CN110652951B - A photocatalytic tubular reactor - Google Patents

Abstract

The invention relates to a photocatalysis tubular reactor, which is characterized in that: the quartz inner cylinder (15) is sleeved outside the quartz inner cylinder (15), and the metal outer cylinder (7) and the quartz inner cylinder (15) are of a split structure; light guide cylinders (9) are arranged on the left side and the right side of the metal outer cylinder (7), light guide columns (10) are arranged in the light guide cylinders, and light passes through the quartz inner cylinder (15) through the light guide columns (10); the upper end and the lower end of the metal outer cylinder (7) are respectively provided with an upper port joint (3-1) and a lower port joint (3-2); the reaction gas and the reaction liquid enter the reactor from the upper port joint (3-1) and flow out from the lower port joint (3-2) after reaction. The high-temperature high-pressure photo-catalytic tubular reactor provided by the invention has the advantages that quartz is taken as a catalyst carrier, left and right two-way illumination is performed, and the long-term use pressure can reach 10MPa at the high temperature of 800 ℃. Breaks through the limit that the photocatalysis tubular reactor can only perform normal pressure experiments, and expands the research range of the photocatalysis field.

Description

A photocatalytic tubular reactor

Technical Field

The present invention relates to the field of chemical reaction devices, and in particular to a tubular reactor used in the fields of photocatalysis, gas-solid phase catalysis, carbon dioxide reduction, photothermal catalysis, photocatalytic synthesis, photocatalytic degradation of organic matter, catalytic degradation of harmful gases (VOCs, NOx, SOx, acetaldehyde, formaldehyde, etc.), thermal catalysis, photochemistry, etc.

Background Art

Photochemical and photocatalytic oxidation are currently the most studied advanced oxidation technologies. The so-called photocatalytic reaction is a chemical reaction carried out under the action of light. Photochemical reactions require molecules to absorb electromagnetic radiation of a specific wavelength, which will be stimulated to produce an excited state of the molecules, and then chemical reactions will occur to generate new substances, or become intermediate chemical products that trigger thermal reactions. The activation energy of photochemical reactions comes from the energy of photons. Photoelectric conversion and photochemical conversion have always been very active research fields in the use of solar energy.

Photocatalytic oxidation technology combines oxidants such as O ₂ and H ₂ O ₂ with light radiation by using photoexcited oxidation. Photodegradation usually refers to the gradual oxidation of organic matter into low molecular intermediates under the action of light, and finally generates CO ₂ , H ₂ O and other ions such as NO ₃ ^- , PO ₄ ^3- , Cl ^- , etc. Photodegradation of organic matter can be divided into direct photodegradation and indirect photodegradation. The former refers to the further chemical reaction after the organic molecules absorb light energy. The latter is that certain substances in the surrounding environment absorb light energy into an excited state, and then induce a series of organic pollution reactions. Indirect photodegradation is more important for organic pollutants that are difficult to biodegrade in the environment. The ways to degrade pollutants using photochemical reactions include photochemical oxidation processes without catalysts and with catalysts. The former mostly uses oxygen and hydrogen peroxide as oxidants to oxidize and decompose pollutants under the irradiation of ultraviolet light; the latter is also called photocatalytic oxidation, which can generally be divided into two types: homogeneous and heterogeneous catalysis. In homogeneous photocatalytic degradation, it is more common to use Fe2 ⁺ or Fe3 ⁺ _{and H2O2} as media, and produce ·OH through the photo-Fenton reaction to degrade pollutants. In heterogeneous photocatalytic degradation, it is more common to add a certain amount of photosensitive semiconductor material to the pollution system, and combine it with a certain amount of light radiation, so that the photosensitive semiconductor is excited to produce electron-hole pairs under the irradiation of light, and the dissolved oxygen, water molecules, etc. adsorbed on the semiconductor react with the electron-holes to produce ·OH and other highly oxidizing free radicals, and then the pollutants are completely or nearly completely mineralized through the hydroxyl addition, substitution, electron transfer, etc. between the pollutants.

