High-purity and high-efficiency distillation device for diphenyl ethane reaction solution

Abstract

The utility model relates to a kind of high-purity high-efficiency diphenylmethane reaction liquid distillation device, more than one regular metal packing section is arranged in upper portion of evaporation tank, evaporation tank top is connected with benzene recovery storage tank by gas phase extraction pipeline with first, second heat exchanger in proper order, heat absorption heat course import of first heat exchanger is connected with reaction liquid inlet pipe, heat absorption heat course export is connected with reboiler bottom feed, reboiler top is connected with evaporation tank middle portion, the gas phase extraction pipeline after second heat exchanger is divided into reflux pipeline, reflux pipeline is connected with evaporation tank upper portion by reflux control valve;Evaporation tank bottom or lower portion is connected with two routes, one is connected with reboiler bottom feed by circulating pipeline with circulation control valve in proper order, another is connected with diphenylmethane storage tank by liquid phase extraction pipeline with extraction control valve, extraction pump in proper order.The device structure is simple, can effectively improve diphenylmethane, benzene distillation separation purity and efficiency, meet the requirement of energy saving and consumption reduction of industrial production simultaneously.

Description

Technical Field

[0001] This utility model relates to a distillation apparatus, specifically a high-purity and high-efficiency diphenyl ethane reaction liquid distillation apparatus. Background Technology

[0002] Currently, industrial production of diphenyl ethane uses benzene and 1,2-dichloroethane as raw materials, typically adding an excess of benzene. This excess benzene helps improve reaction selectivity and suppress polyalkylation byproducts. During the distillation separation of excess benzene from the reaction liquid, although the boiling points of the two are significantly different, there is a phenomenon where the distillate benzene contains about 5% diphenyl ethane. After the distillate benzene is recovered and participates in the diphenyl ethane synthesis reaction, the benzene ring contained therein can be further alkylated, generating high-boiling-point byproducts (such as triphenyl ethane or polymers), which reduces the purity and yield of the diphenyl ethane product and increases energy consumption. Summary of the Invention

[0003] This invention provides a reaction liquid distillation apparatus with a simple structure that can effectively improve the purity and efficiency of distillation separation of diphenyl ethane and benzene.

[0004] The technical solution adopted in this utility model is as follows: a high-purity and high-efficiency distillation device for diphenyl ethane reaction liquid, including an evaporator and a reboiler, wherein the top of the reboiler is connected to the lower part or the lower side of the evaporator, characterized in that: the middle and / or upper part of the evaporator is provided with one or more sections of regular metal packing; the top of the evaporator is connected to a benzene recovery storage tank via a gas phase outlet pipeline with a first and a second heat exchanger in sequence; the heat absorption heat range inlet of the first heat exchanger is connected to the reaction liquid inlet pipe, and the heat absorption heat range outlet is connected to the bottom feed of the reboiler; a reflux pipeline is branched off from the gas phase outlet pipeline after the second heat exchanger, and the reflux pipeline is connected to the upper part of the evaporator via a reflux control valve; two paths are connected from the bottom or lower part of the evaporator, one path is connected to the bottom feed of the reboiler via a circulation pipeline with a circulation control valve in sequence, and the other path is connected to the diphenyl ethane storage tank via a liquid phase outlet pipeline with an outlet control valve and an outlet pump in sequence.

[0005] Furthermore, the structured metal packing section adopts multi-layer wire mesh corrugated packing.

[0006] Furthermore, the outlet position of the circulation pipeline on the evaporator is higher than the outlet position of the liquid phase extraction pipeline on the evaporator.

[0007] Furthermore, the evaporator is also equipped with a drain pipe located at a position lower than that of the liquid phase storage tank on the evaporator.

[0008] Furthermore, the liquid phase extraction pipeline is equipped with an extraction filter located before the extraction control valve.

[0009] Furthermore, a liquid level sensor is installed below the middle of the evaporator. The liquid level sensor is connected to a controller, which is connected to a circulation control valve, a collection control valve, and a collection pump.

[0010] Furthermore, a circulation pump is also installed on the circulation pipeline.

