Low-carbon hydrocracking system and process

Abstract

The low-carbon hydrocracking system comprises a catalytic reaction device and a heating device, the catalytic reaction device comprises a reactor, a separator and a fractionating tower which are communicated in sequence, a tail oil outlet pipe is arranged at the tower bottom of the fractionating tower, and the heating device comprises a heater, a first heat exchanger and a second heat exchanger. Raw oil sequentially passes through the first heat exchanger and the second heat exchanger to enter the reactor, a shock wave heating channel is formed in the heater, and a heat exchange medium completes conversion from kinetic energy to heat energy in the shock wave heating channel and conducts convection heat exchange with the raw oil in the second heat exchanger. According to the low-carbon hydrocracking system and the low-carbon hydrocracking process provided by the invention, the raw oil is preheated by utilizing a shock wave heating principle, fuel does not need to be used, and emission of carbon dioxide and sulfides is reduced.

Description

Technical Field

[0001] The present application belongs to the field of petrochemical technology, and specifically relates to a low-carbon hydrocracking system and process. Background Art

[0002] Hydrocracking is a type of catalytic hydrogenation process. Catalytic hydrogenation is a general term for the catalytic processing of petroleum fractions in the presence of hydrogen. Its main purpose is to improve the processing depth of crude oil, make full use of petroleum resources, improve product quality, increase light oil yield and reduce environmental pollution. Before the cracking reaction, the crude oil needs to be preheated to improve the reaction efficiency. In the prior art, the heating of the crude oil is usually carried out by thermal radiation. The crude oil passes through the furnace tube of the heating furnace, and the combustible gas is continuously introduced into the radiation chamber of the heating furnace. The thermal radiation generated by the gas combustion continuously flushes the furnace tube to achieve the purpose of heating the crude oil. However, a large amount of carbon dioxide and some sulfides will be generated during the combustion process, which is not conducive to environmental protection. Summary of the invention

[0003] In view of the above-mentioned defects or shortcomings, the present application provides a low-carbon hydrocracking system and process, aiming to solve the technical problem of carbon dioxide and sulfide emissions caused by the existing hydrocracking system based on combustion heating.

[0004] To achieve the above objectives, the present application provides a low-carbon hydrocracking system, comprising:

[0005] The catalytic reaction device comprises a reactor, a separator and a fractionation tower which are connected in sequence, and a tail oil outlet pipe is provided at the bottom of the fractionation tower;

[0006] The heating device comprises a heater, a first heat exchanger and a second heat exchanger. A shock wave heating channel is formed in the heater. The tube side of the first heat exchanger is connected to the crude oil feed pipe. The shell side of the first heat exchanger is respectively connected to the discharge port of the reactor and the feed port of the separator. The tube side of the second heat exchanger is respectively connected to the tube side of the first heat exchanger and the reactor. The shell side of the second heat exchanger is connected to the heater.

[0007] In an embodiment of the present application, the catalytic reaction device also includes a first mixer arranged upstream of the first heat exchanger, and the first mixer is connected to the crude oil feed pipe and the tail oil outlet pipe one by one to mix the crude oil and the tail oil and guide them to the first heat exchanger.

[0008] In an embodiment of the present application, the heater includes: an outer shell, a rotating blade grid, a first fixed blade grid and a second fixed blade grid. A shock wave heating channel is formed in the outer shell. The cross-section of the shock wave heating channel is annular. The rotating blade grid, the first fixed blade grid and the second fixed blade grid are all arranged in the shock wave heating channel. The rotating blade grid can rotate around the central axis of the outer shell. The first fixed blade grid is arranged upstream of the rotating blade grid, and the second fixed blade grid is arranged downstream of the rotating blade grid. The heat exchange medium flows in along the first fixed blade grid, is accelerated to sonic or supersonic speed through the rotation of the rotating blade grid and impacts the second fixed blade grid to generate heat.

[0009] In an embodiment of the present application, the heater also includes a plurality of partitions arranged in the shock wave heating channel, the plurality of partitions are used to separate a plurality of heating spaces, and each heating space is provided with a plurality of first fixed blades for forming a first fixed blade grid, and a plurality of second fixed blades for forming a second fixed blade grid.

[0010] In the embodiment of the present application, the first fixed blade has a curved streamline profile and is used to guide the heat exchange medium to the rotating blade row, and the second fixed blade has a curved streamline profile and is used to guide the heat exchange medium out of the heating space.

