Production device and production method of acetal

Abstract

According to the production device and the production method, ethylene glycol is subjected to six units of condensation reaction, separation and refining, esterification reaction, esterification separation, hydrolysis reaction and hydrolysis separation, so that production and refining of diethylene glycol prepared by dehydration condensation of ethylene glycol are realized, and the process conversion rate is increased and the separation difficulty is reduced through byproduct treatment. The production process disclosed by the invention is continuous and easy to operate, and has industrial feasibility.

Description

Technical Field

[0001] The present application relates to a production device and a production method for acetal, belonging to the technical field of chemical industry. Background Art

[0002] Diethylene glycol, also known as diethylene glycol acetal, is commonly used as an organic solvent, antifreeze, desiccant, softener and plasticizer. It is widely used in daily chemical industries such as oils, resins, nitrocellulose, dyes and equipment manufacturing industries. At present, all diethylene glycol products are by-products of ethylene oxide hydration to produce ethylene glycol, generally accounting for 8% to 10% of ethylene glycol production. In recent years, with the continuous development of my country's polyester industry and the continuous increase in the requirements of advanced equipment manufacturing industry, the demand for diethylene glycol has also continued to increase. Therefore, the production attribute of diethylene glycol as a by-product has severely restricted the increase in production capacity, and the exploration of emerging diethylene glycol synthesis routes is particularly urgent.

[0003] Ethylene glycol dehydration condensation is an excellent green production process for diethylene glycol. This method has the characteristics of high conversion rate, but low selectivity, and the by-products can form azeotropes with water. This application proposes a product / by-product separation and purification process scheme based on the product characteristics of the diethylene glycol synthesis method, which can achieve continuous production and improve the overall selectivity of diethylene glycol, and is suitable for industrial continuous production operations. Summary of the invention

[0004] According to one aspect of the present application, a polyacetal production device is provided, the production device comprising a condensation reaction unit A, a separation and refining unit B, an esterification reaction unit C, an esterification separation unit D, a hydrolysis reaction unit E and a hydrolysis separation unit F connected in sequence;

[0005] The separation and purification unit B is connected to the condensation reaction unit A, the hydrolysis reaction unit E and the esterification unit C;

[0006] The hydrolysis separation unit F is connected to the condensation reaction unit A, the esterification separation unit D and the hydrolysis reaction unit E;

[0007] The condensation reaction unit A comprises a condensation preheater, a condensation reactor, and a condensation condenser connected in sequence;

[0008] The separation and refining unit B comprises a dealdehyde tower, a lightness removal tower, a condensation wastewater tower, and a product tower which are connected in sequence;

[0009] The esterification reaction unit C comprises an esterification preheater and an esterification reactor connected in sequence;

[0010] The esterification separation unit D comprises an impurity oil tower, a deesterification tower, and a concentration tower connected in sequence;

[0011] The hydrolysis reaction unit E comprises a hydrolysis preheater and a hydrolysis reactor connected in sequence;

[0012] The hydrolysis separation unit F comprises a dealcoholization tower and a recovery tower which are connected in sequence.

[0013] Optionally, the preheating temperature of the condensation preheater is 100-350°C.

[0014] Optionally, the reaction temperature of the condensation reactor is 100-350°C.

[0015] Optionally, the reaction pressure of the condensation reactor is 100 to 500 kPaA.

[0016] Optionally, the operating temperature of the condensation condenser is 40-200°C.

[0017] Optionally, the reflux ratio of the aldehyde removal tower is 150-350.

[0018] Optionally, the number of theoretical plates of the aldehyde removal tower is 10 to 80.

[0019] Optionally, the top temperature of the aldehyde removal tower is 20-50°C.

[0020] Optionally, the operating pressure of the aldehyde removal tower is 100 to 300 kPaA.

[0021] Optionally, the reflux ratio of the lightness removal tower is 0.5-20.

[0022] Optionally, the lightness removal tower has 10 to 80 theoretical plates.

[0023] Optionally, the top temperature of the lightness removal tower is 50-150°C.

[0024] Optionally, the operating pressure of the lightness removal tower is 100 to 300 kPaA.

[0025] Optionally, the reflux ratio of the condensation wastewater tower is 0.01-5.

[0026] Optionally, the condensation wastewater tower has 10 to 80 theoretical plates.