The photochemical tubular reactors commonly used in laboratories are all single-tube reactors made of high borosilicate glass or quartz glass. Most of the existing single-tube reactors are straight quartz tubes. Due to the limitation of the reactor material, there are often safety issues such as gas leakage caused by reactor breakage during the experiment. The inability to withstand pressure determines that the quartz reactor can only be used for normal pressure experiments, and it is impossible to conduct photocatalytic research in the high-pressure field. Although the all-metal reactor can meet the experimental requirements of high temperature and high pressure, it is not light-transmitting and cannot be used for photocatalytic experiments. At the same time, metal as a catalyst carrier may cause catalyst contamination or participate in catalytic reactions, affecting experimental data. These defects greatly limit the scope of research in the field of photocatalysis.

To load the catalyst into the quartz single tube reactor, you must first fix the temperature measuring thermocouple in the center of the reactor, then fill the bottom of the reaction zone with inert materials such as quartz sand as support, and then put the weighed catalyst in from the top, and make the bed uniform by knocking on the tube wall. It is very troublesome to load the catalyst into this reactor. Putting it in from a high place will cause the catalyst to hang on the wall, the catalyst is unevenly distributed, difficult to control, and the catalyst utilization rate is low; the repeatability of multiple experiments is poor. After the experiment, the residual material in the reaction tube is difficult to clean, and the catalyst residue is easy to block the gas path and contaminate the new catalyst.

Most of the external pipes connected to the reactor are stainless steel pipes. The connection between the quartz reactor and the stainless steel pipe requires a complex sealing structure, which is extremely inconvenient to install and replace. Therefore, the style and structure of the quartz reactor cannot be changed at will. At the same time, the quartz reactor also has the problem of inconvenient vertical fixing.

The original light source's light holes are all located in the middle of the heating furnace, with light passing through the front and back. Due to the existence of the light holes, there is no furnace wire heating in the middle of the furnace, and there is no insulation material at the light holes, so the heat dissipation is fast. This results in a large temperature gradient in the reaction zone of the reactor.

In view of the above-mentioned defects of the existing photocatalytic quartz reactor, the inventors have actively conducted research and innovation in order to create a new type of high-temperature and high-pressure photocatalytic tubular reactor to make it more practical.

Summary of the invention

The present invention provides a photocatalytic tubular reactor, and the technical problems to be solved are as follows: (1) Solving the safety problem that the existing reactor is easy to break and cause gas leakage during the experiment; (2) Solving the need that the existing tubular reactor can only perform normal pressure experiments and cannot perform high pressure tests; (3) Solving the problem that the original catalyst is dropped from a high place, causing the catalyst to hang on the wall, uneven distribution, and difficult to control; (4) Solving the problem that the residual material in the reaction tube is difficult to clean, and the gas path is blocked and the new catalyst is polluted due to the catalyst residue; (5) Solving the problem of inconvenient connection between the quartz reactor and the external pipeline stainless steel pipeline; (6) Solving the problem of inconvenient installation and replacement of the reactor; (7) Solving the problem of inconvenient vertical fixation of the quartz reactor; (8) Solving the problem of large temperature gradient in the reaction zone of the quartz reactor.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

(1) A photocatalytic tubular reactor comprises a metal outer tube and a quartz inner tube. The metal outer tube and the quartz inner tube are separate structures. The metal outer tube is sleeved outside the quartz inner tube, and the quartz inner tube can be taken out separately. Light guide tubes are arranged on the left and right sides of the metal outer tube. Light guide columns are arranged in the light guide tubes, and light passes through the quartz inner tube through the light guide columns. An upper port joint and a lower port joint are respectively arranged at the upper and lower ends of the metal outer tube. The reaction gas and the reaction liquid enter the reactor from the upper port joint and flow out from the lower port joint after the reaction.

(2) According to the photocatalytic tubular reactor described in (1), the quartz inner tube is provided with a flat-mouth quartz reactor, a straight tube sand plate reactor or a sloped quartz sand plate reactor (for the specific structure of the quartz inner tube with a sloped quartz sand plate reactor, please refer to the prior application 201920970907.9 by the patent applicant of the present invention), which is used to fill the catalyst.

(3) According to the photocatalytic tubular reactor described in (1) or (2), the light guide tubes on the left and right sides of the metal outer tube form a cross-shaped structure; and the light guide column is a T-shaped structure.

(4) According to the photocatalytic tubular reactor described in any one of (1) to (3), the metal outer tube is provided with fixed wings (8).

