Adsorption column parking cooling system and method

Abstract

The application belongs to the field of chemical industry and particularly relates to an adsorption tower parking cooling system and method, which comprises a desorbent cooling pipeline, a heat exchanger group is connected to the desorbent cooling pipeline, the desorbent cooling pipeline is connected to the raffinate feed inlet of a raffinate column through a cross pipeline after the heat exchanger group, the gas phase outlet at the top of the raffinate column is connected to a top air cooler, a reflux tank, a reflux pump and the raffinate column through pipelines in sequence, the outlet at the bottom of the raffinate column is connected to an adsorption tower feed pipeline through a pipeline, the desorbent cooling pipeline is connected to the adsorption tower feed pipeline, and the reflux tank is provided with a water package dehydration mechanism. The desorbent cooling process is reformed to the raffinate column, circulation is established in advance, is used before the adsorption tower is cooled, water is removed from the raffinate reflux tank through the water package dehydration, and water is avoided from being brought into the adsorption tower.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical industry, and particularly relates to an adsorption tower parking cooling system and method. BACKGROUND

[0002] After the adsorption tower is parked, it needs to be cooled to ensure that the adsorption tower is in a safe state and prevent the material in the tower from being vaporized due to excessively low pressure of the adsorption tower, thereby damaging the adsorbent. Therefore, the adsorption tower is cooled through a desorbent cooling process, and the cooling speed is controlled. However, the material in the underground contaminated oil tank is also withdrawn through the desorbent cooling process. The withdrawn material contains water, and the water is accumulated at a low point of the process for a long time. When the adsorption tower is parked, part of the accumulated water is brought into the adsorption tower, thereby damaging the performance of the adsorbent. SUMMARY

[0003] In view of the defects in the prior art, the purpose of the present application is to provide an adsorption tower parking cooling system and method, which removes the water accumulated in the desorbent cooling process in advance, meets the cooling requirements of the adsorption tower, and protects the adsorbent.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: an adsorption tower parking cooling system, comprising a desorbent cooling pipeline, a heat exchanger group connected to the desorbent cooling pipeline, the desorbent cooling pipeline connected to a raffinate inlet of a raffinate column through a cross pipeline after the heat exchanger group, a gas phase outlet at the top of the raffinate column connected to a tower top air cooler, a reflux tank, a reflux pump and the raffinate column through pipelines in sequence, a tower bottom outlet of the raffinate column connected to an adsorption tower feed pipeline through a pipeline, the desorbent cooling pipeline connected to the adsorption tower feed pipeline, and a water removal mechanism provided in the reflux tank.

[0005] Further, a double gate valve and an 8-shaped blind plate are provided on the cross pipeline.

[0006] Further, a feed valve is provided on the adsorption tower feed pipeline, an inlet of the desorbent cooling pipeline connected to a front route of the feed valve, an outlet of the desorbent cooling pipeline connected to a rear route of the feed valve, and the desorbent cooling pipeline and the adsorption tower feed pipeline forming a loop; a product tower bottom reboiler is provided on the adsorption tower feed pipeline, and the product tower bottom reboiler is provided on the front route of the inlet of the desorbent cooling pipeline.

[0007] Further, double valves are provided at the inlet and outlet of the desorbent cooling pipeline, the desorbent cooling pipeline connected to a storage tank through a withdrawal pipeline, and the withdrawal pipeline connected to a front route of the outlet double valve.

[0008] Further, the heat exchanger group comprises a desorbent air cooler and a desorbent water cooler, the desorbent cooling pipeline connected to the desorbent air cooler and the desorbent water cooler in sequence, and a water cooling cross line provided in parallel with the desorbent water cooler, two ends of the water cooling cross line connected to a front route and a rear route of the desorbent water cooler.

[0009] Further, the raffinate column is provided with a raffinate column feed bottom heat exchanger, which is connected to the raffinate column feed bottom heat exchanger inlet through a cross-line, and is connected to the raffinate column after heat exchange; the bottom outlet of the raffinate column is connected to the raffinate column bottom pump and the raffinate column feed bottom heat exchanger through a pipeline, and is connected to the adsorption column feed pipeline through a pipeline after heat exchange; the raffinate column is connected to the isomerization reaction system through a side sampling line.

