A para-ester condensation device and condensation process

Abstract

The present application relates to the technical field of para-ester production, and specifically discloses a para-ester condensation device and condensation process. The para-ester condensation device includes a reducing liquid feed pipe, an ethylene oxide inlet pipe, a mixing pipe, a sleeve, a reactor, a cooling pool, a condensation reactor and a gas collection component. The reactor is arranged in the cooling pool, and the reactor is used to receive the reducing liquid and ethylene oxide. The reducing liquid feed pipe and the ethylene oxide are connected to the mixing pipe. The liquid outlet of the mixing pipe is located below the reaction liquid level of the reactor, and the reactor is connected to the condensation reactor. A multi-stage condensation reaction mode is adopted to increase the contact area between ethylene oxide and the reducing liquid, shorten the reaction time, improve the utilization rate of ethylene oxide, and thus increase the reaction rate.

Description

Technical Field

[0001] The present application relates to the technical field of para-ester production, and more specifically to a para-ester condensation device and condensation process. Background Art

[0002] Para-esters, also known as p-aminophenyl-β-hydroxyethyl sulfone sulfate, are important intermediates in the production of reactive dyes, primarily used in the manufacture of KM or M series reactive dyes. In reactive dyes, para-esters possess both an amino group that serves as a diazotizing component and a reactive group that can chemically react to form a dye-fiber covalent bond. This significantly increases dye utilization and enhances economic efficiency.

[0003] Currently, in related research, there are three main methods for synthesizing para-esters: the acetanilide method, the p-nitrochlorobenzene method, and the nitrobenzene method. The nitrobenzene method, which produces para-esters, has a low yield, limited industrial value and commercial prospects, and is not suitable for large-scale production. The p-nitrochlorobenzene method, which produces para-esters at a lower cost, lacks mature production technology. The acetanilide method is a more commonly used method for preparing para-esters. This method uses acetanilide as a raw material and produces the para-ester through steps such as chlorosulfonation, reduction, condensation, and esterification. In the condensation step, ethylene oxide and a reducing solution are added to a reactor to react, preventing them from fully contacting in a short period of time, resulting in problems such as a long reaction time and a low reaction rate. Summary of the Invention

[0004] In order to increase the reaction rate in the condensation step and shorten the condensation reaction time, the present application provides a condensation device and a condensation process for para-ester.

[0005] In the first aspect, the present application provides a condensation device for para-esters, comprising a reducing liquid feed pipe, an ethylene oxide inlet pipe, a mixing pipe, a sleeve, a reactor, a gas collecting assembly, a condensation reactor and a cooling pool, wherein the reactor is arranged in the cooling pool, and the reactor is used to receive the reducing liquid and ethylene oxide, the reducing liquid feed pipe and the ethylene oxide are connected to the mixing pipe, the liquid outlet of the mixing pipe is located below the reaction liquid level of the reactor, and the reactor is connected to the condensation reactor.

[0006] Acetanilide is used to produce a para-ester through the steps of chlorosulfonation, reduction, condensation, and esterification. In the condensation reaction step, the reducing solution and ethylene oxide are directly added to the condensation reaction vessel to react and obtain a condensation solution, which is para-β-hydroxyethylsulfone acetanilide. Due to insufficient contact between the reducing solution and ethylene oxide, the reaction time is long and the reaction rate is low.

[0007] In the present application, the reducing liquid and ethylene oxide are introduced into the reducing liquid feed pipe and the ethylene oxide inlet pipe respectively, and the reducing liquid and ethylene oxide are collected in the mixing pipe, and the first contact is carried out in the mixing pipe, and a primary condensation reaction occurs to produce a primary condensation liquid.

[0008] After the primary condensation reaction, a mixture of a primary condensation liquid, a reducing liquid and ethylene oxide is obtained, which flows into the reactor through the outlet of the mixing tube, and the reducing liquid and ethylene oxide undergo secondary condensation in the reactor. In the present application, the outlet of the mixing tube is located below the liquid level of the reactor reaction liquid, with the purpose of flowing ethylene oxide through the mixed liquid of the primary condensation liquid and the reducing liquid, so that ethylene oxide and the reducing liquid further react. The reaction liquid is a mixture of the reducing liquid and the primary condensation liquid. The function of the reactor is to receive the reducing liquid, ethylene oxide and the primary condensation liquid prepared from the reducing liquid and ethylene oxide. In the present application, the reactor is arranged in an inverted trapezoidal shape, which is larger at the top and smaller at the bottom. Since ethylene oxide is located above the reactor, the inverted trapezoidal shape can increase the contact area between ethylene oxide and the reducing liquid, increase the reaction rate and shorten the reaction time.

