A slurry bed reactor with uniform gas holdup distribution

Abstract

The present application provides a slurry bed reactor with uniform gas holdup distribution, comprising: a barrel, which is internally provided with a containing cavity, and is provided with a feed inlet, a gas inlet, a gas outlet and a liquid outlet which are communicated with the containing cavity; a gas distributor, which is arranged in the containing cavity and is close to the gas inlet and is circumferentially connected with the inner wall of the containing cavity; a plurality of gas holdup distribution adjusting devices, which are arranged in the containing cavity on the side of the gas distributor facing the gas outlet, and comprise a gas inlet part, a liquid inlet part, a mixing part and a gas outlet part, the gas inlet part, the mixing part and the gas outlet part are sequentially and communicatively arranged, the gas inlet part is arranged towards the gas inlet and the cross-sectional diameter gradually increases in the direction towards the gas inlet, the gas outlet part is arranged towards the gas outlet and the cross-sectional diameter gradually increases in the direction towards the gas outlet; the liquid inlet part comprises a first connecting section and a second connecting section which are communicated, the extension direction of the first connecting section is parallel to the line direction of the gas inlet and the gas outlet, and the second connecting section is communicated with the mixing part at the end away from the first connecting section.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical equipment, and in particular to a slurry bed reactor with uniform gas holdup distribution. Background Art

[0002] With the continuous rise in oil prices in recent years, people are paying more and more attention to the development of technologies for producing alternative oil products. These technologies involve producing syngas from coal, natural gas, or other substances. This syngas is then processed through water-gas shift and syngas purification processes, depending on the requirements of the Fischer-Tropsch synthesis catalyst. This treated syngas is then used as a feedstock to produce hydrocarbons through Fischer-Tropsch synthesis, with oxygenated compounds as by-products. These products are then processed using established petroleum processing technologies to produce high-quality, environmentally friendly oil products. The development of Fischer-Tropsch synthesis technology is of great significance to the development of production technologies for alternative oil products.

[0003] The Fischer-Tropsch synthesis reactor is the core reactor of the Fischer-Tropsch synthesis technology. Currently, three-phase slurry bed reactors, capable of producing high hydrocarbon products, are widely used both domestically and internationally. Slurry bed reactors offer advantages such as uniform and easily controllable temperature, a wide gas velocity operating range, high product alpha values, and online catalyst replacement. However, as the reaction proceeds, the reaction bubbles within the reactor continuously coalesce and break, forming an increasing number of large bubbles. This results in a significant uneven distribution of gas holdup along the reactor axis. From the bottom of the reactor upward, the average bubble size increases, and the more large bubbles there are, the lower the gas holdup. Consequently, the gas-liquid mass transfer area decreases, the feed gas conversion rate decreases, and ultimately, the production capacity of the upper portion of the reactor decreases. Summary of the Invention

[0004] In view of this, the present invention provides a slurry bed reactor with uniform gas holdup distribution to solve the above technical problems.

[0005] The slurry bed reactor with uniform gas holdup distribution provided by the present invention comprises:

[0006] A cylinder body, wherein a receiving cavity is provided in the cylinder body, and a feed port, an air inlet, an air outlet and a liquid outlet are formed through the cylinder body and communicated with the receiving cavity;

[0007] A gas distributor is disposed in the accommodating chamber and close to the gas inlet, and the circumference of the gas distributor is circumferentially connected to the inner wall of the accommodating chamber;

[0008] A plurality of gas holdup distribution adjusting devices are arranged in the accommodating cavity on the side of the gas distributor facing the gas outlet, each of the gas holdup distribution adjusting devices comprising a gas inlet portion, a liquid inlet portion, a mixing portion, and a gas outlet portion, wherein the gas inlet portion, the mixing portion, and the gas outlet portion are sequentially and communicatively arranged, the gas inlet portion is arranged towards the gas inlet, and the cross-sectional diameter of the gas inlet portion gradually increases in the direction towards the gas inlet, the gas outlet portion is arranged towards the gas outlet, and the cross-sectional diameter of the gas outlet portion gradually increases in the direction towards the gas outlet; the liquid inlet portion comprises a first connecting segment and a second connecting segment which are in communication, the first connecting segment extends in a direction parallel to the line connecting the gas inlet and the gas outlet, and the second connecting segment is in communication with the mixing portion at one end thereof away from the first connecting segment.

