Gas-liquid mixed flowing photochemical device and operation method thereof

Abstract

The invention provides a gas-liquid mixed flow photochemical device, which belongs to the technical field of continuous flow photochemistry, and comprises a liquid and gas injection part, a four-way mixer, a photoreactor, a gas-liquid separator, a collection part and a circulation part which are connected in sequence. The four-way mixer comprises a gas input port, a liquid input port and a mixture output port; a hollow sphere is arranged in the inner part, millimeter-level small holes are uniformly distributed in the outer wall of the sphere, and the outer wall is tightly connected with the input port and the output port; the contact area of the liquid and the gas is increased by dividing and extruding the liquid in the flowing process of the solution, and the mixing efficiency of the liquid and the gas is improved; the circulation part realizes a reaction path in which gas can be circulated, and the purposes of complete utilization and zero emission of the gas are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of novel continuous flow chemistry, and in particular to a gas-liquid mixed flow photochemical device and an operating method thereof. Background Art

[0002] In recent years, photochemical reactions have been favored by universities, research institutes and industries at home and abroad. This is because compared with traditional chemical reactions, photochemical reactions use light energy to excite molecules to participate in chemical reactions, which has the advantages of high efficiency, energy saving and environmental protection. Photochemical reactions mainly involve excited molecules, which can produce a variety of active substances, and can achieve highly selective and efficient reactions through photosensitizers, catalysts and other means, often allowing the reaction to occur under mild conditions.

[0003] At present, photochemical reactions have broad application prospects in the fields of organic synthesis, drug synthesis, energy conversion, etc. On the other hand, continuous flow reactions have higher production efficiency and better heat and mass transfer performance than batch reactions. The reaction materials held in the continuous flow reactor are significantly reduced compared to batch reactions, so the danger of some flammable and highly toxic reactions can be reduced, thereby reducing the potential safety hazards of the reaction. The continuous flow reaction generally has a smaller amplification effect and is easier to achieve expanded generation. For example, the Chinese utility model patent document with publication number CN207493676U discloses a continuous photochemical reaction device and system, which enables the photochemical reaction to occur continuously by setting a continuous reactor, the reaction raw materials continuously enter the reactor, and the reaction products are continuously discharged from the reactor. This continuous flow reaction can effectively improve the transmission efficiency of light radiation in the reaction mixture, thereby shortening the reaction time, improving the reaction efficiency, and reducing side reactions. However, the utility model does not solve the problem of how to improve the mixing efficiency of reactants and improve the utilization rate of reactants in the stage before the reaction starts. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to improve the mixing efficiency of gas-liquid raw materials and achieve zero emission of gas raw materials in a continuous flow photochemical reaction based on gas-liquid mixing.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] The present invention provides a gas-liquid mixed flow photochemical device, comprising: a liquid and gas injection part, a four-way mixer, a photoreactor, a gas-liquid separator, a collection part and a circulation part connected in sequence;

[0007] The four-way mixer comprises: a gas input port, a liquid input port and a mixture output port; the gas input port is connected to the gas push injection part and the circulation part; the liquid input port is connected to the liquid push injection part; the mixture output port is connected to the photoreactor;

[0008] The interior of the four-way mixer is a hollow sphere, the outer wall of the sphere is evenly distributed with millimeter-level holes, and the outer wall is tightly connected to the input and output ports;

[0009] Furthermore, the liquid push injection unit includes a liquid storage bottle and a liquid injection pump which are connected in sequence.

[0010] The gas push injection unit comprises a gas supply bottle, a pressure reducing valve, a gas flow meter and a one-way valve which are connected in sequence.

[0011] The four-way mixer is made entirely of stainless steel.

[0012] The input port of the gas-liquid separator is connected to the photoreactor, and the output port is connected to the collecting part and the circulating part; a TLC spot plate is arranged at the input port of the gas-liquid separator.

[0013] The collecting part includes a gas collecting bottle and a circulating material bottle; the gas collecting bottle is connected to the gas-liquid separator and is used to collect the residual gas separated after the photoreactor; the circulating material bottle is connected to the gas-liquid separator and is used to collect the solution separated after the photoreactor.

