Pilot test grade temperature-light intensity combined control photochemical continuous flow reactor

Abstract

The invention provides a pilot scale temperature-light intensity combined control photochemical continuous flow reactor, which comprises a light source and a continuous flow reactor main body, the continuous flow reactor main body is a hollow double-layer annular cylindrical structure, and the layer walls of the continuous flow reactor main body have the same shape and are sequentially stacked to form a reaction flow layer and a heat exchange layer which are sequentially arranged from outside to inside; the continuous flow reactor main body is provided with a reaction fluid inlet and a product liquid outlet which are communicated with the reaction flow layer, and a heat exchange medium inlet and a heat exchange medium outlet which are communicated with the heat exchange layer; the whole continuous flow reactor main body is made of high-purity quartz glass of which the light transmittance of a reaction light wavelength region is higher than 95%; the light source surrounds the periphery of the continuous flow reactor main body. According to the photochemical continuous flow reactor, the light intensity is controlled by regulating and controlling the light emitting power of the light source through the adjustable power supply, effective temperature control is achieved through heat exchange between the reaction fluid and the heat exchange medium input into the heat exchange cavity, and the amplification effect is reduced while the flux is improved by adopting the cylinder type structure.

Description

Technical Field

[0001] The invention belongs to the technical field of photochemical reactions, and in particular relates to a pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor. Background Art

[0002] Photochemical processes are a method of using photons as "traceless and environmentally friendly reagents" to make chemical reaction processes more environmentally friendly. In recent years, significant advances in light-emitting diode (LED) technology have led to the development of monochromatic, high-efficiency, durable and high-intensity light sources, which effectively reduces the cost of photons in photochemical applications, making them more economical and environmentally friendly.

[0003] Traditional intermittent reactors, due to their large characteristic size, lead to uneven light distribution, which affects the reaction results. In addition, in photochemical reactions, due to the thermal radiation brought by the light source, for low-boiling point solvents (such as dichloromethane), the solvent will be vaporized, thereby increasing the risk. Continuous flow reactors have attracted widespread attention in photochemical applications because they are expected to solve the problems involved in batch photochemistry. Compared with traditional photochemical tank reactors, continuous flow photoreactors, due to their small reactor volume, not only minimize the risk of failure, but also increase their mass transfer and heat transfer efficiency.

[0004] However, the inner diameter of the channel of a conventional microreactor is 10-1000 μm, so the output is relatively low, and it takes a long time to achieve synthesis above the kilogram level, which is difficult to meet the needs of the industry; Therefore, how to provide an industrial-grade continuous flow reactor that can simultaneously achieve high throughput, uniform illumination and temperature control is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of the above problems, the present invention provides a pilot-scale photochemical continuous flow reactor with combined temperature and light intensity control, in which the light intensity is controlled by regulating the luminous power of the light source through an adjustable power supply, and effective temperature control is achieved by heat exchange between the reaction fluid and the heat exchange medium input into the heat exchange chamber. By adopting a barrel structure, the flux is increased while the amplification effect is reduced.

[0006] To achieve the above object, the present invention adopts the following technical solution: A pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor comprises a light source and a continuous flow reactor body, wherein the continuous flow reactor body is a hollow double-layer annular cylindrical structure, wherein the wall shapes of the layers are the same and are stacked in sequence to form reaction flow layers and heat exchange layers arranged in sequence from the outside to the inside, wherein a reaction fluid inlet and a product liquid outlet connected to the reaction flow layer, as well as a heat exchange medium inlet and a heat exchange medium outlet connected to the heat exchange layer are provided on the continuous flow reactor body; the continuous flow reactor body is made of high-purity quartz glass with a light transmittance of more than 95% in the reaction light wavelength region as a whole; the light source surrounds the circumference of the continuous flow reactor body; and the light source and the continuous flow reactor body are placed in a light-tight space for use.

