A shell-and-tube gas-liquid homogeneous reactor

Abstract

The present invention provides a shell-and-tube gas-liquid homogeneous reactor, which includes an upper head, a reaction section, a homogeneous distribution section and a lower head. The upper head is provided with a discharge port, the lower head is provided with a liquid-phase feed port, the reaction section is provided with a plurality of reaction tubes, the homogeneous distribution section is provided with a plurality of micron-level distribution tubes, and the micron-level distribution tubes are in one-to-one correspondence and communication with the reaction tubes. A gas-phase feed port is provided on the side wall of the homogeneous distribution section between the middle tube sheet and the lower tube sheet. By arranging the homogeneous distribution section, the shell-and-tube gas-liquid homogeneous reactor of the present invention solves the problem that the gas-phase material cannot be uniformly mixed with the liquid-phase material in all the tubes of the reactor, and can enable the gas-phase material and the liquid-phase material to fully contact and flow in all the tubes with an approximately equal proportion composition. There are no phenomena such as gas resistance, deviation flow and bubbly flow that damage the reaction. The gas-phase material and the liquid-phase material are uniformly mixed in each tube, and the conversion rate of the liquid-phase material is improved.

Description

Technical Field

[0001] The present invention belongs to the field of reactors, and in particular relates to a shell-and-tube gas-liquid homogeneous reactor. Background Art

[0002] For the existing reactions of liquid-phase materials and gas-phase materials (such as hydrogenation reactions, oxidation reactions, hydroformylation aldehyde hydrogenation reactions, etc.), since the gas-phase materials are easily subject to external environmental factors such as resistance, temperature, and flow pattern and exhibit irregular dispersion characteristics, it is difficult to form a uniform distribution with the liquid-phase materials in all the tubes of the reactor, resulting in a large difference in the reaction effects in different tubes of the same reactor, easily forming hot spots and the generation of heavy components, affecting the raw material conversion rate and the selectivity of the target product, and the overall reaction effect is not ideal. Only measures of reacting gas-phase materials with gas-phase materials can be taken to solve the above problems.

[0003] At this time, all the liquid-phase materials need to be vaporized into gas-phase materials, which not only greatly increases the energy consumption, but also the catalyst volume space velocity of the gas-phase reaction is generally small (calculated based on the reaction raw materials), resulting in the catalyst loading amount and the volume of the reactor being much higher than those of the liquid-phase reaction, increasing the investment cost significantly, and restricting the processing capacity. At the same time, since some liquid materials cannot be vaporized at the corresponding reaction temperature and pressure, a fixed-bed large recycle ratio reaction system has to be adopted, resulting in large operation investment and high energy consumption.

[0004] Generally, the commonly used micron-level distribution tubes have gas-phase materials inside and liquid-phase materials outside. Usually, a single distribution tube is set at the place where the micron-level distribution tubes are used. The gas-phase materials diffuse from inside the tube to the liquid-phase materials outside the tube. This distribution method is often used in butyraldehyde oxidation reactors. This distribution type is relatively uniform in the surface area of the distribution tube, but large gas bubbles are likely to re-form in other liquid-phase material areas far from the distribution tube, resulting in poor reaction effects.

[0005] How to take effective means to achieve the uniform distribution of liquid-phase materials and gas-phase materials in all the tubes of the reactor is a technical difficulty urgently to be solved in this field. Summary of the Invention

[0006] In view of this, the present invention aims to provide a shell-and-tube gas-liquid homogeneous reactor to promote the uniform mixing of gas-phase materials and liquid-phase materials, improve the conversion rate of liquid-phase materials, and reduce the volume of the reactor.

[0007] To achieve the above object, the technical solution of the present invention is realized as follows:

[0008] A shell-and-tube gas-liquid homogeneous reactor includes a upper head, a reaction section, a homogeneous distribution section, and a lower head that are connected in sequence from top to bottom. An outlet is provided at the upper end of the upper head, and a liquid-phase inlet is provided at the lower end of the lower head.