[0027] Optionally, the top temperature of the condensation wastewater tower is 30-100°C.

[0028] Optionally, the operating pressure of the condensation wastewater tower is 0.1-300 kPaA.

[0029] Optionally, the reflux ratio of the product tower is 5-30.

[0030] Optionally, the product tower has 10 to 80 theoretical plates.

[0031] Optionally, the top temperature of the product tower is 60-150°C.

[0032] Optionally, the operating pressure of the product tower is 0.1 to 150 kPaA.

[0033] Optionally, the preheating temperature of the esterification preheater is 60-150°C.

[0034] Optionally, the reaction temperature of the esterification reactor is 60-150°C.

[0035] Optionally, the reaction pressure of the esterification reactor is 100-500 kPaA.

[0036] Optionally, the reflux ratio of the impurity oil tower is 20-260.

[0037] Optionally, the impurity oil tower has 10 to 80 theoretical plates.

[0038] Optionally, the top temperature of the impurity oil tower is 70-200°C.

[0039] Optionally, the operating pressure of the impurity oil tower is 100-300 kPaA.

[0040] Optionally, the reflux ratio of the deesterification tower is 0.01-5.

[0041] Optionally, the deesterification tower has 10 to 50 theoretical plates.

[0042] Optionally, the top temperature of the deesterification tower is 40-120°C.

[0043] Optionally, the operating pressure of the deesterification tower is 1 to 300 kPaA.

[0044] Optionally, the reflux ratio of the concentration tower is 0.1-5.

[0045] Optionally, the concentration tower has 15 to 80 theoretical plates.

[0046] Optionally, the top temperature of the concentration tower is 40-120°C.

[0047] Optionally, the operating pressure of the concentration tower is 100 to 300 kPaA.

[0048] Optionally, the preheating temperature of the hydrolysis preheater is 80-350°C.

[0049] Optionally, the reaction temperature of the hydrolysis reactor is 80-350°C.

[0050] Optionally, the reaction pressure of the hydrolysis reactor is 100 to 500 kPaA.

[0051] Optionally, the reflux ratio of the dealcoholization tower is 3-30.

[0052] Optionally, the dealcoholization tower has 15 to 80 theoretical plates.

[0053] Optionally, the top temperature of the dealcoholization tower is 40-120°C.

[0054] Optionally, the operating pressure of the dealcoholization tower is 1 to 300 kPaA.

[0055] Optionally, the reflux ratio of the recovery tower is 0.05-20.

[0056] Optionally, the recovery tower has 10 to 65 theoretical plates.

[0057] Optionally, the top temperature of the recovery tower is 40-120°C.

[0058] Optionally, the operating pressure of the recovery tower is 1 to 300 kPaA.

[0059] According to another aspect of the present application, a method for producing acetal is provided, wherein a raw material containing ethylene glycol is introduced into a production device for reaction to obtain diethylene glycol;

[0060] The production device is selected from the production devices described above.

[0061] Optionally, the production method comprises the following steps:

[0062] (1) introducing a raw material containing ethylene glycol into a condensation reaction unit A for condensation reaction to obtain a condensation product containing diethylene glycol;

[0063] (2) passing the condensation product containing diethylene glycol into a separation and purification unit B for purification and separation to obtain diethylene glycol, acetaldehyde, unreacted ethylene glycol, and a by-product containing dioxane;

[0064] Wherein, the diethylene glycol is discharged from the bottom of the product tower;

[0065] The unreacted ethylene glycol enters the condensation reaction unit A to continue the reaction;

[0066] (3) passing a mixture of the byproduct containing dioxane and acetic acid into an esterification reaction unit C for esterification reaction to obtain a product containing ethylene glycol acetate;

[0067] (4) passing the product containing ethylene glycol acetate into an esterification separation unit D for separation and purification to obtain a purified product containing ethylene glycol acetate and recycled acetic acid;

[0068] (5) passing the purified product containing ethylene glycol acetate into a hydrolysis reaction unit E for hydrolysis reaction to obtain a product containing ethylene glycol and acetic acid;

[0069] (6) The product containing ethylene glycol is separated by the hydrolysis separation unit F and then introduced into the condensation reaction unit A as a raw material to participate in the reaction.

[0070] Optionally, in step (1), the raw materials include fresh ethylene glycol, and ethylene glycol produced in separation and refining unit B and hydrolysis separation unit F.