[0007] Furthermore, a heat exchange medium inlet pipe is coaxially arranged inside the continuous flow reactor body, the outlet end of the heat exchange medium inlet pipe is connected to the heat exchange layer, and the inlet end of the heat exchange medium inlet is the heat exchange medium inlet.

[0008] Furthermore, the reaction fluid inlet and the product liquid outlet are respectively arranged on both end faces of the continuous flow reactor body, and the heat exchange medium inlet and the heat exchange medium outlet are located on the end face where the product liquid outlet is located.

[0009] Furthermore, the continuous flow reactor body is a hollow double-layer ring cylindrical structure, including a triangular cone section and a cylindrical section, the reaction fluid inlet is located at the top of the triangular cone section, and the product liquid outlet is located on the end face of the cylindrical section away from the triangular cone end.

[0010] Furthermore, there are multiple product liquid outlets, which are evenly distributed in a ring shape within the ring shape of the reaction fluid layer; there are multiple heat exchange medium outlets, which are evenly distributed in a ring shape within the ring shape of the heat exchange layer; and the outlet end of the heat exchange medium inlet pipe extends to the outside of the end face of the cylindrical section away from the triangular cone end.

[0011] Furthermore, the height of the continuous flow reactor body is 2-5 meters, the thickness of the reaction flow layer is 1-6 mm, the reactor wall thickness is 0.2-3 mm; and the number of the product liquid outlets is 4-12.

[0012] Furthermore, temperature sensors are provided on the inner sides of the heat exchange medium inlet and the heat exchange medium outlet, and temperature sensors are provided on the inner sides of the reaction fluid inlet and the product liquid outlet. The temperature sensors are electrically connected to an external control device and transmit the collected data to the external control device in real time.

[0013] Furthermore, the heat exchange medium inlet and the heat exchange medium outlet are both connected to a delivery hose, and the outside of the delivery hose is coated with a thermal insulation layer; and the inner surface of the continuous flow reactor body is subjected to PVDF spraying treatment.

[0014] Furthermore, the light source is a ring-shaped light source composed of 8-10 light-emitting panels, and the continuous flow reactor body is placed inside the light source, at the same height as the cylindrical section and stacked.

[0015] Furthermore, the light source is an LED light source powered by an adjustable power supply, the power range of the LED light source is 150-15000W, the characteristic emission wavelength is 280-380nm, and the deflection angle of a single LED lamp bead is 60°.

[0016] The pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor of the present invention realizes the regulation of the luminous power of the light source by adjusting the voltage through an adjustable power supply, thereby realizing the control of the light intensity; the temperature of the reaction fluid is controlled by heat exchange between the heat exchange medium and the reaction fluid passing through the microchannel reactor; the cylinder structure realizes the reduction of the amplification effect while increasing the flux; and the uniform distribution of the fluid velocity and pressure inside the continuous flow reactor is realized by designing multiple outlets.

[0017] The present invention has the advantages of high mixing efficiency, controllable light intensity and reaction temperature, uniform illumination, high reaction efficiency, small amplification effect, and easy adjustment of operating flux, and can be widely used in temperature-sensitive light-induced reactions or heat-induced reactions. In addition to being applicable to gas-liquid and liquid-liquid microchannel reactions, the photochemical microreactor can also be applied to reaction processes containing a small amount of solid microparticles (suspended without precipitation) when the inner diameter of the microchannel reactor is expanded to more than 6 mm.

[0018] Compared with the prior art, the present invention has the following beneficial effects: In the pilot-scale temperature-light intensity combined control photochemical continuous flow reactor of the present invention, the photochemical microreactor is arranged inside a light-proof metal shell, and the reaction fluid absorbs photons in the reaction flow layer and performs heat exchange with the heat exchange medium of the input heat exchange layer, thereby obtaining effective temperature control; for photoreactions that are greatly affected by temperature or photoreactions that release a large amount of heat, the reaction temperature can be effectively controlled, and the selectivity and safety of the chemical reaction can be improved. In addition, by adjusting the inner diameter of the tubular microreactor, the flux of the reaction material can be adjusted, thereby adjusting the production capacity of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of the pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor described in the present invention.