[0014] The circulation part comprises an air outlet path and a liquid outlet path, and both the air outlet path and the liquid outlet path are connected to the output port of the gas-liquid separator.

[0015] The gas outlet path comprises a gas collecting bottle, a gas injection pump, a gas flow meter, a one-way valve and a four-way mixer which are connected in sequence.

[0016] The liquid outlet path comprises a circulating material bottle, a liquid injection pump and a four-way mixer which are connected in sequence.

[0017] The present invention also provides an operating method based on the above-mentioned gas-liquid mixed flow photochemical device, and the operating method is specifically as follows:

[0018] The solid raw materials and liquid solvent are mixed into a solution and placed in a liquid storage bottle. Stirring ensures that the solution is clear and does not cause clogging of the pipeline. The solution flows in the liquid pipe through a liquid injection pump and is transported to the liquid input port of the four-way mixer.

[0019] The gas raw material in the gas supply bottle is transported to the gas input port of the four-way mixer through the pressure reducing valve, gas pipe, gas flow meter and one-way valve;

[0020] The gas enters through the gas input port of the four-way mixer through the evenly distributed millimeter-sized holes on the outer wall of the inner sphere, filling the entire sphere;

[0021] The solution expands along the outer wall of the inner sphere through the liquid input port of the four-way mixer under the thrust of the liquid injection pump, enters the sphere through the millimeter-level holes evenly distributed on the outer wall, and is evenly divided into fine liquid flows, which are fully in contact with the gas filling the interior of the sphere; and when leaving the four-way mixer, it is squeezed and divided into fine liquid flows again through the millimeter-level holes evenly distributed on the outer wall of the sphere.

[0022] The solution and gas are uniformly and fully mixed in the four-way mixer and then transported to the photoreactor through the mixing tube for chemical reaction; the outlet of the photoreactor is connected to the gas-liquid separator, and the gas outlet pipe is arranged at the upper end of the gas-liquid separator and the liquid outlet pipe is arranged at the bottom; the solution raw material is detected by observing through the TLC spot plate at the input port of the gas-liquid separator, and if the raw material in the solution is completely converted, the reaction solution is transported to the circulating material bottle for collection, and the gas is transported to the gas collecting bottle for collection; if the raw material in the solution is not completely converted, the reaction system is subjected to gas-liquid separation at the gas-liquid separator, and the gas passes through the gas outlet pipe, the gas collecting bottle, the gas injection pump, the gas flow meter, and the one-way valve and returns to the four-way mixer; the unreacted solution mixture is returned to the circulating material bottle for storage after passing through the liquid outlet pipe; when the liquid injection pump has transported the initial material, the solution stored in the circulating material bottle is re-injected into the four-way mixer to be fully mixed with the gas, and then transported to the photoreactor for reaction; this cycle is repeated until it is detected by the TLC spot plate that the raw material in the solution is completely converted, and the product is collected through the circulating material bottle.

[0023] The advantages of the present invention are:

[0024] (1) The prior art generally uses imported IDEX-P729 high-pressure four-way mixers as mixers, which result in uneven mixing and a small contact area between liquid and gas. For gases such as sulfur hexafluoride SF6 that have chemical stability and non-polar properties, it is difficult to fully mix with solvents. The present invention sets a four-way mixer with a unique structure in a device based on gas-liquid mixing continuous flow photoreaction, so that after the liquid enters the four-way mixer, a fine liquid flow is formed, which is mixed with the gas filling the entire internal space of the mixer, thereby increasing the mixing area; when the liquid leaves the mixing output port of the four-way mixer, it is squeezed again to form a fine liquid flow, thereby increasing the mixing pressure inside the mixer; thereby improving the mixing efficiency of the liquid and gas.

[0025] (2) By setting up a circulation section in the device based on the continuous flow photochemical reaction of gas-liquid mixing, a cyclic reaction path for the continuous flow photochemical reaction is constructed, so that the gas raw materials can be fully utilized and the goal of zero gas emission is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a gas-liquid mixed flow photochemical device according to Example 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of a four-way mixer of a gas-liquid mixed flow photochemical device according to Example 1 of the present invention;

[0028] Figure 3 The target product of a photochemical reaction of a gas-liquid mixture in Example 1 of the present invention is 1 H NMR nuclear magnetic spectrum;

[0029] Figure 4 The target product of a photochemical reaction of a gas-liquid mixture in Example 1 of the present invention is 13 C NMR nuclear magnetic resonance spectrum.