[0011] In an embodiment of the present application, the installation angle of the first fixed blade is between 35° and 75°, the inlet angle of the first fixed blade is between 0° and 45°, and the outlet angle of the first fixed blade is between 35° and 75°; the installation angle of the second fixed blade is between 45° and 85°, the inlet angle of the second fixed blade is between 25° and 65°, and the outlet angle of the second fixed blade is between 25° and 65°.

[0012] In the embodiment of the present application, the rotating blade grid includes a plurality of rotating blades, and each rotating blade has a curved profile toward its rotation direction.

[0013] In the embodiment of the present application, the installation angle of the rotating blade is between 10° and 80°, the inlet angle of the rotating blade is between 35° and 75°, and the outlet angle of the rotating blade is between 35° and 75°.

[0014] In an embodiment of the present application, the low-carbon hydrocracking system includes at least two heaters and a mixer. The mixer is connected to each heater in a one-to-one correspondence and is used to guide the heated heat exchange medium to the heat exchange chamber.

[0015] In an embodiment of the present application, the low-carbon hydrocracking system further includes a waste heat recovery device, which is used to reintroduce the heat exchange medium discharged from the heat exchange chamber into the heat exchange medium inlet of the heater.

[0016] To achieve the above object, the present application also provides a low-carbon hydrocracking process using the above-mentioned low-carbon hydrocracking system, wherein the low-carbon hydrocracking process comprises:

[0017] S1: shock-wave heating the heat exchange medium and introducing it into the shell side of the second heat exchanger;

[0018] S2: Feeding crude oil and hydrogen respectively, the crude oil passes through the first heat exchanger and the second heat exchanger in sequence along the pipeline, and is mixed with hydrogen before entering the reactor;

[0019] S3: performing cracking reaction;

[0020] S4: passing the reaction product into the shell side of the first heat exchanger for cooling;

[0021] S5: separating unreacted hydrogen through a separator;

[0022] S6: distilling naphtha, kerosene, diesel and tail oil through a fractionating tower;

[0023] S7: Collect the tail oil and mix it with the unheated raw oil before the first heat exchanger.

[0024] In the embodiment of the present application, the temperature of the heat exchange medium after being heated in step S1 is between 600-1200°C.

[0025] In the embodiment of the present application, in step S1, the speed of the heat exchange medium entering the shell side of the second heat exchanger is between 30-100 m / s, and the speed of the heat exchange medium flowing out of the shell side of the second heat exchanger is between 10-50 m / s.

[0026] Through the above technical solution, the low-carbon hydrocracking system provided in the embodiment of the present application has the following beneficial effects:

[0027] When the above-mentioned low-carbon hydrocracking system is used, the heat exchange medium is decelerated from sonic or supersonic speed to subsonic speed in the shock wave heating channel of the heater. In this process, part of the kinetic energy of the heat exchange medium is converted into internal energy, thereby increasing the temperature of the heat exchange medium. The heated heat exchange medium enters the shell side of the second heat exchanger along the pipeline. At the same time, the raw oil flows through the tube side of the first heat exchanger and the tube side of the second heat exchanger along the pipeline in sequence for heating. The heated raw oil is mixed with hydrogen and enters the reactor for cracking reaction. The reactants flowing out of the reactor are heat exchanged with the unheated raw oil through the shell side of the first heat exchanger, which not only heats the raw oil but also cools the reactants. The reactants after cooling are first separated from the excess hydrogen by a separator, and finally fractionated into naphtha, kerosene, diesel as finished products and tail oil that needs to continue cracking reaction at the distillation tower. Compared with the existing hydrocracking system, there is no need for combustion, which reduces the emission of carbon dioxide and sulfide, which is beneficial to environmental protection.

[0028] Other features and advantages of the present application will be described in detail in the subsequent specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide an understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application but do not constitute a limitation to the present application. In the accompanying drawings:

[0030] Figure 1 is a schematic diagram of a low-carbon hydrocracking system according to an embodiment of the present application;

[0031] Figure 2 is a schematic cross-sectional view of a heater in a horizontal direction according to an embodiment of the present application;

[0032] Figure 3 is a front schematic diagram of a heater according to an embodiment of the present application;

[0033] Figure 4 is a schematic diagram of a blade at a certain location in a shock wave heating channel according to an embodiment of the present application;

[0034] Figure 5 It is a flow chart of a low-carbon hydrocracking process according to one embodiment of the present application.

