A micro-bubbling hydrogenation reactor and its use

Abstract

The invention relates to a micro-bubble hydrogenation reactor and application thereof. The reactor is provided with a membrane tube micro-bubble generating device in a catalyst bed layer, so that gas can be input into the catalyst bed layer in the form of micro-bubbles, thereby solving the problem of uneven distribution of micro-bubbles in the axial direction in the prior art, and is conducive to strengthening gas-liquid mixing and reducing liquid back-mixing. Meanwhile, the membrane tube micro-bubble generating device has a simple structure and is easy to process and load and unload. The reactor is used in a hydrogenation reaction, and the hydrogenation reaction rate can be controlled by introducing different types of gases into an injection pipe of the reactor, thereby strengthening the controllability of the hydrogenation reaction, avoiding overheating, coking or deactivation of the catalyst, improving the reaction efficiency and extending the service life of the catalyst, and has high industrial application value.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical equipment, and in particular to a micro-bubbling hydrogenation reactor and application thereof. Background Art

[0002] Hydrogenation reactors are commonly used in the petroleum refining industry to convert difficult-to-use heavy residual oil into light oil through hydrocracking reactions. In the actual residual oil hydrogenation industry, local bed overheating, catalyst coking, and severe backmixing often occur. The main reason is the uneven distribution of hydrogen as a dispersed phase. Studies have shown that microbubbles have a larger specific surface area and a slower rising speed than large bubbles, and have a faster dissolution rate and mass transfer efficiency in liquids. Therefore, by evenly arranging microbubble generators in the hydrogenation reactor to generate microbubbles, it is more conducive to the uniform distribution of hydrogen and the enhancement of gas-liquid mixing and mass transfer.

[0003] CN106732308A discloses a novel microbubble gas-liquid reactor, which allows the gas to slowly pass through the bed in the form of microbubbles by configuring a liquid distributor and a gas distributor equipped with a microbubble generator in sections, thereby strengthening gas-liquid mixing and mass transfer, reducing liquid backmixing and reducing gas consumption. CN107497372A discloses a design method for a novel hydrogenation reactor, which provides a hydrogen injection pipe with a microbubble generator between multiple catalyst beds to achieve segmented supplementary injection of hydrogen, and breaks the hydrogen bubbles into smaller pieces through a Johnson net, which can significantly increase the contact area between hydrogen and liquid reactants and improve the diffusion efficiency and reaction efficiency of hydrogen. CN109550418A and CN109966939A disclose a venturi-type microbubble generator and a gas-liquid reactor comprising the microbubble generator. The microbubble generator utilizes the shearing effect of the high-speed and strong turbulent flow formed by the liquid in the venturi tube to break the bubbles multiple times to generate a large number of microbubbles. Installing a gas distribution plate with the microbubble generator above the air inlet of the gas-liquid reactor can greatly improve the gas-liquid mass transfer efficiency.

[0004] The similarity of the above three types of micro-bubble reactors is that they all install micro-bubble generating devices between multiple bed layers. This measure can maintain the micro-bubble shape of the gas and its uniform distribution in the radial direction of the reactor at a certain distance. However, under the action of pressure and coalescence, the bubbles will gradually become larger and unevenly distributed during the rising process, losing the advantage of micro-bubbles participating in the reaction. Therefore, this type of reactor often needs to install a set of micro-bubble generating devices every other bed layer, which not only increases the complexity and cost of reactor design and manufacturing, but also increases the bed pressure drop and energy consumption. In addition, due to the different size distribution of bubbles in the axial direction of the reactor, problems such as local uneven reaction, local bed overheating and catalyst coking are inevitable.

[0005] In order to overcome the problem of uneven axial distribution of bubbles, technicians have also developed other microbubble reaction devices.

[0006] CN103143302A discloses a continuous microbubble reactor, in which multiple transversely arranged transverse microporous tubes and vertically distributed vertical microporous tubes are arranged in multiple reaction chambers. Although this design method is conducive to achieving uniform distribution of gas and improving reaction efficiency, the reactor design is too complicated and the manufacturing cost is high. In addition, the microbubble reactor in the invention is mostly used to treat metal-containing wastewater, but most of the microporous tubes are installed near the slag discharge port, which makes the micropores on the tubes easily blocked by metal-containing precipitates.

[0007] CN208066329U discloses a novel microbubble gas-liquid reactor that utilizes an annular air cavity for uniform air intake in the axial direction. However, the annular air cavity occupies a large amount of the internal space of the reactor, resulting in a relatively small volume of the gas-liquid mixing cavity located at the center of the reactor, which makes the gas-liquid reaction space insufficient and is not conducive to expanding the scale of the reaction.

[0008] In view of the many problems existing in the prior art, there is an urgent need to develop a new, simple, efficient and space-saving microbubble generating device for use in a hydrogenation reactor. By releasing microbubbles into the reaction materials, the axial and radial distribution of hydrogen, the mixing of hydrogen and liquid phase, and the efficiency of the hydrogenation reaction can be adjusted, thereby achieving the purpose of regulating the hydrogenation reaction rate. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a micro-bubble hydrogenation reactor. By arranging a membrane tube micro-bubble generating device in a catalyst bed, the uniform distribution of micro-bubbles in the reactor bed, especially in the axial direction, is better achieved, which is beneficial to strengthening gas-liquid mixing and reducing liquid back-mixing. When the reactor is applied to a hydrogenation reaction, the hydrogenation reaction rate can be controlled by introducing hydrogen and / or an inert gas into an injection pipe, which can improve the hydrogenation reaction efficiency, inhibit an excessively fast hydrogenation reaction, and prolong the service life of the catalyst, thereby enhancing the controllability of the hydrogenation reaction and having a high industrial application value.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a microbubble hydrogenation reactor, the reactor comprising a catalyst bed and a membrane tube microbubble generating device disposed in the catalyst bed.

[0012] The present invention arranges a membrane tube microbubble generating device in the catalyst bed, and each membrane tube on the device penetrates part of the bed and is installed vertically, so that the uniform distribution of microbubbles in the reactor bed, especially in the axial direction, can be better achieved, thereby alleviating the problem of uneven axial distribution of microbubbles in the prior art, and at the same time strengthening gas-liquid mixing and reducing liquid backmixing, which is more conducive to promoting the uniform progress of the reaction in the reactor space, avoiding the phenomenon of local overheating and deactivation of the catalyst, and has high practical application value.

[0013] Preferably, the membrane tube microbubble generating device comprises a microporous membrane tube having micron-sized pores on the tube wall.

[0014] The present invention has no limitation on the materials used to make the microporous membrane tubes on the membrane tube microbubble generating device. Any material known to those skilled in the art that has a certain strength and corrosion resistance and can be used to make membrane tubes may be used. The materials include but are not limited to sintered ceramics or sintered metals.

[0015] When gas is introduced into the microporous membrane tube of the present invention, the gas can pass through the tube wall of the microporous membrane tube to the outside of the membrane tube under the action of pressure, form microbubbles in the shear flow liquid phase, and flow with the liquid phase, thereby promoting gas-liquid mass transfer, making the gas-liquid reaction more uniform, avoiding local overheating and deactivation of the catalyst, and having high industrial application value.

[0016] Preferably, the microporous membrane tube is arranged vertically.

[0017] The micron-sized pores on the wall of the microporous membrane tube of the present invention are randomly generated during the preparation process of the microporous membrane tube. The diameter, flow direction and distribution of the microbubbles generated by the microporous membrane tube can be regulated by controlling the size, direction and distribution of the generated micron-sized pores, thereby obtaining a microporous membrane tube that can be used for hydrogenation reactions.

[0018] Preferably, the average pore size of the micron-sized channels is 1 to 1000 μm, for example, it can be 1 μm, 10 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm or 1000 μm, preferably 20 to 700 μm.

[0019] The average pore size of the micron-sized pores on the tube wall of the microporous membrane tube of the present invention is preferably controlled to be 20 to 700 μm, so as to meet the average diameter of the generated microbubbles between 50 and 800 μm, thereby better meeting the requirements of the hydrogenation reaction.

[0020] Preferably, the micrometer-scale pores on the tube wall of the microporous membrane tube are arranged in an oblique upward direction.

[0021] Preferably, the angle between the micrometer-scale pores and the horizontal direction is 1 to 89°, for example, it can be 1°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° or 89°, preferably 30 to 60°.

