Upstream type fixed bed reaction system

Abstract

The utility model provides an ascending type fixed bed reaction system which comprises a reactor, a catalyst bed layer is arranged in the reactor, a pressing device is arranged on the upper portion of the catalyst bed layer, and a supporting device is arranged on the lower portion of the catalyst bed layer; the pressing device is composed of a pressing cover grating and a movable pressing cover, the upper surface of the catalyst bed layer is covered with the movable pressing cover, and the pressing cover grating is located on the upper portion of the movable pressing cover; the supporting device consists of a rectifier, a supporting grid and a hanging basket, the rectifier is arranged at the lower part of the catalyst bed layer, the supporting grid is positioned at the lower part of the rectifier, and the hanging basket is positioned at the lower part of the supporting grid. The reaction system can fix the catalyst, prevent the catalyst from leaking and reduce the loss of the catalyst; meanwhile, the flow field of the reaction materials is distributed and rectified, so that the reaction efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical engineering, and in particular to an upward fixed bed reaction system. Background Art

[0002] Fixed bed reaction system. Fixed bed reactor is a commonly used chemical reactor. It refers to a reactor filled with granular solid catalysts or solid reactants to form a stacked bed of a certain height. Gas or oil materials flow through the static fixed bed through the gaps between particles, realizing a heterogeneous reaction process. The characteristic of this type of reactor is that the solid particles filled in the equipment are fixed, which is different from the moving bed and fluidized bed in which the solid materials move in the equipment. However, the reaction efficiency of this reaction system is low. At the same time, the catalyst bed is affected by the upward buoyancy and drag of the micro-interface fluid and the disturbance of the flow field, which may cause the bed to loosen and cause a certain degree of wear and crushing of the catalyst and the phenomenon of catalyst leakage.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] The first object of the present invention is to provide an upward fixed-bed reaction system, which can fix the catalyst, prevent catalyst leakage, and reduce catalyst loss; at the same time, distribute and rectify the flow field of the reaction material to improve the reaction efficiency.

[0005] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0006] The present invention provides an upward fixed bed reaction system, comprising:

[0007] A reactor, wherein a catalyst bed is arranged in the reactor, a pressing device is arranged on the upper part of the catalyst bed, and a supporting device is arranged on the lower part of the catalyst bed;

[0008] The clamping device is composed of a gland grid and a movable gland, wherein the movable gland covers the upper surface of the catalyst bed, and the gland grid is located on the upper part of the movable gland;

[0009] The supporting device is composed of a rectifier, a supporting grid and a hanging basket. The rectifier is arranged at the lower part of the catalyst bed, the supporting grid is located at the lower part of the rectifier, and the hanging basket is located at the lower part of the supporting grid.

[0010] When no reaction occurs, the catalyst particles will naturally fall into the support device under the action of gravity; however, when the upward reaction is in progress, the reaction of the material from bottom to top will generate an upward force, overcoming the gravity of the catalyst itself and causing the catalyst to suspend; and when the material stops reacting, the upward force disappears and the catalyst falls. In such a repeated process, the catalyst will be repeatedly hit and broken, so a support device and a clamping device are provided in the present invention. The clamping device can clamp the catalyst, thereby ensuring that the catalyst does not move during the reaction, avoiding the catalyst from being repeatedly hit and eventually broken, thereby reducing the reaction effect.

[0011] Since the catalyst bed itself has a certain weight, if a support device is not set up, it is easy to appear in the actual reaction process that the entire catalyst bed moves down infinitely due to the downward pressure of the moving cover. Therefore, a support device must be set up. The support grid and the cover grid can ensure that the catalyst bed can move within a relatively fixed range. This setting method can ensure that the catalyst is closely arranged to prevent it from breaking; at the same time, the space inside the reaction tank can be reasonably arranged, or multiple layers of catalyst can be set according to the actual reaction requirements.

[0012] The microinterface generator of the present invention belongs to the prior art. Although some microinterface generators are of the pneumatic microinterface generator type, some are of the hydraulic microinterface generator type, and some are of the gas-liquid linkage microinterface generator type, the difference between the types is mainly selected according to different specific working conditions. In addition, the connection between the microinterface generator and the reactor and other equipment, including the connection structure and connection position, depends on the structure of the microinterface generator and is not limited to this.