[0035] Description of Reference Numerals

[0036] 10 Reactor 21 High-pressure separator

[0037] 22 Low pressure separator 30 Fractionation tower

[0038] 40 heater 41 outer shell

[0039] 42 First fixed blade 43 Rotating blade

[0040] 44 Second fixed blade cascade 45 Shock wave heating channel

[0041] 51 first heat exchanger 52 second heat exchanger

[0042] 61 first mixer 62 second mixer

[0043] 63 Third mixer 71 First booster pump

[0044] 72 Second boost pump 80 Cooler DETAILED DESCRIPTION

[0045] The specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0046] The low-carbon hydrocracking system and process of the present application will be described below with reference to the accompanying drawings.

[0047] The present application provides a novel low-carbon hydrocracking system. Figure 1 As shown, in a specific embodiment, the low-carbon hydrocracking system includes:

[0048] The catalytic reaction device comprises a reactor 10, a separator, and a fractionation tower 30 which are connected in sequence, and a tail oil outlet pipe is provided at the bottom of the fractionation tower 30;

[0049] The heating device includes a heater 40, a first heat exchanger 51 and a second heat exchanger 52. A shock wave heating channel 45 is formed in the heater 40. The tube side of the first heat exchanger 51 is connected to the crude oil feed pipe, the shell side of the first heat exchanger 51 is respectively connected to the discharge port of the reactor 10 and the feed port of the separator, the tube side of the second heat exchanger 52 is respectively connected to the tube side of the first heat exchanger 51 and the reactor 10, and the shell side of the second heat exchanger 52 is connected to the heater 40.

[0050] When the above-mentioned low-carbon hydrocracking system is used, the heat exchange medium is decelerated from sonic or supersonic speed to subsonic speed in the shock wave heating channel 45 of the heater 40. In this process, part of the kinetic energy of the heat exchange medium is converted into internal energy, thereby increasing the temperature of the heat exchange medium. The heated heat exchange medium enters the shell side of the second heat exchanger 52 along the pipeline. At the same time, the raw oil flows through the tube side of the first heat exchanger 51 and the tube side of the second heat exchanger 52 along the pipeline in sequence for heating. The heated raw oil is mixed with hydrogen and enters the reactor 10 for cracking reaction. The reactants flowing out of the reactor 10 pass through the shell side and exchange heat with the unheated raw oil, which not only heats the raw oil but also cools the reactants. The reactants after cooling first pass through the separator to separate the excess hydrogen, and finally are fractionated at the fractionation tower 30 into naphtha, kerosene, diesel as finished products and tail oil that needs to continue cracking reaction. Compared with the existing hydrocracking system, there is no need for combustion, which reduces the emission of carbon dioxide and sulfide, which is beneficial to environmental protection.

[0051] Specifically, see Figure 1 The system further includes a first booster pump 71 and a second booster pump 72. The crude oil is pressurized by the first booster pump 71 and flows through the tube side of the first heat exchanger 51 and the tube side of the second heat exchanger 52. The second booster pump 72 is used to pressurize the input hydrogen. A third mixer 63 is provided before the inlet of the reactor 10. The crude oil and hydrogen are mixed by the third mixer 63 and then enter the reactor 10. The reactants flowing out of the reactor 10 are preliminarily cooled in the shell side of the first heat exchanger 51. A cooler 80 is provided between the first heat exchanger 51 and the separator to reduce the reactants to a set temperature before performing subsequent operations such as separating hydrogen and fractionating products.

[0052] Furthermore, the separator includes a high-pressure separator 21 and a low-pressure separator 22, and the catalytic reaction device also includes a fourth mixer 64 arranged between the second booster pump and the third mixer 63, and the fourth mixer 64 is used to mix the hydrogen separated by the high-pressure separator 21 with the hydrogen output by the second booster pump 72 to continue to be used for cracking reaction, thereby improving the utilization rate of hydrogen.

