Slurry bed residue hydroprocessing unit and warm-up method

Abstract

A kind of slurry bed residual oil hydrogenation device and temperature rising method.Solve the problem of slow temperature rising of the bottom of existing hot high separator.It includes hot high separator,hydrogenation reactor,first heat exchanger,second heat exchanger,communication pipeline and preheating system,the temperature rising method steps include: step S1,establish preheating oil system,obtain the oil temperature in preheating pipeline and rise to 150-250 DEG C;Step S2,pressure reduction of reaction system;Step S3,hot high separator pad oil before pipeline oil replacement;Step S4,hot high separator pad oil: pipeline replacement is completed,first plunger valve,first ball valve,second plunger valve are closed in turn,high cut-off valve is opened,hot high separator is given reverse pad oil temperature rising,when the liquid level in hot high separator reaches 20-80%,column cut-off valve and second hand valve are closed.The application reduces the time required in the process of slurry bed residual oil hydrogenation device,save the cost of start-up,improve operating efficiency.

Description

Technical Field

[0001] This invention relates to a slurry bed residue oil hydrogenation system, specifically to a slurry bed residue oil hydrogenation device and a heating method. Background Technology

[0002] In existing slurry-bed residue hydrotreating processes, a crucial step during startup is to preheat the hydrotreating reactor and thermal separator to the minimum permissible pressure (MPT) temperature before pressurization. This is primarily to prevent brittle fracture of the hydrotreating reactor. The current mainstream residue hydrotreating heating process involves: circulating gas being heated to 160°C (constant temperature) in the reactor; this circulating gas then enters the hydrotreating reactor to heat the catalyst, which gradually transfers heat to the reactor walls, from the inner wall to the outer wall; circulating hydrogen enters the thermal separator from the hydrotreating reactor outlet, heating the separator walls; and only after all outer walls reach the required temperature does the subsequent startup process begin. Fixed-bed residue hydrotreating processes are constrained by the temperature requirements of the catalyst bed, and due to the thicker walls of the reactor and thermal separator, reaching the required temperature typically takes 3-5 days, significantly extending the startup time.

[0003] The existing slurry-bed hydrotreating system uses EST technology. Compared with traditional fixed-bed residue hydrotreating units, it differs in the reaction section. The slurry-bed hydrotreating reactor does not contain a fixed-bed catalyst, thus eliminating concerns about catalyst reduction during heating. The current normal heating process is as follows: the circulating gas is gradually heated to a constant temperature of 300°C in the reaction furnace, then enters the hydrotreating reactor. In the hydrotreating reactor, it enters the thermal high-temperature separator using a bottom-in, top-out method. Because the thermal high-temperature separator is an empty tank with the feed inlet at the top, the circulating hydrogen circulates directly from the top outlet, creating a dead zone at the bottom. Furthermore, the thermal high-temperature separator has a wall thickness of 320mm, resulting in slow heat conduction and a slow heating rate, severely hindering the overall start-up progress.

[0004] Many attempts were made to accelerate the heating rate, one of which was to increase the temperature of the disturbed hydrogen, since the flow rate was only 1000 Nm³. 3 / h, the effect on heating the bottom of the hot high-pressure separator is not obvious. The second method is to perform a series pressure operation (this method is commonly used in fixed-bed residue hydrotreating): slightly open the bottom valve of the hot high-pressure separator to increase the bottom flow through series pressure. The slurry bed process differs from traditional residue hydrotreating in the design of the downstream path (from the bottom of the hot high-pressure separator to the heat exchanger). In traditional processes, the pressure of the low-pressure separator is controlled at 2.5 MPa, while in the slurry bed process, due to the high asphaltene and solid content of the slurry, the pressure is directly reduced to 0.4 MPa after pressure reduction and heat exchange from the bottom of the hot high-pressure separator (the safety valve of the downstream low-pressure separator tank is only 0.6 MPa). Therefore, the valve can only maintain a very small opening, and the flow rate is maintained at approximately 1000-3000 Nm³. 3Although the method of pressing the pipeline with a pressure of / h was effective, the screeching sound of the entire pipeline during the pressurization process was very loud, which posed a great challenge to the safe production of the entire start-up process and was too risky. Therefore, this method was gradually abandoned. Summary of the Invention

[0005] To address the problem of slow temperature rise at the bottom of existing hot separators in the background art, this invention provides a slurry bed residue oil hydrogenation device and a heating method.