[0020] Figure 2It is a top view of the pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor described in the present invention.

[0021] Figure 3 It is a structural schematic diagram of the light source described in the present invention.

[0022] Figure 4 This is a flow diagram of the process medium in the pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor described in the present invention.

[0023] Figure 5 This is the light distribution inside the reactor simulated by COMSOL software.

[0024] Figure 6 The figure shows the simulation results of the reactant fluid flow and pressure drop inside the reactor using Fluent software.

[0025] Among them, 1-continuous flow reactor body, 2-LED light source, 3-flange, 4-metal end cover, 11-reaction fluid layer, 12-heat exchange layer, 13-reaction fluid inlet, 14-product liquid outlet, 15-heat exchange medium inlet, 16-heat exchange medium outlet, 17-heat exchange medium inlet pipe, 1a-triangular cone section, 1b-cylindrical section. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1 As shown, a pilot-scale temperature-light intensity combined controlled photochemical continuous flow reactor comprises a light source and a continuous flow reactor body 1, wherein the continuous flow reactor body 1 is a hollow double-layer annular cylindrical structure, wherein the wall shapes of each layer are the same and are stacked in sequence, and comprise reaction fluid layers 11 and heat exchange layers 12 arranged in sequence from the outside to the inside, wherein a reaction fluid inlet 13 and a product liquid outlet 14 connected to the reaction fluid layer 11, as well as a heat exchange medium inlet 15 and a heat exchange medium outlet 16 connected to the heat exchange layer 12 are provided on the continuous flow reactor body 1; in order to ensure good light transmittance, in this embodiment, the continuous flow reactor body 6 is made of high-purity quartz glass with a light transmittance of more than 95% in the reaction light wavelength region as a whole; the LED light source 5 surrounds the continuous flow reactor body 6; the light source and the continuous flow reactor body 6 are placed in a light-tight space for use. Of course, in other embodiments, the material of the continuous flow reactor body 1 may also be selected from other hard materials such as borosilicate glass, transparent acrylic, etc., with a light transmittance higher than 75% in the reaction light wavelength region, as long as good light transmittance is guaranteed.

[0028] The reaction fluid is transported to the reaction fluid layer 11 through a corrosion-resistant three-head pump. The volume flow rate of the reaction fluid is 1-12 L / min. The reaction occurs under the irradiation of the light source. The reaction fluid absorbs photons in the reaction fluid layer 11 and exchanges heat with the heat exchange medium of the input heat exchange layer 12, which is used to control the temperature of the reaction fluid and obtain effective temperature control. For photo reactions that are greatly affected by temperature or photo reactions that release a large amount of heat, the reaction temperature can be effectively controlled to improve the selectivity and safety of chemical reactions.

[0029] In this embodiment, the photochemical continuous flow reactor is placed in a light-proof metal housing. Figure 3 The continuous flow reactor body 1 is fixed between the upper and lower metal end caps 4 of the opaque metal shell by the flange 3, and is a detachable and replaceable structure. The metal shell fully avoids the influence of external light on the reaction, reduces light loss, and provides a certain protection. At this time, the light intensity controller (i.e., adjustable power supply) of the light source is set outside the box or can be integrated on the box, which is convenient for the experimenter to adjust.

[0030] In this embodiment, a heat exchange medium inlet pipe 17 coaxially arranged therewith is provided inside the continuous flow reactor body 1, the outlet end of the heat exchange medium inlet pipe 17 is connected to the heat exchange layer 12, and the inlet end of the heat exchange medium inlet pipe 17 is the heat exchange medium inlet 15.