[0053] It should be noted that in the present application, the heater 40 utilizes the principle of shock wave heating. Shock wave is a gas dynamic phenomenon. For gas flowing at the speed of sound or supersonic speed, its speed will be faster than the conduction of its pressure, thereby superimposing to form waves, and when the rear gas passes through these waves, compression waves or expansion waves will be formed. When the gas in the sonic or supersonic state encounters an obstacle, its compression waves will be superimposed to form a shock wave, which can cause the gas temperature to rise sharply and the speed to drop. In essence, part of the kinetic energy of the gas is converted into internal energy.

[0054] like Figure 1 As shown, in the embodiment of the present application, the catalytic reaction device further includes a first mixer 61 disposed before the first heat exchanger 51, and the first mixer 61 is connected to the feed pipe of the raw oil and the tail oil outlet pipe in a one-to-one correspondence, so as to mix the raw oil and the tail oil and guide them to the first heat exchanger 51. Through the above arrangement, the tail oil remaining after fractionation can be circulated in the hydrocracking system of the present application, and continue to be cracked to increase the yield of finished oil.

[0055] like Figure 2As shown, in the embodiment of the present application, the heater 40 includes: an outer shell 41, a rotating blade cascade 43, a first fixed blade cascade 42 and a second fixed blade cascade 44. A shock wave heating channel 45 is formed in the outer shell 41. The cross-section of the shock wave heating channel 45 is annular. The rotating blade cascade 43, the first fixed blade cascade 42 and the second fixed blade cascade 44 are all arranged in the shock wave heating channel 45. The rotating blade cascade 43 can rotate around the central axis of the outer shell. The first fixed blade cascade 42 is arranged upstream of the rotating blade cascade 43, and the second fixed blade cascade 44 is arranged downstream of the rotating blade cascade 43. The heat exchange medium flows in along the first fixed blade cascade 42, is accelerated to sonic or supersonic speed through the rotation of the rotating blade cascade 43, and impacts the second fixed blade cascade 44 to generate heat. The heat exchange medium moves in a spiral motion with the rotating blades. In this process, the heat exchange medium enters from the inlet of the first fixed blade cascade 42, is accelerated by the rotating blades, and impacts the second fixed blade cascade 44. After completing the conversion of kinetic energy to internal energy, the heat exchange medium enters from the outlet of the second fixed blade cascade 44 to the bladeless area in the shock wave heating channel 45 to complete a cycle of heating the heat exchange medium. The main function of the second fixed blade cascade 44 is to hinder the heat exchange medium in the sonic or supersonic state and increase its temperature. At the same time, the first fixed blade cascade 42 and the second fixed blade cascade 44 also constitute an air duct for the flow of the heat exchange medium. By designing the outer contours and arrangement angles of the first fixed blade cascade 42 and the second fixed blade cascade 44, the heat exchange medium can quickly flow in from the inlet of the first fixed blade cascade 42 and / or quickly flow out from the outlet of the second fixed blade cascade 44.

[0056] Specifically, the relative spacing distance between the first fixed blade cascade 42 and the second fixed blade cascade 44 is adjustable, and the relative spacing between the first fixed blade cascade 42 and the second fixed blade cascade 44 can be specifically set according to the speed of the heat exchange medium to meet the need for accelerating the heat exchange medium. Further, the first fixed blade cascade 42 and the second fixed blade cascade 44 constitute an air duct for the flow of the heat exchange medium. At the first fixed blade cascade 42, the air duct is set in a reduced manner. When the heat exchange medium passes through the first fixed blade cascade 42, it is compressed by the air duct for initial acceleration, and then further accelerated to the speed of sound or supersonic speed under the high-speed rotation of the rotating blade cascade 43.

[0057] It should be noted that, in the present application, “upstream” and “downstream” are defined according to the flow direction of the heat exchange medium. The side where the heat exchange medium flows toward the rotating blade cascade 43 is the upstream, and the side where the heat exchange medium flows out of the rotating blade cascade 43 is the downstream.

[0058] In the embodiment of the present application, the heater 40 further includes a plurality of partitions disposed in the shock wave heating channel 45, the plurality of partitions being used to separate a plurality of heating spaces, each of which is provided with a plurality of first fixed blades for constituting the first fixed blade grid 42, and a plurality of second fixed blades for constituting the second fixed blade grid 44. Although the heat exchange medium can achieve the purpose of heating after impacting the second fixed blade, the temperature increase is limited. In order to meet the actual needs of heating the crude oil, a plurality of heating spaces are separated by providing a plurality of partitions, so that the heat exchange medium passes through the plurality of heating spaces in the shock wave heating channel 45 in sequence. Through this multi-layer design, the heat exchange medium moves spirally along the shock wave heating channel 45 under the drive of the rotating blades, and repeatedly passes through the first fixed blade grid 42, the rotating blade grid 43, and the second fixed blade grid 44, thereby generating shock waves multiple times, and gradually increasing the temperature until the requirement is met.