[0022] Preferably, the porosity of the microporous membrane tube is 0.1 to 0.8, for example, it can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8, preferably 0.3 to 0.6.

[0023] The porosity of the microporous membrane tube of the present invention is determined by the length and diameter of the membrane tube. The porosity of the present invention is selected to be 0.1 to 0.8.

[0024] Preferably, the diameter of the microporous membrane tube is 5 to 150 mm, for example, it can be 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm or 150 mm, preferably 20 to 100 mm.

[0025] Preferably, the microporous membrane tube is a cylindrical or polygonal cylindrical tube.

[0026] Preferably, the microporous membrane tube is of single-channel type or multi-channel type.

[0027] Preferably, the membrane tube microbubble generating device further comprises a gas buffer ring communicating with the microporous membrane tube.

[0028] The gas buffer ring in communication with the microporous membrane tube in the membrane tube microbubble generating device of the present invention is used to buffer the gas introduced from the gas injection pipe, which is beneficial to realize the uniform distribution of the gas flow introduced into each microporous membrane tube, and is easy to control the simultaneous air intake and air cut-off of each microporous membrane tube, while reducing the impact stress of the gas on the microporous membrane tube, and extending the service life of the microporous membrane tube.

[0029] Preferably, the number of the gas buffer rings is 1 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, preferably 2 to 8.

[0030] Preferably, the equivalent inner diameter of the gas buffer ring is 0.01D to 0.15D, for example, it can be 0.01D, 0.02D, 0.05D, 0.06D, 0.08D, 0.10D, 0.12D, 0.13D or 0.15D, preferably 0.05D to 0.10D, wherein D is the inner diameter of the reactor.

[0031] Preferably, the ring width of the gas buffer ring is 0.04D to 0.35D, for example, it can be 0.04D, 0.08D, 0.10D, 0.12D, 0.15D, 0.18D, 0.20D, 0.22D, 0.25D, 0.28D, 0.30D, 0.32D or 0.35D, preferably 0.10D to 0.20D, wherein D is the inner diameter of the reactor.

[0032] The ring width of the gas buffer ring described in the present invention refers to the difference between the equivalent radius of the outer periphery of the gas buffer ring and the equivalent radius of the inner periphery of the ring.

[0033] Preferably, the gas buffer rings are connected to each other through at least two connecting pipes.

[0034] The present invention connects a plurality of gas buffer rings of inner and outer rings by arranging a connecting pipe, thereby ensuring the input of gas in each inner gas buffer ring.

[0035] Preferably, the cross section of the gas buffer ring is circular or regular polygonal.

[0036] The gas buffer ring of the present invention is an annular pipe, and the cross section of the gas buffer ring, that is, the cross section of the pipe through which the gas is introduced, is circular or regular polygonal.

[0037] Preferably, the gas buffer ring is a circular and / or regular polygonal ring structure, wherein typical but non-limiting combinations are: a combination of a circle and an equilateral triangle, a combination of a circle and a square, a combination of an equilateral triangle and a regular hexagon, a combination of an equilateral triangle and a regular octagon, preferably a circle.

[0038] When the number of inner and outer gas buffer rings of the present invention is greater than one, the shapes of the inner and outer buffer rings may be different, the radial spacing between any two adjacent buffer rings may not be equal, and the installation quantity and distribution pattern of the membrane tubes on different buffer rings do not need to remain consistent.

[0039] Preferably, the gas buffer rings are distributed in a concentric manner.

[0040] Preferably, the number of microporous membrane tubes installed on each gas buffer ring is 2 to 100, for example, it can be 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100, preferably 10 to 80.

[0041] The number and distribution pattern of the microporous membrane tubes installed on each gas buffer ring of the present invention can be the same or different, and the present invention does not impose any limitation on this. Any installation method known to those skilled in the art that can achieve uniform distribution of microbubbles can be adopted.

[0042] Preferably, the membrane tube microbubble generating device further comprises a membrane tube fixing ring arranged on the end of the microporous membrane tube opposite to the gas buffer ring.

[0043] The invention provides a membrane tube fixing ring in the membrane tube microbubble generating device so that the microporous membrane tube is fixed between the gas buffer ring and the membrane tube fixing ring, thereby increasing the mechanical strength of the membrane tube microbubble generating device.

[0044] The structure, quantity and distribution of the membrane tube fixing ring of the present invention are the same as those of the gas buffer ring, so they will not be described in detail here.

[0045] Preferably, the membrane tube fixing ring is in communication with the membrane tube.

[0046] The membrane tube fixing ring in the present invention is connected to the membrane tube to form a closed loop channel, so that most of the gas introduced into the membrane tube will not flow out directly from the hollow channel of the membrane tube, but will escape from the micron-sized pores on the tube wall to the bed layer under the action of pressure difference. In addition, the membrane tube fixing ring can also buffer a small amount of gas that has not yet escaped from the micron-sized pores.

[0047] Preferably, the catalyst bed comprises catalyst particles required for hydrogenation reaction.

[0048] The catalyst bed of the present invention is formed by filling catalyst particles required for hydrogenation reaction, wherein hydrogen and liquid phase two reaction materials flow upward in the gaps of the catalyst bed and react under the catalytic action of the catalyst particles.

[0049] Preferably, the number of the catalyst bed is at least one, for example, 2, 3, 4, 5 or 8, preferably 2 to 3.

[0050] The preferred catalyst bed of the present invention is 2 to 3, which can realize multiple distribution of reaction raw materials and hydrogen, better promote gas-liquid mass transfer and hydrogenation reaction, and at the same time, membrane tube microbubble generating devices are respectively arranged in multiple catalyst beds, and gas is input into the bed in the form of microbubbles in multiple stages, which is more conducive to promoting gas-liquid mixing and mass transfer, avoiding local overheating and deactivation of the catalyst, and can further strengthen the control of the hydrogenation reaction in stages, so that it can be better applied in the hydrogenation reaction and has high industrial application value.

[0051] Preferably, the reactor is an upflow micro-bubble hydrogenation reactor.

[0052] Preferably, the reactor further comprises a reactor shell, a feed inlet, a gas-liquid distributor, a gas injection pipe, an exhaust port and a discharge port.

[0053] Preferably, the reactor shell is located at the outermost side of the reactor.

[0054] The reactor shell of the present invention is located at the outermost side of the micro-bubble hydrogenation reactor, and is used for fixing or loading the internal components of the reactor, reaction materials and catalyst particles, and providing space for hydrogenation reaction.

[0055] The present invention has no special restrictions on the material of the reactor shell. Different reaction scales have different requirements for the material of the reactor shell. For example, for industrial-scale large-diameter reactors, the shell should be welded with steel plates or alloy materials; while for laboratory-scale small reactors, the organic glass shell can fully meet the strength requirements required for the experiment.

[0056] Preferably, the reactor shell is formed by welding steel plates or alloy plates.

[0057] Preferably, the reactor shell is cylindrical.

[0058] Preferably, the feed inlet is located directly below the reactor.

[0059] Preferably, the gas-liquid distributor is located above the feed inlet.

[0060] Preferably, the gas-liquid distributor is located below each catalyst bed.

[0061] The present invention installs the gas-liquid distributor under each catalyst bed layer to evenly distribute the gas-liquid two-phase fluid again, so that the gas-liquid contact is more complete, the hydrogenation reaction efficiency is improved and the local overheating and deactivation of the catalyst are avoided.

[0062] The present invention has no limitation on the gas-liquid distributor, and any gas-liquid distributor for distributing gas-liquid two-phase fluid known to those skilled in the art may be used, and its structure includes but is not limited to sieve plate type, bubble type, grooved plate type or chimney type, etc.

[0063] Preferably, the gas-liquid distributor structure is any one of sieve plate type, bubble type, grooved plate type or chimney type, or a combination of at least two of them, wherein typical but non-limiting combinations are: a combination of sieve plate type and bubble type, a combination of sieve plate type and grooved plate type, a combination of sieve plate type and chimney type, a combination of grooved plate type and bubble type, a combination of bubble type and chimney type, preferably a bubble type gas-liquid distributor.

[0064] Preferably, there are at least two gas injection pipes.

[0065] Preferably, the gas injection pipe is located above the gas-liquid distributor.