[0009] In the reactor, the reducing liquid and ethylene oxide undergo a condensation reaction, which releases heat. During this process, the temperature inside the reactor gradually rises. The reaction temperature is controlled at 50-65°C. When the reaction temperature exceeds 65°C, the risk increases. This application places the reactor in a cooling pool to gradually cool the reactor, ensuring the smooth progress of the reaction and reducing the risk.

[0010] After the secondary condensation reaction is carried out, the reaction rate gradually decreases, and a mixture of the secondary condensation reaction liquid and part of the unreacted reducing liquid is obtained. In order not to affect the condensation reaction rate in the reactor, the mixed liquid is passed through a pipeline to the condensation reactor. The gas collection component in this application can collect the ethylene oxide in the reactor and at the same time play a role in stabilizing the pressure in the reactor. The gas collection component injects the collected ethylene oxide into the condensation reactor, and performs a condensation reaction with the unreacted reducing liquid to obtain a tertiary condensation liquid.

[0011] In one embodiment, the reactor is provided with a rotating device capable of rotating along its central axis.

[0012] In this application, the reactor is disposed within a cooling pool and connected via a support and roller bearings, such that the reactor is spaced a certain distance from the cooling pool. Furthermore, a rotating device is provided on the reactor to enable the reactor to rotate along its own central axis. The rotation of the reactor generates centrifugal force, causing the reaction liquid surface within the reactor to form a U-shape, further increasing the contact area between the ethylene oxide and the reducing solution, allowing the ethylene oxide and reducing solution to react further and fully. Furthermore, the rotation of the reactor enables rapid cooling of the reactor.

[0013] In one embodiment, the rotating device includes a gear ring fixedly connected to the side of the reactor away from the reducing liquid feed pipe and the ethylene oxide inlet pipe, a gear mating with the gear ring, a connecting rod fixed to the gear and extending to the outside of the cooling pool, an upper connecting rod is provided at the other end of the connecting rod away from the gear, the connecting rod is connected to the cooling pool through a bearing, and a power element is connected to the end of the connecting rod away from the reactor.

[0014] By adopting the above technical solution, the power element is started, the power element drives the connecting rod to rotate, and then drives the gear fixed to the connecting rod to rotate. The gear and the gear ring fixed to the reactor engage with each other, causing the reactor to rotate.

[0015] In one embodiment, a heater is provided on the reducing liquid feeding pipe to preheat the reducing liquid to 40-45°C.

[0016] In this application, the heater can heat the reducing liquid to increase the activity of the reducing liquid, provide an initial reaction temperature for the reducing liquid and ethylene oxide, accelerate the reaction of the reducing liquid and ethylene oxide, shorten the reaction time, and increase the reaction rate. The heater can be a resistance wire or a liquid pipeline heater.

[0017] In one embodiment, a control unit is provided in the condensation device, and the control unit includes a gravity sensor, a temperature controller, an air inlet valve, a liquid inlet valve and a liquid outlet valve.

[0018] In this application, the control unit primarily controls the reaction liquid within the reactor. A gravity sensor and temperature controller are installed within the reactor to monitor the temperature and weight of the reaction liquid. An air inlet valve is installed on the ethylene oxide inlet pipe to control the ethylene oxide inlet pipe. A liquid inlet valve is installed on the reducing liquid feed pipe to control the reducing liquid feed pipe. A liquid outlet valve is installed on the pipe to control the secondary condensation liquid.