[0059] Specifically, refer to Figure 2 and Figure 3 The heater is arranged in a circular shape as a whole, the shock wave heating channel surrounds the central axis of the heater, the first fixed blade 42, the rotating blade 43 and the second fixed blade 44 also surround the central axis, and the heater also includes a rotor arranged through the central axis, and the rotor drives the rotating blade 43 to rotate around the central axis. The heat exchange medium flows in from the inlet of the outer shell 41, flows along the first fixed blade in the first heating space to the rotating blade 43, accelerates from subsonic speed to sonic speed or supersonic speed through the rotating blade 43, and then impacts the second fixed blade in the heating space and slows down to subsonic speed. In this process, part of the kinetic energy of the heat exchange medium is converted into internal energy, completing the first heating. The heat exchange medium after deceleration enters the bladeless area in the next heating space along the second fixed blade, and then flows along the annular bladeless area to the first fixed blade, and performs the second heating according to the above steps. Repeat the above process, the heat exchange medium enters from the inlet of the outer shell 41, and spirally moves along the shock wave heating channel 45 to the outlet of the outer shell 41. During this movement, the heat exchange medium is repeatedly heated until it reaches the preset temperature. It should be noted that the inlet and the outlet of the outer shell 41 are respectively arranged at the front and rear sides of the outer shell 41 to correspond to the first fixed blade cascade 42 and the second fixed blade cascade 44 respectively.

[0060] Furthermore, the required preset temperature of the heat exchange medium entering the shell side of the second heat exchanger is between 600-1200°C, and the specific temperature needs to be set according to the actual needs of crude oil heating. The method for adjusting the temperature can be to change the number of heaters in working state, or to change the rotation speed of the rotating blade 43 to change the maximum speed of the heat exchange medium. The faster the speed of the heat exchange medium, the greater the kinetic energy, and the more internal energy is converted when impacting the second fixed blade.

[0061] It should be noted that, in a specific embodiment of the present application, the number of the first fixed blades and the second fixed blades can be determined according to the heat load required by the system. Further, the number of the first fixed blades and the second fixed blades is the same, and the number is between 30-40.

[0062] In the embodiment of the present application, the first fixed blade has a curved streamline profile and is used to guide the heat exchange medium to the rotating blade cascade 43, and the second fixed blade has a curved streamline profile and is used to guide the heat exchange medium out of the heating space.

[0063] In an embodiment of the present application, the installation angle of the first fixed blade is between 35° and 75°, the inlet angle of the first fixed blade is between 0° and 45°, and the outlet angle of the first fixed blade is between 35° and 75°; the installation angle of the second fixed blade is between 45° and 85°, the inlet angle of the second fixed blade is between 25° and 65°, and the outlet angle of the second fixed blade is between 25° and 65°.

[0064] In the embodiment of the present application, the rotating blade grid 43 includes a plurality of rotating blades, and each rotating blade has a curved profile facing its rotation direction.

[0065] In the embodiment of the present application, the installation angle of the rotating blade is between 10° and 80°, the inlet angle of the rotating blade is between 35° and 75°, and the outlet angle of the rotating blade is between 35° and 75°.

[0066] refer to Figure 4 , Figure 4 From left to right, there are the first fixed blade of the first fixed blade 42, the rotating blade of the rotating blade 43, and the second fixed blade of the second fixed blade 44. The heat exchange medium moves along the flow channel formed by the three. The angle settings of the first fixed blade, the rotating blade, and the second fixed blade are optimized to achieve effective heating of the heat exchange medium. Specifically, the specific angle settings of the first fixed blade, the rotating blade, and the second fixed blade can be optimized and selected according to the specific fluid dynamics requirements and heating effects. By reasonably setting the installation angles of the first fixed blade, the rotating blade, and the second fixed blade, the heat exchange medium can flow smoothly between the rotating blade and the fixed blade, thereby effectively introducing or exporting the heat exchange medium into or out of the heating space. When selecting the installation angle, factors such as the speed and flow direction of the heat exchange medium, as well as the gap and shape between the blades, can be considered to ensure the best fluid dynamics performance and heat transfer effect.

