WO2020143140A1

WO2020143140A1 - Separation system for slurry bed reactor

Info

Publication number: WO2020143140A1
Application number: PCT/CN2019/086186
Authority: WO
Inventors: 郭中山; 王铁峰; 门卓武; 王峰
Original assignee: 清华大学; 神华宁夏煤业集团有限责任公司; 北京低碳清洁能源研究所
Priority date: 2019-01-10
Filing date: 2019-05-09
Publication date: 2020-07-16
Also published as: CN109603695A; CN109603695B

Abstract

A separation system for a slurry bed reactor, comprising a slurry bed reactor (1) and a first separation device (2) provided in the slurry bed reactor (1); the first separation device (2) is used for performing cyclone separation on a gas flow in the slurry bed reactor (1) and then discharging the gas flow out of the slurry bed reactor (1); the first separation device (2) comprises at least two stages of cyclone separators (13), a gas outlet (16) of the preceding stage cyclone separator (13) is in communication with a gas inlet (15) of the following stage cyclone separator (13), and a gas outlet (16) of the last stage cyclone separator (13) is in communication with the outside of the slurry bed reactor (1).

Description

Separation system of slurry bed reactor

Technical field

The present application relates to the technical field of gas-liquid-solid separation, in particular to a separation system of a slurry bed reactor.

Background technique

At present, Fischer-Tropsch synthesis technology has been successfully industrialized in China. The Fischer-Tropsch synthesis technology is mainly composed of three parts: ① synthesis gas production technology; ② synthesis liquid hydrocarbon production technology; ③ synthesis product processing technology. The typical Fischer-Tropsch synthesis process is as follows: First, coal/natural gas is converted into synthesis gas by gasification or partial oxidation and reformation, and then the synthesis gas is desulfurized and deoxygenated, and then adjusted according to the Fischer-Tropsch synthesis process conditions and catalyst used. H ₂ /CO ratio, then enter the Fischer-Tropsch synthesis reactor to produce mixed hydrocarbons. Finally, different target products can be obtained after the separation and modification of synthetic products.

Since the Fischer-Tropsch synthesis is a strong exothermic reaction, the reaction heat must be removed in time during the reaction, otherwise local hot spots may easily occur in the bed, resulting in rapid catalyst deactivation and reducing the selectivity of long-chain alkane products; in severe cases The instantaneous flying temperature of the reactor may occur, and the device has to be shut down. The use of a slurry bed reactor is one of the effective means to solve this problem, especially for large industrial plants. But the slurry bed reactor also encountered new problems during its use.

Generally speaking, the slurry bed Fischer-Tropsch reactor is a gas-liquid-solid three-phase reactor, and its internal fluid properties are relatively complex. The unreacted gas and the generated low-carbon hydrocarbons and water leave the reactor through the outlet at the top of the reactor. After the catalyst in the reactor is broken and pulverized, the formed fine powder is easily entrained by the high-temperature gas and leaves the reactor from the top. In addition, the catalyst with smaller particles is also easily entrained by the high-temperature gas and leaves the reactor from the top, especially when the operation fluctuates. How to control the fine powder and even the catalyst particles from being taken out of the reactor is one of the problems to be solved. In a large-scale industrial Fischer-Tropsch synthesis reactor, if the design is not reasonable or the operation is not good, the liquid phase in the upper gas phase stream and the catalyst will be too much entrained, resulting in the solid content of the condensed heavy oil separated by the product separation system It is too high to be sent to the processing unit for further processing, especially when too much foam or even flooding happens accidentally at the gas-liquid interface of the reactor. In the published reports, there is no reasonable technical solution to effectively solve this problem.

Summary of the invention

An embodiment of the present application provides a separation system for a slurry bed reactor, including a slurry bed reactor and a first separation device provided in the slurry bed reactor; the first separation device is used to The gas flow in the slurry bed reactor is cyclone separated and then discharged out of the slurry bed reactor; the first separation device includes at least two stages of cyclones, the gas outlet of the previous stage cyclone separator and the latter stage The air inlet of the cyclone separator is connected, and the air outlet of the last stage cyclone separator is connected to the outside of the slurry bed reactor.

Beneficial effect:

In the separation system of the slurry bed reactor according to the embodiment of the present application, a multi-stage cyclone separator is provided inside the slurry bed reactor, which can cyclone separate the gas flow inside the slurry bed reactor and then exit the slurry bed The reactor, as such, can reduce the solid and liquid materials entrained in the gas stream leaving the slurry bed reactor.