[0030] in:

[0031] 1-gas supply bottle; 2-gas pipe; 3-liquid pipe; 4-liquid storage bottle; 5-liquid injection pump; 6-pressure reducing valve; 7-gas flow meter; 8-check valve I; 9-four-way mixer; 10-mixing tube; 11-photoreactor; 12-gas-liquid separator; 13-gas outlet pipe; 14-gas collecting bottle; 15-gas injection pump; 16-gas flow meter; 17-check valve II; 18-liquid outlet pipe; 19-circulating material bottle. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] Embodiment 1 of the present invention discloses a gas-liquid mixed flow photochemical device, such as Figure 1 As shown, it includes: liquid and gas push injection part, four-way mixer, photoreactor, gas-liquid separator, collection part and circulation part connected in sequence. The liquid push injection part includes a liquid storage bottle 4, a liquid injection pump 5 and a liquid pipe 3 connected in sequence. The gas push injection part includes a gas supply bottle 1, a gas pipe 2, a pressure reducing valve 6, a gas flow meter 7, and a one-way valve Ⅰ8 connected in sequence;

[0035] The four-way mixer 9 is as follows Figure 2 As shown, it includes: two gas input ports, a liquid input port and a mixture output port; the gas input port is connected to the gas push injection part and the circulation part; the liquid input port is connected to the liquid push injection part; the mixture output port is connected to the photoreactor 11;

[0036] The interior of the four-way mixer 9 is a hollow sphere, and the outer wall of the sphere is evenly distributed with millimeter-level holes, and the outer wall is tightly connected to the input and output ports;

[0037] Furthermore, the reaction solid raw materials and liquid solvent are prepared into a solution and placed in a liquid storage bottle 4. By stirring, the solution is ensured to be clear and will not cause clogging of the pipeline; the solution flows in the liquid pipe 3 through the liquid injection pump 5 and is transported to the liquid input port of the four-way mixer 9.

[0038] The gas raw material in the gas supply bottle 1 is transported to the gas input port of the four-way mixer 9 through the gas pipe 2, the pressure reducing valve 6, the gas flow meter 7, and the one-way valve I8.

[0039] The gas enters through the gas input port of the four-way mixer 9 through the evenly distributed millimeter-sized holes on the outer wall of the inner sphere, filling the entire sphere;

[0040] The solution expands along the outer wall of the inner sphere through the liquid input port of the four-way mixer 9 under the thrust of the liquid injection pump 5, and enters the sphere through the millimeter-level small holes evenly distributed on the outer wall. The solution is evenly divided into fine liquid flows, which are fully in contact with the gas filling the inside of the sphere, thereby increasing the contact area between the solution and the gas. At the same time, when the solution leaves the mixing output port of the four-way mixer 9, it is squeezed and divided into fine liquid flows again through the millimeter-level small holes evenly distributed on the outer wall of the sphere, thereby increasing the mixing pressure inside the mixer. Thus, the mixing efficiency of liquid and gas is improved.

[0041] The solution and gas are uniformly and fully mixed in the four-way mixer 9 and then transported to the photoreactor 11 through the mixing tube 10 for chemical reaction. The photoreactor includes: a reaction hose, a light source module, and a temperature control module; the reaction hose is connected to the mixing tube 10, and is wound into a column and placed inside the photoreactor 11; the photoreactor 11 chemically reacts the system in the reaction hose. The separation part adopts a gas-liquid separator; the input port of the gas-liquid separator 12 is connected to the above-mentioned reaction hose, and the output port is connected to the circulation part. The collection part includes a gas collection bottle 14 and a circulation material bottle 19; the gas collection bottle 14 collects the remaining gas; the circulation material bottle 19 collects the solution after the reaction. The circulation part includes: an outlet path 13 and a liquid outlet path 18; the outlet path 13 passes through the gas collection bottle 14, the gas injection pump 15, the gas flowmeter 16 and the one-way valve II 17, and is connected to the input port of the four-way mixer 9; the liquid outlet path 18 passes through the circulation material bottle 19 and the liquid injection pump 5 and is connected to the input port of the four-way mixer 9.