[0071] Optionally, in step (3), the acetic acid includes fresh acetic acid and acetic acid produced in the esterification separation unit D cycle.

[0072] As a specific implementation scheme, the present application is implemented through the following technical solutions:

[0073] (1) Fresh ethylene glycol is mixed with ethylene glycol recovered from separation and purification unit B and hydrolysis separation unit F and then sent to condensation reaction unit A, heated to reaction temperature in condensation preheater, sent to condensation reactor, dehydration condensation reaction occurs, and the reaction product is condensed in condensation condenser and then sent to separation and purification unit B;

[0074] (2) The condensed condensation reaction product is sent to the separation and refining unit B, first separated by the aldehyde removal tower, and the by-product acetaldehyde is separated at the top of the tower, and the aldehyde-free material at the bottom of the tower is sent to the lightness removal tower;

[0075] (3) The by-product light impurities are separated from the top of the light removal tower and sent to the esterification reaction unit C, and the dehydrogenation product obtained at the bottom of the tower is sent to the condensation wastewater tower;

[0076] (4) Wastewater is separated from the top of the condensation wastewater tower and sent to the hydrolysis reaction unit E, and the heavy mixture at the bottom of the tower is sent to the product tower;

[0077] (5) The product tower separates the unreacted ethylene glycol raw material at the top of the tower through distillation for recycling, and obtains the diethylene glycol product at the bottom of the tower;

[0078] (6) The by-product light impurities from the top of the light removal tower are sent to the esterification reaction unit C, heated to the reaction temperature by the esterification preheater, and then sent to the esterification reactor. The obtained esterification reaction product is sent to the esterification separation unit D;

[0079] (7) The esterification reaction product first enters the impurity oil tower in the esterification separation unit D, and the impurity oil is separated at the top of the tower. The light product is obtained at the bottom of the tower and sent to the deesterification tower;

[0080] (8) The deesterification tower is operated by distillation to obtain dilute acetic acid at the top of the tower, which is sent to the concentration tower, and acetic ester is obtained at the bottom of the tower and sent to the hydrolysis reaction unit E;

[0081] (9) Dilute acetic acid is separated into wastewater at the top of the concentration tower, part of which is discharged and part of which is sent to the hydrolysis reaction unit E. An acetic acid solution with a concentration meeting the standard is obtained at the bottom of the concentration tower and is sent to the esterification reaction unit C for recycling as an esterification raw material;

[0082] (10) In the hydrolysis reaction unit E, the acetate and wastewater from the esterification separation unit D are mixed, heated to the reaction temperature by a hydrolysis preheater, and sent to the hydrolysis reactor. The obtained hydrolysis reaction product is sent to the hydrolysis separation unit F;

[0083] (11) The hydrolysis reaction product is sent to the hydrolysis separation unit F, first entering the dealcoholization tower, and the ethylene glycol generated by hydrolysis is obtained at the bottom of the tower and sent to the condensation reaction unit A, and the light component obtained at the top of the tower is sent to the recovery tower;

[0084] (12) The dilute acetic acid obtained at the top of the recovery tower is sent to the esterification separation unit D, and the unreacted acetic acid obtained at the bottom of the tower is sent to the hydrolysis reaction unit E.

[0085] In the present application, fresh ethylene glycol is mixed with ethylene glycol recovered from separation and refining unit B and hydrolysis and separation unit F, and then dehydrated and condensed in condensation reaction unit A to obtain a condensation product containing diethylene glycol, which is sent to separation and refining unit B. Separation and refining unit B separates diethylene glycol product, acetaldehyde byproduct, unreacted ethylene glycol, wastewater and byproduct containing dioxane. Acetaldehyde and diethylene glycol are sent out, unreacted ethylene glycol is returned to condensation reaction unit A, wastewater is sent to hydrolysis reaction unit E, and byproducts are sent to esterification reaction unit C. The byproduct containing dioxane from separation and refining unit B enters esterification reaction unit C together with fresh acetic acid and recycled acetic acid from esterification separation unit D, and an esterification reaction occurs to generate ethylene glycol acetate, and the reaction product is sent to esterification separation unit D. Esterification separation unit D separates and purifies the esterification reaction product to obtain ethylene glycol acetate, wastewater and recycled acetic acid. The recycled acetic acid is sent back to the esterification reaction unit C, ethylene glycol acetate and part of the wastewater are sent to the hydrolysis reaction unit E, and the rest of the wastewater is sent out. The wastewater and ethylene glycol acetate from the esterification separation unit D, the wastewater from the separation and refining unit B, and the wastewater from the hydrolysis separation unit F enter the hydrolysis reaction unit E, and the acetic acid and ethylene glycol generated by the hydrolysis reaction are sent to the hydrolysis separation unit F. The recycled ethylene glycol separated by the hydrolysis separation unit F is sent to the condensation reaction unit A, the separated ethyl acetic acid is sent to the esterification separation unit D, and the separated unreacted ethylene glycol acetate is sent to the hydrolysis reaction unit E for recycling.

