Device and method for purifying alpha-methyl styrene from phenol-acetone production by-products

Abstract

The invention belongs to the technical field of byproduct recovery in phenol-acetone production, and particularly relates to a device and a method for purifying alpha-methyl styrene from byproducts in phenol-acetone production. The device comprises a filter, a light component removal tower, an AMS purification tower, a first cooler, a second cooler, a first reflux tank, a second reflux tank, a first reflux pump, a second reflux pump, a first reboiler, a second reboiler and a discharge pump. The alpha-methylstyrene is purified by using the device disclosed by the invention, so that the investment cost of a catalyst for generating cumene through hydrogenation of AMS is saved, the alpha-methylstyrene with high additional value can be recovered, and the economic benefit is improved.

Description

Technical Field

[0001] The invention relates to the technical field of recovery of byproducts from phenol acetone production, and in particular to a device and a method for purifying alpha-methylstyrene from byproducts from phenol acetone production. Background Art

[0002] The phenol acetone unit uses the cumene process to produce phenol acetone, and a large amount of crude by-products containing alpha-methylstyrene (AMS) are produced during the production process. AMS is a colorless liquid with a pungent odor. It polymerizes when heated and is flammable. It is often used in polymerization reactions to produce monomers or modified monomers for adhesive base materials. The traditional process is to hydrogenate AMS to generate cumene and return it to the phenol acetone unit. However, in the AMS hydrogenation process, the catalyst is a precious metal catalyst, which has a high investment cost, and when there is a large difference in the market price of AMS and cumene, the benefits cannot be maximized. Summary of the invention

[0003] The purpose of the present invention is to provide a device and method for purifying alpha-methylstyrene from by-products of phenol acetone production. By purifying and reusing the alpha-methylstyrene, the investment cost of the catalyst is saved, and the high-value-added alpha-methylstyrene can be recovered, thereby improving the economic benefits.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows:

[0005] On one hand, the present invention provides a device for purifying alpha-methylstyrene from byproducts of phenol acetone production, the device comprising: a filter, a lightness removal tower, an AMS purification tower, a first cooler, a second cooler, a first reflux tank, a second reflux tank, a first reflux pump, a second reflux pump, a first reboiler, a second reboiler, and a discharge pump;

[0006] The filter is connected to a lightness removal tower;

[0007] The top outlet of the light-removal tower is connected to the first reflux tank via the first cooler, and the first reflux tank refluxes to the light-removal tower via the first reflux pump;

[0008] The bottom outlet of the light removal tower is connected to the AMS purification tower via a discharge pump;

[0009] The top outlet of the AMS purification tower is connected to the second reflux tank via a second cooler, and the second reflux tank refluxes to the AMS purification tower via a second reflux pump;

[0010] The first reboiler is connected to the bottom of the light removal tower;

[0011] The second reboiler is connected to the bottom of the AMS purification column.

[0012] In the above technical solution, further, the device also includes a third cooler and a vacuum pump, the third cooler is connected to the first reflux tank, and the vacuum pump is connected to the third cooler.

[0013] In the above technical solution, further, the first reboiler is a thermal syphon reboiler.

[0014] In the above technical solution, further, the second reboiler is a thermal syphon reboiler.

[0015] Another aspect of the present invention provides a method for purifying α-methylstyrene from phenol acetone byproduct, the method utilizing the above-mentioned device, the method comprising the following steps:

[0016] (1) The phenol-acetone byproduct is filtered through a filter to remove tiny particle impurities to reduce the impact on downstream equipment. The filtered phenol-acetone byproduct enters a light-removal tower;

[0017] (2) The light-removal tower is heated by 2.3 MPa steam through the first reboiler, and the working pressure of the dehydrogenation tower is -70 to -68 kPa. The vapor phase material of the light-removal tower is condensed by the first cooler and enters the first reflux tank. The material in the first reflux tank is refluxed to the light-removal tower through the first reflux pump, and isopropylbenzene is collected in the other way. The bottom material of the tower enters the AMS purification tower through the discharge pump;

[0018] (3) The AMS purification tower is heated by 2.3 MPa steam through the second reboiler. The working pressure of the AMS purification tower is 8-10 kPa. The vapor phase material at the top of the AMS purification tower is condensed by the second cooler and then enters the second reflux tank. The material in the second reflux tank is refluxed to the AMS purification tower through the second reflux pump. The purified AMS is collected in another way, and tar is collected at the bottom of the tower.