[0011] Furthermore, the heat absorption range of the second heat exchanger is used to supply cooling water or benzene as the feed liquid for the diphenyl ethane reaction.

[0012] Furthermore, before the diphenyl ethane is introduced, a branch of the liquid phase extraction pipeline is sent via a control valve to the evaporator or reboiler.

[0013] Furthermore, the reflux pipeline is connected to the evaporator at a position higher than the structured metal packing section.

[0014] The beneficial effects of this utility model are:

[0015] 1. The evaporator is equipped with a corrugated metal wire mesh, which can effectively improve the separation efficiency, reduce the entrainment of diphenyl ethane in benzene, and improve the distillation effect, thus helping to improve the separation purity of benzene.

[0016] 2. Before distillation, the diphenyl ethane synthesis reaction solution is collected and heat-exchanged with benzene vapor in the first heat exchanger, which increases the temperature before entering the reboiler, thus helping to improve distillation efficiency and reduce energy consumption.

[0017] 3. The reaction liquid is sent to the reboiler through the circulation pipeline in the evaporator. It can be sent to the reboiler as needed by forming a siphon or by a circulation pump and controlling the flow rate, so as to improve the distillation separation effect and efficiency.

[0018] 4. The circulation pipeline, liquid phase extraction pipeline and sewage discharge pipeline are connected in sequence from high to low at the bottom of the evaporator, which can effectively ensure the stability of various performance aspects of circulation, extraction and sewage discharge, and comprehensively ensure the internal circulation efficiency, purity of extracted components, efficiency and effective sewage discharge control.

[0019] 5. Since circulation and liquid phase extraction are continuous operations, the liquid phase extraction pipeline can be branched off to the evaporator or reboiler during the initial stage of equipment startup. Once the liquid phase extraction performance is normal and stable, it is not necessary to send it to the evaporator or reboiler.

[0020] 6. The heat exchange of the second heat exchanger can meet the preheating requirements of hot water or benzene, the raw material for diphenyl ethane reaction in the plant area, and the utilization of energy consumption components in industrial production, which helps to save energy and reduce consumption. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] In the diagram: 1. Evaporator; 2. Structured metal packing section; 3. Gas phase extraction pipeline; 4. First heat exchanger; 5. Second heat exchanger; 6. Benzene recovery storage tank; 7. Reflux pipeline; 8. Reflux control valve; 9. Reactant inlet pipe; 10. Reboiler; 11. Circulation pipeline; 12. Circulation control valve; 13. Circulation pump; 14. Liquid phase extraction pipeline; 15. Extraction control valve; 16. Extraction pump; 17. Diphenyl ethane storage tank; 18. Drain pipe; 19. Liquid level sensor; 20. Controller. Detailed Implementation

[0023] The following explanation, in conjunction with the accompanying drawings, will provide further details.

[0024] Figure 1 The image shows a high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid, comprising an evaporator 1, a structured metal packing section 2, a gas phase extraction pipeline 3, a first heat exchanger 4, a second heat exchanger 5, a benzene recovery storage tank 6, a reflux pipeline 7, a reflux control valve 8, a reaction liquid inlet pipe 9, a reboiler 10, a circulation pipeline 11, a circulation control valve 12, a circulation pump 13, a liquid phase extraction pipeline 14, an extraction control valve 15, an extraction pump 16, a diphenyl ethane storage tank 17, a drain pipe 18, a liquid level sensor 19, and a controller 20.