[0086] In the present application, “fresh ethylene glycol” and “fresh acetic acid” refer to ethylene glycol and acetic acid purchased from commercial channels used directly as raw materials.

[0087] The beneficial effects of this application include:

[0088] The acetal production device disclosed in the present application is used for the separation and purification of diethylene glycol produced by dehydration condensation reaction of ethylene glycol, and the process is continuous and easy to operate, and has industrial feasibility.

[0089] In the acetal production method disclosed in the present application, ethylene glycol is subjected to six units of condensation reaction-separation and purification-esterification reaction-esterification separation-hydrolysis reaction-hydrolysis separation, so as to realize the production and purification of diethylene glycol by dehydration condensation of ethylene glycol, and a diethylene glycol product with a molar concentration of 99.9% can be obtained; and the process conversion rate is improved by by-product treatment, and the separation difficulty is reduced; the process is continuous and easy to operate, and has industrial feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 The present invention is a schematic diagram of a process for producing acetal.

[0091] Figure 2 This is the process flow chart of the condensation reaction unit A and the separation and refining unit B of this application.

[0092] Figure 3 This is the process flow chart of the esterification reaction unit C and the esterification separation unit D of this application.

[0093] Figure 4 It is a process flow chart of hydrolysis reaction unit E and hydrolysis separation unit F.

[0094] Figure 1 In: A, condensation reaction unit; B, separation and refining unit; C, esterification reaction unit; D, esterification separation unit; E, hydrolysis reaction unit; F, hydrolysis separation unit.

[0095] 1. Condensation preheater; 2. Condensation reactor; 3. Condensation condenser; 4. Dealdehyde tower; 5. Lightness removal tower; 6. Condensation wastewater tower; 7. Product tower; 8. Esterification preheater; 9. Esterification reactor; 10. Impurity oil tower; 11. Deesterification tower; 12. Concentration tower; 13. Hydrolysis preheater; 14. Hydrolysis reactor; 15. Dealcoholization tower; 16. Recovery tower. DETAILED DESCRIPTION

[0096] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0097] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0098] Example 1

[0099] like Figure 1 As shown, the acetal production device includes a condensation reaction unit A, a separation and refining unit B, an esterification reaction unit C, an esterification separation unit D, a hydrolysis reaction unit E and a hydrolysis separation unit F.

[0100] like Figure 2 As shown, the condensation reaction unit A includes a condensation preheater 1, a condensation reactor 2 and a condensation condenser 3; the dehydrated condensation raw material is heated to the reaction temperature in the condensation preheater 1 and sent to the condensation reactor 2; the condensation reaction product is condensed in the condensation condenser 3 and sent to the separation and refining unit B. The separation and refining unit B comprises a dealdehyde tower 4, a light impurity removal tower 5, a condensation wastewater tower 6 and a product tower 7; wherein, the separated raw material is sent to the dealdehyde tower 4, the by-product acetaldehyde is separated at the top of the dealdehyde tower 4, the dealdehyde material at the bottom of the dealdehyde tower 4 is sent to the light impurity removal tower 5, the by-product light impurities are separated at the top of the light impurity removal tower 5 and sent to the esterification reaction unit C, the dehydrogenation product obtained at the bottom of the tower is sent to the condensation wastewater tower 6, the wastewater is separated at the top of the condensation wastewater tower 6 and sent to the hydrolysis reaction unit E, and the heavy mixture at the bottom of the condensation wastewater tower 6 is sent to the product tower 7; the product tower 7 separates the unreacted ethylene glycol raw material at the top of the tower by distillation for recycling, and obtains the diethylene glycol product at the bottom of the tower.