[0009] The upper end of the reaction section is fixedly connected with an upper tube sheet, a middle tube sheet is fixedly arranged between the reaction section and the homogeneous distribution section, and the lower end of the homogeneous distribution section is fixedly connected with a lower tube sheet. A plurality of reaction tubes are arranged between the upper tube sheet and the middle tube sheet. The upper ends of the reaction tubes are communicated with the upper head. A plurality of micron-level distribution tubes are arranged between the middle tube sheet and the lower tube sheet. The upper ends of the micron-level distribution tubes are correspondingly communicated with the lower ends of the reaction tubes one by one. The communication modes include but are not limited to forms such as threaded connection, welding, and flange connection. The lower ends of the micron-level distribution tubes are communicated with the lower head. A gas-phase feed port is arranged on the side wall of the homogeneous distribution section between the middle tube sheet and the lower tube sheet. The liquid-phase material enters the reactor from the liquid-phase feed port and enters the micron-level distribution tubes upward. The gas-phase material enters the reactor from the gas-phase feed port and passes through the micropores on the side wall of the micron-level distribution tubes in the homogeneous distribution section and enters the micron-level distribution tubes, where it is uniformly mixed with the liquid-phase material and then jointly enters the reaction tubes upward. A catalyst is installed in the reaction tubes. Under the action of the catalyst, the liquid-phase material reacts with the gas-phase material, and the reaction product is discharged through the discharge port on the upper head.

[0010] The inventive concept of this application lies in: by arranging a homogeneous distribution section before the reaction section and using a certain number of micron-level distribution tubes, the micron-level form of the gas-phase material is mixed with the liquid-phase material, shortening the time for the formed microbubbles to reach the catalyst bed layer, fully ensuring the formation and distribution effect of the microbubbles, and increasing the interfacial area. At the same time, the number of micron-level distribution tubes is the same as that of the reaction tubes, ensuring that the ratio of the gas-phase material to the liquid-phase material in each reaction tube is highly consistent, meeting the key requirement of uniform distribution with the liquid-phase material. At the same time, the circulation amount and reaction pressure of the gas-phase reaction material are reduced, the formation of reaction hot spots is avoided, the raw material conversion rate and the selectivity of the target product are improved, the reaction space velocity is also increased, and the catalyst filling amount and the reactor manufacturing cost are reduced.

[0011] Further, the outer diameter of the reaction tube is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 500 - 20000 mm, and the number is 6 - 10000.

[0012] Further, a spring support is arranged in the reaction tube. When the catalyst in the reaction tube is a solid catalyst, it can play a supporting role. Compared with inert porcelain balls, the spring support can also play a function of preventing eddy current of the material, which is not possessed by porcelain balls. When the liquid-phase catalyst is in the reaction tube, the spring support does not need to be set; preferably, the height of the spring support is 50 - 500 mm.

[0013] Further, the outer diameter of the micron-level distribution tube is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 100 - 5000 mm, the pore diameter is 5 - 1000 μm, and the number is 6 - 10000.

[0014] Further, a heat exchange medium inlet is provided on the side wall at the lower end of the reaction section between the upper tube sheet and the middle tube sheet, and a heat exchange medium outlet is provided at the upper end. The heat exchange medium enters the reaction section through the heat exchange medium inlet and is discharged from the heat exchange medium outlet. For exothermic reactions, the heat exchange medium is used to extract heat, and for endothermic reactions, the heat exchange medium is used to supply heat, enabling flexible control of the reaction temperature.

[0015] Further, a thermometer is also included. The thermometer is fixedly connected to the upper head, and the lower end of the thermometer passes through the upper head and extends into the reaction tubes to monitor whether the temperature in the reaction tubes is within an appropriate range.

[0016] Further, the operating pressure of the tubular gas-liquid homogeneous reactor is -0.1 to 20 MPaG, and the operating temperature is -20 to 600 °C.