[0019] In the above technical solution, further, the material in the first reflux tank enters the third cooler for condensation, so as to minimize the loss of isopropylbenzene in the exhaust gas, and the condensate returns to the first reflux tank by gravity, and the non-condensable gas enters the vacuum pump.

[0020] The beneficial effects of the present invention are:

[0021] The device of the present invention can effectively purify alpha-methylstyrene, which not only saves the investment cost of the catalyst for generating cumene through hydrogenation of AMS, but also can recover high value-added alpha-methylstyrene, thereby improving the economic benefits.

[0022] According to the load calculation of the device of the present invention, 20,000 tons of α-methylstyrene can be produced annually. The market price of α-methylstyrene is 16,500 yuan, and the market price of isopropylbenzene is 9,300 yuan. Ignoring hydrogen, utility consumption, and catalyst prices, a rough calculation shows that the benefits can be increased by (16,500-9,300)*8,000=57.6 million / year. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic structural diagram of a device for purifying α-methylstyrene from by-products of phenol and acetone production;

[0024] In the figure: 1. filter, 2. lightness removal tower, 3. AMS purification tower, 4. first reboiler, 5. second reboiler, 6. discharge pump, 7. first cooler, 8. first reflux tank, 9. second cooler, 10. second reflux tank, 11. first reflux pump, 12. second reflux pump, 13. third cooler, 14. vacuum pump. DETAILED DESCRIPTION

[0025] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0026] A device for purifying α-methylstyrene from a by-product of phenol-acetone production, such as Figure 1 As shown, it includes: a filter 1, a light-removing tower 2, an AMS purification tower 3, a first cooler 7, a second cooler 9, a third cooler 13, a first reflux 8, a second reflux tank 10, a first reflux pump 11, a second reflux pump 12, a first reboiler 4, a second reboiler 5, a discharge pump 6 and a vacuum pump 14; the light-removing tower 2 is used to purify isopropylbenzene in the by-product of phenol acetone production, and the AMS purification tower 3 is used to purify AMS; the filter 1 is connected to the light-removing tower 2, and the filter 1 is used to filter tiny particulate impurities; the top outlet of the light-removing tower 2 is connected to the first reflux tank 8 through the first cooler 7 The first reflux tank 8 is refluxed to the lightness removal tower 2 via the first reflux pump 11; the first reboiler 4 is connected to the bottom of the lightness removal tower 1, and the first reboiler 4 is used to heat the material in the tower; the bottom outlet of the lightness removal tower 2 is connected to the AMS purification tower 3 via a discharge pump 6; the top outlet of the AMS purification tower 3 is connected to the second reflux tank 10 via a second cooler 9, and the second reflux tank 10 is refluxed to the AMS purification tower 3 via a second reflux pump 12; the second reboiler 5 is connected to the bottom of the AMS purification tower 3; the third cooler 13 is connected to the first reflux tank 8, and the vacuum pump 14 is connected to the third cooler 13.

[0027] In the present invention, the first reboiler 4 and the second reboiler 5 are both thermosyphon reboilers, and the heat source is water vapor.

[0028] The method for purifying alpha-methylstyrene from the byproduct of phenol acetone production using the above-mentioned device comprises the following steps:

[0029] (1) Phenol-acetone byproduct is filtered through filter 1 to remove tiny particle impurities to reduce the impact on downstream equipment, and the filtered phenol-acetone byproduct enters lightness removal tower 2;

[0030] (2) The light-removal tower 2 is heated by 2.3 MPa steam through the first reboiler 4, and the working pressure of the dehydrogenation tower 2 is -70 to -68 kPa. The vapor phase material of the light-removal tower 2 is condensed by the first cooler 7 and enters the first reflux tank 8. The material in the first reflux tank 8 is refluxed to the light-removal tower 2 through the first reflux pump 11, and isopropylbenzene is collected in the other way. The bottom material enters the AMS purification tower 3 through the discharge pump;

[0031] (3) The AMS purification tower 3 is heated by 2.3 MPa steam through the second reboiler 5. The working pressure of the AMS purification tower 3 is 8-10 kPa. The vapor phase material at the top of the AMS purification tower 3 is condensed by the second cooler 9 and then enters the second reflux tank 10. The material in the second reflux tank 10 is refluxed to the AMS purification tower 3 through the second reflux pump 12. The purified AMS is collected in another way, and tar is collected at the bottom of the tower.