[0006] The technical solution of this invention is: a slurry bed residue hydrotreating device, comprising: A hot-phase separator for gas-liquid separation, wherein the hot-phase separator is provided with gas phase holes and liquid phase holes; The hydrogenation reactor is connected to the upper part of the high-temperature separator; The first heat exchanger is connected to the gas phase port on the high-temperature separator; The second heat exchanger is connected to the liquid phase port on the heat separator; A connecting pipeline is located between the heat separator and the second heat exchanger. The connecting pipeline is connected to the heat separator through a shut-off valve. The connecting pipeline is equipped with a first plunger valve, a first ball valve, a second plunger valve, and a control valve. The preheating system is connected to the connecting pipeline via a preheating pipeline. The preheating pipeline is equipped with a first manual valve and a second manual valve, which cooperate to control the input of preheating oil. The preheating oil in the preheating pipeline enters the connecting pipeline through the first manual valve and the second manual valve for preheating of the connecting pipeline, and after preheating in the connecting pipeline, it enters the heat separator for preheating in the heat separator.

[0007] As a further improvement of the present invention, it also includes: a vent valve, disposed between the first hand valve and the second hand valve, for draining oil from the preheating pipeline.

[0008] As a further improvement of the present invention, a collection system is connected to a second plunger valve and is used to receive hydraulic oil in the connecting pipeline when the second plunger is open and connected to the collection system.

[0009] As a further improvement of the present invention, the second plunger valve is connected to the second heat exchanger via a control valve.

[0010] As a further improvement of the present invention, there are two connecting pipes, and the two connecting pipes are respectively connected to two second heat exchangers.

[0011] A method for raising the temperature of the above-mentioned slurry bed residue hydrotreating unit includes the following steps: Step S1: Establish a preheating oil system, preheat the hydraulic oil in the preheating system, and flush the preheating oil in the preheating system into the preheating pipeline to raise the oil temperature in the preheating pipeline to 150-250℃. Step S2: Depressurize the reaction system by opening the pressure relief valve on the line after the first heat exchanger, so that the system pressure drops from 4.3 MPa to below 2.0 MPa; Step S3, oil replacement in the pipeline before the hot separator pad oil: First, after preparing the preheating system, start the oil pump to fill the preheating system; then open the first hand valve; sequentially open the first plunger valve, the first ball valve, and the second plunger valve, while keeping the control valve closed; slowly open the second hand valve to flush the preheated oil in the preheating system into the connecting pipeline through the preheating pipeline and return the oil through the second plunger valve; gradually open the second hand valve to replace the oil in the preheating pipeline and connecting pipeline; use a temperature gun to measure the temperature, and stop the replacement when the temperature reaches above 150℃; Step S4, apply oil to the hot-high temperature separator: After the pipeline replacement is completed, close the first plunger valve, the first ball valve, and the second plunger valve in sequence, open the high temperature shut-off valve, and apply reverse oil to the hot-high temperature separator to raise its temperature. Pay attention to the changes in liquid level and density in the hot-high temperature separator. When the liquid level in the hot-high temperature separator reaches 20-80%, close the plunger shut-off valve and the second hand valve.

[0012] As a further improvement of the present invention, in step S3, the valve opening is controlled and the internal operator observes the pressure of the collection system to prevent the valve opening from being too large, which would cause the collection system to be over-pressurized.