BRIEF DESCRIPTION

The drawings are used to provide a further understanding of the technical solutions of the present application, and form part of the specification. They are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

1 is a schematic structural view of a first separation device provided in a slurry bed reactor in a separation system according to an embodiment of the present application;

FIG. 2 is a schematic structural plan view of a first separation device provided in a slurry bed reactor in a separation system according to an embodiment of this application;

3 is a schematic structural diagram of a first-stage cyclone separator of a first separation device according to an embodiment of the present application;

4 is a schematic diagram of the top structure of FIG. 3;

5 is a schematic cross-sectional structural view of a first-stage cyclone separator of a first separation device according to another embodiment of this application;

6 is a partial structural schematic diagram of a first-stage cyclone separator of a first separation device according to yet another embodiment of this application;

7 is a schematic view of the bottom structure of the baffle assembly in FIG. 6;

8 is a schematic structural diagram of a separation system according to an embodiment of the present application;

The reference signs are: 1. Slurry bed reactor, 2. First separation device, 3. Gas outlet pipe, 4. First heat exchanger, 5. Gas-liquid separation tank, 6. Second separation device, 7. Two heat exchangers, 8, oil and gas separation tank, 9, first-stage cyclone separator, 10, second-stage cyclone separator, 11, downcomer, 12, connecting pipe, 13, cyclone separator, 14, shell , 15, air inlet, 16, air outlet, 17, slurry outlet, 18, upper cylinder, 19, lower cylinder, 20, top plate, 21, exhaust pipe, 22, baffle assembly, 23, the first block Plate, 24, second baffle, 25, annular channel, 26, air outlet, 27, downcomer, 28, air inlet.

detailed description

The technical solution of the present application will be further described below with reference to the drawings and through specific implementation manners. It can be understood that the specific embodiments described here are only used for explaining the present application, rather than limiting the present application.

As shown in FIG. 1, an embodiment of the present application provides a separation system for a slurry bed reactor, including a slurry bed reactor 1 and a first separation device 2 provided in the slurry bed reactor 1; The first separation device 2 is used for cyclonic separation of the gas flow in the slurry bed reactor 1 and then discharged out of the slurry bed reactor 1; the first separation device 2 includes at least two stages of cyclone separators 13 The gas outlet of the previous cyclone separator communicates with the gas inlet of the latter cyclone separator, and the gas outlet of the last cyclone separator communicates with the outside of the slurry bed reactor 1.

In the separation system of the slurry bed reactor according to the embodiment of the present application, a multi-stage cyclone separator 13 is provided inside the slurry bed reactor 1, which can separate the gas flow inside the slurry bed reactor 1 after cyclone separation The slurry bed reactor 1 can thus reduce the solid and liquid substances entrained in the gas stream leaving the slurry bed reactor 1.

In this embodiment, the first separation device 2 may choose to set up two, three or more cyclone separators 13 according to the size of the slurry bed reactor 1 and the gas flow generated. Each stage The number of cyclones 13 installed is also not limited. The multi-stage cyclone 13 is used to separate the liquid droplets and solid particles and powder entrained in the gas stream step by step. The separated liquid and solid are returned to the slurry of the slurry bed reactor 1 from the slurry outlet of each cyclone 13 .

As shown in FIG. 2, exemplarily, the at least two-stage cyclone separator 13 includes a first-stage cyclone separator 9 and a second-stage cyclone separator 10. The first-stage cyclone separator 9 is provided as at least two, and The secondary cyclone 10 is provided as one, and the gas outlet of the secondary cyclone 10 is connected to the outside of the slurry bed reactor 1.

The side wall of the cyclone separator 13 is provided with an air inlet 15. The air inlet 15 may be arranged along the tangent direction of the side wall of the cyclone separator 13, or the center axis of the air inlet 15 and the tangent line of the side wall where it is located At an angle of 0-75°, the upper part of the cyclone 13 is provided with an air outlet 16 and the lower part is provided with a slurry outlet 17, which is the discharge of solid particles, powder or/and droplets separated from the gas flow Export. The airflow enters the cyclone chamber inside the cyclone separator 13 through the air inlet 15 of the cyclone separator 13, and after the cyclone separation is performed in the cyclone chamber, the gas is discharged through the upper air outlet 16 and the solid particles separated from the airflow , Powder or/and droplets are discharged from the lower slurry outlet 17. Wherein, the cyclone chamber of the cyclone separator 13 refers to a region where the airflow performs cyclone separation inside the cyclone separator.

The first-stage cyclone separator 9 and the second-stage cyclone separator 10 are provided in the gas phase region of the slurry bed reactor 1, such as the upper part of the slurry bed reactor 1. In order to facilitate the gas flow in the gas phase region in the slurry bed reactor 1 to enter the first stage cyclone 9, the first stage cyclone 9 may be arranged along the circumferential direction of the inner wall of the slurry bed reactor 1, for example It can be set evenly on a circle. The number and size of the first-stage cyclone separator 9 can be calculated and determined according to the size of the slurry bed reactor 1 and the outlet gas volume of the reactor, such as 2-20. Supports may be provided on the inner wall of the gas phase region of the slurry bed reactor 1 for supporting and fixing the first-stage cyclone separator 9 and the second-stage cyclone separator 10.