[0067] In the embodiment of the present application, the low-carbon hydrocracking system includes at least two heaters 40 and a second mixer 62. The second mixer 62 is connected to each heater 40 in a one-to-one correspondence and is used to guide the heated heat exchange medium to the heat exchange chamber. The present application adopts a combination of multiple heaters 40 for heating, so a single heater 40 can be miniaturized for easy installation. When the heating temperature of the crude oil needs to be adjusted, only some of the heaters 40 need to be turned on or off to effectively control the temperature within a certain range; the second mixer 62 mixes the heat exchange medium discharged from the multiple heaters 40 and guides it to the heat exchange chamber at the same rate, so that the airflow in the heat exchange chamber is more stable.

[0068] In the embodiment of the present application, the low-carbon hydrocracking system further includes a waste heat recovery device, which is used to reintroduce the heat exchange medium discharged from the heat exchange chamber into the heat exchange medium inlet of the heater 40. By adopting the waste heat recovery device, the low-carbon hydrocracking system can recover and utilize heat energy to the maximum extent, and the heat exchange medium discharged from the heat exchange chamber is reintroduced into the heater 40 through the waste heat recovery device, so that it participates in the heating process again, thereby reducing energy waste and heat loss, and improving the energy utilization efficiency of the device. This recycling design helps to save energy and reduce carbon emissions, and is in line with the principle of low-carbon environmental protection.

[0069] Specifically, the heat exchange medium may preferably be air, nitrogen or water vapor.

[0070] To achieve the above object, the present application also provides a low-carbon hydrocracking process using the above-mentioned low-carbon hydrocracking system, comprising:

[0071] S1: shock-heating the heat exchange medium and introducing it into the shell side of the second heat exchanger 52;

[0072] S2: Feeding raw oil and hydrogen respectively, the raw oil passes through the first heat exchanger 51 and the second heat exchanger 52 in sequence along the pipeline, and is mixed with hydrogen before entering the reactor 10;

[0073] S3: performing cracking reaction;

[0074] S4: passing the reaction product into the shell side of the first heat exchanger 51 for cooling;

[0075] S5: separating unreacted hydrogen through a separator;

[0076] S6: distilling naphtha, kerosene, diesel and tail oil through a fractionating tower 30;

[0077] S7: collecting the tail oil and mixing it with the unheated raw oil before the first heat exchanger 51.

[0078] In the embodiment of the present application, the temperature of the heat exchange medium after being heated in step S1 is between 600-1200°C.

[0079] In the embodiment of the present application, in step S1, the speed at which the heat exchange medium enters the shell side of the second heat exchanger 52 is between 30-100 m / s, and the speed at which the heat exchange medium flows out of the shell side of the second heat exchanger 52 is between 10-50 m / s. Specifically, the speed at which the heat exchange medium enters the shock wave heating channel 45 is between 50-200 m / s, and the speed at which the heat exchange medium flows out of the shock wave heating channel 45 is between 50-200 m / s, the air pressure at the inlet of the shock wave heating channel 45 is between 2.5-5 bar, and the temperature at the inlet is room temperature or the temperature of the heat exchange medium recovered by the waste heat recovery device.

[0080] refer to Figure 1 In a specific embodiment of the present application, the process of hydrocracking is:

[0081] The tail oil after pressurization by the first booster pump 71 and fractionation is mixed by the first mixer 61 and enters the first heat exchanger 51, performs convective heat exchange with the reaction product flowing out of the reactor, and then enters the second heat exchanger 52 to perform convective heat exchange with the heat exchange medium. After passing through the second heat exchanger, it is mixed with hydrogen in the third mixer 63 and enters the reactor 10; the material after the reaction in the reactor 10 is preliminarily cooled by the first heat exchanger, and then further cooled by the cooler 80 and enters the high-pressure separator 21. The high-pressure separator 21 separates a large amount of hydrogen for circulation. The liquid phase material at the bottom of the high-pressure separator 21 enters the low-pressure separator 22 after decompression. The gas phase material is separated from the top of the low-pressure separator 22. The liquid phase product at the bottom of the low-pressure separator 22 enters the fractionation tower 30 for fractionation to produce naphtha, kerosene and diesel. Unreacted tail oil remains at the bottom of the fractionation tower 30, which can be further circulated and cracked.