[0017] Further, the micron-level distribution tube includes, but is not limited to, one of a metal sintered tube, a metal wire mesh sintered tube, a polytetrafluoroethylene microporous tube, and a ceramic microporous tube.

[0018] Compared with the prior art, the tubular gas-liquid homogeneous reactor of the present invention has the following advantages:

[0019] (1) By providing a homogeneous distribution section, the tubular gas-liquid homogeneous reactor of the present invention solves the problem that the gas-phase material cannot be uniformly mixed with the liquid-phase material in all the reaction tubes of the reactor, enabling the gas-phase material and the liquid-phase material to fully contact and flow in all the reaction tubes with an approximately equal proportion composition. There are no phenomena such as gas resistance, deviation flow, and bubbly flow that damage the reaction. The gas-phase material and the liquid-phase material are uniformly mixed in each reaction tube, and the conversion rate of the liquid-phase material is increased by 10% to 500%.

[0020] (2) The tubular gas-liquid homogeneous reactor of the present invention can participate in the reaction without gasifying the liquid-phase material into a gas-phase material, and the volume of the catalyst and the reactor can be correspondingly reduced. Taking the production of isopropanol by acetone hydrogenation at 50,000 tons / year as an example, the size of the reactor for the gas-phase reaction is φ2000×16000 mm. After using this reactor, the size of the reactor for the liquid-phase reaction is φ1000×9000 mm, and the reactor volume is reduced by about 86%, saving investment and floor space. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic structural diagram of the tubular gas-liquid homogeneous reactor according to the embodiment of the present invention;

[0023] Figure 2Schematic diagram of material distribution and flow direction of the micron-level distribution tube according to the embodiments of the present invention.

[0024] Explanation of reference numerals:

[0025] 1. Upper head; 2. Reaction section; 3. Reaction tubes; 4. Spring support; 5. Middle tube sheet; 6. Homogeneous distribution section; 7. Micron-level distribution tube; 8. Lower head; 9. Thermometer; 10. Upper tube sheet; 11. Lower tube sheet; 12. Flange. Detailed implementation manners

[0026] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0027] The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0028] The shell-and-tube gas-liquid homogeneous reactor of the present invention includes an upper head 1, a reaction section 2, a homogeneous distribution section 6 and a lower head 8 that are connected in sequence from top to bottom. The upper head 1, the reaction section 2 and the homogeneous distribution section 6 are all welded. The homogeneous distribution section 6 and the lower head 8 are connected by a flange 12. An outlet is provided at the upper end of the upper head 1, and a liquid-phase inlet is provided at the lower end of the lower head 8. It further includes a thermometer 9, and the thermometer 9 is fixedly connected to the upper head 1 and the lower end of the thermometer 9 passes through the upper head 1 and extends into the reaction tubes 3.

[0029] An upper tube sheet 10 is fixedly connected to the upper end of the reaction section 2, a middle tube sheet 5 is fixedly arranged between the reaction section 2 and the homogeneous distribution section 6, a lower tube sheet 11 is fixedly connected to the lower end of the homogeneous distribution section 6. A plurality of reaction tubes 3 are arranged between the upper tube sheet 10 and the middle tube sheet 5. The upper ends of the reaction tubes 3 are communicated with the upper head 1. A plurality of micron-level distribution tubes 7 are arranged between the middle tube sheet 5 and the lower tube sheet 11. The micron-level distribution tubes 7 are metal sintered tubes. The upper ends of the micron-level distribution tubes 7 are correspondingly communicated with the lower ends of the reaction tubes 3 one by one, and the communication method is welding. The lower ends of the micron-level distribution tubes 7 are communicated with the lower head 8. A gas-phase inlet is provided on the side wall of the homogeneous distribution section 6 between the middle tube sheet 5 and the lower tube sheet 11.

[0030] The outer diameter of the reaction tubes 3 is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 500 - 20000 mm, and the number is 6 - 10000.

[0031] A spring support 4 is arranged in the reaction tubes 3, and the height of the spring support 4 is 50 - 500 mm.