The position of the inlet of the second-stage cyclone 10 is higher than the position of the outlet of the first-stage cyclone 9 to facilitate the gas exiting from the first-stage cyclone 9 and then enter the second-stage cyclone separation器10. The second-stage cyclone 10 can be disposed above the first-stage cyclone 9, for example, can be located at the center position above the circumference where the first-stage cyclone 9 is located, so that it is advantageous to separate each first-stage cyclone The gas discharged from the separator 9 enters the second-stage cyclone separator 10 through the same path, which is conducive to the convergence and superposition of each air flow in the second-stage cyclone separator 10, and enhances the separation effect in the second-stage cyclone separator 10.

The number of air inlets of the second-stage cyclone separator 10 is the same as the number of first-stage cyclone separators 9, and the air outlet of each first-stage cyclone separator 9 is consistent with the second-stage cyclone The corresponding air inlets of the separator 10 are in communication. In this way, the airflow discharged from the air outlet of each first-stage cyclone 9 can enter the second-stage cyclone 10 from the corresponding air inlet of the second-stage cyclone 10. The second-stage cyclone 10 is provided with multiple air inlets to increase the air intake area and improve the air intake efficiency, thereby reducing the pressure loss of the air flow due to the inlet flow resistance and improving the separation efficiency. The number of air inlets of each first-stage cyclone separator 9 may be one or more, such as 1 to 2.

The air inlet of the second-stage cyclone separator 10 may be provided along the circumferential direction of the second-stage cyclone separator 10, for example, may be evenly arranged in the circumferential direction of the side wall of the second-stage cyclone separator 10, It can be arranged symmetrically in the center (see Figure 2, 8 connecting pipes 12 are respectively connected to the 8 air inlets provided in the circumferential direction of the second stage cyclone 10, and the other end of each connecting pipe 12 is connected to a first stage The air outlets of the cyclone separator 9 are connected, and a total of eight first-stage cyclone separators 9) are provided, and each air inlet is provided along the tangent direction of the side wall, or at the same angle as the tangent of the side wall. In this way, each stream of air discharged from each first-stage cyclone 9 can enter the second-stage cyclone 10 from the corresponding air inlet of the second-stage cyclone 10, and each stream of air flows along the second stage The inner walls of the cyclone chamber of the cyclone separator 10 all rotate and flow the same distance and then merge with the airflow of the other air inlet of the second-stage cyclone separator 10, and the airflow coupling superimposes when meeting, so that the second-stage cyclone separator 10 A uniform, stable and enhanced flow is formed in the cyclone chamber, which further improves the separation effect.

The slurry outlet 17 at the bottom of the cyclone 13 is connected with a downcomer, as shown in FIG. 1, the downcomer 27 at the bottom of the first-stage cyclone 9 and the downcomer 11 at the bottom of the second-stage cyclone 10 . The bottom end of the downcomer extends into the slurry in the slurry bed reactor 1 and can extend 0.3-3 meters below the liquid level of the slurry. The bottom end of the downcomer (downcomer 27 or/and downcomer 11) is closed, and the downcomer is provided with openings on the wall of the slurry, and the number of openings can be set as required. For example, 3-8. The solids and/or liquids separated by the cyclone 13 can flow out of the opening in the side wall of the downcomer into the slurry in the reactor 1. The bottom end of the downcomer is closed, which can prevent the gas in the slurry in the reactor 1 from flowing into the downcomer from the bottom end of the downcomer and flowing upward, affecting the solids and/or liquids separated by the cyclone 13 along the downcomer Flow down.

The downcomer can extend from the slurry outlet 17 at the bottom of the cyclone 13 to the inner wall of the slurry bed reactor 1, and then extend vertically downward near the inner wall of the slurry bed reactor 1 until the bottom of the downcomer The end extends below the liquid level of the slurry in the slurry bed reactor 1. In this way, the obstruction of the plurality of downcomers to the gas flow in the slurry bed reactor 1 can be reduced.

Regarding the cyclone separator 13 of the first separation device 2, the cyclone separators 13 of different stages may be provided with the same or different structures except that the number of intake ports may be different.

In the separation system of the embodiment of the present application, the first separation device 2 adopts a one-to-many two-stage series cyclone separator design structure, and the second-stage cyclone separator 10 is provided with a plurality of intake port structures, which increases the effective intake area , Improve the intake efficiency, reduce the pressure drop, improve the separation efficiency, greatly improve the continuous operation time, can achieve high efficiency, energy saving (low resistance), long-term safe operation.

The cyclone separator 13 includes a housing 14 provided with a cyclone chamber, and an air inlet 15 for introducing airflow into the cyclone chamber is provided on the housing 14, the cyclone The upper end of the cavity is provided with an air outlet 16, and the lower end is provided with a slurry outlet 17. The shape of the main body portion of the housing 14 may be an upper cylindrical-lower conical cylindrical shape, or the entire main body portion is cylindrical. Wherein, the airflow is cyclone-separated in the cyclone chamber, and the solid particles, powder or/and droplets separated from the airflow are discharged from the slurry outlet 17 and the gas is discharged from the gas outlet 16.

