A refining device and refining method for a polymerization product and applications

Abstract

The application discloses a refining device and method and application of a polymerization product, and the refining device comprises a de-aldehyde tower, a de-watering tower, a water distribution tank, a light component removing tower, a by-product tower and a product tower. The reaction product obtained through the dehydration condensation reaction of ethylene glycol contains components such as water, acetaldehyde, diethylene glycol, 1,4-dioxane and 2-methyl dioxolane, and has the characteristics of complex components and multiple azeotrope pairs. The application provides a sequential rectification method by introducing azeotrope-breaking components for the components, so that the diethylene glycol product with high purity and the acetaldehyde and 1,4-dioxane by-products are separated, the process is continuous and easy to operate, and has industrial feasibility.

Description

TECHNICAL FIELD

[0001] The application relates to a refining device and method for a polymerization product and application, and belongs to the technical field of chemical industry. BACKGROUND

[0002] Diethylene glycol, also known as ethylene glycol, is commonly used as an organic solvent, an antifreeze, a moisture absorbent, a softener and a plasticizer, and is widely applied to the daily chemical industry and equipment manufacturing industry such as oils, resins, nitrocellulose and dyes. At present, diethylene glycol products are all by-products of ethylene glycol produced by water hydration of ethylene oxide, and generally account for 8-10% of the yield of ethylene glycol. In recent years, with the continuous development of the polyester industry in China and the continuous increase in the requirements of high-level equipment manufacturing industry, the demand for diethylene glycol is also increasing, and therefore the production attribute of diethylene glycol as a by-product seriously limits the improvement of production capacity, and the exploration of a new diethylene glycol synthesis route is particularly urgent.

[0003] The dehydration and condensation of ethylene glycol is an ideal production process of diethylene glycol, and the application proposes a product / by-product separation and refining process scheme for the reaction product of the diethylene glycol synthesis method, the process is simple, and continuous production can be realized, and is suitable for industrialized continuous production operation. SUMMARY

[0004] According to one aspect of the application, a refining device for a polymerization product is provided, and the refining device comprises a de-aldehyde tower, a de-watering tower, a water separation tank, a de-light tower, a by-product tower and a product tower.

[0005] The de-aldehyde tower is connected with the de-watering tower, the bottom of the de-watering tower is connected with the de-light tower, the de-light tower is connected with the by-product tower, and the by-product tower is connected with the product tower.

[0006] The top of the de-watering tower is connected with the water separation tank, and the discharge port of the water separation tank is connected with the de-watering tower.

[0007] A raw material inlet is arranged on the de-watering tower.

[0008] An outlet for a refined product of the polymerization product is arranged on the product tower.

[0009] Optionally, the reflux ratio of the de-aldehyde tower is 230-350.

[0010] Optionally, the number of theoretical tower plates of the de-aldehyde tower is 10-80.

[0011] Optionally, the top temperature of the de-aldehyde tower is 10-100 DEG C, and the operating pressure is 100-500 kPaA.

[0012] Optionally, the reflux ratio of the de-watering tower is 0.1-30.

[0013] Optionally, the number of theoretical plates of the dehydration column is 10-80.

[0014] Optionally, the overhead temperature of the dehydration column is 40-100℃, and the operating pressure is 100-500 kPaA.

[0015] Optionally, the operating temperature of the water knock-out tank (3) is 40-100℃, and the operating pressure is 100-500 kPaA.

[0016] Optionally, the reflux ratio of the light-removing column (4) is 150-350.

[0017] Optionally, the number of theoretical plates of the light-removing column (4) is 10-80.

[0018] Optionally, the overhead temperature of the light-removing column (4) is 50-150℃, and the operating pressure is 100-300 kPaA.

[0019] Optionally, the reflux ratio of the by-product column is 0.01-5.

[0020] Optionally, the number of theoretical plates of the by-product column is 10-60.

[0021] Optionally, the overhead temperature of the by-product column is 10-100℃, and the operating pressure is 1-100 kPaA.

[0022] Optionally, the reflux ratio of the product column is 3-15.

[0023] Optionally, the number of theoretical plates of the product column is 10-60.

[0024] Optionally, the overhead temperature of the product column is 80-150℃, and the operating pressure is 1-100 kPaA.