[0013] Preferably, as a further specific implementation, any position between the hanging basket or the supporting grid and the rectifier is filled with porcelain balls with a diameter of 2mm-13mm, and a micro-interface unit is provided at the lower part of the hanging basket;

[0014] Preferably, the diameter of the porcelain ball is 4 mm-5 mm.

[0015] Preferably, as a further specific embodiment, the ratio of the diameter to the height of the hanging basket is (20-30):(9-15);

[0016] Preferably, the ratio of the diameter to the height is 21:10.

[0017] Preferably, as a further specific implementation, the gland grid is fixed to the upper surface of the catalyst bed, and the gland grid is evenly provided with holes, and the hole diameter is 1mm-10mm;

[0018] Preferably, the hole diameter is 1 mm-3 mm.

[0019] Preferably, as a further specific embodiment, both ends of the movable gland are movably connected to the inner wall of the reactor, and holes are evenly arranged on the movable gland, and the hole diameter is 1mm-10mm;

[0020] Preferably, the hole diameter is 1 mm-3 mm.

[0021] Preferably, as a further specific implementation, a heavy porcelain ball is arranged between the gland grid and the movable gland, there is no gap between the gland grid and the heavy porcelain ball, and the diameter of the heavy porcelain ball is 5mm-9mm;

[0022] Preferably, the diameter of the heavy porcelain ball is 6mm-7mm.

[0023] Preferably, as a further specific implementation, the support grid is fixed to the lower part of the rectifier, and holes are evenly arranged on the support grid, and the hole diameter is 1mm-10mm;

[0024] Preferably, the hole diameter is 1 mm-3 mm.

[0025] In the present invention, through-holes are provided in both the support device and the pressing device, so as to ensure that the materials involved in the reaction can pass through the holes, and the diameter of the holes should be smaller than the diameter of the porcelain balls used, so as to prevent the porcelain balls from falling due to the excessive diameter of the holes. If the hole diameters on the support grid, the movable gland and the gland grid are set within the range of 1mm-10mm, it can effectively ensure that the reaction materials can pass normally, prevent blockage, and prevent the porcelain balls from falling.

[0026] The movable gland in the present invention is a movable device, and there is no gap between the device and the catalyst, thereby ensuring that the filled catalyst is evenly arranged in a manner that is neither too loose nor too tight. At the same time, the movable gland can change with the height of the catalyst. When the height of the loaded catalyst becomes lower, the movable gland also becomes lower; when the height of the loaded catalyst is higher, the movable gland becomes higher. As the reaction proceeds, the height of the catalyst bed will sink to a certain extent. After the catalyst bed sinks, the catalyst bed compression device can still play the role of compressing the catalyst bed.

[0027] And the top of the mobile gland is provided with heavy porcelain balls, and the diameter of the heavy porcelain balls in the present invention is selected to be 5mm-9mm, and the heavy porcelain balls give the mobile gland a larger force, so that the material moving upward in the reaction process is unlikely to push the mobile gland open, and the catalyst is repeatedly collided and broken. The top of the hanging basket or the support grid is provided with porcelain balls with a diameter of 2mm-13mm, and the optimal ratio of the diameter of the hanging basket to the height is 21:10 at the same time, and the porcelain balls in the hanging basket should be filled with the hanging basket. If the hanging basket provided by this ratio is in a flatter cylindrical shape, the porcelain balls can be spread flat, and the contact area between the support grid and the porcelain balls is increased, so that the force is evenly applied, so that the reactants can make the hanging basket and the porcelain balls therein play a good supporting role in the process of ascending. The diameter of the porcelain balls provided inside the hanging basket in the present invention is 2mm-13mm, and the purpose of selecting this type of porcelain balls is to prevent the porcelain balls from being too heavy and causing the support grid to lose its supporting role, and can play an effective supporting role to the catalyst bed when the upward reaction is carried out.

[0028] When the ceramic balls are placed between the support grid and the rectifier, there is no need to place ceramic balls on the hanging basket. At this time, the height of the ceramic balls should be less than the height of the hanging basket, which also supports the catalyst bed and reduces the supporting pressure of the support grid.