[0032] The outer diameter of the micron-level distribution tubes 7 is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 100 - 5000 mm, the pore diameter is 5 - 1000 μm, and the number is 6 - 10000.

[0033] A heat exchange medium inlet is provided on the lower side wall of the lower end of the reaction section 2 between the upper tube sheet 10 and the middle tube sheet 5, and a heat exchange medium outlet is provided at the upper end. The heat exchange medium enters the reaction section 2 from the heat exchange medium inlet and is discharged from the heat exchange medium outlet.

[0034] Example 1

[0035] (1) The maleic anhydride solution (maleic anhydride concentration is 3% - 30%, and the rest is succinic anhydride) is sent to the liquid-phase feed port at the bottom of the lower head 8 of the reactor through an external pump, and hydrogen is sent to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tubes 3 are filled with solid catalyst.

[0036] (2) Control the feed rate of the maleic anhydride solution to be 5.0 t / h, the feed rate of hydrogen to be 20 Nm 3 / h. Control the flow rate of the liquid-phase material in the reaction tubes 3 to be 0.8 m / s, control the reaction pressure to be 1.0 MPaG, and the outlet pressure of the hydrogen compressor to be 1.5 MPaG. At this time, the pressure difference between the inside and outside of the micro-scale distribution tube 7 is about 0.5 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0037] (3) Analyze and test the reaction product. The conversion rate of the raw material maleic anhydride is about 98.0%, and the product yield is about 97.1%.

[0038] Example 2

[0039] (1) The maleic anhydride solution (maleic anhydride concentration is 3% - 30%, and the rest is succinic anhydride) is sent to the liquid-phase feed port at the bottom of the lower head 8 of the reactor through an external pump, and hydrogen is sent to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tubes 3 are filled with solid catalyst.

[0040] (2) Control the feed rate of the maleic anhydride solution to be 5.0 t / h, the feed rate of hydrogen to be 20 Nm 3 / h. Control the flow rate of the liquid-phase material in the reaction tubes 3 to be 0.8 m / s, control the reaction pressure to be 1.0 MPaG, and the outlet pressure of the hydrogen compressor to be 2.0 MPaG. At this time, the pressure difference between the inside and outside of the micro-scale distribution tube 7 is about 1.0 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0041] (3) Analyze and test the reaction product. The conversion rate of the raw material maleic anhydride is about 98.7%, and the product yield is about 97.9%.

[0042] Example 3

[0043] (1) The maleic anhydride solution (maleic anhydride concentration is 3% - 30%, and the rest is succinic anhydride) is sent to the liquid-phase feed port at the bottom of the lower head 8 of the reactor through an external pump, and hydrogen is sent to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tubes 3 are filled with solid catalyst.

[0044] (2) Control the feed rate of maleic anhydride solution to be 5.0 t / h and the feed rate of hydrogen to be 20 Nm 3 / h. Control the flow rate of the liquid-phase material in the tube bundle to be 0.8 m / s, control the reaction pressure to be 1.0 MPaG, and the outlet pressure of the hydrogen compressor to be 3.0 MPaG. At this time, the internal and external pressure difference of the micron-level distribution tube 7 is about 2.0 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0045] (3) Analyze and test the reaction product. The conversion rate of the raw material maleic anhydride is about 99.7%, and the product yield is about 99.1%.

[0046] Example 4

[0047] (1) Send isobutyraldehyde to the bottom liquid-phase feed port of the lower head 8 of the reactor through an external pump, and send air to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tube bundle 3 is filled with a solid catalyst.

[0048] (2) Control the feed rate of isobutyraldehyde to be 2.0 t / h and the feed rate of air to be 150 Nm 3 / h. Control the flow rate of the liquid-phase material in the tube bundle to be 1.1 m / s, control the reaction pressure to be 0.2 MPaG, and the outlet pressure of the air compressor to be 0.3 MPaG. At this time, the internal and external pressure difference of the micron-level distribution tube 77 is about 0.1 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0049] (3) Analyze and test the reaction product. The conversion rate of the raw material isobutyraldehyde is about 95.0%, and the product yield is about 93.6%.