[0101] like Figure 3 As shown, the esterification reaction unit C includes an esterification preheater 8 and an esterification reactor 9; acetic acid and by-product light impurities are mixed with circulating acetic acid and heated to the reaction temperature by the esterification preheater 8 and then sent to the esterification reactor 9, and the obtained esterification reaction product is sent to the esterification separation unit D. The esterification separation unit D includes an impurity oil tower 10, a deesterification tower 11 and a concentration tower 12; the esterification reaction product is sent to the impurity oil tower 10, and the impurity oil is separated at the top of the impurity oil tower 10, and the de-light product is obtained at the bottom of the impurity oil tower 10 and sent to the deesterification tower 11; the deesterification tower 11 is operated by distillation, and dilute acetic acid is obtained at the top of the deesterification tower 11, which is sent to the concentration tower 12, and acetic ester is obtained at the bottom of the deesterification tower 11 and sent to the hydrolysis reaction unit E; the dilute acetic acid separates wastewater at the top of the concentration tower 12, part of the wastewater is discharged, and part of the wastewater is sent to the hydrolysis reaction unit E, and the acetic acid solution with a concentration reaching the standard is obtained at the bottom of the concentration tower 12, which is sent to the esterification reaction unit C for recycling as an esterification raw material.

[0102] like Figure 4 As shown, the hydrolysis reaction unit E includes a hydrolysis preheater 13 and a hydrolysis reactor 14; the acetate and wastewater from the esterification separation unit D are mixed and heated to the reaction temperature by the hydrolysis preheater 13 and then sent to the hydrolysis reactor 14, and the obtained hydrolysis reaction product is sent to the hydrolysis separation unit F. The hydrolysis separation unit F includes a dealcoholization tower 15 and a recovery tower 16; the hydrolysis reaction product is sent to the dealcoholization tower 15, and the ethylene glycol generated by hydrolysis is obtained at the bottom of the dealcoholization tower 15 and sent to the condensation reaction unit A, and the light component obtained at the top of the dealcoholization tower 15 is sent to the recovery tower 16; the dilute acetic acid obtained at the top of the recovery tower 16 is sent to the esterification separation unit D, and the unreacted acetate obtained at the bottom of the tower is sent to the hydrolysis reaction unit E.

[0103] Example 2

[0104] like Figures 1 to 4As shown, fresh ethylene glycol is mixed with ethylene glycol recovered from separation and purification unit B and hydrolysis separation unit F and then sent to condensation reaction unit A, heated to 210°C in condensation preheater 1, and sent to condensation reactor 2, where dehydration condensation reaction occurs under the conditions of 210°C and 120kPaA to obtain a condensation product containing diethylene glycol. The condensation product containing diethylene glycol is condensed to 110°C in condensation condenser 3 and then completely condensed and sent to separation and purification unit B.