[0029] A rectifier is also provided at the bottom of the catalyst bed. There is no gap between the rectifier, porcelain balls and support grid. The rectifier must be provided at the bottom of the catalyst bed. On the one hand, it can balance the flow field, and on the other hand, it can prevent the porcelain balls from flowing and damaging the support grid.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The dense phase loading method can make the catalyst more evenly distributed in the catalyst bed, thereby improving the reaction efficiency.

[0032] (2) Using a support and pressing device to press the catalyst during the reaction reduces the breakage of the catalyst caused by repeated vibration, thereby effectively reducing the loss of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 : Example 1 is a schematic diagram of the structure of an upward fixed bed reactor with porcelain balls added to a hanging basket;

[0034] Figure 2 : Example 2 is a schematic diagram of the structure of an ascending fixed bed reactor with porcelain balls added to the support grid.

[0035] in:

[0036] 1-Product outlet; 2-Gland cover;

[0037] 3-Heavy porcelain ball; 4-Moving gland;

[0038] 5-catalyst bed; 6-rectifier;

[0039] 7-support grid; 8-ceramic ball;

[0040] 9-micro interface generator; 10-liquid phase inlet;

[0041] 11-hanging basket; 12-gas phase inlet. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0043] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element 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.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In order to more clearly explain the technical solution of the present invention, it is described in the form of specific embodiments below.

[0046] Example 1

[0047] See also Figure 1 , Figure 2 As shown, an upward fixed bed reaction system of an embodiment of the present invention comprises, from top to bottom, a product outlet 1 for reactant flow outflow, a fixed-position pressure cover grid 2, heavy porcelain balls 3 for pressing the catalyst bed, a movable pressure cover 4 for pressing the catalyst bed, a catalyst bed 5 for loading the catalyst, a rectifier 6 for adjusting the flow field, a support grid 7 for supporting the catalyst bed, porcelain balls 8 placed in a hanging basket, a hanging basket 11 for placing porcelain balls, a micro-interface generator 9 for crushing the reactants, and a material inlet 10.

[0048] The practical application of the upward fixed bed reaction system of the present invention includes the following process:

[0049] The catalyst is loaded into the catalyst bed 5 by liquid phase sedimentation, and then a movable pressure cover 4 with a pore diameter of 1 mm is installed until there is no gap between the movable pressure cover 4 and the catalyst. Then a certain amount of nitrogen and heavy oil mixture is introduced from top to bottom, and the bed is pressurized and sedimented for 2h-2.5h. After the sedimentation is completed, the catalyst is refilled to the descending part of the catalyst bed 5 to its initial height, and the above process is repeated 1-3 times.

[0050] Liquid-phase reactants enter the reactor from the liquid-phase inlet 10 at the bottom of the reactor, and gas-phase reactants enter the reactor from the gas-phase inlet 12. Then, gas-phase and liquid-phase reactants are crushed by the microinterface generator 9 and enter the hanging basket 11 filled with 4mm porcelain balls 8. At this time, the height of the hanging basket is 100mm and the diameter is 210mm. The hanging basket 11 and the porcelain balls 8 therein support the support grid 7. The upward reactants produce an upward force for the catalyst bed 5. The catalyst bed 5 itself has a certain gravity. The hanging basket 11 and the porcelain balls 8 therein are for better balancing the force between the two. Subsequently, the reactants passing through the hanging basket 11 continue to ascend to the support grid 7 with a pore diameter of 1mm. The support grid 7 now supports the catalyst bed 5 to prevent the upward reactants or the catalyst bed 5 from being displaced due to the influence of gravity. The reactants continue to move upward, pass through the rectifier 6 for rectification, and then enter the catalyst bed 5. After the reactants are fully reacted by the catalyst in the catalyst bed 5, they continue to move upward from the channel of the movable gland 4, pass through the heavy porcelain ball 3 with a diameter of 6 mm, and pass upward through the gland grid 2 with a channel diameter of 1 mm. The final reaction product flows out from the product outlet 1.

[0051] Example 2

[0052] The practical application of the upward fixed bed reaction system of the present invention includes the following process:

[0053] The catalyst is loaded into the catalyst bed 5 by liquid phase sedimentation, and then a movable pressure cover 4 with a pore diameter of 1 mm is installed until there is no gap between the movable pressure cover 4 and the catalyst. Then a certain amount of nitrogen and heavy oil mixture is introduced from top to bottom, and the bed is pressurized and sedimented for 2h-2.5h. After the sedimentation is completed, the catalyst is refilled to the descending part of the catalyst bed 5 to its initial height, and the above process is repeated 1-3 times.