[0050] Example 5

[0051] (1) Send isobutyraldehyde to the bottom liquid-phase feed port of the lower head 8 of the reactor through an external pump, and send air to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tube bundle 3 is filled with a solid catalyst.

[0052] (2) Control the feed rate of isobutyraldehyde to be 2.0 t / h and the feed rate of air to be 150 Nm 3 / h. Control the flow rate of the liquid-phase material in the tube bundle to be 1.1 m / s, control the reaction pressure to be 0.2 MPaG, and the outlet pressure of the air compressor to be 0.4 MPaG. At this time, the internal and external pressure difference of the micron-level distribution tube 77 is about 0.2 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0053] (3) Analyze and test the reaction product. The conversion rate of the raw material isobutyraldehyde is about 95.6%, and the product yield is about 94.7%.

[0054] Example 6

[0055] (1) Send isobutyraldehyde to the bottom liquid-phase feed port of the lower head 8 of the reactor through an external pump, and send air to the gas-phase feed port of the homogeneous distribution section 6 through an external compressor. The reaction tubes 3 are filled with solid catalysts.

[0056] (2) Control the isobutyraldehyde feed rate to be 2.0 t / h and the air feed rate to be 150 Nm 3 / h. Control the liquid-phase material flow rate in the tubes to be 1.1 m / s, control the reaction pressure to be 0.2 MPaG, and the outlet pressure of the air compressor to be 0.6 MPaG. At this time, the pressure difference inside and outside the micron-level distribution tube 77 is about 0.4 MPaG, and the reaction product flows out from the top discharge port of the upper head 1.

[0057] (3) Analyze and test the reaction product. The conversion rate of the raw material isobutyraldehyde is about 96.3%, and the product yield is about 95.5%.

Claims

1. A shell-and-tube gas-liquid homogeneous reactor, characterized in that: It includes an upper head, a reaction section, a homogeneous distribution section and a lower head. An outlet is provided at the upper end of the upper head, and a liquid-phase feed inlet is provided at the lower end of the lower head. An upper tube sheet is fixedly connected to the upper end of the reaction section. A middle tube sheet is fixedly arranged between the reaction section and the homogeneous distribution section. A lower tube sheet is fixedly connected to the lower end of the homogeneous distribution section. A plurality of reaction tubes are arranged between the upper tube sheet and the middle tube sheet. A plurality of micron-level distribution tubes are arranged between the middle tube sheet and the lower tube sheet. The micron-level distribution tubes are in one-to-one correspondence and communication with the reaction tubes. A gas-phase feed inlet is provided on the side wall of the homogeneous distribution section between the middle tube sheet and the lower tube sheet. The micron-level distribution tube is one of a metal sintered tube, a metal wire mesh sintered tube, a polytetrafluoroethylene microporous tube, and a ceramic microporous tube. Catalysts are installed in the reaction tubes.

2. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: The outer diameter of the reaction tube is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 500 - 20000 mm, and the number is 6 - 10000.

3. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: A spring support is provided in the reaction tube; preferably, the height of the spring support is 50 - 500 mm.

4. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: The outer diameter of the micron-level distribution tube is 10 - 150 mm, the wall thickness is 1 - 8 mm, the length is 100 - 5000 mm, the pore diameter is 5 - 1000 µm, and the number is 6 - 10000.

5. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: A heat exchange medium inlet is provided on the side wall at the lower end of the reaction section between the upper tube sheet and the middle tube sheet, and a heat exchange medium outlet is provided at the upper end.

6. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: It further includes a thermometer. The thermometer is fixedly connected to the upper head and the lower end of the thermometer passes through the upper head and extends into the reaction tube.

7. The shell-and-tube gas-liquid homogeneous reactor according to claim 1, characterized in that: The working pressure of the shell-and-tube gas-liquid homogeneous reactor is -0.1 - 20 MPaG, and the working temperature is -20 - 600 °C.

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