Crude benzene washing oil regeneration and residue dissolving and conveying device

Abstract

The utility model discloses a crude benzene washing oil regeneration and residue dissolving and conveying device, which comprises a debenzolization tower, a regenerator, a residue tank and a benzene washing tower, the regenerator is connected with the debenzolization tower, the regenerator is connected with the residue tank, the debenzolization tower is connected with a lean and rich oil heat exchange system, the lean and rich oil heat exchange system is connected with a rich oil heater, and the rich oil heater is connected with the benzene washing tower. And the rich oil heater is connected with the debenzolization tower. According to the crude benzene washing oil regenerating and residue dissolving and conveying device, the regenerator is connected with the residue tank and the debenzolization tower, lean oil from the debenzolization tower enters the regenerator, and lean oil or washing oil enters the residue tank, so that the flow path of a steam blowing pipeline can be reduced, the moisture of tar can be reduced, the quality of the tar can be ensured, and meanwhile, the consumption of steam for cleaning can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of coking production equipment, and specifically relates to a crude benzene washing oil regeneration and residue dissolution and conveying device. Background Art

[0002] Crude benzene is an important petrochemical product obtained in the coking process, which can be mainly used to produce important organic chemicals such as benzene, xylene, toluene, etc. Crude benzene is a mixture containing various organic substances, which can be absorbed from coal gas using organic washing oil.

[0003] In the crude benzene process, coal gas enters from the bottom of the crude benzene tower and flows out from the coal gas outlet at the top of the tower. Wash oil enters from the top of the tower and contacts with coal gas in reverse to absorb crude benzene in the coal gas. Clean coal gas is returned to the furnace or to the user. The rich oil that has absorbed crude benzene enters the debenzene tower for debenzene. The debenzene tower is a desorption tower. The rich oil provides heat to separate the volatile crude benzene components. The separated lean oil enters the benzene washing tower to participate in absorption again. In this process, not only will the wash oil produce a certain amount of consumption, but many impurities in the coal gas (polymer organic matter, heavy components) will enter the wash oil during the benzene washing process and cannot be separated with the crude benzene in the debenzene tower. With repeated recycling, the quality of the wash oil will deteriorate, seriously affecting the effect of benzene washing.

[0004] Coking plants generally use oil washing regeneration devices to regenerate oil washing. The oil washing regeneration device is essentially a desorption tower device. In terms of technology, 1-2% of the lean oil coming out of the benzene washing tower is sent to the regenerator. Through the heat supply of medium-pressure steam, the lean oil steam will flow out from the top of the equipment and directly enter the bottom of the debenzene tower, returning to the system as a heat source and medium, thereby reducing the impurity content in the oil washing. The heavy component impurities in the oil washing in the regenerator will be discharged from the bottom into the residue tank.

[0005] The organic high molecular weight substances collected in the residue tank are usually added to the tar tank as one of the sources of coal tar.

[0006] The physical characteristics of the high molecular weight organic heavy components in the residue tank are viscous oily liquids with poor fluidity. In order to allow it to be discharged smoothly into the tar tank, the coking plant generally sends the tar from the cold drum process to the residue tank to dissolve the residue. However, tar itself is also a viscous substance, and steam will need to be introduced to purge the residue tank pipeline to avoid blockage. This also causes the tar product to have high moisture content, affecting the quality of the tar. Washing oil has the same physical properties as tar. Using washing oil to clean the residue tank can achieve the same purpose without affecting its quality. In addition, because washing oil has good fluidity at room temperature and less pipe adhesion, it does not need to be cleaned.

[0007] Chinese patent application number 201520891015.1 discloses a washing oil regeneration device for crude benzene production, including a washing oil circulation tank, a lean-rich oil heat exchanger, a tubular heating furnace, a regenerator and a residue tank, the regenerator includes a tower kettle, a tower body, an oil inlet system, a residue outlet, a tower top outlet and a steam inlet, a transition section is provided between the tower body and the tower kettle, 5 layers of tower plates are arranged in the tower body, the oil inlet system includes an oil inlet main pipe, a first lean oil inlet and a second lean oil inlet, the first lean oil inlet is arranged on the lower side of the uppermost tower plate, and the second lean oil inlet is arranged on the lower side of the third tower plate.