[0013] As a further improvement of the present invention, in step 4, if the hot high-temperature separator uses a blowing-type liquid level gauge, and the liquid level shows a false reading when the hydrogen flow rate is insufficient, then the nuclear density meter on the hot high-temperature separator is used for auxiliary judgment, and the padding oil is stopped immediately when the density at the top changes.

[0014] As a further improvement of the present invention, step S5 is also included: observing the heating rate at the bottom of the hot-high temperature separator. If the temperature does not meet the requirements and the heating rate is slow, the hydraulic oil in the hot-high temperature separator can be discharged into the collection system through the shut-off valve, the first ball valve, and the second plunger valve, and steps S3 and S4 can be repeated again.

[0015] As a further improvement of the present invention, the preheating oil in the preheating pipeline is diesel oil at 2-5 MPa and 150-250°C or wax oil at 2-5 MPa and 150-250°C.

[0016] The beneficial effects of this invention are that it significantly reduces the start-up time of slurry bed residue hydrotreating units, saves start-up costs, improves operating efficiency, increases profits, and ensures complete risk control and safe production operations during start-up. This invention also has advantages such as simple structure, convenient assembly, reliable operation, and long service life. Attached Figure Description

[0017] Appendix Figure 1 This is a hydraulic schematic diagram of an embodiment of the present invention.

[0018] In the diagram, 1. Heat separator; 2. Hydrogenation reactor; 3. First heat exchanger; 4. Second heat exchanger; 5. Connecting pipeline; 51. Shut-off valve; 52. First plunger valve; 53. First ball valve; 54. Second plunger valve; 55. Control valve; 6. Preheating system; 61. Preheating pipeline; 62. First manual valve; 63. Second manual valve; 64. Vent valve; 7. Collection system. Detailed Implementation

[0019] The embodiments of the present invention will be further described below with reference to the accompanying drawings: Depend on Figure 1 As shown, a slurry bed residue hydrotreating unit includes: A high-temperature separator 1 is used for gas-liquid separation, and the high-temperature separator is provided with gas phase holes and liquid phase holes; Hydrogenation reactor 2 is connected to the upper part of the thermal separator; The first heat exchanger 3 is connected to the gas phase port on the heat separator; The second heat exchanger 4 is connected to the liquid phase hole on the heat separator; A connecting pipe 5 is located between the heat separator and the second heat exchanger. The connecting pipe is connected to the heat separator through a shut-off valve 51. The connecting pipe is equipped with a first plunger valve 52, a first ball valve 53, a second plunger valve 54, and a control valve 55. The preheating system 6 is connected to the connecting pipeline via a preheating pipeline 61. The preheating pipeline is equipped with a first hand valve 62 and a second hand valve 63, which cooperate to control the input of preheating oil. The preheating oil in the preheating pipeline enters the connecting pipeline through the first and second hand valves for preheating the connecting pipeline, and after preheating in the connecting pipeline, it enters the high-temperature separator for preheating in the high-temperature separator. The beneficial effects of this invention are that it significantly reduces the start-up time required for the slurry bed residue oil hydrotreating unit, saves start-up costs, improves operating efficiency, increases profits, and ensures complete risk control, guaranteeing safe production operations during start-up. This invention also has advantages such as simple structure, convenient assembly, reliable operation, and long service life. In practice, using this method, the required temperature can be reached in only 2-5 hours, a significant reduction compared to the traditional heating time (2-3 days), reducing production costs, saving start-up costs, improving operating efficiency, increasing profits, and ensuring low pressure in the pipeline, thus guaranteeing safe production operations and high product safety during start-up. This invention is applicable to the bottom heating operation process of all slurry flushing systems.

[0020] The invention also includes a vent valve 64, located between the first and second hand valves, for draining oil from the preheating pipeline. This allows the vent valve to be opened to drain the oil from the preheating pipeline, facilitating maintenance.

[0021] The invention also includes a collection system 7, connected to the second plunger valve, for receiving hydraulic oil in the connecting pipeline when the second plunger is open and connected to the collection system. The collection system can recover hydraulic oil from the preheating pipeline and the connecting pipeline for easy reuse. In this invention, a flushing oil circuit can also be provided, which is connected to the high-temperature separator via a shut-off valve.