As shown in FIGS. 3, 4 and 5, for example, the cyclone 13 includes a housing 14 and an exhaust pipe 21 provided in the housing 14, the housing 14 includes a cylindrical upper portion The cylinder 18 and the conical lower cylinder 19 connected to the upper cylinder 18 are connected to the top plate 20 on the top of the upper cylinder 18, and the top plate 20, the upper cylinder 18 and the lower cylinder 19 are welded together. Among them, the area inside the upper cylinder 18 and the lower cylinder 19 outside the exhaust pipe 21 constitutes the cyclone chamber of the cyclone 13 of this embodiment.

The exhaust pipe 21 may be welded to the top plate 20, and the upper end of the exhaust pipe 21 may extend from the opening provided in the top plate 20 (the opening may be provided at the center of the top plate 20) to the outside of the housing 14 and form a cyclone separator The lower end of the air outlet of 13 is located in the upper cylinder 18. Alternatively, the exhaust pipe 21 is completely located in the housing 14, the air outlet 16 is formed on the top plate 20, the air outlet 16 may be located at the center of the top plate 20, and the upper end of the exhaust pipe 21 is welded to the top plate 20 and The air port 16 is in communication, and its lower end is located in the upper cylinder 18. The exhaust pipe 21 may be a circular pipe structure, which is located on the central axis of the housing 14.

The outer wall of the upper cylinder 18 is provided with an air inlet 15 (the air inlet 15 may refer to a small length of air intake duct provided on the outer wall). The air inlet 15 may be provided along the tangent direction of the outer wall, or as The angle between the tangent to the outer wall is 0-75°, that is, the angle between the center axis of the air inlet 15 and the tangent to the outer wall at the air inlet 15 is 0-75°. A slurry outlet 17 is provided at the lower end of the lower cylinder 19.

Regarding the size of the cyclone separator, for example, the height of the exhaust pipe 21 in the upper cylinder 18 is 60% to 100% of the height of the upper cylinder 18, and the diameter of the exhaust pipe 21 is the upper part 20% to 70% of the diameter of the cylinder 18, and the height ratio of the upper cylinder 18 and the lower cylinder 19 is 0.6 to 1.2.

As another embodiment, reference may be made to the structure of the second-stage cyclone separator 10 in FIG. 1. The cyclone 13 includes a casing 14 and an exhaust pipe 21 provided in the casing 14. The casing 14 includes a cylindrical body and upper and lower seal heads provided at both ends of the cylindrical body. The head and the lower head are welded to the cylinder body respectively. The upper head and the lower head may be elliptical heads, the exhaust pipe 21 is welded to the upper head, the upper end of the upper head extends out of the housing 14 from the opening in the upper head, and forms the outlet of the cyclone 13气口16。 16. Air port 16. An air inlet 15 is provided on the outer wall of the cylindrical body, and a slurry outlet 17 is provided at the bottom of the lower head. Among them, the area inside the cylindrical body of the outer casing 14 of the exhaust pipe 21 constitutes the cyclone chamber of the cyclone 13 of this embodiment. The exhaust pipe 21 may be a circular tubular structure, the depth of which is inserted into the casing 14 is 25%-75% of the height of the casing 14; the diameter of the exhaust pipe 21 may be 40%-70% of the diameter of the cylindrical body. The upper end of the exhaust pipe 21 of the second-stage cyclone 10 can be extended from the opening at the top of the slurry bed reactor 1 and connected to the gas outlet pipe 3, and the diameter of the exhaust pipe 21 can be the diameter of the opening at the top of the slurry bed reactor 1 70 to 110%. The structure of the cyclone separator of this embodiment, except that the shape of the housing 14 is different from that of the cyclone separator shown in FIGS. 3-5, other structures may be set to be the same as the structure of the cyclone separator shown in FIGS. 3-5.

In order to reduce the secondary entrainment phenomenon in the cyclone separator 13, the lower part of the cyclone chamber is provided with a baffle assembly 22, the baffle assembly 22 includes a first baffle 23, the first baffle 23 and all An annular channel 25 is formed between the chamber walls of the swirl chamber. Exemplarily, as shown in FIG. 5, the baffle assembly 22 is disposed in a conical lower cylinder 19. The baffle assembly 22 includes a first baffle 23, and the first baffle 23 and the inner wall of the lower cylinder 19 An annular channel 25 is formed between them, wherein the first baffle 23 may be a circular plate-like structure, which may be arranged horizontally, and the area of the first baffle 23 may be 1/4 of the cross-sectional area of the same horizontal plane of the lower cylinder 19 3/4.