[0009] Optionally, the gas holdup distribution adjusting device further comprises a shearing plate provided in the gas outlet portion, the shearing plate is provided with shearing holes, and the circumferential direction of the shearing plate is connected with the inner wall of the gas outlet portion.

[0010] Optionally, the ratio of the cross-sectional diameter of the shearing plate to the cross-sectional diameter of the mixing portion is 1:1-4:1.

[0011] Optionally, the gas holdup distribution adjusting device further comprises an aggregation portion, the aggregation portion is a hollow structure, is in communication with one end of the first connecting segment away from the second connecting segment, and the cross-sectional diameter of the aggregation portion gradually increases in the direction towards the gas outlet.

[0012] Optionally, the ratio of the cross-sectional diameter of the aggregation portion at the end thereof towards the gas outlet to the cross-sectional diameter of the aggregation portion at the end thereof towards the gas inlet is 3:1-10:1.

[0013] Optionally, the ratio of the cross-sectional diameter of the liquid inlet portion to the cross-sectional diameter of the mixing portion is 1:8-1:2.

[0014] Optionally, the slurry bed reactor with uniform gas holdup distribution further comprises a heat exchanger arranged in the accommodating cavity on the side of the gas distributor facing the gas outlet.

[0015] Optionally, the slurry bed reactor with uniform gas holdup distribution further comprises a liquid-solid separator arranged at the liquid outlet.

[0016] Optionally, the slurry bed reactor with uniform gas holdup distribution further comprises a gas-liquid separator arranged at the gas outlet.

[0017] Optionally, the slurry bed reactor with uniform gas holdup distribution further includes: a circulation pipeline, a first end of the circulation pipeline is connected to the gas outlet, and a second end of the circulation pipeline is connected to the gas inlet.

[0018] Compared with the prior art, the above technical solution provided by the present invention has at least the following beneficial effects:

[0019] By adopting the slurry bed reactor with uniform gas holdup distribution of the present invention, with the aid of a gas holdup distribution regulating device arranged in the middle of the cylinder, larger bubbles rising there are sheared into smaller bubbles, and the gas distribution in the upper part of the reactor is restored to the gas distribution state at the bottom of the reactor to the greatest extent, thereby solving the problem of uneven gas holdup distribution in the upper and lower sections of the reactor, increasing the gas-liquid mass transfer area in the upper part of the reactor, improving the conversion rate of the feed gas, and ultimately improving the total production capacity of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a slurry bed reactor with uniform gas holdup distribution according to one embodiment of the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the gas holdup distribution regulating device in the reactor shown;

[0022] Figure 3 for Figure 1 Schematic diagram of the distribution of the gas holdup distribution regulating device in the reactor shown;

[0023] Figure 4 for Figure 1 The radial gas holdup distribution curve at the position 1m above and below the gas holdup distribution regulating device in the reactor shown;

[0024] Figure 5 for Figure 1 A graph showing the change in the amount of steam discharged from the heat exchangers on the upper and lower sides of the gas holdup distribution regulating device in the reactor as a function of time;

[0025] Figure 6 This is a radial gas holdup distribution curve in the middle of the reactor when no gas holdup distribution adjustment device is installed;

[0026] Figure 7 This is a graph showing the change in the amount of steam discharged from the heat exchangers located in the upper and lower sections of the reactor over time when the gas holdup distribution adjustment device is not installed.

[0027] Reference numerals:

[0028] 1: Cylinder; 101: Air inlet; 102: Air outlet; 103: Liquid outlet; 2: Gas distributor; 3: Gas holdup distribution adjustment device; 301: Air inlet; 302: Liquid inlet; 3021: First connecting section; 3022: Second connecting section; 303: Mixing section; 304: Exhaust section; 305: Shear plate; 306: Aggregation section; 4: Heat exchanger; 5: Liquid-solid separator; 6: Gas-liquid separator. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0030] Figure 1 Schematic diagram of a slurry bed reactor with uniform gas holdup distribution according to one embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the gas holdup distribution adjustment device in the reactor shown.