[0042] Furthermore, in actual operation, Figure 1As shown, the reaction solid raw materials and liquid raw materials are prepared into a solution and placed in a liquid storage bottle 4. By stirring, the solution is ensured to be clear and will not cause the pipeline to be blocked. Preferably, a suction filter head can also be installed at the inlet of the hose. The solution is transported in the liquid pipe 3 by the liquid injection pump 5 and enters the four-way mixer 9; the liquid injection pump 5 can set the liquid flow rate, which can make the liquid flow evenly in the pipeline, which is simple, convenient and easy to operate. The gas raw material in the gas supply bottle 1 passes through the pressure reducing valve 6, the gas pipe 2 and the gas flow meter 7, and the one-way valve I8, and enters the four-way mixer 9; the gas flow meter 7 can control the gas flow rate to match the liquid flow rate; the one-way valve I8 can prevent the liquid from flowing back into the gas path.

[0043] Furthermore, the four-way mixer 9 connects the gas pipe 2 and the liquid pipe 3, where the gas and liquid are evenly and fully mixed. The gas raw material is evenly mixed with the solution through the four-way mixer 9 and then transported to the photoreactor 11 through the mixing tube 10 for chemical reaction; the photoreactor 11 includes a reaction hose, a light source module, and a temperature control module. The reaction hose is wound into a ring in the photoreactor so that the light source can evenly illuminate the gas-liquid mixed system therein, increase the illumination area, and improve the reaction efficiency; the light source module provides light energy to make the reactants enter an excited state. The temperature control module can heat or cool the reaction system to reach the optimal temperature required for the chemical reaction. By setting the temperature by yourself, it is simple and easy to operate.

[0044] Further, the outlet of the photoreactor is connected to the gas-liquid separator 12. An outlet pipe 13 is arranged at the upper end of the gas-liquid separator 12, a liquid outlet pipe 18 is arranged at the bottom of the gas-liquid separator 12, and a TLC spot plate is arranged at the input port of the gas-liquid separator 12. Through the TLC spot plate observation, the solution raw material is detected. If the raw material in the solution is completely converted, the reaction solution is transported to the circulating material bottle 19 for collection, and the gas is transported to the gas collecting bottle 14 for collection; if the raw material in the solution is not completely converted, the reaction system is separated into gas and liquid at the gas-liquid separator 12 and transported to the circulation part, that is, the gas returns to the four-way mixer 9 after passing through the outlet pipe 13, the gas collecting bottle 14, the gas injection pump 15, the gas flow meter 16, and the one-way valve II 17, and the end of the outlet pipe 13 is connected to the four-way mixer 9; the gas injection pump 15 can well control the flow rate of the unreacted gas, better participate in the subsequent reaction, and also achieve the purpose of zero gas emission. The gas flow meter 16 can more intuitively observe the cumulative flow and instantaneous flow. At the same time, the unreacted solution, raw materials and target products are returned to the circulating material bottle 19 for storage after passing through the liquid outlet pipe 18; when the liquid injection pump 5 has delivered the original material, the solution stored in the circulating material bottle 19 is re-injected into the four-way mixer 9 to be fully mixed with the gas, and then delivered to the photoreactor for reaction again. This cycle is repeated until the raw materials in the solution are completely converted through TLC spot plate observation, and the product is collected through the circulating material bottle 19.

[0045] Preferably, in this embodiment, the raw material solution is limited, while the supply of gas can be unlimited. The gas raw material always circulates in the device until the solution raw material is completely converted, the chemical reaction stops, and the solution product is collected for subsequent operations. Therefore, zero emission of reaction gas can be achieved.

[0046] Preferably, in the above-mentioned cyclic reaction, the flow rate can be set, the liquid flow rate is controlled by the liquid injection pump 5, and the gas flow rate is controlled by the gas injection pump 15, so as to achieve the material ratio designed in the experiment.