[0031] It can be understood that, compared with introducing the heat exchange medium at a certain point in the heat exchange layer 12, introducing the heat exchange medium into the heat exchange layer 12 through the heat exchange medium inlet pipe 17 can better control the uniform distribution of the heat exchange medium in the heat exchange layer 12.

[0032] like Figure 3 As shown, the condensed medium flows into the heat exchange layer 12 from the heat exchange medium inlet pipe 17, and then flows out through the heat exchange medium outlet 16. The heat exchange medium uses condensed water from the public works of the pilot base; the volume flow rate of the heat exchange medium is controlled within 5-100L / min, and is appropriately adjusted according to the predetermined reaction temperature, reaction heat, light source power and other environments. In particular, the greater the light source power, the stronger the light intensity, and the faster the photoreaction rate, the higher the flow rate of the required heat exchange medium. In addition, in order to monitor the temperature of the heat exchange medium in real time, a temperature sensor (such as a thermocouple, an infrared thermal sensor, etc.) is provided inside the heat exchange layer 12, and the temperature sensors are respectively arranged on the sides of the heat exchange medium inlet 15 and the heat exchange medium inlet 16. The temperature sensor can be electrically connected to an external control device (conventional commercially available products are sufficient) to transmit the collected data to the external control device in real time.

[0033] In some embodiments, the volume flow rate of the reaction fluid is 1-12 L / min. Fluent software was used to simulate the fluid flow in the continuous flow reactor body 1, as shown in FIG. Figure 5 As shown, the flow velocity and pressure drop distribution in each part of the reactor are uniform.

[0034] Furthermore, the reaction fluid inlet 13 and the product liquid outlet 14 are respectively arranged on the end surfaces of the continuous flow reactor body 1, and the heat exchange medium inlet 15 and the heat exchange medium outlet 16 are located on the end surface where the product liquid outlet 14 is located.

[0035] like Figure 1 and Figure 3 As shown, in this embodiment, the continuous flow reactor body is a hollow double-layered cylindrical structure, including a triangular cone section 1a and a cylindrical section 1b, the reaction fluid inlet 13 is located at the top of the triangular cone section 1a, and the product liquid outlet 14 is located on the end surface of the cylindrical section 1b away from the triangular cone end. Of course, in other embodiments, a regular hollow three-dimensional configuration such as a cuboid may also be used.

[0036] It can be understood that the reaction fluid flows into the triangular pyramid section 1a of the reactor from the reaction fluid inlet 13. The triangular pyramid structure makes the distribution of the fluid more uniform (e.g. Figure 5 As shown in FIG. 1 ), the heat exchange medium then flows into the cylindrical section 1b of the reactor and is irradiated by the LED light source 2. Similarly, the heat exchange medium can also be evenly distributed through the triangular pyramid structure to enhance the heat exchange effect inside the reactor.

[0037] Furthermore, in order to achieve uniform distribution of fluid velocity and pressure inside the continuous flow reactor, the number of the product liquid outlets 14 is 8 to 24, which are evenly distributed in the ring shape of the reactor body 6; the number of the heat exchange medium outlets 16 is multiple, which are evenly distributed in the ring shape of the heat exchange layer 12; the outlet end of the heat exchange medium inlet pipe 17 extends to the outer side of the end face of the cylindrical section 1b away from the triangular cone section 1a. Figure 1 As shown, in this embodiment, the number of the product liquid outlets 14 is 8, and the number of the heat exchange medium outlets 16 is 4. Of course, in other embodiments, the number of the product liquid outlets 14 can also be 4, 6, 10, 12, etc., and the number of the heat exchange medium outlets 16 can also be 6 or 8, etc.

[0038] In order to better monitor temperature changes, a temperature sensor (such as a thermocouple, an infrared thermal sensor, etc.) is provided inside the continuous flow reactor body 1. The temperature sensors are respectively arranged on the inner side of the reaction fluid inlet 13 and the product liquid outlet 14. The temperature sensor can be electrically connected to an external control device (conventional commercially available products can be used) to transmit the collected data to the external control device in real time.