[0019] Open the air inlet and liquid inlet valves, close the liquid outlet valve, and pass the reducing liquid and ethylene oxide into the mixer for primary condensation to produce a primary condensation liquid. The mixture of the primary condensation liquid, reducing liquid, and ethylene oxide flows into the reactor to continue the reaction. Since ethylene oxide is a gas and is located above the reactor, as the mixture of the primary condensation liquid, reducing liquid, and ethylene oxide in the reactor gradually increases, the ethylene oxide above the reactor is gradually compressed and discharged from the reactor, collecting in the gas collection assembly. As the reaction temperature gradually rises, the cooling water in the cooling pool cools the reactor to control the reaction temperature between 50-65°C. As the mixture of the primary condensation liquid, reducing liquid, and ethylene oxide further increases, the reaction temperature will continue to rise, reaching above 65°C. At this time, the temperature controller starts to work, closes the air inlet and liquid inlet valves, opens the liquid outlet valve, and discharges the reaction liquid in the reactor through a pipe into the condensation reactor for a third-stage condensation. Similarly, when the reaction liquid in the reactor reaches a certain weight, the gravity sensor activates, closing the air and liquid inlet valves and opening the liquid outlet valve, allowing the reaction liquid to flow into the condensation reactor for tertiary condensation. When the temperature or weight in the reactor reaches a certain lower limit, the air and liquid inlet valves are opened, and the liquid outlet valve is closed, allowing the reducing solution and ethylene oxide to continue flowing and reacting.

[0020] In one embodiment, the pipe and the casing are respectively connected to the reactor in a rotary sealing manner.

[0021] In the present application, in order to realize the rotation of the reactor, the pipeline and the casing are both rotatably sealed and connected to the reactor, and the casing mainly includes a reducing liquid feed pipe, an ethylene oxide inlet pipe and an outlet pipe in the gas collecting assembly.

[0022] Preferably, the pipeline is arranged in a serpentine shape.

[0023] When the secondary condensation liquid flows into the condensation reactor through the pipeline, the secondary condensation liquid has a certain temperature. The serpentine arrangement of the pipeline can extend the flow time of the secondary condensation liquid and achieve the purpose of heat dissipation.

[0024] In a second aspect, the present application provides a condensation process for a para-ester, which is prepared using the para-ester condensation device described in the present application, comprising the following steps:

[0025] S1: heating the reducing solution to obtain a heated reducing solution;

[0026] S2: The heated reducing liquid and ethylene oxide are respectively introduced into the mixing tube through the reducing liquid feed pipe and the ethylene oxide inlet pipe to perform primary condensation to obtain a primary condensation liquid;

[0027] S3: the primary condensation liquid flows into the reactor to undergo secondary condensation to obtain a secondary condensation liquid;

[0028] S4: Finally, the secondary condensation liquid is flowed into the condensation reactor through a pipeline, and condensed three times to obtain a tertiary condensation liquid.

[0029] In the present application, the preparation of para-ester mainly includes the steps of chlorosulfonation, reduction, condensation and esterification. The present application heats the reducing liquid obtained through the reduction step to increase the activity of the reducing liquid and the reaction rate. Ethylene oxide is introduced into the ethylene oxide inlet pipe and contacts the reducing liquid in the mixing tube, whereby a primary condensation occurs to obtain a primary condensation liquid. Since the reducing liquid and ethylene oxide are not completely reacted in the mixing tube, the reducing liquid, ethylene oxide and the primary condensation liquid flow into the reactor. In the reactor, the reducing liquid and ethylene oxide continue to react, a secondary condensation occurs, and a secondary condensation liquid is obtained. As the reducing liquid, ethylene oxide, the primary condensation liquid and the secondary condensation liquid gradually increase in the reactor, the ethylene oxide is compressed into the gas collecting assembly for collection. When the temperature or weight in the reactor reaches a certain upper limit, the primary condensation liquid, the secondary condensation liquid and the unreacted reducing liquid in the reactor flow into the condensation reactor, and the ethylene oxide in the gas collecting assembly is also introduced into the condensation reactor for three-stage condensation to obtain a three-stage condensation liquid. In the condensation reactor are the primary condensation liquid, the secondary condensation liquid and the tertiary condensation liquid. The primary condensation liquid, the secondary condensation liquid and the tertiary condensation liquid described in this application are all p-β-hydroxyethyl sulfone acetanilide. The p-β-hydroxyethyl sulfone acetanilide is then used for an esterification reaction to obtain a para-ester.

[0030] In one embodiment, the reaction temperature of the secondary condensation is 50-65°C.