[0047] Preferably, when all the solution raw materials in this experiment have reacted completely, the gas supply is stopped, and the remaining gas in the system is transported to the gas collecting bottle 14 for collection, thereby further achieving the purpose of zero gas emission.

[0048] Preferably, the gas-liquid separator 12 described in the embodiment of the present invention can accurately control the collection amount or circulation amount of the solution when the solution product is collected or the solution is circulated again through the liquid outlet path, thereby ensuring that a certain volume of solution is always maintained in the gas-liquid separator to avoid gas leakage when the solution product is collected.

[0049] Based on the above device and its operation mode, the embodiment of the present invention also discloses a specific gas-liquid mixed continuous flow photochemical reaction experiment to verify the operation mode and effect of the device. The chemical reaction experiment is as follows:

[0050] The raw material 3-methylbenzoic acid (0.3 g) and the photocatalyst (Ir[dF(CF3)ppy]2(dtbpy))PF6 (14 mg, 0.5 mol%) were loaded into the liquid storage bottle 4 (25.0 mL) equipped with a perforated rubber stopper and a magnetic stirring bar, and then anhydrous MeCN (5 mL), DIPEA (2 mL, 5.0 equivalents) and diethylamine (2.3 mL, 10.0 equivalents) were added to the liquid storage bottle 4 through a syringe, and the solution was stirred until clear by the magnetic stirring bar. The pipette of the injection pump 5 was placed in the hole of the rubber stopper. After preparation, the gas supply bottle 1 and the pressure reducing valve 6 were opened, and the gas flow meter 7 was used to adjust the gas flow to 1.5 SCCM, and the SF6 gas entered the mixer 9 through the one-way valve Ⅰ8. At the same time, the liquid outlet speed was adjusted to 0.02 mL / min, and the injection pump 5 was started, and it entered the four-way mixer 9 through the liquid pipe 3. The photoreactor 11 is turned on, and the gas-liquid mixture enters the photoreactor 11 through the mixing tube 10 to perform a continuous flow reaction. The gas-liquid mixture after the reaction is separated into gas and liquid in the gas-liquid separator 12.

[0051] Further, after all the reaction solution was injected, the reaction was closed by TLC spot plate observation to confirm that the raw materials in the solution had been completely converted, and the reaction solution was separated from the circulating material bottle 19. The reaction solution was quenched by adding a saturated NH4Cl solution, and extracted three times with ethyl acetate, the organic layers were combined, the solvent was removed under vacuum, and the residue was purified by silica gel flash column chromatography (petroleum ether / ethyl acetate=10 / 1) to obtain a yellow liquid product N,N-diethyl-3-methylbenzamide (266.7 mg, 63%).

[0052] Specifically, the reaction equation is:

[0053]

[0054] The target product N,N-diethyl-3-methylbenzamide (N,N-diethyl-3-methylbenzamide) NMR data are as follows: Figure 3 and Figure 4 As shown,

[0055] 1 H NMR (600MHz, CDCl3) δ7.27-7.25(m,1H),7.19-7.13(m,3H),3.54(s,2H),3.25(s,2H),2.36(s,3H),1.24(s,3H),1.09(s,3H).

[0056] 13 C NMR (150MHz, CDCl3) δ171.5,138.2,137.3,129.8,128.2,126.9,123.2,43.3,39.2,21.4,14.2,12.9.

[0057] In particular, in order to further prove the effect of the present invention on improving the gas-liquid mixing efficiency, as a comparative experiment, the four-way mixer used in the above experimental device was replaced with a commonly used IDEX-P729 high-pressure four-way, which only provides channels in four directions and has no special internal structure. The above experiment uses the same amount of raw materials, the same operating steps, and the same reaction conditions to obtain a yellow liquid product N,N-diethyl-3-methylbenzamide (130.7 mg, 31%). Compared with the four-way mixer of the present invention, the yield decreases significantly. It shows that the efficiency of gas-liquid mixing is improved by using the four-way mixer of the present invention.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas-liquid mixed flow photochemical device, characterized in that: It includes the following parts connected in sequence: liquid and gas injection part, four-way mixer, photoreactor, gas-liquid separator, collection part and circulation part; The four-way mixer comprises: a gas input port, a liquid input port and a mixture output port; the gas input port is connected to the gas push injection part and the circulation part; the liquid input port is connected to the liquid push injection part; the mixture output port is connected to the photoreactor; The interior of the four-way mixer is a hollow sphere, and millimeter-level small holes are evenly distributed on the outer wall of the sphere, and the outer wall is tightly connected with the input and output ports.