[0066] Preferably, the gas injection pipes are located on both sides of the lower part of the catalyst bed.

[0067] The present invention arranges the gas injection pipes on both sides of the lower part of the catalyst bed layer, so that the membrane tube microbubble generating device can better penetrate the catalyst bed layer.

[0068] Preferably, the exhaust port is located directly above the reactor.

[0069] The present invention provides an exhaust port directly above the reactor for exhausting excess hydrogen or inert gas that does not participate in the reaction.

[0070] Preferably, the discharge port is located on the upper side of the reactor.

[0071] The discharge port of the present invention is arranged on one side above the micro-bubble hydrogenation reactor, and is used for laterally discharging the liquid phase materials that have participated in the reaction.

[0072] Preferably, the membrane tube microbubble generating device in the reactor is connected to the reactor shell through at least two connecting shafts and is fixed inside the catalyst bed.

[0073] Preferably, the membrane tube fixing ring in the membrane tube microbubble generating device is connected to at least two connecting shafts.

[0074] The present invention connects the membrane tube fixing ring with at least two connecting shafts, so that the membrane tube microbubble generating device is more firmly fixed in the catalyst bed layer, and the mechanical strength of the reactor can be better guaranteed.

[0075] Preferably, the gas buffer ring in the membrane tube microbubble generating device is horizontally arranged in the reactor shell.

[0076] Preferably, the gas buffer ring in the membrane tube microbubble generating device is directly connected to the gas injection pipe.

[0077] The present invention is connected to the gas injection pipe through a gas buffer ring, and gas can be introduced into the membrane tube microbubble generating device through the gas injection pipe, wherein hydrogen or inert gas can be injected into the gas injection pipe as a supplementary gas, the injection of hydrogen can promote the hydrogenation reaction, and the injection of inert gas can inhibit the excessively fast hydrogenation reaction, thereby achieving the effect of regulating the reaction rate.

[0078] Preferably, the length of the microporous membrane tube in the membrane tube microbubble generating device is less than or equal to the filling height of the catalyst bed.

[0079] Preferably, the microporous membrane tubes in the membrane tube microbubble generating device are symmetrically distributed along the gas buffer ring with the axial center of the reactor shell as the axis.

[0080] Preferably, a metal screen is provided below the discharge port of the reactor.

[0081] The present invention provides a metal screen to block catalyst particles in the bed layer to prevent the catalyst particles from being carried out of the reactor by the gas-liquid two-phase fluid.

[0082] Preferably, the equivalent diameter of the metal mesh holes is smaller than the average particle size of the catalyst particles.

[0083] In the present invention, the equivalent diameter of the metal screen mesh is set to be smaller than the particle size of the catalyst particles to ensure that the particles will not drill out of the mesh holes.

[0084] In a second aspect, the present invention provides a method for controlling a micro-bubble hydrogenation reaction, wherein the method uses the micro-bubble hydrogenation reactor described in the first aspect to carry out a hydrogenation reaction.

[0085] The present invention adopts the micro-bubble hydrogenation reactor described in the first aspect to carry out hydrogenation reaction, which can not only generate uniform micro-bubbles to fully contact with the liquid phase material, thereby alleviating the problem of local overheating and deactivation of the catalyst, but also can control the type and flow rate of the gas introduced into the injection pipe of the hydrogenation reactor to control the hydrogenation reaction rate, thereby enhancing the controllability of the hydrogenation reaction and having high industrial application value.

[0086] Preferably, the method comprises the following steps: during the hydrogenation reaction, hydrogen and / or inert gas is introduced into the injection pipe of the micro-bubble hydrogenation reactor to control the hydrogenation reaction rate.

[0087] When hydrogen is introduced into the injection pipe, the hydrogenation reaction rate can be accelerated, the reaction is promoted, and the hydrogenation reaction efficiency is improved; but when the hydrogenation reaction speed is too fast, an inert gas can be introduced into the injection pipe to reduce the hydrogen partial pressure in the bed, slow down the hydrogenation reaction rate, prevent the catalyst from being deactivated, and extend the service life of the catalyst, so as to achieve the purpose of effectively controlling the hydrogenation reaction and have high practical value.

[0088] Preferably, the inert gas is nitrogen and / or helium.

[0089] Preferably, the volume flow rate Q of the gas introduced into the gas injection pipe is 2 The hydrogen volume flow rate Q from the feed port shall not exceed 1 Half of Q 2 ≤50%Q 1 , for example, it could be 50% Q 1 48%Q 1 45%Q 1 42%Q 1 40%Q 1 38%Q 1 , 35%Q 1 、30%Q 1 , 28%Q 1 , 25%Q 1 , 22%Q 1 , 20%Q 1 、15%Q 1 、10%Q 1 , 5%Q 1 or 1%Q 1 , preferably Q 2 ≤20%Q 1 .

[0090] Preferably, when no gas is introduced into the gas injection pipe, the pressure in the microporous membrane tube is maintained to be greater than the pressure in the catalyst bed.

[0091] When no gas is injected into the gas injection pipe, in order to prevent the reaction material from flowing back out of the gas injection pipe through the membrane tube microbubble generating device, the present invention should maintain the pressure in the microporous membrane tube slightly greater than the pressure in the catalyst bed.

[0092] In a third aspect, the present invention provides use of the microbubble hydrogenation reactor described in the first aspect in a hydrogenation reaction, preferably in oil hydrogenation, and more preferably in residual oil hydrogenation.

[0093] The micro-bubble hydrogenation reactor provided in the first aspect of the present invention is used in the hydrogenation reaction, which can not only realize the full contact between the gas phase hydrogen and the liquid phase material in the form of axially uniformly distributed microbubbles, but also improve the gas-liquid mass transfer efficiency and the hydrogenation reaction efficiency, and alleviate the phenomenon of local overheating and deactivation of the catalyst. At the same time, the purpose of controlling the hydrogenation reaction can be achieved by introducing gases of different types and flow rates, and has high industrial application value.

[0094] The micro-bubble hydrogenation reactor provided in the first aspect of the present invention is particularly suitable for use in residue oil hydrogenation reactions. This is because local bed overheating, catalyst coking and severe backmixing are very likely to occur during industrial residue oil hydrogenation. The micro-bubble hydrogenation reactor provided in the first aspect of the present invention can well solve the problem of uneven axial distribution of hydrogen, and can prevent the residue oil hydrogenation reaction rate from being too fast by introducing inert gas, thereby greatly improving the current status of industrial residue oil hydrogenation.

[0095] The method for applying the microbubble hydrogenation reactor described in the first aspect of the present invention in a hydrogenation reaction comprises the following steps:

[0096] (1) The liquid raw materials and the main hydrogen gas of the reaction are introduced into the reactor shell through the feed port, and then introduced into the catalyst bed after being evenly distributed by the gas-liquid distributor. The liquid raw materials and the main hydrogen gas undergo a hydrogenation reaction under the catalytic action of the catalyst particles;

[0097] (2) During the hydrogenation reaction, hydrogen and / or inert gas are introduced into the injection pipe of the microbubble hydrogenation reactor to control the hydrogenation reaction rate, wherein the volume flow rate Q of the gas introduced into the injection pipe is 2 The hydrogen volume flow rate Q from the feed port shall not exceed 1 Half of Q 2 ≤50%Q 1 ;

[0098] (3) The liquid phase product after the reaction is completed is discharged from the reactor through the discharge port, and the unreacted hydrogen and / or inert gas is discharged from the reactor through the exhaust port.