[0008] It is desirable to provide an improved crude benzene wash oil regeneration and residue dissolution and transportation device, particularly a device for improving tar quality. Utility Model Content

[0009] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a crude benzene washing oil regeneration and residue dissolution and transportation device, the purpose of which is to ensure the quality of tar and reduce the amount of steam used for pipeline cleaning during the washing oil residue dissolution and transportation process.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a crude benzene washing oil regeneration and residue dissolution and transportation device, including a debenzene tower, a regenerator, a residue tank, a light and heavy lean oil separation tank and a benzene washing tower, the regenerator is connected to the debenzene tower, the regenerator is connected to the residue tank, the debenzene tower is connected to a poor and rich oil heat exchange system, the poor and rich oil heat exchange system is connected to an oil-rich heater, the oil-rich heater is connected to the debenzene tower, the poor and rich oil heat exchange system is connected to the light and heavy lean oil separation tank, and the light and heavy lean oil separation tank is connected to the residue tank.

[0011] The lean-rich oil heat exchange system comprises a first-stage lean-rich oil heat exchanger and a second-stage lean-rich oil heat exchanger connected to each other, the second-stage lean-rich oil heat exchanger is connected to the debenzene tower via a hot lean oil pump, the first-stage lean-rich oil heat exchanger is connected to a lean oil cooling system, and the lean oil cooling system is connected to the benzene washing tower.

[0012] The lean oil cooling system comprises a first-stage lean oil cooler and a second-stage lean oil cooler connected to each other, the first-stage lean oil cooler is connected to the first-stage lean-rich oil heat exchanger, the first-stage lean-rich oil heat exchanger is connected to the second-stage lean-rich oil heat exchanger, and the second-stage lean-rich oil heat exchanger is connected to the debenzene tower.

[0013] The first stage lean-rich oil heat exchanger and the second stage lean-rich oil heat exchanger are connected to a light-heavy lean oil separation tank, and the light-heavy lean oil separation tank is connected to the residue tank.

[0014] The light-heavy lean oil separation tank is connected to the light lean oil pump, and the light lean oil pump is connected to the first-stage lean oil cooler.

[0015] The benzene washing tower is connected to the rich oil tank, the rich oil tank is connected to the rich oil pump, and the rich oil pump is connected to the first stage lean-rich oil heat exchanger.

[0016] The utility model discloses a crude benzene washing oil regeneration and residue dissolving and conveying device, a regenerator is connected with a residue tank and a debenzene tower, the lean oil from the debenzene tower enters the regenerator, and the washing oil enters the residue tank, which can reduce the process of steam purge pipeline, reduce the water content of tar, ensure the quality of tar, and at the same time reduce the consumption of steam for cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] This specification includes the following drawings, which show the following contents:

[0018] Figure 1 This is a schematic diagram of the structure of the crude benzene washing oil regeneration and residue dissolution and conveying device of the utility model;

[0019] The markings in the figure are: 1. benzene removal tower; 2. regenerator; 3. residue tank; 4. benzene washing tower; 5. first-stage lean-rich oil heat exchanger; 6. second-stage lean-rich oil heat exchanger; 7. first-stage lean oil cooler; 8. second-stage lean oil cooler; 9. light and heavy lean oil separation tank; 10. light lean oil pump; 11. rich oil tank; 12. rich oil pump; 13. hot lean oil pump; 14. rich oil heater. DETAILED DESCRIPTION

[0020] The specific implementation methods of the utility model are further explained in detail below with reference to the accompanying drawings through the description of embodiments, with the aim of helping technicians in the field to have a more complete, accurate and in-depth understanding of the concept and technical solution of the utility model and facilitating its implementation.

[0021] like Figure 1 As shown, the utility model provides a crude benzene washing oil regeneration and residue dissolution and transportation device, comprising a debenzene tower 1, a regenerator 2, a residue tank 3 and a benzene washing tower 4, the regenerator 2 is connected to the debenzene tower 1, the regenerator 2 is connected to the residue tank 3, the debenzene tower 1 is connected to a lean-rich oil heat exchange system, the lean-rich oil heat exchange system is connected to a rich oil heater 14, and the rich oil heater 14 is connected to the debenzene tower 1.