[0039] Furthermore, the height of the continuous flow reactor body 1 is 2-5 meters, the thickness of the reaction flow layer is 1-6 mm, and the thickness of the reactor wall is 0.2-3 mm.

[0040] The reaction fluid passing through the continuous flow reactor body 1 can be a single-phase solution or a gas-liquid or liquid-liquid two-phase mixture. When the thickness of the reaction fluid layer 11 is greater than 2 mm, the reaction fluid can also be a mixed liquid containing a small amount of solid microparticles (suspended but not precipitated).

[0041] It is understandable that the flow layer thickness of the continuous flow reactor body 1 located in the cylinder structure is only 1-6 mm, and the narrow spacing makes the back mixing of the fluid flow negligible, and the flow form is close to the plug flow. The height of the continuous flow reactor body 1 reaches 2-5 meters, which ensures a larger internal volume and a larger operating flux of the reactor. Therefore, the cylinder structure design can achieve the reduction of the amplification effect while increasing the flux.

[0042] Furthermore, the reaction fluid inlet 13 and the product liquid outlet 14 are both connected to a delivery hose, and the outside of the delivery hose is coated with a layer of aluminum foil as a light shielding layer to reduce the impact of external light on the reaction. The heat exchange medium inlet 15 and the heat exchange medium outlet 16 are both connected to a delivery hose, and the delivery pipe is a rubber conduit, and the outside of the delivery hose is coated with an insulation layer to avoid temperature differences caused by heat loss; the inner surface of the continuous flow reactor body is treated with PVDF spraying, which is resistant to bromide ion corrosion and ultraviolet radiation.

[0043] In this embodiment, the light source is a high-power adjustable LED light source 2, such as Figure 2 As shown, the power range of the LED light source 2 is 150~1500W, and the characteristic emission wavelength is 280~380nm. Preferably, the deflection angle of a single LED lamp bead is 60°. In order to fully and evenly irradiate the continuous flow reactor body 1, the LED light source 2 uses 8-10 independent LED light panels to form a circle with an inner diameter of 0.684m. The irradiation width of a single LED light panel is 0.1m, and the irradiation height is 1.8-5.5m (matching the height of the reactor body). In this embodiment, the continuous flow reactor body 1 is placed inside the light source, at the same height as the cylindrical section and stacked. The outer peripheral side of the LED light source 2 is provided with a water cooling system (such as Figure 2As shown), in order to reduce the heat generated during the use of the LED and maintain the service life of the LED. The LED light source 2 is provided with a temperature sensor, which is arranged in the back of the LED light source 2. The LED light source 2 is powered by an adjustable power supply, and the luminous power of the LED light source 2 can be controlled by adjusting the voltage of the adjustable power supply, thereby controlling the light intensity of the reaction light emitted by the light source, and the emission wavelength of the reaction light is selected and adjusted according to the reaction.

[0044] like Figure 5 As shown in Figure 1, when the deflection angle of the LED lamp bead is 60°, the irradiation inside the reactor simulated by COMSOL is uniform. Figure 3 As shown, cold air is used to blow the LED irradiation surface and the continuous flow reactor body 1 to remove the heat generated during the LED irradiation process.

[0045] When the photochemical continuous flow reactor described in the present invention is in operation, the luminous power of the LED light source 2 can be controllably adjusted by adjusting the output of the adjustable power supply, thereby achieving regulation of the intensity of the reaction light emitted by the LED light source 2; the heat exchange between the heat exchange medium and the reaction fluid can be controlled by adjusting the volume flow rate and initial temperature of the heat exchange medium, thereby achieving heat / temperature regulation in the continuous flow reactor body 1.

[0046] In addition, by adjusting the inner diameter of the photochemical continuous flow reactor, the flux of the reaction materials can be adjusted, thereby adjusting the production capacity of the reactor.