[0031] like Figure 1 and Figure 2 As shown, the slurry bed reactor with uniform gas holdup distribution includes a cylinder 1, a gas distributor 2 and a plurality of gas holdup distribution adjustment devices 3.

[0032] The cylinder 1 is provided with a containing cavity, the cylinder 1 is provided with a feed inlet, an air inlet 101, an air outlet 102 and a liquid outlet 103 which communicate with the containing cavity; the gas distributor 2 is arranged in the containing cavity and is arranged close to the air inlet 101, the circumferential direction of the gas distributor 2 is connected with the inner wall of the containing cavity; a plurality of gas content distribution adjusting devices 3 are arranged in the containing cavity on the side of the gas distributor 2 which faces the air outlet 102, each gas content distribution adjusting device 3 comprises an air inlet part 301, a liquid inlet part 302, a mixing part 303 and an air outlet part 304, wherein the air inlet part 301, the mixing part 303 and the air outlet part 304 are sequentially and communicatively arranged, the air inlet part 301 is arranged towards the air inlet 101 and the cross-sectional diameter gradually increases in the direction towards the air inlet 101, the air outlet part is arranged towards the air outlet 102 and the cross-sectional diameter gradually increases in the direction towards the air outlet 102; the liquid inlet part 302 comprises a first connecting section 3021 and a second connecting section 3022 which are in communication, the extension direction of the first connecting section 3021 is parallel to the line direction of the air inlet 101 and the air outlet 102, and one end of the second connecting section 3022 which is away from the first connecting section 3021 is in communication with the mixing part 303.

[0033] When in use, a plurality of gas content distribution adjusting devices 3 are arranged in the middle part of the cylinder 1, liquid wax and catalyst are pre-loaded in the cylinder 1, raw material gas (synthesis gas of carbon monoxide and hydrogen) is input through the air inlet 101, the raw material gas is decomposed into small bubbles after passing through the gas distributor 2, and is uniformly distributed in the cylinder 1 and starts to react under the action of the catalyst. With the progress of the reaction, the reaction bubbles are continuously coalesced and broken, forming more and more large bubbles, when the large bubbles rise to the gas content distribution adjusting device 3, they enter the air inlet part 301 together with the fluid and flow through the mixing part 303, at the same time, the gas-liquid mixed fluid in the cylinder 1 enters the first connecting section 3021 of the liquid inlet part 302 in the vertical direction, and due to the density difference, the gas in the gas-liquid mixed fluid rises in the first connecting section 3021 and is discharged, only the liquid flows into the second connecting section 3022 and then flows into the mixing part 303 through the second connecting section 3022, and impacts the bubbles flowing into the mixing part 303 through the air inlet part 301, shearing the large bubbles into small bubbles, the small bubbles after shearing enter the air outlet part 304 through the mixing part 303, and then are discharged into the containing cavity again to continue to participate in the reaction. After the reaction is completed, the heavy products generated are discharged through the liquid outlet 103, and the tail gas is discharged through the air outlet 102.

[0034] By using the slurry bed reactor with uniform gas holdup distribution of the present invention, with the help of the gas holdup distribution regulating device 3 provided in the middle of the cylinder 1, the larger bubbles rising there are sheared into smaller bubbles, and the gas distribution in the upper part of the reactor is restored to the gas distribution state at the bottom of the reactor to the greatest extent, thereby solving the problem of uneven gas holdup distribution in the upper and lower sections of the reactor, increasing the gas-liquid mass transfer area in the upper part of the reactor, improving the conversion rate of the raw gas, and ultimately improving the total production capacity of the reactor.