[0025] According to another aspect of the present application, there is provided a refining method of a polymerization product, which comprises:

[0026] introducing the polymerization product into a reaction device, and rectifying to obtain a refined product of the polymerization product;

[0027] The reaction device is selected from the refining devices of the polymerization product as described above.

[0028] Optionally, the polymerization product comprises the following components in terms of molar composition:

[0029]

[0030] Optionally, the refining method comprises the following steps:

[0031] (1) The polymerization product is sent into the de-aldehyde column as raw material, and is distilled to obtain by-product acetaldehyde at the top of the de-aldehyde column;

[0032] (2) The de-acetaldehyde mixture at the bottom of the de-aldehyde column is mixed with a dehydrating agent in the dehydrating column, and is distilled to obtain dehydrated material at the bottom of the dehydrating column, which is sent into the de-light column. The product at the bottom of the de-light column is sent into the by-product column after distillation, and the product at the bottom of the by-product column is sent into the product column after distillation;

[0033] The by-product column obtains 1,4-dioxane at the top, and the product column obtains crude ethylene glycol at the top and diethylene glycol at the bottom;

[0034] (3) The mixture containing water and the dehydrated de-azeotrope at the top of the dehydrating column is sent into the water separator to obtain waste water and dehydrated de-azeotrope, and the dehydrated de-azeotrope is sent into the dehydrating column again.

[0035] Optionally, the refining method of the polymerization product comprises the following steps:

[0036] 1) The de-aldehyde column 1 is provided with a separation raw material inlet, and uses micro-positive pressure total condensation distillation to obtain by-product acetaldehyde at the top and de-acetaldehyde mixture at the bottom;

[0037] 2) The de-acetaldehyde mixture at the bottom of the de-aldehyde column 1 is mixed with a de-azeotrope, and is sent into the dehydrating column 2. The dehydrating column 2 uses atmospheric distillation to obtain a mixture of water and de-azeotrope at the top and dehydrated material at the bottom;

[0038] 3) The top of the dehydrating column 2 is connected with the water separator 3, and the material is separated into layers in the water separator 3 to obtain waste water and dehydrated de-azeotrope. The de-azeotrope outlet is connected with the dehydrating column 2 inlet;

[0039] 4) The bottom of the dehydrating column 2 is connected with the de-light column 4. The de-light column 4 is provided with a light impurity outlet and pipeline at the top, and is connected with the by-product column 5 at the bottom;

[0040] 5) The by-product column 5 is provided with a by-product 1,4-dioxane outlet and pipeline at the top, and is connected with the product column 6 at the bottom.

[0041] 6) The product column 6 is provided with a crude ethylene glycol raw material outlet at the top, and obtains diethylene glycol product at the bottom.

[0042] Optionally, the de-azeotrope is selected from at least one of benzene, dimethylbenzene, acetone and cyclohexane.

[0043] According to another aspect of the present application, the refining device of the above-mentioned polymerization product is applied to the separation and refinement of the ethylene glycol dehydration polymerization reaction product.

[0044] In the present application, a refining method of polymerization product, using the mixed product obtained by the dehydration condensation reaction of ethylene glycol as raw material (the molar composition of the raw material is 0.1-10% of ethylene glycol, 15-32% of diethylene glycol, 5-20% of 1,4-dioxane, 0.01-0.5% of acetaldehyde, 0.01-0.5% of 2-methyl dioxolane, and 25-70% of water), the refining device comprises the following parts: deacetaldehyde column 1, dehydration column 2, water separation tank 3, light component removal column 4, by-product column 5, and product column 6. The condensation reaction product is first sent to the deacetaldehyde column 1, and the by-product acetaldehyde is separated at the top, and the mixture at the bottom is sent to the dehydration column 2. The breaking azeotrope component is introduced into the upper part of the dehydration column 2, and the oil-water two-phase mixture is obtained at the top, which is separated into layers in the water separation tank 3 to obtain waste water and the breaking azeotrope agent for recycling. The dehydration mixture at the bottom of the dehydration column 2 is sent to the light component removal column 4, and the light impurity oil is obtained at the top, and the dehydrogenation mixture obtained at the bottom is sent to the by-product column 5, and the by-product 1,4-dioxane is separated at the top, and the ethylene glycol / diethylene glycol mixture obtained at the bottom is sent to the product column 6. The unreacted ethylene glycol is obtained at the top of the product column 6, and the diethylene glycol product is obtained at the bottom.