[0022] Specifically, if Figure 1 As shown, the lean-rich oil heat exchange system includes a first-stage lean-rich oil heat exchanger 5 and a second-stage lean-rich oil heat exchanger 6 connected to each other, the second-stage lean-rich oil heat exchanger 6 is connected to the debenzene tower 1 through a hot lean oil pump 13, the first-stage lean-rich oil heat exchanger 5 is connected to the lean oil cooling system, and the lean oil cooling system is connected to the benzene washing tower 4. The lean oil cooling system includes a first-stage lean oil cooler 7 and a second-stage lean oil cooler 8 connected to each other, the first-stage lean oil cooler 7 is connected to the first-stage lean-rich oil heat exchanger 5, and the second-stage lean-rich oil heat exchanger 6 is connected to the benzene washing tower 4.

[0023] like Figure 1As shown, the oil inlet of the hot lean oil pump 13 is connected to the debenzene tower 1, and the oil outlet of the hot lean oil pump 13 is connected to the second-stage lean-rich oil heat exchanger 6 and the regenerator 2. The lean oil from the debenzene tower 1 enters the regenerator 2 according to 1-2% of its circulation volume. The oil washing steam generated by steam heating is discharged from the top of the debenzene tower 1, returns to the debenzene tower 1 as one of the heat sources and the medium to return to the system for cyclic treatment, and the residue flows out from the bottom of the regenerator 2 and is placed in the residue tank 3.

[0024] like Figure 1 As shown, the residue tank 3 is connected to the coil heat exchanger, and the room temperature wash oil is heated to 50-90°C by the coil heat exchanger and then added to the residue tank 3. The liquid level added to the residue tank 3 is about 1 / 3-2 / 5 of the total volume of the residue tank 3 to dissolve the high molecular weight component residue. The actual volume after dissolution is about 1 / 2-3 / 4 of the total volume of the residue tank 3, and then it is sent to the tar storage tank of the oil depot.

[0025] like Figure 1 As shown, the first stage lean-rich oil heat exchanger 5 and the second stage lean-rich oil heat exchanger 6 are connected to the light-heavy lean oil separation tank 9, the light-heavy lean oil separation tank 9 is connected to the light lean oil pump 10, and the light lean oil pump 10 is connected to the first stage lean oil cooler 7. The light-heavy lean oil separation tank 9 is connected to the residue tank 3, and the lean oil leaving the benzene removal tower 1 has a temperature of 50-90°C after heat exchange through the first stage lean-rich oil heat exchanger 5 or the second stage lean-rich oil heat exchanger 6. This part of the lean oil is connected to the light-heavy lean oil separation tank 9 through a pipeline. In the light-heavy lean oil separation tank 9, the light and heavy lean oils are separated, and the upper layer of light lean oil is sent to the first stage lean oil cooler 7 by the light lean oil pump 10 for further cooling, while the lower layer of heavy lean oil is directly passed into the residue tank 3 by self-pressure, reducing the coil heating process.

[0026] The heavy lean oil level added to the residue tank 3 is about 1 / 3 to 2 / 5 of the total volume of the residue tank 3 to dissolve the high molecular weight residue. The actual volume after dissolution is about 1 / 2 to 3 / 4 of the tank capacity, and then sent to the tar storage tank of the oil depot.

[0027] The residue generated by the system is cleaned 2 to 4 times a month, and the lean oil at 50 to 90°C after the lean-rich oil heat exchanger is directly added to the residue tank 3 to dissolve the residue, and the wash oil is directly added to the system; only when the amount of lean oil is insufficient, can the wash oil be directly added to the residue tank 3 to dissolve the residue.

[0028] like Figure 1 As shown, one end of the second-stage lean oil cooler 8 is connected to the first-stage lean oil cooler 7, and the other end of the second-stage lean oil cooler 8 is connected to the benzene washing tower 4. After the above-mentioned light lean oil merges with the lean oil after the first-stage lean-rich oil heat exchanger 5 and enters the benzene washing tower 4, it also needs to continue to cool down to 20-25°C through the first-stage lean oil cooler 7 and the second-stage lean oil cooler 8.

[0029] like Figure 1As shown, the benzene washing tower 4 is connected to the rich oil tank 11, the rich oil tank 11 is connected to the rich oil pump 12, and the rich oil pump 12 is connected to a section of the lean-rich oil heat exchanger 5.