To further reduce the secondary entrainment phenomenon, the baffle assembly 22 further includes at least one second baffle 24, the second baffle 24 is disposed on the lower side of the first baffle 23, and the second baffle 24 is used to block the rotational movement of the airflow entering below the first baffle 23. Exemplarily, as shown in FIGS. 6 and 7, one side of the plurality of second baffles 24 is fixed together, and the other side is arranged in a dispersed manner, and the upper ends of the plurality of second baffles 24 are fixed on the On the lower side of the first baffle 23, the lower ends of the plurality of second baffles 24 are fixed on the housing 14 of the cyclone 13. Wherein, the included angle between two adjacent second baffles 24 can be set to be the same or different, such as 25-120 degrees.

The gas stream leaving the slurry in the slurry bed reactor 1 enters its cyclone chamber through the air inlet on the side of the first-stage cyclone 9; the liquid and solid particles or powder entrained in the gas phase must maintain linear movement and hit the shell The inner wall of 14 slides down due to resistance; the light-weight mixed gas enters the cyclone cavity, where most of the particles are in the outer area of the cyclone cavity, and a few particles with smaller particles rotate in the inner area of the cyclone cavity, after further downward acceleration Reaching the bottom of the conical lower cylinder 19, most of the gas is folded back at the surface of the first baffle 23 of the baffle assembly 22, forming a strong internal swirling upward airflow, and finally entering the exhaust pipe 21, leaving the cyclone separator 13 upward. This prevents the airflow from directly entering the bottom of the conical lower cylinder 19 and causing secondary entrainment of particles by the airflow, thereby improving the separation efficiency of the cyclone 13; on the other hand, reducing the air volume at the lower part of the lower cylinder 19, Conducive to the sliding of particles.

The droplets and solid particles or powder in the air flow are separated from the air flow under the action of centrifugal force, and are thrown toward the wall surface of the cyclone 13 along the wall surface through the annular channel between the first baffle 23 and the inner wall of the housing 14 25 enters the bottom of the conical lower cylinder 19, and then returns down the downcomer to the slurry in the slurry bed reactor 1. The remaining part of the gas enters the bottom of the conical lower cylindrical body 19 from the annular passage 25 between the first baffle 23 and the inner wall of the housing 14, and enters the lower cylindrical body 19 through the annular passage 25 due to the blocking effect of the second baffle 24 The gas at the bottom loses its swirling characteristics and is blocked by the first baffle 23 when turning back upward, so most of it moves downward through the downcomer, further reducing secondary entrainment.

For further separation and energy utilization of the gas stream leaving the first separation device 2, the separation system further includes a first heat exchanger 4 and a gas-liquid separation tank 5, the first heat exchanger 4 is used to make the final The airflow discharged from the first-level cyclone separator exchanges heat with the gas entering the slurry bed reactor 1, and the gas-liquid separation tank 5 is used to collect the final heat exchanged by the first heat exchanger 4. The airflow discharged from the primary cyclone separator.

Some of the chemical reactions occurring in the slurry bed reactor 1 are exothermic reactions. The gas stream leaving the slurry bed reactor 1 has a relatively high temperature. After the high-temperature gas stream is discharged from the first separation device 2, it passes through the first heat exchange The heat exchange of the device 4 can reduce the temperature of the gas flow on the one hand, cause the high-boiling substances in the gas flow to condense, and form droplets with unseparated solid particles or powder, and then separate from the gas flow in the gas-liquid separation tank 5; On the one hand, the gas entering the slurry bed reactor 1 can be heated.

In order to further separate the liquid droplets, solid particles or powders entrained in the gas flow, a second separation device 6 is provided in the gas-liquid separation tank 5, and the second separation device 6 is used to separate the gas-liquid separation tank 5 After the cyclone separation of the airflow, the gas-liquid separation tank 5 is discharged, and the second separation device 6 includes at least one cyclone separator. Among them, the second separation device 6 of this embodiment is provided in the upper part of the gas-liquid separation tank 5, and the droplets, solid particles, and powder separated by the second separation device 6 can be collected in the gas-liquid separation tank 5.

The second separation device 6 can adopt the same structure as the first separation device 2, for example, a two-stage cyclone separator can be provided, the first-stage cyclone separator is set to two or more, and the second-stage cyclone separator is set to One. Refer to the first separation device 2 for the structure and arrangement of the cyclone separators of each stage of the second separation device 6.

The gas flow from the first heat exchanger 4 can enter the gas-liquid separation tank 5 from the inlet provided on the side of the gas-liquid separation tank 5. After the droplets condensed in the gas flow are separated in the gas-liquid separation tank 5, the gas flow enters the second The separation device 6 performs separation, and after being separated by the second separation device 6, the gas-liquid separation tank 5 is discharged.

In this embodiment, the separation system may further include a second heat exchanger 7 and an oil-gas separation tank 8, the second heat exchanger 7 is used to make the gas flow discharged from the gas-liquid separation tank 5 enter the slurry The gas in the state-bed reactor 1 performs heat exchange, and the oil-gas separation tank 8 is used to collect the gas flow discharged from the gas-liquid separation tank 5 after heat exchange through the second heat exchanger 7.

