the first heat exchanger, the first heat exchanger is connected to the first mixing tank, the first mixing tank is connected to the heater via the reactor feed pump, the heater is connected to the fixed-bed reactor, the fixed-bed reactor is connected to the cooler, the cooler is connected to the reaction liquid tank, the reaction liquid tank is connected to the first distillation column via the first distillation column feed pump, the upper end of the first distillation column is connected to the first condenser, the first condenser is connected to the upper end of the first reflux tank, the first reflux tank is connected to the first reflux pump and the first column top discharge pump, the first reflux pump is connected to the upper part of the first distillation column, the first column top discharge pump is connected to the second mixing tank, one end of the first reboiler is connected to the bottom of the first distillation column, and the other end is connected to the bottom pipe of the first distillation column and the first column bottom discharge pump, the first column bottom discharge pump is connected to the first heat exchanger; The second mixing tank is connected to the second distillation column via a second distillation column feed pump. The upper end of the second distillation column is connected to the second condenser. The second condenser is connected to the upper end of the second reflux tank. The second reflux tank is connected to the second reflux pump and the second column top discharge pump. The second reflux pump is connected to the upper part of the second distillation column. The second column top discharge pump is connected to the third distillation column. One end of the second reboiler is connected to the bottom of the second distillation column, and the other end is connected to the bottom pipe of the second distillation column and the second column bottom discharge pump. The second column bottom discharge pump is connected to the third reboiler. The upper end of the third distillation column is connected to the third condenser, the third condenser is connected to the upper end of the third reflux tank, the third reflux tank is connected to the third reflux pump and the third column top discharge pump, the third reflux pump is connected to the upper part of the third distillation column, the third column top discharge pump is connected to the second mixing tank, one end of the third reboiler is connected to the bottom of the third distillation column, and the other end is connected to the bottom pipe of the third distillation column and the third column bottom discharge pump, and the third reboiler is also connected to the first mixing tank; The first heat exchanger is connected to the fourth distillation column, the upper end of the fourth distillation column is connected to the fourth condenser, the fourth condenser is connected to the vacuum pump and the upper end of the fourth reflux tank, the fourth reflux tank is connected to the fourth reflux pump and the fourth column top discharge pump, the fourth reflux pump is connected to the upper part of the fourth distillation column, the fourth column top discharge pump is connected to the second heat exchanger, one end of the fourth reboiler is connected to the bottom of the fourth distillation column, and the other end is connected to the bottom pipe of the fourth distillation column and the fourth column bottom discharge pump, the fourth column bottom discharge pump is connected to the second heat exchanger, and the second heat exchanger is connected to the first mixing tank.

2. The preparation system for ethylene glycol tert-butyl ether acetate according to claim 1, characterized in that, The fixed-bed reactor is filled with a strong base catalyst.

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