(5) According to the photocatalytic tubular reactor described in any one of (1) to (4), the upper port joint is sealed with an SAE split flange (SAE is the abbreviation of the American Society of Automotive Engineers, and the flange manufactured according to SAE standards is called an SAE flange), and the lower port joint is sealed with an SAE split flange; the light guide tubes on the left and right sides are sealed with flanges; and the external connecting pipeline adopts a ferrule structure.

(6) According to the photocatalytic tubular reactor described in any one of (1) to (5), the photocatalytic tubular reactor is connected to the heating furnace through the fixed wing clamp, and the light guide tube and the clamping flange are located in the heating furnace.

(7) According to the photocatalytic tubular reactor described in any one of (1) to (6), the upper port joint is provided with a liquid injection port and an air inlet, and the liquid injection port and the air inlet are both metal ferrule interfaces; the lower port joint is provided with an exhaust port, a temperature control port and a thermocouple sleeve, and the exhaust port and the temperature control port are both metal ferrule interfaces.

(8) In the photocatalytic tubular reactor according to any one of items (1) to (7), a thermocouple sleeve is placed in the temperature control port, the thermocouple sleeve is a metal blind tube with one end sealed, and the thermocouple sleeve and the temperature control port are sealed and connected by a metal ferrule; a temperature measuring thermocouple is placed in the thermocouple sleeve.

(9) According to the photocatalytic tubular reactor described in any one of (1) to (8), two annular grooves are provided on the outer portion of the lower port joint, and the annular grooves cooperate with the sealing ring; and a standard straight thread is reserved inside the lower port joint.

(10) According to the photocatalytic tubular reactor described in any one of (1) to (9), the metal outer tube is a seamless tube, and the seamless tube is made of a metal material resistant to high temperature and high pressure; the light guide tube is made of a metal material resistant to high temperature and high pressure, and is welded to the metal outer tube.

(11) In the photocatalytic tubular reactor according to any one of items (1) to (10), the light guide column is a T-shaped structure, integrally formed, and made of a light-transmitting material such as quartz or sapphire.

(12) According to the photocatalytic tubular reactor described in any one of (1) to (11), the light guide tube and the light guide column are sealed and connected by a flange structure, and the sealed connection structure includes a welding flange, a high-temperature gasket, a copper ring and a clamping flange.

(13) In the photocatalytic tubular reactor according to any one of (1) to (12), the quartz inner tube is installed on the port joint, and the port joint is provided with an annular groove, and a sealing ring is provided in the groove.

(14) According to the photocatalytic tubular reactor described in any one of (1) to (6), the heating furnace is an open furnace, and the cross-shaped groove matching the reactor is located on the opening plane of the heating furnace; the heating furnace has three-stage temperature control, and the middle section is supplemented and adjusted by the upper and lower sections to ensure the length of the constant temperature zone.

The present invention provides a photocatalytic tubular reactor, which has the following beneficial technical effects:

1. The photocatalytic tubular reactor includes a metal outer cylinder and a quartz inner cylinder. The metal outer cylinder and the quartz inner cylinder are separate structures, and the metal outer cylinder is sleeved outside the quartz inner cylinder. The metal outer cylinder and the light guide cylinder are used to withstand the pressure difference between the inside and outside of the reactor during the experiment; while the quartz inner cylinder made of quartz material is used as a catalyst carrier, located inside the metal outer cylinder, and the pressure difference between the inside and outside is equal, and it does not bear pressure during the experiment. It solves the safety problems of the original pure quartz reactor, such as reactor fragmentation and gas leakage due to pressure fluctuations during the reaction.

The metal outer tube and the light guide tube are both made of seamless tubes resistant to high temperature and high pressure, and the two are reinforced and welded. The upper and lower ends of the metal outer tube are sealed with SAE split flanges to the port joints. The inside of the light guide tube and the light guide column are sealed with a flange structure, and the T-shaped structure of the light guide column facilitates the installation of high-temperature gasket seals. The above materials and structures determine that the reactor can use quartz as a catalyst carrier, bidirectional illumination on the left and right, and high temperature of 800°C, and the long-term use pressure can reach 10MPa. It solves the problem that the existing tubular reactor can only perform normal pressure experiments and cannot perform high pressure experiments. It expands the research scope in the field of photocatalysis. The catalyst is located on the quartz inner tube, and the transparent quartz inner tube does not affect the illumination, nor does it contact the metal outer tube to affect the experimental data.