[0035] like Figure 1 As shown, in this embodiment, the air inlet 101 is opened at the center of the bottom end of the cylinder 1, the air outlet 102 is opened at the center of the top end of the cylinder 1, and the liquid outlet 103 is opened at the center of the left wall of the cylinder 1. The gas distributor 2 is close to the bottom end of the cylinder 1, perpendicular to the axial direction of the cylinder 1, and covers the cross-section of the cylinder 1 to ensure that the raw gas entering the cylinder 1 can pass through the gas distributor 2 and be decomposed into small bubbles. When the bubbles react and rise to the middle of the cylinder 1, the bubble size distribution is uneven, that is, the upper and lower sections of the cylinder 1 begin to have obvious uneven gas content distribution. Therefore, a plurality of the gas content distribution adjustment devices 3 are set in the middle of the cylinder 1. As shown Figure 1 、 Figure 2As shown, the air inlet 301, the mixing section 303 and the exhaust section 304 are connected in sequence, and the cross sections are all circular, and the cross-sectional diameters of the air inlet 301 and the exhaust section 304 gradually decrease in the direction toward the mixing section 303, and the cross-sectional diameters of the three are the same at the connection point, thereby forming a Venturi tube structure, forming a negative pressure inside, and no external power is required, so that the mixed fluid of gas and liquid can smoothly enter the mixing section 303 through the air inlet 301, and at the same time, the liquid can smoothly enter the mixing section 303 through the liquid inlet 302 connected to the mixing section 303, thereby shearing the large bubbles entering the mixing section 303, and the small bubbles after shearing are smoothly discharged into the cylinder 1 through the exhaust section 304 along with the fluid. In this embodiment, the second connecting section 3022 is vertically arranged with the mixing section 303, so that the fluid entering the mixing section 303 through the second connecting section 3022 is in vertical contact with the large bubbles entering the mixing section 303 through the air inlet 301, so as to achieve a better effect of shearing large bubbles. In this embodiment, the first connecting section 3021 is vertically connected with the second connecting section 3022. In order to reduce the internal fluid resistance, the connection between the two can be set to an arc-shaped transition. In order to ensure the normal progress of the reaction, the raw gas needs to enter the cylinder 1 at a gas speed of 5-40cm / s after passing through the gas distributor 2 to participate in the reaction, and the gas phase flow rate is maintained between 8-25cm / s when discharged from the air outlet 102 after the reaction is completed. In order for the gas-liquid mixture to enter the air inlet 301 smoothly and to be able to be smoothly discharged from the exhaust section 304 after the large bubbles are sheared into small bubbles, the raw gas should be kept at a speed of 5-40cm / s. Figure 2 The angles between the left and right oblique sides of the longitudinal sections of the air inlet portion 301 and the exhaust portion 304 and the horizontal plane are both set to 20-75°, and more preferably 30-60°.

[0036] Figure 3 for Figure 1 The diagram shows the distribution of the gas holdup distribution adjustment devices 3 within the reactor. As the reaction proceeds within the cylinder 1, bubbles continuously coalesce and break into large bubbles during their ascent, resulting in uneven gas holdup distribution in the upper and lower sections of the cylinder 1. Furthermore, in the radial direction of the cylinder 1, the bubbles in the middle are smaller, while those in the surrounding areas are larger. This results in an uneven gas holdup distribution with high gas holdup in the middle and low gas holdup in the surrounding areas. Therefore, to simultaneously address the uneven gas holdup distribution in both the axially upper and lower sections and in the radial direction within the cylinder 1, multiple gas holdup distribution adjustment devices 3 are disposed in the middle of the cylinder 1, and are arranged as two concentric rings around the axis of the cylinder 1. Six gas holdup distribution adjustment devices 3 are arranged at equal intervals in the ring close to the axis of the cylinder 1, and twelve gas holdup distribution adjustment devices 3 are arranged at equal intervals in the ring away from the axis of the cylinder 1.

[0037] The shape and size of the cylinder 1, the specific specifications and models of the gas distributor 2, the number of gas holdup distribution adjustment devices 3, and their specific arrangement positions within the cylinder 1 can all be adjusted according to actual application conditions. The gas distributor 2 and the venturi tube structure are both mature existing technologies, and their specific working principles will not be repeated here.

[0038] Optionally, the gas holdup distribution adjustment device 3 further includes a shear plate 305 having shear holes formed therethrough, and is disposed in the exhaust portion 304. The shear plate 305 is circumferentially connected to the inner wall of the exhaust portion 304. Large bubbles entering the mixing portion 303 are sheared by the fluid introduced into the mixing portion 303 through the liquid inlet portion 302 to form small bubbles. This arrangement allows the sheared small bubbles to undergo secondary liquid-phase shearing through the shear holes formed therethrough when passing through the shear plate 305, thereby obtaining smaller-sized microbubbles, thereby further increasing the gas-liquid contact area.