[0105] The condensed condensation product containing diethylene glycol is sent to the separation and refining unit B, and first separated by the aldehyde removal tower 4. The top pressure of the aldehyde removal tower 4 is 150 kPaA, the top temperature is 32°C, 30 theoretical plates are set, and the reflux ratio is 305.3. The by-product acetaldehyde with a molar concentration of 99.6% is separated at the top of the tower, and the aldehyde removal material at the bottom of the aldehyde removal tower 4 is sent to the light removal tower 5. The top pressure of the light removal tower 5 is 110 kPaA, the top temperature is 91°C, 30 theoretical plates are set, and the reflux ratio is 5. The by-product light impurities are separated at the top of the light removal tower 5 and sent to the esterification reaction unit C. The dehydrogenation product obtained at the bottom of the light removal tower 5 is sent to the condensation wastewater tower 6. The top pressure of condensation wastewater tower 6 is 10kPaA, the top temperature is 46°C, 30 theoretical plates are provided, and the reflux ratio is 0.5. Wastewater is separated at the top of condensation wastewater tower 6 and sent to hydrolysis reaction unit E, and the heavy mixture at the bottom of condensation wastewater tower 6 is sent to product tower 7. The top pressure of product tower 7 is 5kPaA, the top temperature is 117°C, 40 theoretical plates are provided, and the reflux ratio is 15. Unreacted ethylene glycol raw materials are separated at the top of the tower by rectification and recycled, and diethylene glycol products with a molar concentration of 99.9% are obtained at the bottom of the tower. The by-product light impurities from the top of light removal tower 5 are sent to esterification reaction unit C, heated to 98°C by esterification preheater 8, and then sent to esterification reactor 9. Esterification reaction occurs under the operating conditions of 98°C and 110kPaA to generate ethylene glycol acetate, and the esterification reaction product ethylene glycol acetate is sent to esterification separation unit D. The esterification reaction product, ethylene glycol acetate, first enters the impurity oil tower 10 in the esterification separation unit D. The impurity oil tower 10 has a top pressure of 110 kPaA, a top temperature of 90°C, 32 theoretical plates, and a reflux ratio of 180. Impurity oil is separated at the top of the tower, and a light product is obtained at the bottom of the tower and sent to the deesterification tower 11. The top pressure of the deesterification tower 11 is 30 kPaA, the top temperature is 70°C, 20 theoretical plates are set, and the reflux ratio is 0.08. Through distillation operation, dilute acetic acid is obtained at the top of the tower and sent to the concentration tower 12. Acetic ester is obtained at the bottom of the tower and sent to the hydrolysis reaction unit E. The top pressure of the concentration tower 12 is 110 kPaA, the top temperature is 102°C, 30 theoretical plates are provided, and the reflux ratio is 2. The dilute acetic acid separates wastewater at the top of the concentration tower 12, part of the wastewater is discharged, and part of the wastewater is sent to the hydrolysis reaction unit E. The circulating acetic acid solution with a concentration that meets the standard is obtained at the bottom of the concentration tower 12 and is sent to the esterification reaction unit C for recycling as an esterification raw material. In the hydrolysis reaction unit E, the acetate from the esterification separation unit D and the wastewater are mixed, heated to 150°C by the hydrolysis preheater 13, and sent to the hydrolysis reactor 14. The hydrolysis reaction occurs under the operating conditions of 150°C and 130 kPaA, and the obtained hydrolysis reaction product is sent to the hydrolysis separation unit F. The hydrolysis reaction product is sent to the hydrolysis separation unit F, and first enters the dealcoholization tower 15. The top pressure of the dealcoholization tower 15 is 10 kPaA, the top temperature is 56°C, 60 theoretical plates are set, and the reflux ratio is 14. The ethylene glycol generated by hydrolysis is obtained at the bottom of the dealcoholization tower 15 and sent to the condensation reaction unit A. The light component obtained at the top of the tower is sent to the recovery tower 16.The top pressure of recovery tower 16 is 30 kPaA, the top temperature is 76° C., 20 theoretical plates are provided, the reflux ratio is 0.2, the dilute acetic acid obtained at the top of recovery tower 16 is sent to the esterification separation unit D, and the unreacted acetic acid obtained at the bottom of recovery tower 16 is sent to the hydrolysis reaction unit E.

[0106] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A production device for acetal, characterized in that: The production device comprises a condensation reaction unit A, a separation and refining unit B, an esterification reaction unit C, an esterification separation unit D, a hydrolysis reaction unit E and a hydrolysis separation unit F which are connected in sequence; The separation and purification unit B is connected to the condensation reaction unit A, the hydrolysis reaction unit E and the esterification unit C; The hydrolysis separation unit F is connected to the condensation reaction unit A, the esterification separation unit D and the hydrolysis reaction unit E; The condensation reaction unit A comprises a condensation preheater (1), a condensation reactor (2), and a condensation condenser (3) which are connected in sequence; The separation and purification unit B comprises a dealdehyde tower (4), a lightness removal tower (5), a condensation wastewater tower (6), and a product tower (7) which are connected in sequence; The esterification reaction unit C comprises an esterification preheater (8) and an esterification reactor (9) which are connected in sequence; The esterification separation unit D comprises an impurity oil tower (10), a deesterification tower (11), and a concentration tower (12) which are connected in sequence; The hydrolysis reaction unit E comprises a hydrolysis preheater (13) and a hydrolysis reactor (14) connected in sequence; The hydrolysis separation unit F comprises a dealcoholization tower (15) and a recovery tower (16) which are connected in sequence.

2. The production device according to claim 1, characterized in that: The preheating temperature of the condensation preheater (1) is 100 to 350°C; Preferably, the reaction temperature of the condensation reactor (2) is 100 to 350°C, and the reaction pressure is 100 to 500 kPaA; Preferably, the operating temperature of the condensation condenser (3) is 40-200°C.