[0022] The second plunger valve is connected to the second heat exchanger via a control valve. The control valve is configured to open, allowing the connecting pipe to be connected to the second heat exchanger. Typically, the first heat exchanger is a standard heat exchanger (high-pass heat exchanger), and the second heat exchanger is a spiral plate heat exchanger.

[0023] There are two connecting pipes, each connecting to a different second heat exchanger. This allows the liquid from the heat separator to pass through different second heat exchangers during operation, resulting in higher efficiency.

[0024] A method for raising the temperature of a slurry bed residue hydrotreating unit, comprising the following steps: Step S1: Establish a preheating oil system, preheat the hydraulic oil in the preheating system, and flush the preheating oil in the preheating system into the preheating pipeline to raise the oil temperature in the preheating pipeline to 150-250℃. Step S2: Depressurize the reaction system by opening the pressure relief valve on the line after the first heat exchanger, so that the system pressure drops from 4.3 MPa to below 2.0 MPa; Step S3, oil replacement in the pipeline before the hot separator pad oil: First, after preparing the preheating system, start the oil pump to fill the preheating system; then open the first hand valve; sequentially open the first plunger valve, the first ball valve, and the second plunger valve, while keeping the control valve closed; slowly open the second hand valve to flush the preheated oil in the preheating system into the connecting pipeline through the preheating pipeline and return the oil through the second plunger valve; gradually open the second hand valve to replace the oil in the preheating pipeline and connecting pipeline; use a temperature gun to measure the temperature, and stop the replacement when the temperature reaches above 150℃; Step S4, providing oil cushioning to the hot-hydrogen separator: After pipeline replacement, sequentially close the first plunger valve, the first ball valve, and the second plunger valve, and open the high-pressure shut-off valve to provide reverse oil cushioning for heating of the hot-hydrogen separator. Monitor the liquid level and density changes within the hot-hydrogen separator. When the liquid level in the hot-hydrogen separator reaches 20-80%, close the plunger shut-off valve and the second hand valve. The beneficial effects of this invention are that it significantly reduces the time required for start-up of the slurry bed residue hydrotreating unit, saves start-up costs, improves operating efficiency, increases profits, and ensures complete risk control, guaranteeing safe production operations during start-up.

[0025] In step S3, the valve opening must be controlled, and the operator must observe the pressure of the collection system to prevent the valve opening from being too large, which could lead to overpressure in the collection system.

[0026] In step 4, if the hot-hydrogen separator uses a purge-type level gauge, and the level reading is false due to insufficient hydrogen flow, the nuclear density meter on the hot-hydrogen separator will be used for auxiliary judgment. The oil leveling process will be stopped immediately when the density at the top changes. This prevents hydraulic oil from the hot-hydrogen separator from being carried into the gas path.

[0027] The invention also includes step S5, which involves observing the heating rate at the bottom of the heat exchanger. If the temperature is below the required level and the heating rate is slow, the hydraulic oil inside the heat exchanger can be discharged into the collection system through a shut-off valve, a first ball valve, and a second plunger valve, and steps S3 and S4 can be repeated. This can improve heat exchange efficiency and reduce preheating time.

[0028] The preheating oil in the preheating pipeline is diesel oil at 2-5 MPa and 150-250°C or wax oil at 2-5 MPa and 150-250°C.

[0029] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0031] Please note to all technical personnel: Although the present invention has been described according to the specific embodiments above, the inventive concept of the present invention is not limited to this invention. Any modifications that utilize the inventive concept will be included within the scope of protection of the patent rights of the present invention.