2. The metal outer cylinder and the quartz inner cylinder are separate structures, and the quartz inner cylinder can be taken out separately. After the quartz inner cylinder is taken out, it is very convenient to load the catalyst, and the loading method, loading amount, loading thickness and uniformity can be accurately controlled. It solves the problem of the original catalyst hanging on the wall caused by the catalyst being put in from a high place, uneven distribution of the catalyst, poor control, and inconsistency in multiple experiments.

3. The upper port connector is provided with a liquid injection port and an air inlet, and the liquid injection port and the air inlet are metal ferrule interfaces. The lower port connector is provided with an exhaust port, a temperature control port and a thermocouple sleeve, and the exhaust port and the temperature control port are metal ferrule interfaces. A thermocouple sleeve is placed in the temperature control port, and the thermocouple sleeve is a metal blind tube with one end sealed. The thermocouple sleeve and the temperature control port are sealed and connected with a metal ferrule. The ferrule connection method is simple and convenient, and has high pressure resistance, which solves the problem of inconvenient connection between the quartz reactor and the external pipeline stainless steel pipeline.

4. The quartz sand plate on the quartz inner tube is located at the top of the quartz inner tube, which is convenient for cleaning the residual material on the sand plate. This solves the problem of gas path blocking and new catalyst contamination caused by catalyst residue.

5. There is an annular groove on the outside of the port connector, and a sealing ring is placed in the annular groove. Users can install different quartz inner cylinders according to their needs. The operation is simple and convenient, and the installation and removal of the quartz inner cylinder can be completed manually. Solve the problem of inconvenient installation and replacement of the reactor. At the same time, the port connector has a standard straight thread reserved inside to facilitate the connection of other styles of reactors.

6. A circular fixing wing is welded in the middle and upper part of the metal outer cylinder, and the fixing wing is stuck on the upper part of the heating furnace, which solves the problem of inconvenient vertical fixing of the reactor.

7. The heating furnace is an open furnace. The cross-shaped groove that matches the reactor is located on the opening plane of the furnace, which does not affect the heating of the furnace wire in the middle of the furnace; the light-transmitting parts such as the cross-shaped light guide tube, light guide column, welding flange, and clamping flange are all in the reactor, which minimizes heat dissipation; at the same time, the heating furnace has three-stage temperature control, and the middle section is supplemented and adjusted by the upper and lower sections, which solves the problem of large temperature gradient in the reaction zone of the reactor.

8. The light guide column in the light guide tube is made of light-transmitting materials such as quartz and sapphire, and is integrally formed. One end is connected to the light source through a flange, and the other end is connected to the quartz reactor, which reduces light loss and improves lighting efficiency.

The photocatalytic tubular reactor provided by the present invention can effectively combine the external pipeline, the light path and the heating furnace, and is an ideal reactor in a high-temperature and high-pressure photocatalytic environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG1 is a schematic diagram of a photocatalytic tubular reactor according to the present invention;

The numbers in the figure are: A is the reaction gas flow inlet, B is the quartz inner cylinder, C is the reaction gas flow outlet, and D is the light source.

FIG2 is a 2D diagram of a photocatalytic tubular reactor according to the present invention;

Numbers in the figure: 1-1. Liquid filling port, 1-2. Temperature control port, 2-1. Air inlet, 2-2. Air outlet, 3-1. Upper port joint, 3-2. Lower port joint, 4-1. SAE split flange, 4-2. SAE split flange, 5-1. Upper O-ring, 5-2. Lower O-ring, 6-1. Upper seat flange, 6-2. Lower seat flange, 7. Metal outer cylinder, 8. Fixed wing, 9. Light guide cylinder, 10. Light guide column, 11. Welding flange, 12. High temperature pad, 13. Copper ring, 14. Compression flange, 15. Quartz inner cylinder, 16. Sealing ring, 17. Thermocouple sleeve, 18. Thermocouple.