[0039] like Figure 2 As shown, in this embodiment, the shear plate 305 is positioned at a lower center position within the exhaust portion 304 and is perpendicular to the axial direction of the exhaust portion 304. The shear holes can be shaped in at least one of a circle, a triangle, a square, or a rectangle, and can be arranged in at least one of a triangular or square pattern, with an equivalent diameter of 2-5 mm. The shape and size of the shear plate 305, the number and specifications of the shear holes, and the specific location of the shear plate 305 within the exhaust portion 304 can be adjusted according to actual application.

[0040] Optionally, the ratio of the cross-sectional diameter of the shear plate 305 to the cross-sectional diameter of the mixing portion 303 is 1:1-4:1. This configuration can more effectively perform secondary shearing on the small bubbles discharged from the mixing portion 303 after the primary shearing.

[0041] like Figure 2 As shown, in this embodiment, the shear plate 305 is arranged at the lower center of the exhaust part 304, and the cross-sectional diameter is approximately twice the cross-sectional diameter of the mixing part 303. The position of the shear plate 305 can be adjusted up and down to adapt to its different sizes.

[0042] Optionally, the gas holdup distribution adjustment device 3 further includes a gathering portion 306. The gathering portion 306 is a hollow structure that is connected to the end of the first connecting section 3021 that is away from the second connecting section 3022. The cross-sectional diameter of the gathering portion 306 gradually increases toward the gas outlet 102. This arrangement allows the gathering portion 306, which is configured as an approximately inverted cone, to more quickly introduce fluid into the liquid inlet 302, while also facilitating faster upward discharge of gas that has entered the liquid inlet 302.

[0043] In this embodiment, the cross section of the gathering portion 306 is circular, and the end with the smaller cross section is connected to the liquid inlet portion 302, forming an inverted cone as a whole. The specific shape and size of the gathering portion 306 can be adjusted according to actual application conditions.

[0044] Optionally, the ratio of the cross-sectional diameter of the end of the gathering portion 306 facing the gas outlet 102 to the cross-sectional diameter of the end facing the gas inlet 101 is 3:1-10:1. This arrangement facilitates the fluid in the cylinder 1 to flow into the gathering portion 306 more quickly, and at the same time facilitates the rapid and sufficient discharge of the gas entering the liquid inlet 302 through the gathering portion 306 provided with the diverging opening after rising. In order to achieve a more optimized effect, the ratio of the cross-sectional diameters of the ends of the gathering portion 306 facing the gas outlet 102 and the gas inlet 101 can be set to 5:1-8:1.

[0045] like Figure 2 As shown, in this embodiment, the gathering portion 306 is configured to be an approximate inverted cone. In order to allow the fluid to flow smoothly into the liquid inlet portion 302 along the gathering portion 306, the angle between the oblique sides of the left and right side walls of the longitudinal section of the gathering portion 306 and the horizontal plane is set to 20-75°, and more preferably 30-60°.

[0046] Optionally, the ratio of the cross-sectional diameter of the liquid inlet 302 to the cross-sectional diameter of the mixing section 303 is 1:8-1:2. This configuration can utilize the internal negative pressure generated by the Venturi structure to fully draw the fluid flowing into the liquid inlet 302 into the mixing section 303, while also allowing the fluid drawn into the mixing section 303 to sufficiently shear large bubbles entering the mixing section 303.

[0047] Optionally, the slurry bed reactor with uniform gas holdup distribution further includes a heat exchanger 4, which is disposed within the accommodating chamber on the side of the gas distributor 2 facing the gas outlet 102. Fischer-Tropsch synthesis is an exothermic reaction, and the heat within the cylinder 1 is absorbed by the heat exchanger 4 and then carried out of the cylinder 1, thereby maintaining a stable temperature within the cylinder 1 and facilitating the continued normal progress of the reaction.