[0099] Compared with the prior art, the present invention has at least the following beneficial effects:

[0100] (1) The membrane tube microbubble generating device in the microbubble hydrogenation reactor provided by the present invention has each membrane tube penetrating part of the bed arranged vertically, which can be used to divert hydrogen into the hydrogenation reactor in the form of microbubbles, thereby achieving uniform distribution of microbubbles in the reactor bed, especially in the axial direction, which is more conducive to enhancing gas-liquid mixing. On the basis of a slight increase in pressure drop, its Peclet number is increased to ≥4.85, and can reach up to 5.82, and the liquid phase volume mass transfer coefficient is increased to ≥0.0047s -1 , the maximum is increased to 0.0086s -1 , which significantly reduces liquid backmixing, enhances gas-liquid mass transfer, and promotes the uniformity of hydrogenation reaction in space;

[0101] (2) The microbubble hydrogenation reactor provided by the present invention improves the utilization rate of hydrogen and the efficiency of hydrogenation reaction by generating microbubbles, thereby reducing the total amount of hydrogen used;

[0102] (3) The micro-bubble hydrogenation reaction control method provided by the present invention can use the membrane tube micro-bubble generating device to introduce an appropriate amount of inert gas into the reactor to inhibit the excessively fast hydrogenation reaction, enhance the controllability of the hydrogenation reaction, avoid the occurrence of catalyst overheating, coking and deactivation, and extend the service life of the catalyst;

[0103] (4) The membrane tube microbubble generating device in the microbubble hydrogenation reactor provided by the present invention has a simple structure and is easy to process, so it is convenient to install and disassemble in the hydrogenation reactor. Moreover, the entire microbubble hydrogenation reactor does not require additional power equipment, has low energy consumption, does not have sealing problems of power machinery, is easy to assemble, maintain and repair, and can operate stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 It is a schematic cross-sectional view of a membrane tube microbubble generating device provided by the present invention in which gas buffer rings are distributed in concentric circles in a catalyst bed.

[0105] Figure 2 It is a cross-sectional schematic diagram of a membrane tube microbubble generating device provided by the present invention in which gas buffer rings are distributed in concentric regular hexagons in a catalyst bed.

[0106] Figure 3 It is a cross-sectional schematic diagram of a membrane tube microbubble generating device provided by the present invention in which gas buffer rings are distributed in a concentric regular quadrilateral in a catalyst bed.

[0107] Figure 4 It is a schematic structural diagram of the micro-bubble hydrogenation reactor provided in Example 1 of the present invention.

[0108] Figure 5 It is a schematic diagram of the axial cross-sectional structure of a single-channel microporous membrane tube used in the microbubble hydrogenation reactor provided in Example 1 of the present invention.

[0109] Figure 6 It is a schematic diagram of the structure of the micro-bubble hydrogenation reactor provided in Example 5 of the present invention.

[0110] In the figure: 1-feed port; 2-reactor shell; 3-gas-liquid distributor; 31-first gas-liquid distributor; 32-second gas-liquid distributor; 4-gas injection pipe; 41-first gas injection pipe; 42-second gas injection pipe; 5-membrane tube microbubble generating device; 51-first membrane tube microbubble generating device; 52-second membrane tube microbubble generating device; 6-catalyst bed; 61-first catalyst bed; 62-second catalyst bed; 7-metal screen; 8-exhaust port; 9-discharge port; 10-connecting shaft; 11-membrane tube fixing ring; 12-microporous membrane tube; 13-gas buffer ring; 14-connecting pipe; 15-microporous membrane; 16-micron-level pores.

[0111] It should be noted that the terms such as "upper", "lower", "inner" and "outer" in the above description are used to indicate the orientation or positional relationship of the structures shown in the accompanying drawings, wherein "lower" refers to the direction close to the horizontal ground when the micro-bubble hydrogenation reactor is working normally, "upper" means the direction opposite to "lower", "inner" refers to the direction close to the central axis of the micro-bubble hydrogenation reactor, and "outer" means the direction opposite to "inner". DETAILED DESCRIPTION

[0112] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0113] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0114] The cross-sectional schematic diagram of the membrane tube microbubble generating device in the catalyst bed of the present invention is as follows: Figures 1 to 3 As shown, from Figures 1 to 3 It can be seen that the membrane tube microbubble generating device is connected to the reactor shell through at least two connecting shafts 10. When there is more than one gas buffer ring, the membrane tube microbubble generating device 5 is also provided with at least two connecting tubes 14 as auxiliary components, and the connecting tubes 14 are used to connect multiple concentric gas buffer rings 13 of the inner and outer rings.

[0115] Among them, Figure 1 As shown in the marking, each membrane tube on the gas buffer ring 13 is numbered T nθ , the two subscripts n and θ represent the relative position of the membrane tube, n represents the number of the gas buffer ring connected to the membrane tube, n = 1 represents the outermost gas buffer ring, the larger the n, the closer the gas buffer ring is to the inside of the reactor, and the value range of n is 1 to 10;

[0116] like Figures 1 to 3 As shown in the mark, θ represents the angle formed by rotating counterclockwise from the center of the bed section horizontally to the right to the line connecting the center of the membrane tube, and the value range of θ is 0 to 360°.

[0117] The shape and structure of the gas buffer ring in the membrane tube microbubble generating device of the present invention is not limited to a circular ring, and may also be other regular polygonal rings, such as Figure 2 The following are concentric regular hexagons: Figure 3 Shown are concentric regular quadrilaterals.

[0118] 1. Implementation

[0119] Example 1

[0120] This embodiment provides an upflow micro-bubble hydrogenation reactor, such as Figure 4As shown, the reactor comprises a reactor body and a membrane tube microbubble generating device 5;

[0121] The reactor body comprises a cylindrical reactor shell 2 with an inner diameter of 280 mm arranged at the outermost side of the reactor, a gas-liquid distributor 3, a gas injection pipe 4, a catalyst bed 6 and a metal screen 7 are sequentially arranged inside the reactor shell 2 from bottom to top, the gas injection pipe 4 is located on both sides of the lower part of the catalyst bed 6, a feed port 1 is arranged directly below the reactor shell 2, an exhaust port 8 is arranged directly above the reactor shell 2, and a discharge port 9 is arranged on one side above; the reactor shell 2 is made of organic glass, the catalyst bed 6 includes catalyst particles required for the hydrogenation reaction, the gas-liquid distributor 3 is a sieve plate type distributor, the aperture of the sieve holes on the distributor is 5.0 mm, the sieve holes are arranged in an equilateral triangle, the opening rate of the distributor is 0.125, the filling height of the catalyst bed 6 is 1030 mm, the average particle size of the catalyst particles is 3.0 mm, the bed porosity is 0.353, and the diameter of the gas injection pipe 4 is 20 mm;

[0122] The membrane tube microbubble generating device 5 comprises a membrane tube fixing ring 11, a cylindrical single-channel microporous membrane tube 12 with micrometer-level pores 16 on the tube wall, and a gas buffer ring 13. Figure 5 As shown, the microporous membrane tube 12 is formed by curling a microporous membrane 15, with a total of 8 tubes, each of which has a diameter of 10 mm and a height of 700 mm. The average pore size of the micron-scale pores 16 on the microporous membrane tube 12 is 400 μm, the angle with the horizontal direction is 45°, and the opening rate is 0.53; the gas buffer ring 13 is a single circular ring with an equivalent inner diameter of 25 mm and a ring width of 50 mm. The microporous membrane tubes 12 are evenly distributed along the gas buffer ring 13, and the structure, quantity and distribution form of the membrane tube fixing ring 11 are the same as those of the gas buffer ring 13;

[0123] The membrane tube fixing ring 11 in the membrane tube microbubble generating device 5 is connected to the reactor shell 2 through two connecting shafts 10 and is fixed inside the catalyst bed 6, wherein the gas buffer ring 13 is horizontally arranged in the reactor shell 2 and directly connected to the gas injection pipe 4, and the microporous membrane tube 12 is symmetrically distributed along the gas buffer ring 13 with the axial center of the reactor shell 2 as the axis.

[0124] The application method of the upflow micro-bubbling hydrogenation reactor provided in this embodiment in the hydrogenation reaction comprises the following steps:

[0125] (1) The liquid raw material and the main hydrogen gas of the reaction are introduced into the reactor shell 2 through the feed port 1, and are evenly distributed through the gas-liquid distributor 3 and then introduced into the catalyst bed 6. The liquid raw material and the main hydrogen gas undergo a hydrogenation reaction under the catalytic action of the catalyst particles;

[0126] (2) During the hydrogenation reaction, hydrogen and / or inert gas is introduced into the injection pipe 4 of the microbubble hydrogenation reactor to control the hydrogenation reaction rate, wherein the volume flow rate Q of the gas introduced into the injection pipe 4 is 2 No more than the hydrogen volume flow Q introduced from feed port 1 1 Half of Q 2 ≤50%Q 1 ;

[0127] (3) The liquid phase product after the reaction is completed is discharged from the reactor through the discharge port 9, and the hydrogen and / or inert gas that has not reacted completely is discharged from the reactor through the exhaust port 8.