[0054] Liquid-phase reactants enter the reactor from the liquid-phase inlet 10 at the bottom of the reactor, and gas-phase reactants enter the reactor from the gas-phase inlet 12. Then, the gas-phase and liquid-phase reactants pass through the microinterface generator 9, and the reactants are crushed and then continue upward through an empty hanging basket with a height of 100 mm and a diameter of 210 mm. At this time, the catalyst bed 5 and the support grid 7 with a pore diameter of 1 mm are filled with porcelain balls 8 with a diameter of 4 mm, and the role of the porcelain balls 8 and the hanging basket 11 is consistent with that in Example 1. The reactants continue to ascend, are rectified by the rectifier 6, and then enter the catalyst bed 5. After the reactants are fully reacted by the catalyst in the catalyst bed 5, they continue upward from the pore of the mobile gland 4, pass through the heavy porcelain balls 3 with a diameter of 6 mm, and pass upward through the gland grid 2 with a pore diameter of 1 mm, and the reaction product finally obtained flows out from the product outlet 1.

[0055] Example 3

[0056] The only difference between this embodiment and embodiment 1 is that the hole diameter of the support grid is changed to 10 mm.

[0057] Example 4

[0058] The only difference between this embodiment and embodiment 1 is that the hole diameter of the support grid is changed to 3 mm.

[0059] Example 5

[0060] The only difference between this embodiment and embodiment 1 is that the hole diameter of the movable gland is changed to 10 mm.

[0061] Example 6

[0062] The only difference between this embodiment and embodiment 1 is that the hole diameter of the movable gland is changed to 3 mm.

[0063] Example 7

[0064] The only difference between this embodiment and embodiment 1 is that the diameter of the porcelain ball is changed to 2 mm.

[0065] Example 8

[0066] The only difference between this embodiment and embodiment 1 is that the diameter of the porcelain ball is changed to 13 mm.

[0067] Example 9

[0068] The only difference between this embodiment and embodiment 1 is that the diameter of the porcelain ball is changed to 4 mm.

[0069] Example 10

[0070] The only difference between this embodiment and embodiment 1 is that the diameter of the heavy porcelain ball is changed to 5 mm.

[0071] Embodiment 11

[0072] The only difference between this embodiment and embodiment 1 is that the diameter of the heavy porcelain ball is changed to 9 mm.

[0073] Example 12

[0074] The only difference between this embodiment and embodiment 1 is that the diameter of the heavy porcelain ball is changed to 7 mm.

[0075] Example 13

[0076] The only difference between this embodiment and embodiment 1 is that the specifications of the hanging basket are changed to a diameter of 200 mm and a height of 9 mm.

[0077] Embodiment 14

[0078] The only difference between this embodiment and embodiment 1 is that the specifications of the hanging basket are changed to a diameter of 300 mm and a height of 9 mm.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is that the diameter of the heavy porcelain ball is changed to 15 mm.

[0081] Comparative Example 2

[0082] This comparative example is different from Example 1 in that no heavy porcelain balls are used.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 1 is that heavy porcelain balls and movable glands are not used.

[0085] Comparative Example 4

[0086] Compared with Example 1, this comparative example does not use a hanging basket, a porcelain ball and a supporting grid.

[0087] Comparative Example 5

[0088] Compared with Example 1, the hanging basket used in this comparative example has a diameter of 100 mm and a height of 150 mm.

[0089] Experimental Example 1

[0090] The catalyst after the reaction is completed is recovered, and the broken catalyst and the catalyst with a complete shape are distinguished. The catalyst with a complete shape is weighed and the experimental data is recorded.