The gas stream discharged from the gas-liquid separation tank 5 may also have a higher temperature, and the temperature of the gas stream can be further reduced by the second heat exchanger 7 to condense high-boiling substances in the gas stream and form a liquid with unseparated solid particles or powder On the other hand, the gas entering the slurry bed reactor 1 can be preheated. The gas is preheated by the second heat exchanger 7 and sent to the first preheater. The oil-gas separation tank 8 is used for three-phase separation of oil, water, and gas. The air flow discharged from the gas-liquid separation tank 5 is heat-exchanged by the second heat exchanger 7 and enters the oil-gas separation tank 8 for three-phase oil, water, and gas. Separate.

The separation system of the embodiment of the present application can effectively solve the problem that the high-temperature oil and gas flowing out of the top of the slurry bed reactor 1 of the existing industrial device entrains catalyst particles or powder, resulting in the blocking of the separation system, and is suitable for large-scale slurry bed Fischer-Tropsch synthesis The device can ensure the continuous and stable operation of the Fischer-Tropsch synthesis system.

An embodiment in which the separation system of the embodiment of the present application is applied to a Fischer-Tropsch synthesis system is given below.

Referring to FIGS. 8 and 1, during the preparation of mixed hydrocarbons from synthesis gas, the synthesis gas S3 having a H ₂ /CO molar ratio suitable for Fischer-Tropsch synthesis is preheated to a set temperature, and then from the bottom of the slurry bed reactor 1 The reaction gas inlet enters the slurry bed reactor 1, passes through the gas distributor, becomes bubbles, and then disperses and rises into the reactor (that is, the slurry bed reactor 1), and contacts and reacts with the catalyst particles suspended in the liquid wax. Produce mixed hydrocarbons. The operating conditions of the reactor may be: a pressure of 1.5 to 4.0 MPa, a temperature of 190 to 310°C, and a fresh synthesis gas H ₂ /CO molar ratio of 1.3 to 2.4. The high-temperature oil-gas mixture such as light oil and gas, water and unreacted synthesis gas formed by the reaction leaves the slurry and moves upward. High-temperature oil and gas inevitably entrains a certain amount of droplets, catalyst particles or powder during the ascent. If a large amount of these catalyst particles or powder is entrained by the high-temperature gas from the top of the reactor and leaves the reactor, the solid content of the condensed heavy oil separated by the product separation system will be too high to be sent to the processing unit for further processing. In addition, it is entrained Catalyst particles or powder not only aggravate the wear of pipes and pumps, but also easily deposit in pipes and separation equipment, which affects the stable operation of the device.

The high-temperature oil and gas leaving the slurry first enters the first-stage cyclone 9 and enters its cyclone chamber through the air inlet on the side of the first-stage cyclone 9; as the liquid and solid particles and powder entrained in the gas phase must maintain linear movement, When the inner wall of the shell is hit by resistance, it slides down; the light-weight mixed gas enters the cyclone cavity, where most of the particles are in the outer area of the cyclone cavity, and a few particles with smaller particles rotate in the inner area of the cyclone cavity, further accelerated downward After reaching the bottom of the cone-shaped lower cylinder, most of the gas is folded back at the surface of the first baffle 23 of the baffle assembly 22, forming a strong internal swirling upward airflow, and finally entering the exhaust pipe 21, leaving the first stage cyclone separation upward器9. This can prevent the airflow from directly entering the bottom of the conical lower cylinder 19 and cause secondary entrainment of particles by the airflow, thereby improving the separation efficiency of the cyclone separator; on the other hand, reducing the air volume in the lower part of the lower cylinder 19, there are Conducive to the sliding of particles.

The droplets and solid particles or powder in the air flow are separated from the air flow under the action of centrifugal force, and are thrown toward the wall surface of the cyclone separator, passing along the wall surface downward through the annular channel 25 between the first baffle 23 and the inner wall of the housing 14 It enters the bottom of the conical lower cylinder 19 and then returns down the downcomer to the slurry in the slurry bed reactor 1. The remaining part of the gas enters the bottom of the conical lower cylindrical body 19 from the annular passage 25 between the first baffle 23 and the inner wall of the housing 14, and enters the lower cylindrical body 19 through the annular passage 25 due to the blocking effect of the second baffle 24 The gas at the bottom loses its swirling characteristics and is blocked by the first baffle 23 when turning back upward, so most of it moves downward through the downcomer, further reducing secondary entrainment.

The solid-liquid mixture and the entrained partial gas separated by the first-stage cyclone separator 9 enter the downcomer 27 from the slurry outlet of the conical lower cylinder 19 and return down to the slurry in the reactor 1. Most of the gas leaves the first stage cyclone 9 upward through the air outlet at the top of the first stage cyclone 9 and enters the second stage cyclone 10. After separation by the second-stage cyclone 10, the gas outlet 26 at the top of the second-stage cyclone 10 leaves the first separation device 2 upward, and flows out of the reactor 1. Among them, a small amount of liquid and solid particles or powder that are not separated in the first-stage cyclone 9 are further separated in the second-stage cyclone 10, thereby further reducing the liquid and solid particles or powder carried in the gas.