[0082] The following are specific examples and comparative examples of the present application.

[0083] Example 1

[0084] Taking the 900,000 tons / year hydrocracking system as an example, the initial temperature of the crude oil is 40°C, and the temperature of the crude oil after heating is 350°C, and the required heat load is 25,000KW. The heater 40 is equipped with 36 first fixed blades, 36 second fixed blades, and 72 rotating blades. The installation angle of the first fixed blade is 56.5°, the inlet angle is 1°, and the outlet angle is 49.9°; the installation angle of the second fixed blade is 75.52°, the inlet angle is 54.12°, and the outlet angle is 35.4°; the installation angle of the rotating blade is 74.7°, the inlet angle is 42.7°, and the outlet angle is 41.87. The rotating blade 43 rotates at a speed of 7500rpm, the heat exchange medium is air, the speed of air entering the heater 40 is 115m / s, and the air is heated from 25°C to 870°C by the heater 40. The number of heaters 40 is one. In this system, the carbon emissions generated by heating the crude oil can be ignored.

[0085] Comparative Example 1

[0086] Taking the 900,000 tons / year original hydrocracking system as an example, the initial temperature of the crude oil is 40°C, the temperature of the crude oil after heating is 350°C, the branch temperature difference does not exceed 10°C, the temperature in the radiation room does not exceed 850°C, the fuel used is methane, and the annual carbon emissions are approximately 36,000 tons.

[0087] Example 2

[0088] Taking the 1.3 million tons / year hydrocracking system as an example, the raw oil is heavy oil and tail oil distilled from the fractionation tower 30, the initial temperature of the raw oil is 40°C, the temperature of the raw oil after heating is 350°C, the required heat load is 37000KW, and the heater 40 is equipped with 40 first fixed blades, 40 second fixed blades, and 80 rotating blades. The installation angle of the first fixed blade is 56.5°, the inlet angle is 1°, and the outlet angle is 49.9°; the installation angle of the second fixed blade is 75.52°, the inlet angle is 54.12°, and the outlet angle is 35.4°; the installation angle of the rotating blade is 74.7°, the inlet angle is 42.7°, and the outlet angle is 41.87. The rotating blade 43 rotates at a speed of 7500rpm, the heat exchange medium is air, the speed of air entering the heater 40 is 115m / s, and the air is heated from 25°C to 870°C by the heater 40. The number of heaters 40 is two. In this system, the carbon emissions generated by heating the raw oil are negligible.

[0089] Comparative Example 2

[0090] Taking the 1.3 million tons / year hydrocracking system as an example, the initial temperature of the crude oil is 40°C, the temperature of the crude oil after heating is 350°C, the branch temperature difference does not exceed 15°C, the temperature in the radiation room does not exceed 850°C, the fuel used is methane, and the annual carbon emissions are approximately 50,000 tons.

[0091] Through the above embodiments and comparative examples, the low-carbon hydrocracking system of the present application not only achieves the purpose of hydrocracking but also reduces the generation of carbon dioxide and sulfide, which is beneficial to environmental protection.

[0092] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0093] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0095] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A low-carbon hydrocracking system, characterized in that: include: A catalytic reaction device comprises a reactor (10), a separator, and a fractionation tower (30) which are connected in sequence, wherein a tail oil outlet pipe is provided at the bottom of the fractionation tower (30); The heating device comprises a heater (40), a first heat exchanger (51) and a second heat exchanger (52); a shock wave heating channel (45) is formed in the heater (40); the tube side of the first heat exchanger (51) is connected to the feed pipe of the crude oil; the shell side of the first heat exchanger (51) is respectively connected to the discharge port of the reactor (10) and the feed port of the separator; the tube side of the second heat exchanger (52) is respectively connected to the tube side of the first heat exchanger (51) and the reactor (10); and the shell side of the second heat exchanger (52) is connected to the heater (40).

2. The low-carbon hydrocracking system according to claim 1, characterized in that: The catalytic reaction device also includes a first mixer (61) arranged upstream of the first heat exchanger (51), and the first mixer (61) is connected to the raw oil feed pipe and the tail oil outlet pipe in a one-to-one correspondence, so as to mix the raw oil and the tail oil and guide them to the first heat exchanger (51).