[0045] The beneficial effects that can be produced by the present application include:

[0046] The refining method of polymerization product provided by the present application has the characteristics of complex components and multiple azeotrope coexistence in the reaction product obtained by the dehydration condensation reaction of ethylene glycol, acetaldehyde, diethylene glycol, 1,4-dioxane, 2-methyl dioxolane, etc. The present application provides a sequence rectification method by introducing a breaking azeotrope component, so as to separate the diethylene glycol product with high purity and the by-products of acetaldehyde and 1,4-dioxane, and the process is continuous and easy to operate, and has industrial feasibility. It can be used for the separation and refining of the polymerization product of ethylene glycol dehydration, and the process is continuous and simple, and is suitable for industrial continuous production operation. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 Figure 1 is a structural schematic diagram of the refining device of the polymerization product in Example 1 of the present application.

[0048] Wherein:

[0049] 1, deacetaldehyde column; 2, dehydration column; 3, water separation tank; 4, light component removal column; 5, by-product column; 6, product column. DETAILED DESCRIPTION

[0050] The present application will be described in detail below in combination with examples, but the present application is not limited to these examples.

[0051] The raw materials in the examples of the present application are all purchased through commercial channels unless otherwise specified.

[0052] Example 1

[0053] AsFigure 1 The refining device for the polymerization product comprises a de-aldehyde column 1, a de-watering column 2, a water separation tank 3, a de-light column 4, a by-product column 5, and a product column 6. The de-aldehyde column 1 is connected with the de-watering column 2, the bottom of the de-watering column 2 is connected with the de-light column 4, the de-light column 4 is connected with the by-product column 5, and the by-product column 5 is connected with the product column 6. The top of the de-watering column 2 is connected with the water separation tank 3, and the discharge port of the water separation tank 3 is connected with the de-watering column 2. The de-watering column 2 is provided with a raw material inlet. The product column 6 is provided with an outlet for the refined product of the polymerization product.

[0054] Example 2

[0055] The condensation reaction product (molar composition: ethylene glycol 2.1%, diethylene glycol 27.9%, 1,4-dioxane 13.8%, acetaldehyde 0.16%, 2-methyldioxolane 0.16%, and water 55.9%) is first sent to the de-aldehyde column 1. The top pressure of the de-aldehyde column 1 is 150 kPaA, the top temperature is 32°C, 30 theoretical plates are provided, and the reflux ratio is 250. Acetaldehyde is separated at the top. The mixture at the bottom of the de-aldehyde column 1 is sent to the de-watering column 2. The top pressure of the de-watering column 2 is 110 kPaA, the top temperature of the de-watering column 2 is 56°C, 50 theoretical plates are provided, and the reflux ratio is 10. Cyclohexane is introduced into the upper part as a de-azeotrope breaker. A two-phase mixture of cyclohexane and water is obtained at the top of the de-watering column 2 and is sent to the water separation tank 3. The two-phase mixture is separated at 56°C and 110 kPaA to obtain waste water and recycled cyclohexane. The de-watering mixture at the bottom of the de-watering column 2 is sent to the de-light column 4. The top pressure of the de-light column 4 is 110 kPaA, the top temperature is 84°C, 50 theoretical plates are provided, and the reflux ratio is 290. Light impurity oil containing 2-methyldioxolane is obtained at the top of the de-light column 4. The de-hydrogenation mixture obtained at the bottom of the de-light column 4 is sent to the by-product column 5. The top pressure of the by-product column 5 is 10 kPaA, the top temperature is 39°C, 25 theoretical plates are provided, and the reflux ratio is 0.8. By-product 1,4-dioxane with a molar concentration of 99.9% is separated at the top. The ethylene glycol / diethylene glycol mixture obtained at the bottom is sent to the product column 6. The top pressure of the product column 6 is 5 kPaA, the top temperature is 117°C, 35 theoretical plates are provided, and the reflux ratio is 8.6. Unreacted ethylene glycol is obtained at the top of the product column 6. Diethylene glycol product with a molar concentration of 99.96% is obtained at the bottom of the product column 6.