Claims

1. A slurry bed residue hydrotreating unit, characterized in that... :include: A hot-phase separator for gas-liquid separation, wherein the hot-phase separator is provided with gas phase holes and liquid phase holes; The hydrogenation reactor is connected to the upper part of the thermal separator; The first heat exchanger is connected to the gas phase port on the high-temperature separator; The second heat exchanger is connected to the liquid phase port on the heat separator; A connecting pipeline is located between the heat separator and the second heat exchanger. The connecting pipeline is connected to the heat separator through a shut-off valve. The connecting pipeline is equipped with a first plunger valve, a first ball valve, a second plunger valve, and a control valve. The preheating system is connected to the connecting pipeline via a preheating pipeline. The preheating pipeline is equipped with a first manual valve and a second manual valve, which cooperate to control the input of preheating oil. The preheating oil in the preheating pipeline enters the connecting pipeline through the first manual valve and the second manual valve for preheating of the connecting pipeline, and after preheating in the connecting pipeline, it enters the heat separator for preheating in the heat separator. A vent valve, located between the first and second manual valves, is used to drain oil from the preheating pipeline.

2. The slurry bed residue hydrotreating unit according to claim 1, characterized in that... It also includes a collection system connected to the second plunger valve, which is used to receive hydraulic oil in the connecting pipeline when the second plunger valve is open and connected to the collection system.

3. The slurry bed residue hydrotreating unit according to claim 1, characterized in that... The second plunger valve is connected to the second heat exchanger via a control valve.

4. The slurry bed residue hydrotreating unit according to claim 1, characterized in that... There are two connecting pipes, and the two connecting pipes are respectively connected to two second heat exchangers.

5. A method for raising the temperature of a slurry bed residue hydrotreating unit according to any one of claims 1-4, characterized in that: The steps include: Step S1: Establish a preheating oil system, preheat the hydraulic oil in the preheating system, and flush the preheating oil in the preheating system into the preheating pipeline to raise the oil temperature in the preheating pipeline to 150-250℃. Step S2: Depressurize the reaction system by opening the pressure relief valve on the line after the first heat exchanger, so that the system pressure drops from 4.3 MPa to below 2.0 MPa; Step S3, oil replacement in the pipeline before the hot separator pad oil: First, after preparing the preheating system, start the oil pump to fill the preheating system; then open the first hand valve; sequentially open the first plunger valve, the first ball valve, and the second plunger valve, while keeping the control valve closed; slowly open the second hand valve to flush the preheated oil in the preheating system into the connecting pipeline through the preheating pipeline and return the oil through the second plunger valve; gradually open the second hand valve to replace the oil in the preheating pipeline and connecting pipeline; use a temperature gun to measure the temperature, and stop the replacement when the temperature reaches above 150℃; Step S4, apply oil to the hot-high temperature separator: After the pipeline replacement is completed, close the first plunger valve, the first ball valve, and the second plunger valve in sequence, open the shut-off valve, and apply reverse oil to the hot-high temperature separator to raise its temperature. Pay attention to the changes in liquid level and density in the hot-high temperature separator. When the liquid level in the hot-high temperature separator reaches 20-80%, close the shut-off valve and the second hand valve.

6. The heating method according to claim 5, characterized in that... In step S3, the valve opening must be controlled, and the operator must observe the pressure of the collection system to prevent the valve opening from being too large, which could lead to overpressure in the collection system.

7. The heating method according to claim 5, characterized in that... In step 4, if the hot-air separator uses a purge-type level gauge, and the level reading is false when the hydrogen flow is insufficient, the nuclear density meter on the hot-air separator is used for auxiliary judgment. When the density at the top changes, the oil padding should be stopped immediately.

8. The heating method according to claim 5, characterized in that... The process also includes step S5, which involves observing the heating rate at the bottom of the hot-heat separator. If the temperature is not up to the required level and the heating rate is slow, the hydraulic oil in the hot-heat separator is discharged into the collection system through the shut-off valve, the first ball valve, and the second plunger valve, and steps S3 and S4 are repeated.

9. The heating method according to claim 5, characterized in that... The preheating oil in the preheating pipeline is diesel oil at 2-5 MPa and 150-250°C or wax oil at 2-5 MPa and 150-250°C.

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