[0032] In order to minimize the loss of isopropylbenzene in the exhaust gas, the material in the first reflux tank 8 enters the third cooler 13 for condensation, and the condensate returns to the first reflux tank 8 by gravity, and the non-condensable gas enters the vacuum pump 14.

[0033] Example 1

[0034] (1) The phenol-acetone byproduct at 45°C is filtered through filter 1 to remove tiny particle impurities to reduce the impact on downstream equipment. The filtered phenol-acetone byproduct enters light-removal tower 2;

[0035] (2) The light-removal tower 2 is heated by 2.3 MPa steam through the first reboiler 4, and the working pressure of the dehydrogenation tower 2 is -70 kPa. The vapor phase material of the light-removal tower 2 is condensed by the first cooler 7 from the tower top outlet and enters the first reflux tank 8. The material in the first reflux tank 8 is refluxed to the light-removal tower 2 through the first reflux pump 11, and isopropylbenzene is collected in another way. The bottom material enters the AMS purification tower 3 through the discharge pump 6;

[0036] (3) The AMS purification tower 3 is heated by 2.3 MPa steam through the second reboiler 5. The working pressure of the AMS purification tower 3 is 10 kPa. The vapor phase material of the AMS purification tower 3 is condensed by the second cooler 9 from the top outlet and enters the second reflux tank 10. The material in the second reflux tank 10 is refluxed to the AMS purification tower 3 through the second reflux pump 12. The purified AMS is collected in another way. Tar is collected at the bottom of the tower. The purity of the purified AMS is 99.9%.

[0037] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the implementation methods. The protection scope of the present invention shall be subject to the scope defined in the claims. Other different forms of changes or modifications may be made based on the above description. Obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A device for purifying α-methylstyrene from phenol-acetone by-products, It is characterized in that The device comprises: a filter, a lightness removal tower, an AMS purification tower, a first cooler, a second cooler, a first reflux tank, a second reflux tank, a first reflux pump, a second reflux pump, a first reboiler, a second reboiler, and a discharge pump; The filter is connected to a lightness removal tower; The top outlet of the light-removal tower is connected to the first reflux tank via the first cooler, and the first reflux tank refluxes to the light-removal tower via the first reflux pump; The bottom outlet of the light removal tower is connected to the AMS purification tower via a discharge pump; The top outlet of the AMS purification tower is connected to the second reflux tank via a second cooler, and the second reflux tank refluxes to the AMS purification tower via a second reflux pump; The first reboiler is connected to the bottom of the light removal tower; The second reboiler is connected to the bottom of the AMS purification column.

2. The device for purifying alpha-methylstyrene from phenol-acetone byproduct according to claim 1, It is characterized in that The device also includes a third cooler and a vacuum pump, wherein the third cooler is connected to the first reflux tank, and the vacuum pump is connected to the third cooler.

3. The device for purifying alpha-methylstyrene from phenol-acetone byproduct according to claim 1, It is characterized in that The first reboiler is a thermosyphon reboiler.

4. The device for purifying alpha-methylstyrene from phenol-acetone byproduct according to claim 1, It is characterized in that The second reboiler is a thermosyphon reboiler.

5. A method for purifying α-methylstyrene from phenol acetone by-product, It is characterized in that The method utilizes the device according to any one of claims 1 to 4, and the method comprises the following steps: (1) filtering the phenol-acetone byproduct to remove particulate impurities through a filter, and the filtered phenol-acetone byproduct enters a light-removal tower; (2) The light-removal tower is heated by 2.3 MPa steam through the first reboiler, and the working pressure of the dehydrogenation tower is -70 to -68 kPa. The vapor phase material of the light-removal tower is condensed by the first cooler and enters the first reflux tank. The material in the first reflux tank is refluxed to the light-removal tower through the first reflux pump, and isopropylbenzene is collected in the other way. The bottom material of the tower enters the AMS purification tower through the discharge pump; (3) The AMS purification tower is heated by 2.3 MPa steam through the second reboiler. The working pressure of the AMS purification tower is 8-10 kPa. The vapor phase material at the top of the AMS purification tower is condensed by the second cooler and then enters the second reflux tank. The material in the second reflux tank is refluxed to the AMS purification tower through the second reflux pump. The purified AMS is collected in another way, and tar is collected at the bottom of the tower.

6. The method for purifying alpha-methylstyrene from phenol-acetone byproduct according to claim 5, It is characterized in that The gaseous material in the first reflux tank enters the third cooler for condensation, and the condensate returns to the first reflux tank by gravity, and the non-condensable gas enters the vacuum pump.

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