[0031] Preferably, the reaction temperature of the secondary condensation is 60°C.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. This application adopts a multi-stage condensation reaction mode to increase the contact area between ethylene oxide and the reducing liquid, shorten the reaction time, improve the utilization rate of ethylene oxide, and thus increase the reaction rate;

[0034] 2. In the present application, a rotating device is preferably provided on the reactor to realize the rotation of the reactor and generate centrifugal force, so that the reaction liquid in the reactor is U-shaped, further increasing the contact area between the ethylene oxide and the reducing liquid and improving the reaction rate;

[0035] 3. The present application preferably sets up a reactor and a condensation reactor. As time goes by, the reaction rate of the reducing liquid and ethylene oxide in the reactor gradually decreases. The reducing liquid and ethylene oxide are passed into the condensation reactor for condensation, which does not affect the reaction rate of the reducing liquid and ethylene oxide in the reactor, thereby shortening the overall condensation reaction time.

[0036] 4. In this application, a control unit is preferably provided to realize the control of the reaction liquid in the reactor, which is more suitable for batch production and has a high market application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the structural arrangement of the condensation device in Example 1;

[0038] Figure 2 This is a schematic diagram of the structural arrangement of the condensation device in Example 2;

[0039] In the figure, 1. reducing liquid feed pipe; 11. heater; 2. ethylene oxide inlet pipe; 21. mixing tube; 22. sulfuric acid inlet pipe; 23. casing; 24. pipeline; 241. liquid outlet valve; 3. reactor; 31. support body; 311. roller bearing; 32. cooling pool; 33. water inlet; 34. water outlet; 4. condensation reactor; 5. gas collecting assembly; 51. outlet pipe; 52. air chamber; 53. fan; 54. gas collecting pipe; 55. blowing pipe; 6. rotating device; 61. gear ring; 62. gear; 63. connecting rod; 64. power element; 7. air inlet valve; 71. liquid inlet valve; 72. temperature controller; 73. gravity sensor. DETAILED DESCRIPTION

[0040] Below in conjunction with accompanying drawing and embodiment, the application is described in further detail.In the application, with acetanilide as raw material, para-ester is prepared through four steps such as chlorosulfonation, reduction, condensation and esterification, and equipment and element used in chlorosulfonation, reduction and esterification step are not drawn in the accompanying drawings.In addition, condensation device described in the application is fixed on mounting rack, and mounting rack is well known in the art, and those skilled in the art can design according to actual needs, and are not drawn in the application, and will not be repeated here.All the other such as power element, heater, gear ring and gear are well known in the art, and structure is not disclosed, and can be selected voluntarily according to actual needs.

[0041] Example

[0042] Example 1

[0043] Reference Figure 1 The condensation device for para-ester includes a reducing liquid feed pipe 1, a heater 11 provided on the reducing liquid feed pipe 1 for heating the reducing liquid, an ethylene oxide inlet pipe 2, a mixing pipe 21, a sleeve 23, a reactor 3, a cooling pool 32, a condensation reactor 4 and a gas collecting assembly 5. The reducing liquid feed pipe 1, the ethylene oxide inlet pipe 2 and the mixing pipe 21 are integrally formed, and the reducing liquid and ethylene oxide are preliminarily mixed in the mixing pipe 21. The mixing pipe 21 is inserted from the sleeve 23 and extends into the interior of the reactor 3. The outlet of the mixing pipe 21 is located below the reaction liquid level in the reactor 3. In addition, a sulfuric acid inlet pipe 22 is also inserted into the sleeve 23 to adjust the pH value of the reaction liquid in the reactor 3.

[0044] Reactor 3 is a hollow truncated cone with a larger top and smaller bottom. It is located within a cooling pool 32. Four supports 31 and roller bearings 311 are provided within the cooling pool 32. These supports 31 and roller bearings 311 support the reactor 3, ensuring a certain distance between the outer circumference of the reactor 3 and the cooling pool 32. A water inlet 33 and a water outlet 34 are provided on the cooling pool 32 to allow for the entry and discharge of cooling water. The cooling water within the cooling pool 32 cools the reactor 3.

[0045] The reactor 3 and the condensation reactor 4 are connected by a pipe 24, the other end of which is fixed to the reactor 3 and the other end of which is fixed to the condensation reactor 4. The condensation reactor 4 is a rectangular parallelepiped with a hollow interior, and the upper surface of the condensation reactor 4 gradually rises from the connection point of the pipe 24.