FIG3 is a practical structural diagram of a photocatalytic tubular reactor of the present invention;

The numbers in the figure are: 1-1. Liquid injection port, 1-2. Temperature control port, 2-1. Air inlet, 2-2. Air outlet, 3-1. Upper port joint, 3-2. Lower port joint, 4-1. SAE split flange, 4-2. SAE split flange, 5-1. Upper O-ring, 5-2. Lower O-ring, 6-1. Upper seat flange, 6-2. Lower seat flange, 7. Metal outer cylinder, 8. Fixed wing, 9. Light guide cylinder, 10. Light guide column, 11. Welding flange, 12. High temperature pad, 13. Copper ring, 14. Clamping flange, 15. Quartz inner cylinder, 16. Sealing ring, 17. Thermocouple sleeve, 18. Thermocouple, 19. Furnace tile, 20. Heating furnace.

FIG. 4 a is a schematic diagram of a flat tube reactor having a quartz inner cylinder.

FIG. 4 b is a schematic diagram of a reactor in which the inner quartz cylinder is a beveled quartz sand plate.

FIG. 4 c is a schematic diagram of a quartz inner tube in the form of a straight tube sand plate reactor.

DETAILED DESCRIPTION

Example:

Fig. 1 is a schematic diagram of the photocatalytic tubular reactor of the present invention, wherein A is the reaction gas inlet, B is the quartz inner tube, C is the reaction gas outlet, and D is the light source.

As shown in Figure 2, a photocatalytic tubular reactor includes a liquid injection port 1-1, a temperature control port 1-2, an air inlet 2-1, an air outlet 2-2, an upper port joint 3-1, a lower port joint 3-2, an SAE split flange 4-1, an SAE split flange 4-2, an upper O-ring 5-1, a lower O-ring 5-2, an upper seat flange 6-1, a lower seat flange 6-2, a metal outer tube 7, a fixed wing 8, a light guide tube 9, a light guide column 10, a welding flange 11, a high-temperature pad 12, a copper ring 13, a clamping flange 14, a quartz inner tube 15, a sealing ring 16, a thermocouple sleeve 17, a thermocouple 18, a furnace tile 19, and a heating furnace 20. The metal outer tube 7 and the quartz inner tube 15 are split structures. The metal outer tube 7 is sleeved outside the quartz inner tube 15, and the quartz inner tube 15 can be taken out separately; light guide tubes 9 are provided on the left and right sides of the metal outer tube 7, and light guide columns 10 are installed in the light guide tubes, and light passes through the quartz inner tube 15 through the light guide columns 10; the upper and lower ends of the metal outer tube 7 are respectively provided with upper port joints 3-1 and lower port joints 3-2; the reaction gas and reaction liquid enter the reactor from the upper port joint 3-1, and flow out from the lower port joint 3-2 after the reaction. The light guide tubes 9 on the left and right sides of the metal outer tube 7 form a cross-shaped structure; the light guide column 10 is a T-shaped structure. The metal outer tube 7 is provided with fixed wings 8. The light guide tube 9 and the light guide column 10 are sealed and connected by a flange structure, and the sealing connection structure includes a welding flange 11, a high temperature pad 12, a copper ring 13 and a clamping flange 14. The quartz inner tube 15 is installed on the port joint 3-2, and the port joint 3-2 is provided with an annular groove, and a sealing ring 16 is provided in the groove.

The quartz inner cylinder 15 is provided with a flat quartz reactor, a straight tube sand plate reactor or an inclined quartz sand plate reactor for filling the catalyst. The catalyst is located inside the quartz inner cylinder 15, and the transparent quartz inner cylinder 15 does not affect the illumination, nor does it contact with the metal outer cylinder 7 to affect the experimental data. The quartz inner cylinder 15 is of detachable design (the applicant of the present invention has previously applied for patents 201920970907.9 and 201920970911.5 in their entirety as the content of the present invention), and different styles can be adopted according to needs: (1) a flat tube reactor (as shown in FIG. 4 a), in which the catalyst loading thickness is small and can accept double-sided illumination; (2) an inclined quartz sand plate reactor (as shown in FIG. 4 b), for the specific structure of the quartz inner cylinder with an inclined quartz sand plate reactor, refer to the applicant of the present invention's prior application 201920970907.9, a quartz sand plate is provided on the inclined surface, and the quartz sand plate is inclined in design. A cofferdam is provided on the quartz sand plate to prevent the catalyst from sliding off; the top of the temperature measuring thermocouple contacts the bottom of the quartz sand plate, and the contact portion is exactly at the center of the reactor, which can accurately measure the center temperature of the reactor; (3) a straight tube sand plate reactor (as shown in FIG. 4 c), which is provided with a sand plate, has low cost and large catalyst loading capacity.