[0128] Example 2

[0129] This embodiment provides an upflow micro-bubble hydrogenation reactor, the reactor comprising a reactor body and a membrane tube micro-bubble generating device 5;

[0130] The reactor body comprises a cylindrical reactor shell 2 with an inner diameter of 280 mm arranged at the outermost side of the reactor, a gas-liquid distributor 3, a gas injection pipe 4, a catalyst bed 6 and a metal screen 7 are sequentially arranged inside the reactor shell 2 from bottom to top, the gas injection pipe 4 is located on both sides of the lower part of the catalyst bed 6, a feed port 1 is arranged directly below the reactor shell 2, an exhaust port 8 is arranged directly above the reactor shell 2, and a discharge port 9 is arranged on one side above; the reactor shell 2 is made of organic glass, the catalyst bed 6 includes catalyst particles required for the hydrogenation reaction, the gas-liquid distributor 3 is a sieve plate type distributor, the aperture of the sieve holes on the distributor is 2.0 mm, the sieve holes are arranged in a concentric circle manner, the opening rate of the distributor is 0.125, the filling height of the catalyst bed 6 is 1030 mm, the average particle size of the catalyst particles is 3.0 mm, the bed porosity is 0.353, and the diameter of the gas injection pipe 4 is 20 mm;

[0131] The membrane tube microbubble generating device 5 comprises a membrane tube fixing ring 11, a microporous membrane tube 12 of a regular hexagonal columnar single channel with micron-scale pores 16 on the tube wall, and a gas buffer ring 13. The microporous membrane tube 12 is formed by curling a microporous membrane 15, and there are 12 in total. The equivalent tube diameter of each microporous membrane tube 12 is 20 mm, and the tube height is 700 mm. The average pore diameter of the micron-scale pores 16 on the microporous membrane tube 12 is 100 μm, the angle with the horizontal direction is 60°, and the opening rate is 0.58; the gas buffer ring 13 is a single regular hexagonal ring, the equivalent inner diameter of the ring is 28 mm, the ring width is 45 mm, the microporous membrane tubes 12 are evenly distributed along the gas buffer ring 13, and the structure, quantity and distribution form of the membrane tube fixing ring 11 are the same as those of the gas buffer ring 13;

[0132] The membrane tube fixing ring 11 in the membrane tube microbubble generating device 5 is connected to the reactor shell 2 through two connecting shafts 10 and is fixed inside the catalyst bed 6, wherein the gas buffer ring 13 is horizontally arranged in the reactor shell 2 and directly connected to the gas injection pipe 4, and the microporous membrane tube 12 is symmetrically distributed along the gas buffer ring 13 with the axial center of the reactor shell 2 as the axis.

[0133] The application method of the upflow micro-bubble hydrogenation reactor provided in this embodiment in the hydrogenation reaction is the same as that in Example 1.

[0134] Example 3

[0135] This embodiment provides an upflow micro-bubble hydrogenation reactor, the reactor comprising a reactor body and a membrane tube micro-bubble generating device 5;

[0136] The reactor body comprises a cylindrical reactor shell 2 with an inner diameter of 400 mm arranged at the outermost side of the reactor, a gas-liquid distributor 3, a gas injection pipe 4, a catalyst bed 6 and a metal screen 7 are sequentially arranged inside the reactor shell 2 from bottom to top, the gas injection pipe 4 is located on both sides of the lower part of the catalyst bed 6, a feed port 1 is arranged directly below the reactor shell 2, an exhaust port 8 is arranged directly above the reactor shell 2, and a discharge port 9 is arranged on one side above; the reactor shell 2 is made of organic glass, the catalyst bed 6 includes catalyst particles required for the hydrogenation reaction, the gas-liquid distributor 3 is a sieve plate type distributor, the aperture of the sieve holes on the distributor is 5.0 mm, the sieve holes are arranged in a concentric circle manner, the opening rate of the distributor is 0.215, the filling height of the catalyst bed 6 is 1030 mm, the average particle size of the catalyst particles is 6.0 mm, the bed porosity is 0.366, and the diameter of the gas injection pipe 4 is 30 mm;

[0137] The membrane tube microbubble generating device 5 comprises a membrane tube fixing ring 11, a cylindrical single-channel microporous membrane tube 12 with micron-level pores 16 on the tube wall, a gas buffer ring 13 and a connecting pipe 14, wherein the gas buffer ring 13 is an inner and outer ring, the inner ring has an equivalent inner diameter of 25 mm, the inner ring has a ring width of 45 mm, the outer ring has an equivalent inner diameter of 30 mm, and the outer ring has a ring width of 120 mm; the microporous membrane tube 12 is formed by curling a microporous membrane 15, the inner gas buffer ring is connected with 8 roots, and the outer gas buffer ring is connected with 8 roots. There are 16 microporous membrane tubes 12, each with a diameter of 20 mm and a height of 700 mm. The average pore size of the micron-sized pores 16 on the microporous membrane tubes 12 is 700 μm, the angle with the horizontal direction is 30°, the opening rate is 0.45, and the microporous membrane tubes 12 are evenly distributed along the gas buffer ring 13; there are two connecting pipes 14 with an inner diameter of 25 mm, which are used to connect the two gas buffer rings inside and outside. The structure, quantity and distribution form of the membrane tube fixing ring 11 are the same as those of the gas buffer ring 13.

[0138] The membrane tube fixing ring 11 in the membrane tube microbubble generating device 5 is connected to the reactor shell 2 through two connecting shafts 10 and is fixed inside the catalyst bed 6, wherein the gas buffer ring 13 is horizontally arranged in the reactor shell 2 and directly connected to the gas injection pipe 4, and the microporous membrane tube 12 is symmetrically distributed along the gas buffer ring 13 with the axial center of the reactor shell 2 as the axis.

[0139] The application method of the upflow micro-bubble hydrogenation reactor provided in this embodiment in the hydrogenation reaction is the same as that in Example 1.

[0140] Example 4

[0141] This embodiment provides an upflow micro-bubble hydrogenation reactor, the reactor comprising a reactor body and a membrane tube micro-bubble generating device 5;

[0142] The reactor body comprises a cylindrical reactor shell 2 with an inner diameter of 400 mm arranged at the outermost side of the reactor, wherein a gas-liquid distributor 3, an air injection pipe 4, a catalyst bed 6 and a metal screen 7 are sequentially arranged inside the reactor shell 2 from bottom to top, wherein the air injection pipe 4 is located on both sides of the lower part of the catalyst bed 6, a feed port 1 is arranged directly below the reactor shell 2, an exhaust port 8 is arranged directly above the reactor shell 2, and a discharge port 9 is arranged on one side above; the reactor shell 2 is made of organic glass, and the catalyst bed 6 contains The catalyst particles required for the hydrogenation reaction are included, the gas-liquid distributor 3 is a bubble-cap type distributor, the aperture of the bubble cap hole on the distributor is 10.0 mm, the sieve holes are arranged in a regular triangle format, the opening rate of the distributor is 0.215, the filling height of the catalyst bed 6 is 1030 mm, the average particle size of the catalyst particles is 6.0 mm, the bed porosity is 0.366, a layer of metal screen is arranged above the bubble-cap type distributor to carry the catalyst particles and prevent the particles from clogging the bubble cap holes, and the diameter of the gas injection pipe 4 is 30 mm;

[0143] The membrane tube microbubble generating device 5 comprises a membrane tube fixing ring 11, a cylindrical single-channel microporous membrane tube 12 with micron-level pores 16 on the tube wall, a gas buffer ring 13 and a connecting pipe 14, wherein the gas buffer ring 13 is an inner and outer ring, the inner ring has an equivalent inner diameter of 25 mm, the inner ring has a ring width of 45 mm, the outer ring has an equivalent inner diameter of 30 mm, and the outer ring has a ring width of 120 mm; the microporous membrane tube 12 is formed by curling a microporous membrane 15, the inner gas buffer ring is connected with 8 roots, and the outer gas buffer ring is connected with 8 roots. There are 16 microporous membrane tubes 12, each with a diameter of 20mm and a height of 700mm. The average pore size of the micron-scale pores 16 on the microporous membrane tube 12 is 700μm, the angle with the horizontal direction is 30°, the opening rate is 0.45, and the microporous membrane tubes 12 are evenly distributed along the gas buffer ring 13; there are two connecting pipes 14, with an inner diameter of 25mm, which are used to connect the two gas buffer rings inside and outside. The structure, quantity and distribution form of the membrane tube fixing ring 11 are the same as those of the gas buffer ring 13;

[0144] The membrane tube fixing ring 11 in the membrane tube microbubble generating device 5 is connected to the reactor shell 2 through two connecting shafts 10 and is fixed inside the catalyst bed 6, wherein the gas buffer ring 13 is horizontally arranged in the reactor shell 2 and directly connected to the gas injection pipe 4, and the microporous membrane tube 12 is symmetrically distributed along the gas buffer ring 13 with the axial center of the reactor shell 2 as the axis.