[0030] The crude benzene washing oil regeneration and residue dissolution and conveying device of the above structure has the following advantages:

[0031] 1. Compared with the tar cleaning residue tank 3, the residue tank 3 of the utility model uses washing oil for cleaning, which reduces the process of steam purge pipeline, reduces the moisture of tar, ensures the quality of tar, and reduces the steam consumption for cleaning;

[0032] 2. When cleaning the residue tank 3, lean oil at 50-90°C is preferred. The appropriate temperature reduces the heat exchange link of the coil and reduces energy consumption.

[0033] 3. Washing oil has good fluidity. Adding it to the tar tank can reduce the viscosity of tar and reduce the condensation and deposition of high boiling point and tar residue in tar.

[0034] 4. Taking the lean oil after the lean-rich oil heat exchanger 5 can effectively utilize the heat of the hot lean oil to heat the rich oil, while reducing the amount of lean oil entering the lean oil cooler and reducing the consumption of cooling water;

[0035] 5. Use lean oil to enter the residue tank 3 to dissolve the residue, which can avoid the increase of washing oil consumption caused by directly using washing oil to heat the residue and then send it to the residue tank 3 to dissolve the residue. At the same time, it can reduce the temperature and energy consumption required for heating the washing oil coil;

[0036] 6. By adopting the light-heavy lean oil separation tank 9, the heavy components in the lean oil can be discharged to the residue tank 3, reducing the loss of light components in the lean oil. At the same time, the quality and temperature of the lean oil entering the residue tank 3 can be adjusted to ensure better dissolution of the residue while retaining the high-quality light components in the lean oil;

[0037] 7. The utility model is an effective supplement to the thermal regeneration method of crude benzene washing oil, that is, it adopts physical separation to directly discharge the heavy lean oil of poor quality, thus reducing the energy consumption increased by thermal regeneration.

[0038] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model; or the above concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A crude benzene washing oil regeneration and residue dissolution and transportation device, comprising a debenzene tower, a regenerator, a residue tank, a light and heavy lean oil separation tank and a benzene washing tower, wherein the regenerator is connected to the debenzene tower, and is characterized in that: The regenerator is connected to the residue tank, the debenzene tower is connected to the lean-rich oil heat exchange system, the lean-rich oil heat exchange system is connected to the rich oil heater, the rich oil heater is connected to the debenzene tower, the lean-rich oil heat exchange system is connected to the light-heavy lean oil separation tank, and the light-heavy lean oil separation tank is connected to the residue tank.

2. The crude benzene wash oil regeneration and residue dissolution and conveying device according to claim 1 is characterized in that: The lean-rich oil heat exchange system comprises a first-stage lean-rich oil heat exchanger and a second-stage lean-rich oil heat exchanger connected to each other, the second-stage lean-rich oil heat exchanger is connected to the debenzene tower via a hot lean oil pump, the first-stage lean-rich oil heat exchanger is connected to a lean oil cooling system, and the lean oil cooling system is connected to the benzene washing tower.

3. The crude benzene wash oil regeneration and residue dissolution and conveying device according to claim 2 is characterized in that: The lean oil cooling system comprises a first-stage lean oil cooler and a second-stage lean oil cooler connected to each other, the first-stage lean oil cooler is connected to the first-stage lean-rich oil heat exchanger, the first-stage lean-rich oil heat exchanger is connected to the second-stage lean-rich oil heat exchanger, and the second-stage lean-rich oil heat exchanger is connected to the debenzene tower.

4. The crude benzene wash oil regeneration and residue dissolution and conveying device according to claim 3 is characterized in that: The first stage lean-rich oil heat exchanger and the second stage lean-rich oil heat exchanger are connected to a light-heavy lean oil separation tank, and the light-heavy lean oil separation tank is connected to the residue tank.

5. The crude benzene wash oil regeneration and residue dissolution and conveying device according to claim 4 is characterized in that: The light-heavy lean oil separation tank is connected to the light lean oil pump, and the light lean oil pump is connected to the first-stage lean oil cooler.

6. The crude benzene wash oil regeneration and residue dissolution and conveying device according to any one of claims 2 to 5, characterized in that: The benzene washing tower is connected to the rich oil tank, the rich oil tank is connected to the rich oil pump, and the rich oil pump is connected to the first stage lean-rich oil heat exchanger.

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