[0048] like Figure 1 As shown, in this embodiment, two sets of heat exchangers 4 are installed within the cylinder 1, located in the upper and lower sections of the cylinder 1, respectively. The gas holdup distribution adjustment device 3 is disposed between the two sets. The heat exchangers 4 utilize heat exchange tubes that fill the radial space within the cylinder 1. The inlet and outlet pipes of the heat exchange tubes extend through the cylinder 1 and connect to external circulation equipment. High-temperature water flows within the heat exchange tubes, absorbing heat released by the reaction within the cylinder 1 and causing a phase change. The latent heat of the high-temperature water's phase change is then used to remove heat from the cylinder 1, maintaining a stable temperature within the cylinder 1. The amount of steam converted to steam within the heat exchange tubes can also be measured. Since Fischer-Tropsch synthesis is an exothermic reaction, a greater amount of steam indicates greater heat absorption, greater heat release within the cylinder 1, and a more complete reaction, further demonstrating a high conversion rate and gas holdup of the feed gas within the cylinder 1. After installing the gas holdup distribution adjustment device 3, there is no significant difference in the gas holdup distribution between the upper and lower sections of the cylinder 1, and thus no significant difference in the total amount of steam discharged from the two sets of heat exchange tubes located in the upper and lower sections of the cylinder 1. Depending on the actual application, the heat exchanger 4 can be of any specification and model, as long as it can remove the heat generated by the reaction within the cylinder 1 and ensure the continued normal progress of the reaction.

[0049] Optionally, the slurry bed reactor with a uniform gas holdup distribution further includes a liquid-solid separator 5, which is disposed at the liquid outlet 103. This arrangement filters and separates the liquid-solid mixture discharged from the cylinder 1 after the reaction is completed, preventing the solid catalyst from being discharged, thereby saving costs. The liquid-solid separator 5 can adopt any structural form that can separate liquids and solids, as long as it can intercept the solid catalyst within the cylinder 1.

[0050] Optionally, the slurry bed reactor with a uniform gas holdup distribution further includes a gas-liquid separator 6, which is disposed at the gas outlet 102. This arrangement filters the liquid contained in the gas discharged from the cylinder 1 after the reaction is completed, preventing the liquid from being discharged and keeping the discharged gas dry. The gas-liquid separator 6 can adopt any structural form capable of separating gas and liquid.

[0051] Optionally, the slurry bed reactor with uniform gas holdup distribution further includes a circulation line (not shown), a first end of the circulation line being connected to the gas outlet 102, and a second end of the circulation line being connected to the gas inlet 101. The tail gas discharged through the gas outlet 102 contains some unreacted raw gas. Re-transporting the tail gas back to the cylinder 1 allows the raw gas in the tail gas to re-participate in the reaction, thereby improving the utilization rate of the raw gas.

[0052] During the reaction, fresh feed gas is continuously fed into the cylinder 1. In order to maintain the pressure in the cylinder 1 stable, part of the tail gas discharged through the gas outlet 102 is sent to the subsequent equipment for treatment, and part is sent back to the cylinder 1 through the circulation pipeline.

[0053] The application will be further described below in combination with examples and comparative examples:

[0054] Example

[0055] The diameter of the cylinder 1 is 5.8 m, the tangential height is 40 m, and the liquid level control height is 32 m. A set of heat exchangers 4 in the form of heat exchange column tubes are arranged at the upper and lower sections of the cylinder 1, and the bottom of the lower heat exchange column tube is 500 mm away from the lower end of the cylinder 1. Between the two sets of heat exchangers 4, a plurality of gas holdup distribution adjusting devices 3 are arranged in the middle of the cylinder 1. The plurality of gas holdup distribution adjusting devices 3 are distributed in two layers along the radial concentric circles. Six gas holdup distribution adjusting devices 3 are equally spaced in the inner layer, and twelve gas holdup distribution adjusting devices 3 are equally spaced in the outer layer, as shown in Figure 1 and Figure 3 .

[0056] The pressure of the gas phase entering the reactor is 2.9 MPa, and the reactor temperature is 260°C. The reactor uses an iron-based Fischer-Tropsch synthesis catalyst, and the catalyst inventory of the reactor under stable state is 26 tons. The volume space velocity of the feed gas is 5000 h -1 , and most of the tail gas is recycled back to the reactor. The amount of circulating gas can ensure that the gas empty tower gas velocity at the gas inlet 101 of the reactor is stable at 0.30 m / s.