[0145] The application method of the upflow micro-bubble hydrogenation reactor provided in this embodiment in the hydrogenation reaction is the same as that in Example 1.

[0146] Example 5

[0147] This embodiment provides an upflow micro-bubble hydrogenation reactor, such as Figure 6 As shown, the difference between the reactor and Example 1 is that two stages of catalyst beds 6 and corresponding gas-liquid distributors 3, gas injection pipes 4 and membrane tube microbubble generating devices 5 are provided in the reactor body, and the rest are the same as Example 1, and its specific structure includes:

[0148] The reactor body comprises a cylindrical reactor shell 2 with an inner diameter of 280 mm arranged at the outermost side of the reactor, wherein a gas-liquid distributor 31, a gas injection pipe 41, a catalyst bed 61, a gas-liquid distributor 32, a gas injection pipe 42, a catalyst bed 62 and a metal screen 7 are sequentially arranged inside the reactor shell 2 from bottom to top, wherein the gas injection pipe 41 and the gas injection pipe 42 are respectively located on both sides of the lower part of the catalyst bed 61 and the catalyst bed 62, a feed port 1 is arranged directly below the reactor shell 2, an exhaust port 8 is arranged directly above the reactor shell 2, and a discharge port 9 is arranged on one side above; the reactor shell 2 consists of The catalyst bed 61 and the catalyst bed 62 are made of organic glass, and the catalyst particles required for the hydrogenation reaction are included in the catalyst bed 61 and the catalyst bed 62. The gas-liquid distributor 31 and the gas-liquid distributor 32 are both sieve plate distributors, and the aperture of the sieve holes on the distributor is 5.0 mm, and the sieve holes are arranged in a regular triangle format. The opening rate of the distributor is 0.125, and the filling heights of the catalyst bed 61 and the catalyst bed 62 are 465 mm and 565 mm respectively. The average particle size of the catalyst particles in the two beds is 3.0 mm, and the total porosity of the beds is 0.353. The diameters of the gas injection pipes 41 and 42 are 20 mm;

[0149] The membrane tube microbubble generating device 51 and the membrane tube microbubble generating device 52 have the same structure, both of which include a membrane tube fixing ring 11, a cylindrical single-channel microporous membrane tube 12 with micron-scale pores 16 on the tube wall, and a gas buffer ring 13. The microporous membrane tube 12 is formed by curling a microporous membrane 15, and there are 8 of them in total. Each microporous membrane tube 12 has a diameter of 10 mm and a tube height of 350 mm. The average pore size of the micron-scale pores 16 on the microporous membrane tube 12 is 400 μm, the angle with the horizontal direction is 45°, and the opening rate is 0.53; the gas buffer ring 13 is a single circular ring with an equivalent inner diameter of 25 mm and a ring width of 50 mm. The microporous membrane tubes 12 are evenly distributed along the gas buffer ring 13, and the structure, quantity and distribution form of the membrane tube fixing ring 11 are the same as those of the gas buffer ring 13;

[0150] The membrane tube fixing rings 11 in the membrane tube microbubble generating device 51 and the membrane tube microbubble generating device 52 are respectively connected to the reactor shell 2 through two connecting shafts 10, and are respectively fixed in the catalyst bed 61 and the catalyst bed 62, wherein the gas buffer ring 13 is horizontally arranged in the reactor shell 2 and directly communicates with the gas injection pipe 41 and the gas injection pipe 42, and the microporous membrane tube 12 is symmetrically distributed along the gas buffer ring 13 with the axial center of the reactor shell 2 as the axis.

[0151] The application method of the upflow micro-bubbling hydrogenation reactor provided in this embodiment in the hydrogenation reaction comprises the following steps:

[0152] (1) The liquid raw material and the main hydrogen gas of the reaction are introduced into the reactor shell 2 through the feed port 1, and are uniformly distributed by the gas-liquid distributor 31 and then introduced into the catalyst bed 61. After passing through the catalyst bed 61, the liquid raw material and the main hydrogen gas are redistributed by the gas-liquid distributor 32 and then introduced into the catalyst bed 62. The liquid raw material and the main hydrogen gas undergo a hydrogenation reaction under the catalytic action of the catalyst particles;

[0153] (2) During the hydrogenation reaction, hydrogen and / or inert gas are introduced into the injection pipe 41 and the gas injection pipe 42 of the microbubble hydrogenation reactor to control the hydrogenation reaction rate, wherein the total volume flow rate Q of the gas introduced into the gas injection pipe 41 and the gas injection pipe 42 is 2 No more than the hydrogen volume flow Q introduced from feed port 1 1 Half of Q 2 ≤50%Q 1 ;

[0154] (3) The liquid phase product after the reaction is completed is discharged from the reactor through the discharge port 9, and the hydrogen and / or inert gas that has not reacted completely is discharged from the reactor through the exhaust port 8.

[0155] Comparative Example 1

[0156] This comparative example provides an upflow hydrogenation reactor, which is the same as Example 1 except that the reactor does not include a membrane tube microbubble generating device and a gas injection pipe connected thereto and corresponding connection relationships;

[0157] The reactor specifically comprises: a cylindrical reactor shell with an inner diameter of 280 mm arranged at the outermost side of the reactor, a gas-liquid distributor, a catalyst bed and a metal screen are arranged in sequence from bottom to top inside the reactor shell, a feed port is arranged directly below the reactor shell, an exhaust port is arranged directly above the reactor shell, and a discharge port is arranged on the upper side; the reactor shell is made of organic glass, the catalyst bed includes catalyst particles required for the hydrogenation reaction, the gas-liquid distributor is a sieve plate type distributor, the aperture of the sieve holes on the distributor is 5.0 mm, the sieve holes are arranged in a regular triangle format, the opening rate of the distributor is 0.125, the filling height of the catalyst bed is 1030 mm, the average particle size of the catalyst particles is 3.0 mm, and the bed porosity is 0.353.

[0158] The application method of the upflow hydrogenation reactor provided in this comparative example in the hydrogenation reaction comprises the following steps:

[0159] (1) The liquid raw materials and the main hydrogen gas of the reaction are introduced into the reactor shell through the feed port, and then introduced into the catalyst bed after being evenly distributed by the gas-liquid distributor. The liquid raw materials and the main hydrogen gas undergo a hydrogenation reaction under the catalytic action of the catalyst particles;

[0160] (2) The liquid phase product after the reaction is completed is discharged from the reactor through the discharge port, and the unreacted hydrogen is discharged from the reactor through the exhaust port.

[0161] 2. Test Examples and Comparative Test Examples

[0162] The present invention conducts flow, mixing and mass transfer parameter test experiments on the upflow hydrogenation reactor provided in Examples 1 to 5 and Comparative Example 1.

[0163] Since the industrial oil hydrogenation reaction is often carried out under high temperature and high pressure conditions, and the oil under high temperature and high pressure is a Newtonian fluid, its physical parameters such as density and kinematic viscosity are similar to the physical parameters of water at room temperature, and the micro-bubble hydrogenation reactor provided by the present invention mainly realizes better uniform distribution of microbubbles in the reactor bed, especially in the axial direction, which is beneficial to enhance gas-liquid mixing and reduce liquid backmixing. Therefore, fluid dynamics parameters such as fluid flow and mixing are investigated in the test examples and test comparison examples. At the same time, considering the safety, energy saving and cost issues during the implementation of the experiment, the test examples and test comparison examples adopt a cold model experimental method, using water instead of liquid phase materials and air instead of hydrogen to conduct experiments at room temperature and pressure.