3. The production device according to claim 1, characterized in that: The reflux ratio of the dealdehyde tower (4) is 150-350, the number of theoretical plates is 10-80, the tower top temperature is 20-50° C., and the operating pressure is 100-300 kPaA; Preferably, the reflux ratio of the light-removal tower (5) is 0.5-20, the number of theoretical plates is 10-80, the tower top temperature is 50-150° C., and the operating pressure is 100-300 kPaA.

4. The production device according to claim 1, characterized in that: The condensation wastewater tower (6) has a reflux ratio of 0.01 to 5, a theoretical plate number of 10 to 80, a tower top temperature of 30 to 100° C., and an operating pressure of 0.1 to 300 kPaA; Preferably, the reflux ratio of the product tower (7) is 5 to 30, the number of theoretical plates is 10 to 80, the tower top temperature is 60 to 150° C., and the operating pressure is 0.1 to 150 kPaA.

5. The production device according to claim 1, characterized in that: The preheating temperature of the esterification preheater (8) is 60 to 150°C; Preferably, the reaction temperature of the esterification reactor (9) is 60-150°C, and the reaction pressure is 100-500 kPaA; Preferably, the impurity oil tower (10) has a reflux ratio of 20 to 260, a theoretical plate number of 10 to 80, a tower top temperature of 70 to 200° C., and an operating pressure of 100 to 300 kPaA; Preferably, the reflux ratio of the deesterification tower (11) is 0.01 to 5, the number of theoretical plates is 10 to 50, the top temperature is 40 to 120° C., and the operating pressure is 1 to 300 kPaA; Preferably, the reflux ratio of the concentration tower (12) is 0.1 to 5, the number of theoretical plates is 15 to 80, the tower top temperature is 40 to 120° C., and the operating pressure is 100 to 300 kPaA.

6. The production device according to claim 1, characterized in that: The preheating temperature of the hydrolysis preheater (13) is 80 to 350°C; Preferably, the reaction temperature of the hydrolysis reactor (14) is 80-350°C, and the reaction pressure is 100-500 kPaA.

7. The production device according to claim 1, characterized in that: The dealcoholization tower (15) has a reflux ratio of 3 to 30, a theoretical plate number of 15 to 80, a tower top temperature of 40 to 120° C., and an operating pressure of 1 to 300 kPaA; Preferably, the reflux ratio of the recovery tower (16) is 0.05-20, the number of theoretical plates is 10-65, the top temperature is 40-120°C, and the operating pressure is 1-300 kPaA.

8. A method for producing acetal, characterized in that: The production method comprises: The raw material containing ethylene glycol is introduced into the production device for reaction to obtain diethylene glycol; The production device is selected from the production device according to any one of claims 1 to 7.

9. The production method according to claim 8, characterized in that: The production method comprises the following steps: (1) introducing a raw material containing ethylene glycol into a condensation reaction unit A for condensation reaction to obtain a condensation product containing diethylene glycol; (2) passing the condensation product containing diethylene glycol into a separation and purification unit B for purification and separation to obtain diethylene glycol, acetaldehyde, unreacted ethylene glycol, and a by-product containing dioxane; wherein the diethylene glycol is discharged from the bottom of the product tower (7); The unreacted ethylene glycol enters the condensation reaction unit A to continue the reaction; (3) passing a mixture of the byproduct containing dioxane and acetic acid into an esterification reaction unit C for esterification reaction to obtain a product containing ethylene glycol acetate; (4) passing the product containing ethylene glycol acetate into an esterification separation unit D for separation and purification to obtain a purified product containing ethylene glycol acetate and recycled acetic acid; (5) passing the purified product containing ethylene glycol acetate into a hydrolysis reaction unit E for hydrolysis reaction to obtain a product containing ethylene glycol and acetic acid; (6) The product containing ethylene glycol is separated by the hydrolysis separation unit F and then introduced into the condensation reaction unit A as a raw material to participate in the reaction.

10. The production method according to claim 8, characterized in that: In the step (1), the raw materials include fresh ethylene glycol, ethylene glycol produced in the separation and refining unit B and the hydrolysis separation unit F; Preferably, in step (3), the acetic acid includes fresh acetic acid and acetic acid produced in the esterification separation unit D cycle.

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