[0025] The upper part of the evaporator 1 is provided with a section of regular metal packing 2. The top of the evaporator 1 is connected to two paths after passing through the gas phase exit pipeline 3 with the first and second heat exchangers 4 and 5 in sequence. One path is connected to the benzene recovery storage tank 6, and the other path is connected to the upper part of the regular metal packing section 2 of the evaporator 1 through the return pipeline 7 with the return control valve 8. The heat absorption heat range inlet of the first heat exchanger 4 is connected to the reaction liquid inlet pipe 9, and the heat absorption heat range outlet is connected to the bottom feed of the reboiler 10. The top of the reboiler 10 is connected to the middle or lower middle part of the evaporator 1. The liquid level sensor 19 is installed below the middle part of the evaporator 1. The liquid level sensor 19 is connected to the circulation pipeline 11, the liquid phase exit pipeline 14 and the drain pipe 18 in sequence below the reboiler access position. The circulation pipeline 11 is connected to the bottom feed of the reboiler 10 in sequence through the circulation control valve 12 and the circulation pump 13 in sequence. The liquid phase exit pipeline 14 is connected to the diphenyl ethane storage tank 17 in sequence through the exit control valve 15 and the exit pump 16 in sequence.

[0026] In this implementation, the structured metal packing section 2 uses multi-layer wire mesh corrugated packing, or other existing metal packing.

[0027] In this embodiment, the liquid level sensor is connected to the controller, and the controller is connected to the circulation control valve, circulation pump, extraction control valve, and extraction pump.

[0028] In this embodiment, the heat absorption range of the second heat exchanger is used to supply cooling water or benzene, the feed liquid for the diphenyl ethane reaction, thereby improving the thermal energy utilization rate of the plant area.

[0029] In this embodiment, the drain pipe is typically located at the bottom.

[0030] Based on this embodiment, control valves, pumps, check valves, flow meters, and controllers are installed on each pipeline for integrated control, which is existing technology. The improvement of this embodiment using the above-mentioned existing technology falls within the protection scope of this application.

[0031] Based on this embodiment, a branch of the liquid phase extraction pipeline can be separated before the diphenyl ethane is introduced and sent to the evaporator or reboiler via a control valve.

[0032] Based on this embodiment, the circulation pump can be eliminated, and the siphon effect can be achieved by utilizing the height difference between the evaporator and the reboiler.

[0033] Based on this embodiment, a production filter can be installed on the liquid phase production pipeline before the production control valve.

Claims

1. A high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid, comprising an evaporator and a reboiler, wherein the top of the reboiler is connected to the lower part or lower side of the evaporator, characterized in that: The evaporator is provided with one or more sections of regular metal packing in the middle and / or upper part. The top of the evaporator is connected to the benzene recovery storage tank via a gas phase exit pipeline with a first and a second heat exchanger in sequence. The heat absorption inlet of the first heat exchanger is connected to the reaction liquid inlet pipe, and the heat absorption outlet is connected to the bottom feed of the reboiler. A reflux pipeline is branched off from the gas phase exit pipeline after the second heat exchanger. The reflux pipeline is connected to the upper part of the evaporator via a reflux control valve. Two paths are connected from the bottom or lower part of the evaporator. One path is connected to the bottom feed of the reboiler via a circulation pipeline with a circulation control valve in sequence, and the other path is connected to the diphenyl ethane storage tank via a liquid phase exit pipeline with an exit control valve and an exit pump in sequence.

2. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: The structured metal packing section uses multi-layer wire mesh corrugated packing.

3. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: The connection point of the circulation pipeline on the evaporator is higher than the connection point of the liquid phase extraction pipeline on the evaporator.

4. A high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1 or 3, characterized in that: The evaporator is also equipped with a drain pipe located at a position lower than that of the liquid phase storage tank on the evaporator.

5. A high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1 or 3, characterized in that: The liquid phase extraction pipeline is equipped with an extraction filter located before the extraction control valve.

6. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: A liquid level sensor is installed below the middle of the evaporator. The liquid level sensor is connected to a controller, which is connected to a circulation control valve, a production control valve, and a production pump.

7. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: A circulation pump is also installed on the circulation pipeline.

8. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: The heat absorption range of the second heat exchanger is used to supply cooling water or benzene as a feed liquid for the diphenyl ethane reaction.

9. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: Before diphenyl ethane is introduced, a branch of the liquid phase extraction pipeline is sent to the evaporator or reboiler via a control valve.

10. The high-purity and high-efficiency distillation apparatus for diphenyl ethane reaction liquid according to claim 1, characterized in that: The reflux pipeline is connected to the evaporator at a position higher than the structured metal packing section.

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