[0057] The test results show that the catalyst performance of the reactor can maintain a CO total conversion rate of more than 98%, a methane selectivity of less than 3%, and a C5+ product yield of 170 g / Nm 3 of feed gas; the carbon dioxide selectivity is stable at less than 18%; and the C5+ product production capacity of a single reactor reaches 210,000 tons / year.

[0058] Due to the presence of the gas holdup distribution adjusting device 3, the radial gas holdup distribution in the cylinder 1 has changed greatly. Through the optical fiber probe method, the radial gas holdup distribution curve at the position 1 m above and below the gas holdup distribution adjusting device 3 in the reactor is obtained, as shown in Figure 4 , wherein r is the distance between the point where the gas holdup is measured and the axis of the cylinder 1, R is the radius of the cylinder 1, and r / R is greater, indicating that the point where the gas holdup is measured is farther away from the axis of the cylinder 1. From Figure 4It can be seen that at a position 1 m below the gas holdup distribution regulating device 3, the difference between the gas holdup at the axis of the cylinder 1 and the gas holdup near the inner wall of the cylinder 1 is relatively large, indicating that the gas holdup distribution in the radial direction is not uniform enough. However, at a position 1 m above the gas holdup distribution regulating device 3, after the shearing action of the gas holdup distribution regulating device 3 on large bubbles, the difference between the gas holdup at the axis of the cylinder 1 and the gas holdup near the inner wall of the cylinder 1 is very small, indicating that after the large bubbles are sheared into small bubbles, the gas holdup distribution in the radial direction is relatively uniform.

[0059] The amount of steam generated in the upper and lower sets of heat exchange tubes was measured and the Figure 5 The graph shows the change of steam volume discharged from the heat exchangers 4 on the upper and lower sides of the gas holdup distribution regulating device 3 over time. Due to the presence of the gas holdup distribution regulating device 3, large bubbles rising between the two groups of heat exchange tubes are sheared into small bubbles, thereby improving the gas holdup in the upper part of the cylinder 1 and the conversion rate of the raw gas, making the gas holdup distribution in the upper and lower sections of the cylinder 1 relatively uniform, so that the upper and lower sections of the cylinder 1 can fully react. Figure 5 It can be seen from the test results that during the stable operation of the reactor (taking about 200 hours as an example), the amount of steam brought out by the heat exchanger 4 in the upper and lower sections of the cylinder 1 is not much different, with a numerical difference of about 30t / h, which means that the upper and lower sections of the cylinder 1 have undergone sufficient reactions, releasing similar heat, and the raw gas conversion rate is not much different.

[0060] Comparative Example

[0061] The cylinder 1 has a diameter of 5.8 meters, a tangential height of 40 meters, and a liquid level control height of 32 meters. A set of heat exchangers 4 in the form of heat exchange tubes is installed in the upper and lower sections of the cylinder 1, with the bottom of the lower heat exchange tubes 500 mm from the lower end of the cylinder 1. The gas holdup distribution adjustment device 3 is not installed between the two sets of heat exchangers 4.

[0062] The pressure of the gas phase entering the reactor is 2.9 MPa, and the reactor temperature is 260°C. The reactor uses an iron-based Fischer-Tropsch synthesis catalyst, with a catalyst storage capacity of 26 tons in the reactor under stable conditions, and a volumetric space velocity of 5000 h -1 Except for the exhaust gas, most of it is recycled back to the reactor. The amount of recycled gas can ensure that the superficial gas velocity of the gas at the reactor inlet 101 is stable at 0.30m / s.

[0063] The test results show that the catalyst performance of the reactor can maintain a total CO conversion rate of 96%, a methane selectivity of 3.5%, and a C5+ product yield of 160g / Nm 3Raw gas; carbon dioxide selectivity is stable at 20%; the C5+ product production capacity of a single reactor reaches 166,000 tons / year, which is lower than the production capacity of the reactor provided with the gas holdup distribution regulating device 3.