The high-temperature oil and gas S5 leaving the slurry bed reactor 1 enters the first heat exchanger 4. In the first heat exchanger 4, the high-temperature oil and gas S5 exchanges heat with the circulating gas S3 that enters the bottom of the slurry bed reactor 1 and lowers the temperature, so that the high-boiling point material in the high-temperature oil and gas condenses and forms a liquid with unseparated catalyst particles or powder drop. At the same time, the circulating gas S3 is heated up.

The oil and gas S6 that has undergone heat exchange and temperature reduction through the first heat exchanger 4 enters the gas-liquid separation tank 5 from the side. In the gas-liquid separation tank 5, the condensed droplets move downward, and the oil and gas enter the second separation device 6 upward. After separation by the second separation device 6, the droplets, catalyst particles or powder in the oil and gas are further separated, flow into the gas-liquid separation tank 5 through the downcomer, and discharged from the bottom of the gas-liquid separation tank 5.

The oil and gas S7 leaving the gas-liquid separation tank 5 enters the second heat exchanger 7. In the second heat exchanger 7, the oil gas S7 exchanges heat with the circulating gas S1 entering the second heat exchanger 7 and lowers the temperature, so that the light oil and synthetic water in the oil gas condense, and at the same time preheats the circulating gas S1 to increase the temperature .

The oil-water-gas mixture from the second heat exchanger 7 is sent to the oil-gas separation tank 8, where the oil-water-gas mixture is subjected to three-phase oil-water-gas separation to obtain synthetic water S10, light oil S11, and Fischer-Tropsch synthesis. Exhaust S12.

In one embodiment, the operating conditions of the slurry bed reactor 1 are: a pressure of 3.0 MPa, a temperature of 273° C., and a fresh synthesis gas H ₂ /CO molar ratio of 1.9. Twelve first-stage cyclone separators 9 of the first separation device 2 are provided symmetrically, and one second-stage cyclone separator is provided. The depth at which the bottom of the exhaust pipe 21 of the first-stage cyclone 9 is inserted into the upper cylinder 18 is 70% of the height 18 of the upper cylinder; the diameter of the exhaust pipe 21 is 50% of the diameter of the upper cylinder 18. The ratio of the height of the upper cylinder 18 to the height of the conical lower cylinder 19 is 0.9. The area of the first baffle 23 of the baffle assembly 22 is 3/4 of the cross-sectional area of the lower cylinder 19 on the same horizontal plane. The lower end of the downcomer is closed, it extends into the reactor 1 below the slurry liquid level, and four rectangular openings are provided on the side wall of the lower end of the downcomer. The side of the upper cylinder 18 of the first-stage cyclone 9 is provided with a gas inlet, and the angle between the inlet gas flow direction and the tangent of the cylinder is 5 degrees. The side of the casing of the second-stage cyclone 10 is provided with 12 uniformly distributed gas inlet pipes, which are respectively connected to the air outlets on the top of the corresponding first-stage cyclone 9; the inlet gas flow direction is tangent to the cylinder The included angle is 15 degrees. The depth of the bottom of the exhaust pipe 21 of the second-stage cyclone separator 10 inserted into the separator casing is 45% of the height of the casing; the diameter of the exhaust pipe 21 is 55% of the diameter of the separator body barrel, which is a slurry bed 100% of the diameter of the top opening of the reactor 1. Six first-stage cyclone separators of the second separation device 6 are arranged symmetrically, and one second-stage cyclone separator is provided. The structure and arrangement form are the same as those of the first separation device 2.

The high-temperature oil and gas S5 exchanges heat with the circulating gas S3 flowing through the shell side of the first heat exchanger 4 through the tube side of the first heat exchanger 4. The temperature of the oil and gas S6 leaving the first heat exchanger 4 is controlled to 160 degrees; the temperature of the circulating gas S3 entering the first heat exchanger 4 is 120 degrees.

The temperature of the oil and gas S7 leaving the gas-liquid separation tank 5 is controlled at 120 degrees. The oil and gas S7 exchange heat with the circulating gas S1 flowing through the shell side of the second heat exchanger 7 through the tube side of the second heat exchanger 7. The temperature of the oil-water-gas mixture S9 leaving the second heat exchanger 7 is controlled at 65 degrees.

In the above embodiment, when the high-temperature oil and gas leaves the slurry bed reactor 1, the mass ratio of the entrained solid catalyst particles and powder to the total hydrocarbon mass is less than 0.01%; the oil and gas flowing from the top of the gas-liquid separation tank 5 cannot be detected Solid particles or powder.

The above embodiment more clearly illustrates the advantages of the method and equipment of the separation system of the embodiment of the present application. The solid catalyst particles and powder entrained in the high-temperature oil and gas are effectively removed, which solves the problem that the heat exchange equipment in the existing device is often blocked. problem.