[0046] The gas collecting assembly 5 includes an air outlet pipe 51, an air chamber 52, a blower 53, an air collecting pipe 54 and an air blowing pipe 55. The gas collecting assembly 5 can realize the recycling of ethylene oxide. One end of the air outlet pipe 51 is inserted from the sleeve 23 and connected to the reactor 3. The other end of the air outlet pipe 51 is connected to the air chamber 52, which is used to collect the ethylene oxide in the reactor 3 and store it in the air chamber 52. A one-way valve (the one-way valve is not shown) is provided on the air outlet pipe 51 to prevent ethylene oxide from flowing from the air chamber 52 to the reactor 3. One end of the air blowing pipe 55 is connected to the blower 53, and the other end of the air blowing pipe 55 is connected to the condensation reactor 4 and is located below the liquid level of the reaction liquid in the condensation reactor 4. The blower 53 can pass the ethylene oxide in the air chamber 52 into the condensation reactor 4 through the air blowing pipe 55. One end of the gas manifold 54 is connected to the gas chamber 52, and the other end of the gas manifold 54 is connected to the condensation reactor 4 and is located at the highest point on the upper surface of the condensation reactor 4. A one-way valve (not shown) is provided on the gas manifold 54 to prevent ethylene oxide from flowing from the gas chamber 52 to the condensation reactor 4.

[0047] After the reduction reaction, a reducing liquid is obtained. The reducing liquid is heated to 40°C in a heater 11 to increase the activity of the reducing liquid. The heated reducing liquid is introduced into the mixing tube 21 through the reducing liquid feed pipe 1, and ethylene oxide gas is simultaneously introduced into the mixing tube 21 through the ethylene oxide inlet pipe 2. At this time, the reducing liquid and ethylene oxide undergo primary condensation in the mixing tube 21 to produce a primary condensation liquid. Since the reducing liquid and ethylene oxide do not react completely in the mixing tube 21, the reducing liquid, ethylene oxide, and primary condensation liquid gradually converge in the reactor, submerging the outlet of the mixing tube 21.

[0048] As the reducing liquid and ethylene oxide continue to be introduced, the reducing liquid and ethylene oxide undergo a secondary condensation reaction in reactor 3 to produce a secondary condensation liquid. In reactor 3, ethylene oxide gas passes through the mixture of the reducing liquid and the primary condensation liquid and gradually gathers above reactor 3 without reacting with the reducing liquid. The unreacted ethylene oxide is collected in the gas chamber 52 by the gas collecting component 5. As the reaction of ethylene oxide and the reducing liquid proceeds, the reaction rate in reactor 3 gradually decreases. At this point, the reactor 3 contains a mixture of the reducing liquid, the primary condensation liquid, and the secondary condensation liquid. The mixture of the reducing liquid, the primary condensation liquid, and the secondary condensation liquid in reactor 3 is discharged into the condensation reactor 4 using pipeline 24. The fan 53 is turned on to pass the ethylene oxide in the gas chamber 52 into the condensation reactor 4, where it undergoes a tertiary condensation reaction with the reducing liquid to produce a tertiary condensation liquid. At this time, the condensation reactor 4 contains the primary condensation liquid, the secondary condensation liquid and the tertiary condensation liquid, and the excess ethylene oxide is collected in the gas chamber 52 through the gas collecting pipe 54 .

[0049] When the secondary condensation occurs in the reactor 3 , the water inlet 33 and the water outlet 34 are opened to circulate the cooling water in the cooling pool 32 , thereby reducing the temperature of the reactor 3 .

[0050] The reaction rate of ethylene oxide and reducing liquid in reactor 3 is higher than that in condensation reactor 4. The ethylene oxide and reducing liquid with lower reaction rate in reactor 3 are flowed into condensation reactor 4 without hindering the reaction of the newly introduced ethylene oxide and reducing liquid in reactor 3. As a whole, the reaction time can be shortened and the efficiency can be improved.