[0056] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed above, the present application is not limited thereto. Any person skilled in the art can make some changes or modifications to the disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments and belong to the scope of the technical solution.

Claims

1. A device for refining a polymerization product, characterized by The refining device comprises a de-aldehyde column (1), a de-watering column (2), a water separation tank (3), a de-light column (4), a by-product column (5), and a product column (6); The bottom of the de-aldehyde column (1) is connected with the de-watering column (2), the bottom of the de-watering column (2) is connected with the de-light column (4), the bottom of the de-light column (4) is connected with the by-product column (5), and the bottom of the by-product column (5) is connected with the product column (6); The top of the de-watering column (2) is connected with the water separation tank (3), and the discharge port of the water separation tank (3) is connected with the de-watering column (2); The de-watering column (2) is provided with a raw material inlet; The product column (6) is provided with an outlet for the refined product of the polymerization product.

2. The finishing apparatus according to claim 1, characterized by The reflux ratio of the de-aldehyde column (1) is 230-350; The theoretical plate number of the de-aldehyde column (1) is 10-80; The top temperature of the de-aldehyde column (1) is 10-100 ℃, and the operating pressure is 100-500 kPaA.

3. The finishing apparatus according to claim 1, characterized by The reflux ratio of the de-watering column (2) is 0.1-30; The theoretical plate number of the de-watering column (2) is 10-80; The top temperature of the de-watering column (2) is 40-100 ℃, and the operating pressure is 100-500 kPaA.

4. The finishing apparatus according to claim 1, wherein The operating temperature of the water separation tank (3) is 40-100 ℃, and the operating pressure is 100-500 kPaA; The reflux ratio of the de-light column (4) is 150-350; The theoretical plate number of the de-light column (4) is 10-80; The top temperature of the de-light column (4) is 50-150 ℃, and the operating pressure is 100-300 kPaA.

5. The finishing apparatus according to claim 1, wherein The reflux ratio of the by-product column (5) is 0.01-5; The theoretical plate number of the by-product column (5) is 10-60; The top temperature of the by-product column (5) is 10-100 ℃, and the operating pressure is 1-100 kPaA.

6. The finishing apparatus of claim 1, wherein The reflux ratio of the product column (6) is 3-15; The theoretical plate number of the product column (6) is 10-60; The top temperature of the product column (6) is 80-150 ℃, and the operating pressure is 1-100 kPaA.

7. A method for refining a polymerization product, characterized by, The refining method comprises the following steps: The polymerization product is introduced into a reaction device as a raw material, and is subjected to rectification to obtain a refined product of the polymerization product; The reaction device is selected from the refining device of the polymerization product according to any one of claims 1 to 6.

8. The method of claim 7, wherein the refining is performed by a method comprising: According to the molar composition, the polymerization product comprises the following components: Ethylene glycol 0.1-10%; Diethylene glycol 15-32%; 1,4-dioxane 5-20%; Acetaldehyde 0.01-0.5%; 2-methyl dioxolane 0.01-0.5%; Water 25-70%.

9. The method of claim 7, wherein the refining is performed by a method comprising: The refining method comprises the following steps: (1) The polymerization product is introduced into the de-aldehyde column as a raw material, and is subjected to rectification to obtain by-product acetaldehyde at the top of the de-aldehyde column; (2) The de-acetaldehyde mixture at the bottom of the de-aldehyde column is mixed with a de-azeotrope agent, and is subjected to rectification, and the de-watering material at the bottom of the de-watering column is introduced into the de-light column, and the product at the bottom of the de-light column is introduced into the by-product column and is subjected to rectification, and the product at the bottom of the by-product column is introduced into the product column and is subjected to rectification; The overhead of the by-product column obtains 1,4-dioxane; the overhead of the product column obtains crude ethylene glycol, and the bottom thereof obtains diethylene glycol; (3) The mixture containing water and the broken azeotrope on the top of the dehydration column enters a water trap, is separated into layers, to obtain waste water and the dehydrated broken azeotrope, and the dehydrated broken azeotrope reenters the dehydration column; The broken azeotrope is selected from at least one of benzene, xylene, acetone, and cyclohexane.

10. Use of a refining device of the polymeric product according to any one of claims 1 to 6 in the separation and refining of the polymeric reaction product of the dehydration of ethylene glycol.

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