In the description of the embodiments of the present application, unless otherwise clearly specified and defined, the terms "connection", "fixed connection", "installation", and "assembly" should be understood in a broad sense, for example, it can be a fixed connection or a Detachable connection, or integral connection; the terms "installation", "connection", "fixed connection" can be directly connected, indirectly connected through an intermediate medium, or the internal communication between two components. For those of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the present application may be understood in specific situations.

Claims

A separation system for a slurry bed reactor, characterized in that it includes a slurry bed reactor and a first separation device provided in the slurry bed reactor;

The first separation device is used to separate the airflow in the slurry bed reactor after cyclone separation and exit the slurry bed reactor;

The first separation device includes at least two-stage cyclone separator, the air outlet of the previous cyclone separator is connected to the air inlet of the latter cyclone separator, and the air outlet of the last stage cyclone separator is connected to the slurry The exterior of the state bed reactor.
The separation system according to claim 1, wherein the at least two-stage cyclone separator includes a first-stage cyclone separator and a second-stage cyclone separator, and the first-stage cyclone separator is provided with at least two, first There is one secondary cyclone, and the gas outlet of the secondary cyclone is connected to the outside of the slurry bed reactor.
The separation system according to claim 2, wherein the number of air inlets of the second-stage cyclone separator is the same as the number of the first-stage cyclone separators, and each of the first-stage cyclone separators The air outlet of the separator communicates with the corresponding air inlet of the second-stage cyclone separator.
The separation system according to claim 3, wherein the air inlet of the second-stage cyclone separator is provided along the circumferential direction of the second-stage cyclone separator.
The separation system according to claim 2, wherein the first-stage cyclone separator is disposed along the circumference of the inner wall of the slurry bed reactor, and the inlet of the second-stage cyclone separator The position is higher than the position of the air outlet of the first-stage cyclone separator.
The separation system according to claim 2, wherein the air inlet is provided on the side wall of the first-stage cyclone separator, and the central axis of the air inlet and the side wall are on the The angle of the tangent line at the air inlet is 0-75°.
The separation system according to claim 2, wherein the slurry outlet at the bottom of the cyclone separator is connected with a downcomer, and the bottom end of the downcomer extends into the slurry in the slurry bed reactor In this case, the bottom end of the downcomer is closed, and the downcomer is provided with an opening on the wall of the tube in the slurry.
The separation system according to claim 2, wherein the cyclone separator includes a housing, a cyclone chamber is provided in the housing, and a gas flow is introduced into the cyclone chamber on the housing Air inlet, the upper end of the swirl chamber is provided with an air outlet, and the lower end is provided with a slurry outlet, and the lower part of the swirl chamber is provided with a baffle assembly, the baffle assembly includes a first baffle, the An annular channel is formed between the first baffle and the cavity wall of the swirl chamber.
The separation system according to claim 8, wherein the baffle assembly further includes at least one second baffle, the second baffle is disposed on the lower side of the first baffle, and the second The baffle is used to block the rotational movement of the airflow entering below the first baffle.
The separation system according to claim 9, wherein one side of the plurality of second baffles is fixed together and the other side is arranged in a dispersed manner, and the upper ends of the plurality of second baffles are fixed to the first On the lower side of a baffle, the lower ends of the plurality of second baffles are fixed on the housing.
The separation system according to claim 2, wherein the cyclone separator includes a casing and an exhaust pipe provided in the casing, and the air outlet of the cyclone separator communicates with the exhaust pipe, The housing includes a cylindrical upper cylinder and a conical lower cylinder;

The height of the exhaust pipe in the upper cylinder is 60% to 100% of the height of the upper cylinder, and the diameter of the exhaust pipe is 20% to 70% of the diameter of the upper cylinder. The height ratio of the two lower cylinders is 0.6 to 1.2.
The separation system according to claim 1, wherein the separation system further comprises a first heat exchanger and a gas-liquid separation tank, the first heat exchanger is used to make the airflow discharged from the last stage cyclone separator It exchanges heat with the gas entering the slurry bed reactor, and the gas-liquid separation tank is used to collect the airflow discharged from the last cyclone separator after heat exchange through the first heat exchanger.
The separation system according to claim 12, wherein a second separation device is provided in the gas-liquid separation tank, and the second separation device is used for cyclonic separation of the airflow in the gas-liquid separation tank To discharge the gas-liquid separation tank, the second separation device includes at least one cyclone separator.
The separation system according to claim 12, characterized in that the separation system further comprises a second heat exchanger and an oil-gas separation tank, and the second heat exchanger is used to make the gas flow and discharge from the gas-liquid separation tank enter The gas in the slurry bed reactor performs heat exchange, and the oil-gas separation tank is used to collect the gas flow discharged from the gas-liquid separation tank after heat exchange through the second heat exchanger.