[0164] Test cases 1 to 5

[0165] Test Examples 1 to 5 were tested using the upflow hydrogenation reactor provided in Example 1, wherein the volume flow rate of air introduced at the feed port 1 was fixed at Q 1 =30m 3 ·h -1 The volume flow rate of water entering is fixed at Q L =6.5L·min -1 The volume flow rate of air introduced into the air injection pipe 4 is Q 2 , Q in test cases 1 to 5 2 1.0%Q 1 5.0%Q 1 、10.0%Q 1 , 15.0%Q 1 and 20.0%Q 1 , keeping other conditions unchanged, the specific test parameters and results are shown in Table 1.

[0166] Test cases 6 to 8

[0167] Test Examples 6 to 8 were tested using the upflow hydrogenation reactors provided in Examples 2 to 4, respectively, wherein the volume flow rate of air introduced at the feed port 1 was fixed at Q 1 =30m 3 ·h -1 The volume flow rate of water entering is fixed at Q L =6.5L·min -1The volume flow rate of air introduced into the air injection pipe 4 of test examples 6 to 8 is Q 2 30.0%Q 1 , 40.0%Q 1 and 50.0%Q 1 ,The specific test parameters and results are shown in Table 1.

[0168] Test Example 9

[0169] Test Example 9 uses the upflow hydrogenation reactor provided in Example 5 for testing, wherein the volume flow rate of air introduced at the feed inlet and the volume flow rate of water introduced at the feed inlet are kept the same as those in Test Examples 1 to 5, that is, the volume flow rate of air introduced at the feed inlet is fixed at Q 1 =30m 3 ·h -1 The volume flow rate of water entering is fixed at Q L =6.5L·min -1 The volume flow rate of air introduced into the gas injection pipe 41 is Q 21 The volume flow rate of air introduced into the gas injection pipe 42 is Q 22 , Q in test case 9 21 and Q 22 Both 10.0%Q 1 ,The specific test parameters and results are shown in Table 1.

[0170] Test Comparative Example 1

[0171] Comparative Example 1 The upflow hydrogenation reactor provided in Comparative Example 1 was used for testing, wherein the volume flow rate of air introduced at the feed inlet and the volume flow rate of water introduced at the feed inlet were kept the same as those in Test Examples 1 to 5, that is, the volume flow rate of air introduced at the feed inlet was fixed at Q 1 =30m 3 ·h -1 The volume flow rate of water entering is fixed at Q L =6.5L·min -1 The specific test results are shown in Table 1.

[0172] 3. Measurement methods and results

[0173] Bed pressure drop measurement method: MPM4730 intelligent pressure transmitters are installed on the upper and lower sides of the catalyst bed and at different heights. During the experiment, the pressure at each height point of the catalyst bed is measured in real time. After the pressure at each point is basically stable, the pressure difference between the upper and lower sides of the bed is calculated to obtain the bed pressure drop.

[0174] Peclet number measurement method: Peclet number refers to the ratio of fluid convection rate to diffusion rate, and is often used to characterize the degree of back mixing in the reactor. The larger the value, the smaller the back mixing. The present invention uses traditional response technology to measure the residence time distribution of the microbubble hydrogenation reactor, and calculates the Peclet number by combining the one-dimensional axial diffusion model with the residence time distribution. The pulse tracer method is used to quickly inject 30mL of 4.0mol·L at the feed inlet of the reactor after the device is running stably. -1 KCl solution is used as a tracer, and a DDS-307 conductivity meter is used at the discharge port of the reactor in conjunction with a USB7660A data acquisition card to collect voltage signal data in the liquid phase material in real time. According to the voltage-(tracer) concentration calibration curve completed in advance before the experiment, the collected voltage signal data can be converted into tracer concentration values, and the tracer residence time distribution curve can be drawn. The dimensionless variance σ can be obtained by analyzing and calculating the residence time distribution curve. θ 2 Finally, the Peclet number can be obtained according to the solution of the closed axial diffusion model, that is, equation (1).

[0175]

[0176] Liquid phase volume mass transfer coefficient measurement method: physical absorption method is used to determine the liquid phase volume mass transfer coefficient k L a. Prepare 5.0% Na 2 SO 3 The oxygen-free solution was placed in the storage tank. During the experiment, Na 2 SO 3 The solution and air are introduced into the reactor from the feed port at the same time, and the dissolved oxygen concentration of the solution is measured and recorded in real time using a JPSJ-605 dissolved oxygen analyzer at the discharge port. After the value is basically stable, the average value c is calculated. out , and the liquid phase volume mass transfer coefficient k is obtained according to the following formula (2): L a.

[0177]

[0178] Among them, Q in the above formula L Represents Na at the feed inlet 2 SO 3 Volume flow rate of the solution, V c is the total volume of the catalyst bed, c * represents the saturated dissolved oxygen concentration in the solution at the experimental temperature, c in and c out are the dissolved oxygen concentrations in the solution at the reactor inlet and outlet, respectively, and c in =0.

[0179] The experimental results of test examples 1 to 9 and test comparative example 1 are shown in Table 1.

[0180] Table 1

[0181]

[0182]

[0183] From Table 1, we can see the following points:

[0184] (1) It can be seen from the comprehensive test examples 1 to 9 that the micro-bubble hydrogenation reactor provided by the present invention has good mass transfer effects under different test conditions, and the liquid phase volume mass transfer coefficient is ≥0.0047s -1 , Pelect number ≥ 4.85, and the bed pressure drop is ≤ 13.75 kPa, indicating that the micro-bubble hydrogenation reactor provided by the present invention generates microbubbles in the reactor bed through the membrane tube microbubble generating device, which enhances the gas-liquid mass transfer and reduces the back-mixing phenomenon without much increase in pressure drop, and can be well applied to hydrogenation reactions, and has great industrial application value;

[0185] (2) It can be seen from the comprehensive test examples 1 to 5 and the test comparative example 1 that the test examples 1 to 5 adopt the micro-bubble hydrogenation reactor provided by Example 1 and inject air of different volume flow rates into the gas injection pipe. Compared with the test comparative example 1 using the hydrogenation reactor provided by comparative example 1 without additional injection of air, the Pelect numbers of the test examples 1 to 5 are all ≥4.85, the highest can reach 5.33, and the liquid phase volume mass transfer coefficient is all ≥0.0047s -1 , up to 0.0072s -1 , and the pressure drop is ≤12.85kPa, while the Pelect number in the test comparative example 1 is 4.81 and the liquid phase volume mass transfer coefficient is 0.0044s -1 , the pressure drop is 11.23 kPa, which shows that the micro-bubble hydrogenation reactor provided by the present invention not only increases the pressure drop less on the basis of increasing the flow rate, but also greatly alleviates the gas-liquid back-mixing phenomenon, improves the gas-liquid phase mass transfer efficiency, and has a high industrial application prospect;

[0186] (3) It can be seen from the comprehensive test examples 1 to 5 that the volume flow rate of 1.0% Q is injected into the gas injection pipe in turn. 1 5.0%Q 1 、10.0%Q 1 , 15.0%Q 1 and 20.0%Q 1 The Peclet number of air increased from 4.85 to 5.33, and the liquid phase volume mass transfer coefficient increased from 0.0047s -1 Improved to 0.0072s-1 , the pressure drop only increased from 11.68 kPa to 12.85 kPa, which shows that with the increase of the volume flow rate injected in the gas injection pipe, the gas-liquid backmixing phenomenon of the micro-bubble hydrogenation reactor provided by the present invention is significantly reduced and the liquid phase volume mass transfer coefficient is significantly increased, and the bed pressure drop in the micro-bubble hydrogenation reactor increases slightly. Under the same device and other conditions, the increase in pressure drop after the flow rate increases is a normal phenomenon;

[0187] (4) It can be seen from the combination of Test Example 5 and Test Example 9 that Test Example 9 adopts the micro-bubble hydrogenation reactor provided in Example 5 and injects 10.0% Q 1 The volume flow rate of air is 20.0% Q. 1 For air volume flow rate, the Pelect number of test case 9 is 5.82, and the liquid phase volume mass transfer coefficient is 0.0086s -1 , while in test case 5, the Pelect number is 5.33 and the liquid phase volume mass transfer coefficient is 0.0072s -1 This shows that the present invention can further alleviate the gas-liquid backmixing phenomenon and improve the gas-liquid mass transfer efficiency by preferably adopting a two-stage micro-bubble hydrogenation reactor without substantially increasing the pressure drop.