[0010] Further, the adsorption column parking cooling system further comprises an underground tank for recycling the closed discharge material in the adsorption column system, and the underground tank outlet is provided with an underground tank outlet pump, which is connected to the raffinate column, the desorbent regeneration column and the desorbent cooling pipeline, respectively.

[0011] Further, the underground tank outlet pump is provided with a return tank line for adjusting the outlet pressure and flow of the pump, and the return tank line returns to the underground tank, and a sight glass is arranged on the return tank line at the outlet of the underground tank outlet pump.

[0012] Further, the underground tank outlet pump is provided with an outlet flow meter.

[0013] Further, the water removal mechanism is provided with a drainage line.

[0014] The adsorption column parking cooling method is as follows: the raffinate and the extract column bottom desorbent are combined, cooled by the product column bottom reboiler, and then sequentially pass through the desorbent air cooler and the desorbent water cooler, the cooled desorbent is sent to the raffinate column feed bottom heat exchanger through a cross-line, and then sent to the raffinate column after heat exchange, the stored water in the desorbent water cooler inlet and outlet pipeline is sent to the raffinate column top gas phase outlet with C8 aromatic hydrocarbon, cooled to the reflux tank through the column top air cooler, the stored water is removed by the water package of the reflux tank, and then the desorbent cooling process is used for adsorption column cooling.

[0015] Further, the temperature of the desorbent entering the adsorption column is not lower than 25℃ of the current temperature of the adsorption column.

[0016] The beneficial effects of the present application are: the desorbent cooling process is modified to the raffinate column, the circulation is established in advance, and is used before the adsorption column cooling, the water is removed by the reflux tank water package of the raffinate column, and the water is prevented from being brought into the adsorption column. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a process flow diagram of the adsorption column parking cooling system of the present application;

[0018] In the figure: 1, desorbent cooling pipeline, 2, cross pipeline, 3, raffinate column, a, raffinate feed inlet, b, overhead vapor phase outlet, c, C8 aromatic reflux port, d, desorbent column bottom outlet, e, side draw line, 4, overhead air cooler, 5, reflux tank, 6, reflux pump, 7, adsorption column feed pipeline, 8, water package water removal mechanism, 9, double gate valve, 10, 8-shaped blind plate, 11, feed valve, 12, product column bottom reboiler, 13, oil return pipeline, 14, desorbent air cooler, 15, desorbent water cooler, 16, water-cooled cross line, 17, raffinate column feed bottom heat exchanger, 18, raffinate column bottom pump, 19, underground tank, 20, underground tank outlet pump, 21, return tank line, 22, sight glass, 23, outlet flowmeter;

[0019] A, raffinate column bottom, B, adsorption column, C, storage tank, D, isomerization reaction system, E, raffinate column feed mixing tank, F, desorbent regeneration column. DETAILED DESCRIPTION

[0020] In order to make the structure and function of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application.

[0021] Referring to the drawings Figure 1 The adsorption column parking cooling system comprises a desorbent cooling pipeline 1, a heat exchanger group is connected to the desorbent cooling pipeline 1, the desorbent cooling pipeline 1 is connected to the raffinate feed inlet a of the raffinate column 3 through the cross pipeline 2 after the heat exchanger group, the overhead vapor phase outlet b of the raffinate column is connected to the overhead air cooler 4, the reflux tank 5, the reflux pump 6 and the reflux port c of the raffinate column 3 in sequence through pipelines, the column bottom outlet d of the raffinate column is connected to the adsorption column feed pipeline 7 through a pipeline, the desorbent cooling pipeline 1 is connected to the adsorption column feed pipeline 7, the reflux tank 5 is provided with a water package water removal mechanism 8, and the water package water removal mechanism 8 is provided with a drain line.

[0022] Further, the cross pipeline 2 is provided with a double gate valve 9 and an 8-shaped blind plate 10.

[0023] Further, the adsorption column feed pipeline 7 is provided with a feed valve 11, the inlet of the desorbent cooling pipeline is connected to the front route of the feed valve 11, the outlet of the desorbent cooling pipeline is connected to the rear route of the feed valve 11, the desorbent cooling pipeline 1 and the adsorption column feed pipeline 7 form a loop, and the adsorption column feed pipeline 7 is provided with a product column bottom reboiler 12, and the product column bottom reboiler 12 is arranged on the front route of the desorbent cooling pipeline inlet.