[0051] Example 2

[0052] Reference Figure 2 , based on Example 1, further includes a rotating device 6 and a control unit. The rotating device 6 includes a gear ring 61 fixed to the side of the reactor 3 away from the sleeve 23, a gear 62 matched with the gear ring 61, a circular connecting rod 63 fixed to the gear 62, the connecting rod 63 is coaxial with the gear 62, the connecting rod 63 is connected to the cooling pool 32 through a bearing, and the end of the connecting rod 63 away from the gear 62 is connected to a power element 64, which is a motor. The sleeve 23 and the pipe 24 are respectively connected to the reactor 3 for rotation and sealing. The rotating device 6 can realize the rotation of the reactor 3 along its own centerline axis, generate centrifugal force, make the reaction liquid surface in the reactor 3 U-shaped, increase the contact area between ethylene oxide and the reducing liquid, and increase the reaction rate. In addition, the pipe 24 is set in a serpentine shape, which prolongs the flow time of the reaction liquid in the reactor 3 before the condensation reaction kettle 4, thereby cooling the reaction liquid.

[0053] The control unit includes a gravity sensor 73 and a temperature controller 72 disposed within the reactor 3, capable of monitoring the reaction temperature and weight within the reactor 3. It also includes an inlet valve 71 disposed on the reducing liquid feed pipe 1, an inlet valve 7 disposed on the ethylene oxide inlet pipe 2, and a liquid outlet valve 241 disposed on the pipeline 24.

[0054] When secondary condensation is taking place in reactor 3, the motor is started, rotating connecting rod 63, thereby driving gear 62 and ring gear 61, and thus rotating reactor 3. Within reactor 3, as the reducing liquid and ethylene oxide gradually increase, the production of primary condensation liquid and secondary condensation also gradually increases. When the weight within reactor 3 reaches a certain upper limit, gravity sensor 73 activates, closing air inlet valve 7 and liquid inlet valve 71, opening liquid outlet valve 241, and allowing the primary condensation liquid, secondary condensation liquid, and a small amount of reducing liquid within reactor 3 to flow through pipe 24 into condensation reactor 4. Blower 53 then passes ethylene oxide within air chamber 52 into condensation reactor 4 for continued reaction, producing tertiary condensation liquid. When the weight within reactor 3 reaches a certain lower limit, air inlet valve 7 and liquid inlet valve 71 are opened, closing liquid outlet valve 241, and continuing the reaction within reactor 3. Similarly, when the reaction temperature in reactor 3 exceeds 65°C, temperature controller 72 begins operation, closing air inlet valve 7 and liquid inlet valve 71, opening liquid outlet valve 241, and allowing the primary condensation liquid, secondary condensation liquid, and a small amount of reducing liquid in reactor 3 to flow into condensation reactor 4 through pipeline 24. Blower 53 then passes the ethylene oxide in air chamber 52 into condensation reactor 4 for continued reaction, producing a tertiary condensation liquid. When the reaction temperature in reactor 3 falls below 50°C, air inlet valve 7 and liquid inlet valve 71 are opened, liquid outlet valve 241 is closed, and the reaction in reactor 3 continues.

[0055] Comparative Example

[0056] Comparative Example 1

[0057] The condensation device of Comparative Example 1 includes a condensation reactor 4 , and a reducing liquid feed pipe 1 and an ethylene oxide inlet pipe 2 arranged on the condensation reactor 4 .

[0058] Performance testing

[0059] The condensation apparatus described in Examples 1-2 and Comparative Example 1 was used. In the chlorosulfonation, reduction, and esterification steps, the equipment and amounts of raw materials used were the same. The amount of ethylene oxide used in the condensation step was also the same. The reaction time in the condensation step was tested, and the specific tests are shown in Table 1.

[0060] (a) Sulfonation reaction: After adding 20 mol of fuming sulfuric acid to a reaction tank, the temperature was lowered to 12°C, 5 mol of chlorosulfonic acid was added, and the reaction was stirred for 2 hours. Then, 10 mol of acetanilide was added, and the reaction temperature was controlled at 15°C and the reaction was carried out for 4 hours.