The upper port joint 3-1 is sealed with an SAE split flange 4-1, and the lower port joint 3-2 is sealed with an SAE split flange 4-2; the left and right light guide tubes 9 are sealed with flanges 14; and the external connection pipeline adopts a ferrule structure. The upper port joint 3-1 is provided with a liquid injection port 1-1 and an air inlet 2-1, and the liquid injection port 1-1 and the air inlet 2-1 are both metal ferrule interfaces; the lower port joint 3-2 is provided with an exhaust port 2-2, a temperature control port 1-2 and a thermocouple sleeve 17, and the exhaust port 2-2 and the temperature control port 1-2 are both metal ferrule interfaces. A thermocouple sleeve 17 is placed in the temperature control port 1-2, and the thermocouple sleeve 17 is a metal blind tube with one end sealed. The thermocouple sleeve 17 and the temperature control port 1-2 are sealed and connected with a metal ferrule; the temperature measuring thermocouple 18 is placed in the thermocouple sleeve 17.

The lower port connector 3-2 is provided with two annular grooves at the outer position, and the annular grooves cooperate with the sealing ring 16; the lower port connector 3-2 has a standard straight thread reserved inside. The metal outer tube 7 is a seamless tube, and the seamless tube is made of a metal material resistant to high temperature and high pressure; the light guide tube 9 is made of a metal material resistant to high temperature and high pressure, and is welded to the metal outer tube 7. The light guide column 10 is a T-shaped structure, integrally formed, and made of quartz or sapphire light-transmitting material.

As shown in FIG3 , the photocatalytic tubular reactor is connected to the heating furnace 20 through the fixed wing 8, and the light guide tube 9 and the clamping flange 14 are in the heating furnace 20. The heating furnace 20 is an open furnace, and the cross-shaped groove matched with the reactor is located on the opening plane of the heating furnace 20; the heating furnace 20 has three-stage temperature control, and the middle section is supplemented and adjusted by the upper and lower sections to ensure the length of the constant temperature zone. The reactor is vertically installed with the fixed wing 8 clamped on the upper part of the heating furnace 20. The heating furnace 20 is an open furnace, and the cross-shaped groove matched with the reactor is located on the opening plane of the furnace, which does not affect the heating of the furnace wire in the middle position of the furnace; the light-transmitting parts such as the cross-shaped light guide tube 9 and the clamping flange 14 are all in the heating furnace 20, which minimizes heat dissipation; at the same time, the heating furnace 20 has three-stage temperature control, and the middle section is supplemented and adjusted by the upper and lower sections to ensure the length of the constant temperature zone.

When using a photocatalytic tubular reactor, the light source directly irradiates the catalyst in the quartz inner tube 15 through the light guide column 10 in the light guide tube 9. The reaction gas enters from the air inlet 2-1 and is discharged from the exhaust port 2-2; the reaction liquid enters from the liquid injection port 1-1; the catalyst is spread on the top of the quartz inner tube 15. The reaction gas entering from above passes through the catalyst particles, and after the reaction, it flows out from the exhaust port 2-2. In this process, the catalyst can fully contact the reaction gas. At the same time, the quartz inner tube can fully receive the light from the side direction, the light is uniform, and the light area is large.

In the experiment, the quartz inner tube 15 is located inside the reactor, and there is no pressure difference between the inside and outside of the quartz inner tube 15, and there is no danger of fragmentation. The metal outer tube 7 and the light guide tube 9 are made of heat-resistant and high-pressure resistant metal materials, the left and right light holes are sealed with flanges, and the upper and lower port joints are sealed with SAE split flanges. This high-temperature and high-pressure photocatalytic tubular reactor can use quartz as a catalyst carrier, bidirectional illumination on the left and right, and high temperature of 800°C, and the pressure can reach 10MPa for a long time, breaking the limitation that photocatalytic tubular reactors can only perform normal pressure experiments, and expanding the research scope in the field of photocatalysis.