[0047] exist Figures 1 to 4 The delivery pump, collection bottle and other related equipment and devices are not shown, but the relevant technical personnel in this field can connect and modify them as needed.

[0048] Those skilled in the art should understand that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pilot-scale temperature-light intensity combined control photochemical continuous flow reactor, characterized in that: The invention comprises a light source and a continuous flow reactor body, wherein the continuous flow reactor body is a hollow double-layer annular cylindrical structure, wherein the wall shapes of the layers are the same and are stacked in sequence to form reaction fluid layers and heat exchange layers arranged in sequence from the outside to the inside, and the continuous flow reactor body is provided with a reaction fluid inlet and a product liquid outlet connected to the reaction fluid layer, as well as a heat exchange medium inlet and a heat exchange medium outlet connected to the heat exchange layer; the continuous flow reactor body is made of high-purity quartz glass with a light transmittance of higher than 95% in the reaction light wavelength region; the light source surrounds the circumference of the continuous flow reactor body; the light source and the continuous flow reactor body are placed in a light-tight space for use.

2. The photochemical continuous flow reactor according to claim 1, characterized in that: A heat exchange medium flow pipe coaxially arranged therewith is provided inside the continuous flow reactor body, the outlet end of the heat exchange medium inlet pipe is connected to the heat exchange layer, and the inlet end of the heat exchange medium flow pipe is the outlet for the heat exchange medium to flow out of the heat exchange layer.

3. The photochemical continuous flow reactor according to claim 2, characterized in that: The reaction fluid inlet and the product liquid outlet are respectively arranged on the end surfaces of both ends of the continuous flow reactor body, and the heat exchange medium inlet and the heat exchange medium outlet are located on the end surface where the product liquid outlet is located.

4. The photochemical continuous flow reactor according to claim 3, characterized in that: The continuous flow reactor body is a hollow double-layered cylindrical structure, including a triangular cone section and a cylindrical section. The reaction fluid inlet is located at the top of the triangular cone section, and the product liquid outlet is located on the end surface of the cylindrical section away from the triangular cone end.

5. The photochemical continuous flow reactor according to claim 4, characterized in that: There are multiple product liquid outlets, which are evenly distributed in a ring shape within the ring shape of the reaction fluid layer; there are multiple heat exchange medium outlets, which are evenly distributed in a ring shape within the ring shape of the heat exchange layer; the outlet end of the heat exchange medium inlet pipe extends to the outside of the end face of the cylindrical section away from the triangular cone end.

6. The photochemical continuous flow reactor according to claim 5, characterized in that: The height of the continuous flow reactor body is 2-5 meters, the thickness of the reaction flow layer is 1-6 mm, the reactor wall thickness is 0.2-3 mm; the number of the product liquid outlets is 4-12.

7. The photochemical continuous flow reactor according to claim 6, characterized in that: Temperature sensors are provided inside the heat exchange medium inlet and the heat exchange medium outlet, and temperature sensors are provided inside the reaction fluid inlet and the product liquid outlet. The temperature sensors are electrically connected to an external control device and transmit the collected data to the external control device in real time.

8. The photochemical continuous flow reactor according to claim 1, characterized in that: The heat exchange medium inlet and the heat exchange medium outlet are both connected with a delivery hose, and the outside of the delivery hose is coated with a heat insulation layer; the inner surface of the continuous flow reactor body is subjected to PVDF spraying treatment.

9. The photochemical continuous flow reactor according to any one of claims 4 to 8, characterized in that: The light source is a ring-shaped light source composed of 8 to 10 light-emitting panels. The continuous flow reactor body is placed inside the light source, at the same height as the cylindrical section and is stacked.

10. The photochemical continuous flow reactor according to claim 9, characterized in that: The light source is an LED light source powered by an adjustable power supply. The power range of the LED light source is 150-1500W, the characteristic emission wavelength is 280-380nm, and the deflection angle of a single LED lamp bead is 60°.

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