[0188] In summary, the liquid phase volume mass transfer coefficient of the microbubble hydrogenation reactor provided by the present invention is ≥0.0047s under different test conditions. -1 , Pelect number ≥ 4.85, and the bed pressure drop is ≤ 13.75 kPa, which solves the problem of uneven distribution of microbubbles in the axial direction in the prior art, strengthens gas-liquid mass transfer and reduces backmixing without much increase in pressure drop, and the membrane tube microbubble generating device has a simple structure and is easy to process and load and unload; the microbubble hydrogenation reactor is applied to hydrogenation reactions, which can enhance the controllability of hydrogenation reactions, improve reaction efficiency, avoid overheating, coking or deactivation of catalysts, and has high practical application value.

[0189] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A microbubble hydrogenation reactor, characterized in that: The reactor comprises a catalyst bed and a membrane tube microbubble generating device arranged in the catalyst bed; The membrane tube microbubble generating device comprises a microporous membrane tube with micron-sized pores on the tube wall; the average pore size of the micron-sized pores is 20 to 1000 μm; the membrane tube microbubble generating device also comprises a gas buffer ring connected to the microporous membrane tube; the reactor also comprises a reactor shell, a feed inlet, a gas-liquid distributor, an injection pipe, an exhaust port and a discharge port; the gas buffer ring in the membrane tube microbubble generating device is directly connected to the injection pipe.

2. The reactor according to claim 1, characterized in that The average pore size of the micron-sized pores is 20-700 μm.

3. The reactor according to claim 1, characterized in that The micron-scale pores on the tube wall of the microporous membrane tube are arranged in an oblique upward direction.

4. The reactor according to claim 1, characterized in that The angle between the micrometer-scale pores and the horizontal direction is 1-89°.

5. The reactor according to claim 4, characterized in that The angle between the micrometer-scale pores and the horizontal direction is 30-60°.

6. The reactor according to claim 1, characterized in that The porosity of the microporous membrane tube is 0.1-0.

8.

7. The reactor according to claim 6, characterized in that The porosity of the microporous membrane tube is 0.3-0.

6.

8. The reactor according to claim 1, characterized in that The diameter of the microporous membrane tube is 5-150 mm.

9. The reactor according to claim 8, characterized in that The diameter of the microporous membrane tube is 20-100 mm.

10. The reactor according to claim 1, characterized in that The microporous membrane tube is of single-channel type or multi-channel type.

11. The reactor according to claim 1, characterized in that The number of the gas buffer rings is 1 to 10.

12. The reactor according to claim 11, characterized in that The number of the gas buffer rings is 2 to 8.

13. The reactor according to claim 1, characterized in that The equivalent inner diameter of the gas buffer ring is 0.01D-0.15D, where D is the inner diameter of the reactor.

14. The reactor according to claim 13, characterized in that The equivalent inner diameter of the gas buffer ring is 0.05D-0.10D, where D is the inner diameter of the reactor.

15. The reactor according to claim 1, characterized in that The ring width of the gas buffer ring is 0.04D-0.35D, wherein D is the inner diameter of the reactor.

16. The reactor according to claim 15, characterized in that The ring width of the gas buffer ring is 0.10D-0.20D, wherein D is the inner diameter of the reactor.

17. The reactor according to claim 1, characterized in that The gas buffer rings are connected to each other through at least two connecting pipes.

18. The reactor according to claim 1, characterized in that The cross section of the gas buffer ring is circular or regular polygonal.

19. The reactor according to claim 1, characterized in that The gas buffer ring is a circular and / or regular polygonal ring structure.

20. The reactor according to claim 19, characterized in that The gas buffer ring is circular.

21. The reactor according to claim 1, characterized in that The distribution form of the gas buffer rings is concentric distribution.

22. The reactor according to claim 11, characterized in that The number of microporous membrane tubes installed on each gas buffer ring is 2 to 100.

23. The reactor according to claim 22, characterized in that The number of microporous membrane tubes installed on each gas buffer ring is 10 to 80.

24. The reactor according to claim 1, characterized in that The membrane tube microbubble generating device also includes a membrane tube fixing ring arranged on the end of the microporous membrane tube opposite to the gas buffer ring.

25. The reactor according to claim 24, characterized in that The membrane tube fixing ring is communicated with the membrane tube.

26. The reactor according to claim 1, characterized in that The catalyst bed includes catalyst particles required for the hydrogenation reaction.

27. The reactor according to claim 1, characterized in that The number of the catalyst bed is at least one.

28. The reactor according to claim 27, characterized in that The number of catalyst beds is 2 to 3.

29. The reactor according to claim 1, characterized in that The reactor is an upflow micro-bubble hydrogenation reactor.

30. The reactor according to claim 1, characterized in that The reactor shell is located at the outermost side of the reactor.

31. The reactor according to claim 1, characterized in that The reactor shell is cylindrical.

32. The reactor according to claim 1, characterized in that The feed inlet is located directly below the reactor.

33. The reactor according to claim 1, characterized in that The gas-liquid distributor is located above the feed inlet.

34. The reactor according to claim 1, characterized in that The gas-liquid distributor is located below each catalyst bed layer.

35. The reactor according to claim 1, characterized in that There are at least two gas injection pipes.

36. The reactor according to claim 1, characterized in that The gas injection pipe is located above the gas-liquid distributor.

37. The reactor according to claim 1, characterized in that The gas injection pipes are located on both sides of the lower part of the catalyst bed.

38. The reactor according to claim 1, characterized in that The exhaust port is located just above the reactor.

39. The reactor according to claim 1, characterized in that The discharge port is located at one side above the reactor.

40. The reactor according to claim 1, characterized in that The membrane tube microbubble generating device in the reactor is connected to the reactor shell through at least two connecting shafts and is fixed inside the catalyst bed.

41. The reactor according to claim 24, characterized in that The membrane tube fixing ring in the membrane tube microbubble generating device is connected to at least two connecting shafts.

42. The reactor according to claim 1, characterized in that The gas buffer ring in the membrane tube microbubble generating device is horizontally arranged in the reactor shell.

43. The reactor according to claim 1, characterized in that The length of the microporous membrane tube in the membrane tube microbubble generating device is less than or equal to the filling height of the catalyst bed.

44. The reactor according to claim 1, characterized in that The microporous membrane tubes in the membrane tube microbubble generating device are symmetrically distributed along the gas buffer ring with the axial center of the reactor shell as the axis.

45. The reactor according to claim 26, characterized in that A metal screen is arranged below the discharge port of the reactor.

46. ​​The reactor according to claim 45, characterized in that The equivalent diameter of the metal mesh openings is smaller than the average particle size of the catalyst particles.

47. A micro-bubbling hydrogenation reaction control method, characterized in that: The method adopts the micro-bubble hydrogenation reactor described in any one of claims 1 to 46 to carry out the hydrogenation reaction.

48. The method according to claim 47, characterized in that The method comprises the following steps: During the hydrogenation reaction, hydrogen and / or inert gas is introduced into the gas injection pipe of the micro-bubble hydrogenation reactor to control the hydrogenation reaction rate.

49. The method according to claim 48, characterized in that The inert gas is nitrogen and / or helium.

50. The method according to claim 48, characterized in that The volume flow rate Q2 of the gas introduced into the gas injection pipe does not exceed half of the volume flow rate Q1 of the hydrogen introduced from the feed port, that is, Q2≤50%Q1.

51. The method according to claim 50, characterized in that The volume flow rate Q2 of the gas introduced into the gas injection pipe does not exceed half of the volume flow rate Q1 of the hydrogen introduced from the feed port, that is, Q2≤20%Q1.

52. The method of claim 48, wherein: When no gas is introduced into the gas injection pipe, the pressure in the microporous membrane tube is kept greater than the pressure in the catalyst bed.

53. Use of the microbubble hydrogenation reactor according to any one of claims 1 to 46 in a hydrogenation reaction, characterized in that: The use includes use of the micro-bubble hydrogenation reactor in oil hydrogenation.

54. The use according to claim 53, characterized in that The use includes use of the micro-bubble hydrogenation reactor in residual oil hydrogenation.

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