The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims (13)

1. A photocatalytic tubular reactor, characterized in that: it comprises a metal outer cylinder (7) and a quartz inner cylinder (15), the metal outer cylinder (7) and the quartz inner cylinder (15) are split structures, the metal outer cylinder (7) is sleeved outside the quartz inner cylinder (15); the left and right sides of the metal outer cylinder (7) are provided with light guide cylinders (9), and a light guide column (10) is installed in the light guide cylinder, the light guide cylinder (9) and the light guide column (10) are sealed and connected with a light source by a flange structure, and the sealed connection structure comprises a welding flange (11), a high temperature pad (12), a copper ring (13) and a clamping flange (14), Light passes through the quartz inner cylinder (15) through the light guide column (10); the light guide cylinder (9) and the clamping flange (14) are located in a heating furnace (20); an upper port joint (3-1) and a lower port joint (3-2) are respectively provided at the upper and lower ends of the metal outer cylinder (7); the reaction gas and the reaction liquid enter the reactor from the upper port joint (3-1) and flow out from the lower port joint (3-2) after the reaction; the metal outer cylinder (7) is a seamless tube made of a metal material resistant to high temperature and high pressure, and the metal outer cylinder (7) is used to withstand the pressure difference between the inside and outside of the reactor during the experiment. 2. The photocatalytic tubular reactor according to claim 1 is characterized in that the quartz inner tube (15) is provided with a flat-mouth quartz reactor, a straight tube sand plate reactor or an inclined quartz sand plate reactor for filling the catalyst. 3. The photocatalytic tubular reactor according to claim 2 is characterized in that: the light guide tubes (9) on the left and right sides of the metal outer tube (7) form a cross-shaped structure; and the light guide column (10) is a T-shaped structure. 4. The photocatalytic tubular reactor according to claim 3, characterized in that: the metal outer cylinder (7) is provided with fixed wings (8). 5. The photocatalytic tubular reactor according to claim 4 is characterized in that: the upper port joint (3-1) is sealed with an SAE split flange (4-1); the lower port joint (3-2) is sealed with an SAE split flange (4-2); the left and right light guide tubes (9) are sealed with flanges (14); and the external connecting pipeline adopts a ferrule structure. 6. The photocatalytic tubular reactor according to claim 5 is characterized in that the photocatalytic tubular reactor is connected to the heating furnace (20) via a fixed wing (8). 7. The photocatalytic tubular reactor according to claim 1 is characterized in that: the upper port joint (3-1) is provided with a liquid injection port (1-1) and an air inlet (2-1), and the liquid injection port (1-1) and the air inlet (2-1) are both metal ferrule interfaces; the lower port joint (3-2) is provided with an exhaust port (2-2), a temperature control port (1-2) and a thermocouple sleeve (17), and the exhaust port (2-2) and the temperature control port (1-2) are both metal ferrule interfaces. 8. The photocatalytic tubular reactor according to claim 7 is characterized in that: a thermocouple sleeve (17) is placed in the temperature control port (1-2), and the thermocouple sleeve (17) is a metal blind tube with one end sealed, and a metal ferrule is used to seal the thermocouple sleeve (17) and the temperature control port (1-2); a temperature measuring thermocouple (18) is placed in the thermocouple sleeve (17). 9. The photocatalytic tubular reactor according to claim 1 is characterized in that: two annular grooves are provided at the outer position of the lower port joint (3-2), and the annular grooves cooperate with the sealing ring (16); and a standard straight thread is reserved inside the lower port joint (3-2). 10. The photocatalytic tubular reactor according to claim 1, characterized in that the light guide tube (9) is made of a metal material resistant to high temperature and high pressure, and is welded to the metal outer tube (7). 11. The photocatalytic tubular reactor according to claim 1 is characterized in that: the light guide column (10) is a T-shaped structure, integrally formed, and made of quartz or sapphire light-transmitting material. 12. The photocatalytic tubular reactor according to any one of claims 1 to 11, characterized in that the quartz inner cylinder (15) is installed on the port joint (3-2), the port joint (3-2) is provided with an annular groove, and a sealing ring (16) is provided in the groove. 13. The photocatalytic tubular reactor according to claim 6 is characterized in that: the heating furnace (20) is an open furnace, and the cross-shaped groove matching the reactor is located on the opening plane of the heating furnace (20); the heating furnace (20) has three-stage temperature control, and the middle section is supplemented and adjusted by the upper and lower sections to ensure the length of the constant temperature zone.