2. A gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The liquid push injection unit comprises a liquid storage bottle and a liquid injection pump which are connected in sequence.

3. A gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The gas push injection unit comprises a gas supply bottle, a pressure reducing valve, a gas flow meter and a one-way valve which are connected in sequence.

4. A gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The whole material of the four-way mixer is stainless steel.

5. The gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The input port of the gas-liquid separator is connected to the photoreactor, and the output port is connected to the collecting part and the circulating part; a TLC spot plate is arranged at the input port of the gas-liquid separator.

6. A gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The collecting part includes a gas collecting bottle and a circulating material bottle; the gas collecting bottle is connected to the gas-liquid separator and is used to collect the residual gas separated after the photoreactor; the circulating material bottle is connected to the gas-liquid separator and is used to collect the solution separated after the photoreactor.

7. The gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The circulation part comprises an air outlet path and a liquid outlet path, and both the air outlet path and the liquid outlet path are connected to the output port of the gas-liquid separator.

8. The gas-liquid mixed flow photochemical device according to claim 6, characterized in that: The gas outlet path comprises a gas collecting bottle, a gas injection pump, a gas flow meter, a one-way valve and a four-way mixer which are connected in sequence.

9. The gas-liquid mixed flow photochemical device according to claim 1, characterized in that: The liquid outlet path comprises a circulating material bottle, a liquid injection pump and a four-way mixer which are connected in sequence.

10. An operating method of the gas-liquid mixed flow photochemical device according to any one of claims 1 to 9, characterized in that: The operation method is as follows: The solid raw materials and liquid solvent are mixed into a solution and placed in a liquid storage bottle. Stirring ensures that the solution is clear and does not cause clogging of the pipeline. The solution flows in the liquid pipe through a liquid injection pump and is transported to the liquid input port of the four-way mixer. The gas raw material in the gas supply bottle is transported to the gas input port of the four-way mixer through the pressure reducing valve, gas pipe, gas flow meter and one-way valve; The gas enters through the gas input port of the four-way mixer through the evenly distributed millimeter-sized holes on the outer wall of the inner sphere, filling the entire sphere; The solution is expanded along the outer wall of the inner sphere through the liquid input port of the four-way mixer under the thrust of the liquid injection pump, and enters the sphere through the millimeter-level small holes evenly distributed on the outer wall. The solution is evenly divided into fine liquid flows, which are fully in contact with the gas filling the inside of the sphere; and when leaving the four-way mixer, it is squeezed and divided into fine liquid flows again through the millimeter-level small holes evenly distributed on the outer wall of the sphere; The solution and gas are uniformly and fully mixed in the four-way mixer and then transported to the photoreactor through the mixing tube for chemical reaction; the outlet of the photoreactor is connected to the gas-liquid separator, and the gas outlet pipe is arranged at the upper end of the gas-liquid separator and the liquid outlet pipe is arranged at the bottom; the solution raw material is detected by observing through the TLC spot plate at the input port of the gas-liquid separator, and if the raw material in the solution is completely converted, the reaction solution is transported to the circulating material bottle for collection, and the gas is transported to the gas collecting bottle for collection; if the raw material in the solution is not completely converted, the reaction system is subjected to gas-liquid separation at the gas-liquid separator, and the gas passes through the gas outlet pipe, the gas collecting bottle, the gas injection pump, the gas flow meter, and the one-way valve and returns to the four-way mixer; the unreacted solution mixture is returned to the circulating material bottle for storage after passing through the liquid outlet pipe; when the liquid injection pump has transported the initial material, the solution stored in the circulating material bottle is re-injected into the four-way mixer to be fully mixed with the gas, and then transported to the photoreactor for reaction; this cycle is repeated until it is detected by the TLC spot plate that the raw material in the solution is completely converted, and the product is collected through the circulating material bottle.

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