[0061] (b) Chlorination reaction: The reaction solution was heated to 45°C, 14 mol of thionyl chloride was added, and carbon tetrachloride was added as an auxiliary agent, and the reaction was continued for 4 hours;

[0062] (c) Reduction reaction: add 10 mol of sodium sulfite, stir evenly, control the reaction temperature to 28°C, use sodium hydroxide solution to maintain pH = 7.5, and react for 2.5 hours to obtain a reduction reaction solution;

[0063] (d) Condensation reaction: 15 mol of ethylene oxide was added to the reduction reaction solution, and the reaction temperature was controlled at 60° C.; condensation was carried out using the condensation apparatus described in Examples 1-2 and Comparative Example 1. The amount of reducing solution in the condensation reaction vessel was detected, and the reaction time was recorded when the amount of reducing solution reached zero;

[0064] (e) Hydrolysis and esterification: Sulfuric acid was added for esterification, the temperature was raised to 102°C, hydrolysis was carried out for 2.5 hours, and then the temperature was raised to 132°C and esterification was carried out for 4 hours to obtain the para-ester.

[0065] Table 1 Condensation reaction time

[0066] Group Condensation reaction time Example 1 2.6h Example 2 1.8h Comparative Example 1 4h

[0067] As can be seen from Examples 1-2 and Comparative Example 1 in conjunction with Table 1, the condensation device prepared in the application is used to perform staged condensation of ethylene oxide and the reducing liquid. By configuring the mixing tube, the rotating device, and the like, the contact area between ethylene oxide and the reducing liquid can be increased, the utilization rate of ethylene oxide and the reducing liquid can be improved, the condensation reaction time can be shortened, and the reaction rate can be increased.

[0068] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A para-ester condensation device, characterized in that: The invention comprises a reducing liquid feed pipe (1), an ethylene oxide air inlet pipe (2), a mixing pipe (21), a sleeve (23), a pipeline (24), a reactor (3), a cooling pool (32), a condensation reactor (4) and a gas collecting component (5), wherein the reactor (3) is arranged in the cooling pool (32), the reactor (3) is used to receive reducing liquid and ethylene oxide, the reducing liquid feed pipe (1) and the ethylene oxide are connected with the mixing pipe (21), the liquid outlet of the mixing pipe (21) is located below the reaction liquid level of the reactor (3), the reactor (3) is connected with the condensation reactor (4) through the pipeline (24), and the reactor (3) is arranged in an inverted trapezoidal shape, with a larger upper portion and a smaller lower portion; The reactor (3) is provided with a rotating device (6) capable of rotating along its own central axis; the rotating device (6) includes a gear ring (61) fixedly connected to the side of the reactor (3) away from the reducing liquid feed pipe (1) and the ethylene oxide inlet pipe (2), a gear (62) matched with the gear ring (61), a connecting rod (63) fixedly connected to the gear (62) and extending to the outside of the cooling pool (32), a connecting rod (63) is provided at the other end of the connecting rod (63) away from the gear (62), the connecting rod (63) is connected to the cooling pool (32) through a bearing, and a power element (64) is connected to the end of the connecting rod (63) away from the reactor (3).

2. The para-ester condensation device according to claim 1, characterized in that A heater (11) is provided on the reducing liquid feeding pipe (1) to preheat the reducing liquid to 40-45°C.

3. The para-ester condensation device according to claim 1, characterized in that A control unit is provided in the condensation device, and the control unit includes an air inlet valve (7), a liquid inlet valve (71), a liquid outlet valve (241), a temperature controller (72) and a gravity sensor (73).

4. The para-ester condensation device according to claim 1, characterized in that The sleeve (23) and the pipe (24) are respectively connected to the reactor (3) in a rotary sealing manner.

5. The para-ester condensation device according to claim 1, characterized in that The pipeline (24) is arranged in a serpentine shape.

6. A process for condensing a para-ester, characterized in that: The condensation device for the para-ester according to any one of claims 1 to 5 comprises the following steps: S1: heating the reducing solution to obtain a heated reducing solution; S2: The heated reducing liquid and ethylene oxide are respectively introduced into the mixing tube (21) through the reducing liquid feed pipe (1) and the ethylene oxide inlet pipe (2) to perform primary condensation to obtain a primary condensation liquid; S3: the primary condensation liquid flows into the reactor (3) to undergo secondary condensation to obtain a secondary condensation liquid; S4: Finally, the secondary condensation liquid is flowed into the condensation reaction kettle (4) through the pipeline (24) to carry out three condensations to obtain a tertiary condensation liquid.

7. The condensation process for para-ester according to claim 6, characterized in that: The reaction temperature of the secondary condensation is 50-65°C.

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