[0024] Further, the inlet and outlet of the desorbent cooling pipeline 1 are provided with double valves, the desorbent cooling pipeline 1 is connected with the storage tank C through the oil return pipeline 13, and the oil return pipeline 13 is connected in front of the outlet double valve.

[0025] Further, the heat exchanger group comprises a desorbent air cooler 14 and a desorbent water cooler 15, the desorbent cooling pipeline 1 is connected with the desorbent air cooler 14 and the desorbent water cooler 15 in sequence, and the desorbent water cooler 15 is provided with a water cooling cross line 16 in parallel, and the two ends of the water cooling cross line 16 are connected in front of and behind the desorbent water cooler 15.

[0026] Further, the raffinate column 3 is provided with a raffinate column feed bottom heat exchanger 17, the cross pipeline 2 is connected to the inlet of the raffinate column feed bottom heat exchanger 17, and after heat exchange through the raffinate column feed bottom heat exchanger 17, is connected with the raffinate feed port a of the raffinate column 3; the bottom outlet d of the raffinate column 3 is connected with the raffinate column bottom pump 18 and the raffinate column feed bottom heat exchanger 17 through a pipeline, and after heat exchange through the raffinate column feed bottom heat exchanger 17, is connected to the adsorption column feed pipeline 7 through a pipeline; the raffinate column 3 is connected to the isomerization reaction system D through a side sampling line e.

[0027] Based on the above technical scheme, it needs to be explained that the raffinate column 3 is fed through a raffinate column feed mixing tank E, the raffinate column feed mixing tank E is connected to the inlet of the raffinate column feed bottom heat exchanger 17, and the raffinate column feed mixing tank E is used to reduce the influence of feed composition change on the operation of the raffinate column. The raffinate column feed bottom heat exchanger 17 exchanges heat between the raffinate column feed and the bottom discharge.

[0028] Further, the adsorption column parking cooling system further comprises an underground tank 19 for recycling the closed discharge materials in the adsorption column system, an underground tank outlet pump 20 is arranged at the outlet of the underground tank 19, and the underground tank outlet pump 10 is connected with the raffinate column 3, the desorbent regeneration column F and the desorbent cooling pipeline 1 respectively.

[0029] Further, the underground tank outlet pump 20 is provided with a return tank line 21 for adjusting the outlet pressure and flow of the pump, the return tank line 21 returns to the underground tank 19, and a sight glass 22 is arranged at the outlet of the underground tank outlet pump 20 on the return tank line 21. The underground tank outlet pump 20 is provided with an outlet flow meter 23.

[0030] Based on the above technical scheme, it should be noted that the underground tank 19 is mainly C8 aromatic hydrocarbon and desorbent. The underground tank 19 mainly recovers the material discharged in the closed adsorption tower system, and sends it to the raffinate column 3 or the desorbent regeneration tower F through the pump outlet or flows to the storage tank C through the desorbent air cooler 14 and the desorbent water cooler 15 process, and the pump outlet has a return tank line 21 with a sight glass 22, which adjusts the pump outlet pressure and flow. The underground tank inlet pipeline is mainly the closed discharge pipeline in the adsorption tower system, which is combined to form an underground closed discharge pipeline network to recover and discharge the material. The desorbent regeneration tower F is used to remove heavy materials accumulated in the desorbent for a long time.

[0031] The method for cooling the adsorption tower during shutdown comprises the following steps: the raffinate and the desorbent at the bottom of the extract column are combined, cooled by the product tower bottom reboiler 12, and then sequentially cooled by the desorbent air cooler 14 and the desorbent water cooler 15; the cooled desorbent is sent to the raffinate column feed tower bottom heat exchanger 17 through the cross pipeline 2 for heat exchange, and then sent to the raffinate column 3; the stored water in the desorbent water cooler 14 inlet and outlet pipeline is removed with C8 aromatic hydrocarbon to the raffinate column top gas phase outlet, cooled to the reflux tank 5 through the tower top air cooler 4, and then removed by the reflux tank water package; and the desorbent cooling process is used for adsorption tower cooling.