[0064] The radial gas holdup distribution at the middle position of the two sets of heat exchangers 4 was measured by the fiber optic probe method and obtained Figure 6 The radial gas holdup distribution curve of the reactor center when the gas holdup distribution regulating device 3 is not provided is shown in FIG. Figure 6 It can be seen that the radial gas holdup distribution is obviously uneven, and the gas holdup at the center of the cylinder 1 is obviously higher than that at the side wall.

[0065] The amount of steam generated in the upper and lower sets of heat exchange tubes was measured and the Figure 7 The graph shown is a graph showing the change in the amount of steam discharged from the heat exchangers 4 located in the upper and lower sections of the reactor over time when the gas holdup distribution regulating device 3 is not provided. Figure 7 The test results show that during the stable operation of the reactor (taking about 200 hours as an example), the amount of steam brought out by the heat exchangers 4 in the upper and lower sections of the reactor is quite different. The heat brought out by the heat exchanger 4 in the lower part of the reactor is significantly higher than that in the upper part of the reactor. The numerical difference is about 100t / h, indicating that the degree of Fischer-Tropsch synthesis reaction in the upper and lower sections of the reactor, that is, the conversion rate of raw gas, is quite different.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A slurry bed reactor with uniform gas holdup distribution, characterized in that: include: A cylinder body, wherein a receiving cavity is provided in the cylinder body, and a feed port, an air inlet, an air outlet and a liquid outlet are formed through the cylinder body and communicated with the receiving cavity; A gas distributor is disposed in the accommodating chamber and close to the gas inlet, and the circumference of the gas distributor is circumferentially connected to the inner wall of the accommodating chamber; A plurality of gas content distribution regulating devices are installed in the accommodating cavity on the side of the gas distributor facing the gas outlet, and each of the gas content distribution regulating devices includes an air inlet, a liquid inlet, a mixing section and an exhaust section, wherein the air inlet, the mixing section and the exhaust section are connected in sequence, the air inlet is arranged toward the air inlet, and the cross-sectional diameter gradually increases in the direction toward the air inlet, and the air outlet is arranged toward the air outlet, and the cross-sectional diameter gradually increases in the direction toward the air outlet; the liquid inlet includes a first connecting section and a second connecting section that are connected, the extension direction of the first connecting section is parallel to the connecting direction of the air inlet and the air outlet, and the end of the second connecting section that is away from the first connecting section is connected to the mixing section.

2. The slurry bed reactor with uniform gas holdup distribution according to claim 1, characterized in that: The gas holdup distribution regulating device further comprises: A shear plate is provided with a shear hole through the shear plate, and is arranged in the exhaust portion. The circumference of the shear plate is connected to the circumference of the inner wall of the exhaust portion.

3. The slurry bed reactor with uniform gas holdup distribution according to claim 2, characterized in that: The ratio of the cross-sectional diameter of the shear plate to the cross-sectional diameter of the mixing portion is 1:1-4:

1.

4. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: The gas holdup distribution regulating device further comprises: The gathering portion is a hollow structure, connected to an end of the first connecting section away from the second connecting section, and the cross-sectional diameter of the gathering portion gradually increases in a direction toward the air outlet.

5. The slurry bed reactor with uniform gas holdup distribution according to claim 4, characterized in that: The ratio of the cross-sectional diameter of the end portion of the gathering portion facing the air outlet to the cross-sectional diameter of the end portion facing the air inlet is 3:1-10:

1.

6. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: The ratio of the cross-sectional diameter of the liquid inlet portion to the cross-sectional diameter of the mixing portion is 1:8-1:

2.

7. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: Also includes: A heat exchanger is arranged in the accommodating cavity on the side of the gas distributor facing the gas outlet.

8. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: Also includes: A liquid-solid separator is arranged at the liquid outlet.

9. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: Also includes: A gas-liquid separator is arranged at the gas outlet.

10. The slurry bed reactor with uniform gas holdup distribution according to any one of claims 1 to 3, characterized in that: Also includes: A circulation pipeline, wherein a first end of the circulation pipeline is connected to the air outlet, and a second end of the circulation pipeline is connected to the air inlet.

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