[0091] Recovery rate = mass of intact catalyst / mass of catalyst in initial state × 100%

[0092] Table 1 Recovery rates of the embodiments and comparative examples

[0093] Group Recovery rate (%) Example 1 99 Example 2 99 Example 3 93 Example 4 92 Example 5 95 Example 6 91 Example 7 93 Example 8 92 Example 9 94 Example 10 93 Embodiment 11 92 Example 12 95 Example 13 96 Embodiment 14 94 Comparative Example 1 66 Comparative Example 2 59 Comparative Example 3 58 Comparative Example 4 59 Comparative Example 5 73

[0094] As can be seen from the experimental data of the embodiments and comparative examples, when the dense phase packing method is used to cooperate with the supporting device and the pressing device at the same time, the catalyst can be evenly arranged, ensuring that the catalyst does not vibrate and break with the entry or departure of the reactants, ensuring the integrity of the catalyst and increasing the service life of the catalyst. Therefore, when the pressing device is not used, although the catalyst can be guaranteed to be tightly and evenly arranged when it is just filled in, the bottom-up movement of the reactants during the reaction process can cause the catalyst to vibrate strongly, eventually causing the catalyst to break. Similarly, if the supporting device is not set at the bottom of the catalyst bed, the common displacement of the mobile gland and the catalyst will be caused, so that the mobile gland cannot be pressed, causing the catalyst to break.

[0095] In the actual operation process, the diameter of the porcelain balls and the heavy porcelain balls, as well as the position of the porcelain balls (i.e., loaded in the hanging basket or loaded between the catalyst bed and the support grid) should be selected according to the physical and chemical properties of the reactants. When a reactant with a larger viscosity is selected, the porcelain balls should be loaded between the catalyst bed and the support grid; and when the viscosity of the reactant is smaller, the porcelain balls should be loaded in the hanging basket. This loading method can play a better supporting role. At the same time, the selection of heavy porcelain balls needs to be selected according to the flow rate of the reactants. When the flow rate of the reactants is higher, the selected heavy porcelain balls have a larger mass; and when the flow rate of the reactants is lower, the mass of the heavy porcelain balls should be smaller. However, the above-mentioned scheme has a better supporting effect on the catalyst bed in the technical scheme selected by the present invention, and can effectively improve the recovery efficiency of the catalyst.

[0096] 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 replace some or all of the technical features therein with equivalents. 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. An upward fixed bed reaction system, characterized in that: include: A reactor, wherein a catalyst bed is arranged in the reactor, a pressing device is arranged on the upper part of the catalyst bed, and a supporting device is arranged on the lower part of the catalyst bed; The clamping device is composed of a gland grid and a movable gland, wherein the movable gland covers the upper surface of the catalyst bed, and the gland grid is located on the upper part of the movable gland; The supporting device is composed of a rectifier, a supporting grid and a hanging basket. The rectifier is arranged at the lower part of the catalyst bed, the supporting grid is located at the lower part of the rectifier, and the hanging basket is located at the lower part of the supporting grid.

2. The upward fixed bed reaction system according to claim 1, characterized in that: Ceramic balls with a diameter of 2mm-13mm are loaded at any position between the hanging basket or the supporting grid and the rectifier, and a micro-interface unit is arranged at the lower part of the hanging basket.

3. The upward fixed bed reaction system according to claim 2, characterized in that:

3. The diameter of the porcelain ball is 4mm-5mm.

4. The upward fixed bed reaction system according to claim 1, characterized in that: The ratio of the diameter to the height of the hanging basket is (20-30):(9-15).

5. The upward fixed bed reaction system according to claim 4, characterized in that: The ratio of the diameter to the height is 21:

10.

6. The upward fixed bed reaction system according to claim 1, characterized in that: The gland grid is fixed on the upper surface of the catalyst bed, and holes are evenly arranged on the gland grid, and the hole diameter is 1mm-10mm.

7. The upward fixed bed reaction system according to claim 6, characterized in that: The diameter of the pores is 1 mm to 3 mm.

8. The upward fixed bed reaction system according to claim 1, characterized in that: Both ends of the movable gland are movably connected to the inner wall of the reactor, and holes are evenly arranged on the movable gland, and the hole diameter is 1mm-10mm.

9. The upward fixed bed reaction system according to claim 1, characterized in that: A heavy porcelain ball is arranged between the pressure cover grid and the movable pressure cover, there is no gap between the pressure cover grid and the heavy porcelain ball, and the diameter of the heavy porcelain ball is 5mm-9mm.

10. The upward fixed bed reaction system according to claim 1, characterized in that: The support grid is fixed to the lower part of the rectifier, and holes are evenly arranged on the support grid, and the hole diameter is 1mm-10mm.

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