[0032] Further, the temperature of the desorbent entering the adsorption tower is not lower than the current temperature of the adsorption tower, which is 25℃.

[0033] Based on the above technical scheme, it should be noted that the pipelines and reactors are controlled by valves to control the opening and closing, as shown in the attached Figure 1 Therefore, no further description is provided.

[0034] The present application solves the problem of long-term accumulation of stored water at the low point of the desorbent cooling process, and the use of the process during adsorption tower shutdown will bring part of the stored water into the adsorption tower, thereby damaging the performance of the adsorbent. The desorbent cooling process is modified to the raffinate column, the circulation is established in advance, the water is removed by the raffinate column reflux tank water package, and the desorbent cooling process is used before the adsorption tower cooling to avoid water entering the adsorption tower. The adsorption tower is cooled and the adsorbent is protected.

[0035] The specific working principle is as follows:

[0036] Normal process: the material (C8 aromatic hydrocarbon + desorbent) in the raffinate column feed mixing tank E is heated by the raffinate column feed tower bottom heat exchanger 17 and then enters the raffinate column 3; the raffinate column top gas phase (C8 aromatic hydrocarbon) is cooled to liquid phase by the tower top air cooler 4 and then enters the reflux tank 5; the material in the reflux tank 5 is sent to the raffinate column 3 by the reflux pump 6 as reflux; the stored water in the reflux tank 5 is removed by the water package; the (C8 aromatic hydrocarbon) taken from the raffinate column side line is sent to the isomerization reaction system as liquid feed; the raffinate column bottom material (desorbent) is cooled by the raffinate column bottom pump 18 and then enters the raffinate column feed tower bottom heat exchanger 17; the material from the raffinate column feed tower bottom heat exchanger 17 is combined with the material from the extract column bottom (desorbent), cooled by the product tower bottom reboiler 12, and then enters the adsorption tower B for adsorption separation.

[0037] The underground tank 19 material is sent to the raffinate column 3 or the desorbent regeneration column F through the underground tank outlet pump 20, or is sent to the storage tank C through the desorbent air cooler 14 and the desorbent water cooler 15, and the flow path is selected according to the sampling analysis result of the underground tank 19 material. The underground tank outlet pump 20 outlet minimum backflow line returns to the underground tank, and is used for adjusting the pump outlet pressure and flow.

[0038] Desorbent cooling process: the raffinate and the desorbent at the bottom of the extract column are combined, are cooled by the product column bottom reboiler 12, are cooled by the desorbent air cooler 14, are cooled by the desorbent water cooler 15, and finally cool the whole adsorption column. The desorbent temperature entering the adsorption column cannot be lower than the current temperature 25 DEG C of the adsorption column, so as to avoid damaging the internal parts of the adsorption column, that is, the adsorption column temperature-desorbent temperature ≤ 25 DEG C, which can be adjusted by the desorbent air cooler 14 and the desorbent water cooler 15. The disadvantage of this flow path is that water may be stored in the low point of the desorbent water cooler inlet and outlet pipeline, which will directly damage the adsorbent in the adsorption column.

[0039] Improved process: the raffinate and the desorbent at the bottom of the extract column are combined, are cooled by the product column bottom reboiler 12, are cooled by the desorbent air cooler 14, are cooled by the desorbent water cooler 15, are sent to the underground tank oil return line through the improved cross line, are sent to the raffinate column feed bottom heat exchanger 17, are sent to the raffinate column 3, and the water stored in the desorbent water cooler inlet and outlet pipeline is removed with C8 aromatic hydrocarbons to the raffinate column top gas phase, is cooled by the column top air cooler 4 to the reflux tank 5, and is removed by the water in the reflux tank 5. After the water is removed, the desorbent cooling process is used for adsorption column cooling, so as to protect the adsorbent from being damaged by water.

[0040] The above only lists the best embodiments of the present application. Obviously, the present application is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or thought of by those skilled in the art from the disclosure of the present application should be considered as falling within the protection scope of the present application.