3. The low-carbon hydrocracking system according to claim 1, characterized in that: The heater (40) comprises: An outer shell (41), wherein the shock wave heating channel (45) is formed in the outer shell (41), and the cross section of the shock wave heating channel (45) is annular; A rotating blade cascade (43) is disposed in the shock wave heating channel (45) and rotates around a central axis; A first fixed blade cascade (42) and a second fixed blade cascade (44) are arranged in the shock wave heating channel (45), wherein the first fixed blade cascade (42) is arranged upstream of the rotating blade cascade (43), and the second fixed blade cascade (44) is arranged downstream of the rotating blade cascade (43), and a heat exchange medium flows in along the first fixed blade cascade (42), rotates through the rotating blade cascade (43) and is accelerated to sonic or supersonic speed and impacts the The second fixed blade row (44) is used to generate heat.

4. The low-carbon hydrocracking system according to claim 3, characterized in that: The heater (40) further comprises a plurality of partitions arranged in the shock wave heating channel (45), the plurality of partitions being used to separate a plurality of heating spaces, and each of the heating spaces being provided with a plurality of first fixed blades for constituting the first fixed blade grid (42) and a plurality of second fixed blades for constituting the second fixed blade grid (44).

5. The low-carbon hydrocracking system according to claim 4, characterized in that: The first fixed blade has a curved streamline profile and is used to guide the heat exchange medium to the rotating blade grid (43), and the second fixed blade has a curved streamline profile and is used to guide the heat exchange medium out of the heating space.

6. The low-carbon hydrocracking system according to claim 5, characterized in that: The installation angle of the first fixed blade is between 35° and 75°, the inlet angle of the first fixed blade is between 0° and 45°, and the outlet angle of the first fixed blade is between 35° and 75°; the installation angle of the second fixed blade is between 45° and 85°, the inlet angle of the second fixed blade is between 25° and 65°, and the outlet angle of the second fixed blade is between 25° and 65°.

7. The low-carbon hydrocracking system according to claim 4, characterized in that: The rotating blade grid (43) comprises a plurality of rotating blades, each of which has a curved profile facing its rotation direction.

8. The low-carbon hydrocracking system according to claim 7, characterized in that: The installation angle of the rotating blade is between 10° and 80°, the inlet angle of the rotating blade is between 35° and 75°, and the outlet angle of the rotating blade is between 35° and 75°.

9. The low-carbon hydrocracking system according to any one of claims 1 to 8, characterized in that: The heating device comprises at least two of the heaters (40) and a second mixer (62), wherein the second mixer (62) is connected to each of the heaters (40) in a one-to-one correspondence and is used to guide the heated heat exchange medium to the shell side of the first heat exchanger (51).

10. The low-carbon hydrocracking system according to any one of claims 1 to 8, characterized in that: The heating device further comprises a waste heat recovery device, which is used to reintroduce the heat exchange medium discharged from the shell side of the first heat exchanger (51) into the inlet of the heater (40).

11. A low-carbon hydrocracking process, characterized in that: The process adopts the low-carbon hydrocracking system according to any one of claims 1 to 9 and performs the steps: S1: shock-wave heating the heat exchange medium and introducing the heat exchange medium into the shell side of the second heat exchanger (52); S2: introducing raw oil and hydrogen respectively, the raw oil passes through the first heat exchanger (51) and the second heat exchanger (52) in sequence along the pipeline, and is mixed with the hydrogen before entering the reactor (10); S3: performing cracking reaction; S4: passing the reaction product into the shell side of the first heat exchanger (51) for cooling; S5: separating unreacted hydrogen through the separator; S6: fractionating naphtha, kerosene, diesel and tail oil through the fractionation tower (30); S7: collecting the tail oil and mixing it with the unheated raw oil before the first heat exchanger (51).

12. The low-carbon hydrocracking process according to claim 11, characterized in that: The temperature of the heat exchange medium after heating in step S1 is between 600-1200°C.

13. The low-carbon hydrocracking process according to claim 11, characterized in that: In the step S1, the speed at which the heat exchange medium enters the shell side of the second heat exchanger (52) is between 30-100 m / s, and the speed at which the heat exchange medium flows out of the shell side of the second heat exchanger (52) is between 10-50 m / s.

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