Claims

1. An adsorption tower parking cooling system, characterized in that: The desorbent cooling pipeline is connected with a heat exchanger group, and the desorbent cooling pipeline is connected to the raffinate feed inlet of the raffinate column through a cross pipeline after the heat exchanger group. The overhead gas phase outlet of the raffinate column is connected with a top air cooler, a reflux tank, a reflux pump and the raffinate column in sequence through pipelines. The bottom outlet of the raffinate column is connected to the adsorption column feed pipeline through a pipeline. The desorbent cooling pipeline is connected to the adsorption column feed pipeline. The reflux tank is provided with a water package water removal mechanism. A double gate valve and an 8-shaped blind plate are arranged on the cross pipeline. The raffinate column is provided with a raffinate column feed bottom heat exchanger. The cross pipeline is connected to the inlet of the raffinate column feed bottom heat exchanger. The raffinate column feed bottom heat exchanger is connected to the raffinate column feed inlet after heat exchange. The bottom outlet of the raffinate column is connected to a raffinate column bottom pump and the raffinate column feed bottom heat exchanger through a pipeline. The raffinate column feed bottom heat exchanger is connected to the adsorption column feed pipeline through a pipeline after heat exchange. The raffinate column feeds the raffinate column feed mixing tank. The heat exchanger group includes a desorbent air cooler and a desorbent water cooler. The desorbent cooling pipeline is connected with the desorbent air cooler and the desorbent water cooler in sequence. An underground tank for recovering closed discharge materials in the adsorption column system is further included. An underground tank outlet pump is arranged at the outlet of the underground tank. The underground tank outlet pump is connected to the raffinate column, the desorbent regeneration column and the desorbent cooling pipeline respectively. The underground tank materials are sent to the raffinate column or the desorbent regeneration column through the outlet of the underground tank outlet pump or are returned to the storage tank through the desorbent air cooler-desorbent water cooler process.

2. The adsorption tower parking and cooling system according to claim 1, characterized in that: A feed valve is arranged on the adsorption column feed pipeline. The inlet of the desorbent cooling pipeline is connected to the front of the feed valve. The outlet of the desorbent cooling pipeline is connected to the rear of the feed valve. The desorbent cooling pipeline and the adsorption column feed pipeline form a loop. A product column bottom reboiler is arranged on the adsorption column feed pipeline. The product column bottom reboiler is arranged on the front of the inlet of the desorbent cooling pipeline.

3. The adsorption tower parking and cooling system of claim 1, wherein: Double valves are arranged at the inlet and the outlet of the desorbent cooling pipeline. The desorbent cooling pipeline is connected to the storage tank through a return oil pipeline. The return oil pipeline is connected to the front of the outlet double valve.

4. The adsorption tower parking and cooling system of claim 1, wherein: The desorbent water cooler is connected with a water cooling cross line in parallel. The two ends of the water cooling cross line are connected to the front and the rear of the desorbent water cooler.

5. The adsorption tower parking and cooling system of claim 1, wherein: The raffinate column is connected to the isomerization reaction system through a side sampling line.

6. The adsorption tower parking and cooling system of claim 1, wherein: The underground tank outlet pump is provided with a return tank line for adjusting the outlet pressure and flow of the pump. The return tank line returns to the underground tank. A sight glass is arranged at the outlet of the underground tank outlet pump on the return tank line. The underground tank outlet pump is provided with an outlet flow meter.

7. The cooling method of the adsorption tower parking cooling system according to any one of claims 1-6, characterized in that: The raffinate and the extract column bottom desorbent are combined. After cooling by the product column bottom reboiler, the raffinate is cooled by the desorbent air cooler and the desorbent water cooler in sequence. The cooled desorbent is sent to the raffinate column feed bottom heat exchanger through the cross pipeline and then is sent to the raffinate column. The stored water of the desorbent when passing through the desorbent water cooler inlet and outlet pipelines is sent to the raffinate column top gas phase outlet together with the C8 aromatic hydrocarbon. The stored water is cooled to the reflux tank through the top air cooler. The water in the water package of the reflux tank is removed. The desorbent is cooled through the desorbent cooling process for the adsorption column cooling.

8. The cooling method of the adsorption tower parking cooling system according to claim 7, characterized in that: The temperature of the desorbent entering the adsorption tower is not less than 25℃ than the current temperature of the adsorption tower.

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