A spray / spray-enhanced industrial photocatalytic reactor and method thereof

Abstract

This invention discloses a spray / spray-enhanced industrial photocatalytic reactor and its method. The reactor includes a light-transmitting and pressure-resistant reaction chamber, a spray / spray unit, a lighting unit, a gas-liquid separation unit, and a pressure control unit. By atomizing the liquid to be reacted into microdroplet clusters and / or forming a thin liquid film, the equivalent optical path of the liquid phase is significantly shortened, improving light penetration and photon utilization. Simultaneously, combined with pressure control structures such as back pressure valves and pressure stabilizing tanks, and gas-liquid separation / demisting structures, controllable pressure and low pressure drop are achieved under continuous operation. The reaction chamber material is not limited to quartz glass, but can also be borosilicate glass, tempered glass, transparent ceramics, or sapphire, etc.; the light source is not limited to LEDs, but can also be xenon lamps, halogen lamps, mercury lamps, lasers, or sunlight simulators, etc. The system can operate in a cyclic or multi-stage series, suitable for the scale-up and integration of various industrial photocatalytic processes.

Description

Technical Field

[0001] This invention relates to the field of industrial photocatalytic reaction and reactor engineering, and in particular to a photocatalytic reactor and method thereof that enhances light penetration by forming a thin liquid layer or microdroplets through spraying / spraying and achieves continuous operation by combining pressure regulation. Background Technology

[0002] Photocatalytic reactions generally suffer from the engineering bottleneck of "limited penetration depth of light into the liquid layer": In traditional stirred tanks, tubular or plate reactors, the effective penetration depth of the light source in the liquid medium is usually only in the millimeter to centimeter range. When the liquid layer thickens, the concentration increases, or there is scattering / absorption in the system, the photon utilization rate decreases significantly, resulting in a decrease in reaction rate, an increase in energy consumption, and difficulty in scale-up.

[0003] On the other hand, continuous industrial operation is often accompanied by fluid resistance and pressure drop problems: in order to obtain higher mass transfer or thinner liquid film, it is often necessary to increase the circulation flow rate or use high-pressure pumps, which will introduce higher system pressure, sealing and safety risks, and increase equipment costs.

[0004] Therefore, there is an urgent need for a photocatalytic reactor structure and operation method that can simultaneously solve the problems of limited light penetration and pressure / pressure drop constraints on an industrial scale. Summary of the Invention

[0005] 3.1 Purpose of the Invention The purpose of this invention is to provide a spray / spray-enhanced industrial photocatalytic reactor and its method, which significantly shortens the optical path and improves photon utilization by dispersing the reaction liquid into microdroplets or thin liquid films; and reduces system pressure drop and pressure risk while meeting continuous operation requirements by setting up pressure regulation and gas-liquid separation / stabilization units.

[0006] 3.2 Technical Solution To achieve the above objectives, the present invention provides the following technical solutions (not limited to the following embodiments, all of which fall within the protection scope of the present invention): (1) Reaction chamber: It is a light-transmitting and pressure-resistant tubular or cylindrical reaction chamber, preferably a tubular structure; its material can be quartz glass, borosilicate glass, tempered glass, transparent ceramic, sapphire or a combination of the above materials, or a metal or composite material pressure-bearing jacket can be set outside the light-transmitting material to achieve both light transmission and pressure resistance.

[0007] (2) Spray / spray unit: located at the top, side or inside of the reaction chamber, used to atomize / spray the liquid to be reacted into micro-droplet groups or form a thin liquid film flowing along the inner wall. The spraying method is not limited to high-pressure nozzle, Venturi spray (gas-liquid ejection / two-fluid injection), ultrasonic atomization, rotary atomization, capillary atomization or a combination thereof.

[0008] (3) Illumination unit: Located on the outside or inside of the reaction chamber, it provides illumination to the reaction area. The light source is not limited to LED array, xenon lamp, halogen lamp, mercury lamp, laser, sunlight simulator or combination thereof; it can be used with reflectors, lenses, optical fibers or light guide structures to achieve uniform illumination and energy utilization.

[0009] (4) Pressure and process unit: Pressure stabilizing tank, back pressure valve, throttle valve, pressure relief valve, safety valve or combination thereof are installed at the reactor inlet and outlet to achieve pressure regulation; and gas-liquid separator / demister is installed to separate the gas phase and liquid phase, reduce droplet entrainment and stabilize circulation.

[0010] (5) Circulation or series connection: The reactor can be a single-unit circulation mode (liquid phase reflux to the supply tank) or multiple units in series mode (cascade reactor) to meet different conversion rates, residence times and scale-up requirements; it can also be combined into a circulation-series system.

[0011] 3.3 Beneficial Effects By dispersing liquids into microdroplets or thin liquid films through spraying / spraying, the equivalent optical path is significantly reduced, light penetration and bulk utilization are improved, thereby enhancing the reaction rate and quantum efficiency.

[0012] The reaction zone exists in the form of droplets / films, which increases the light-receiving area per unit volume, facilitating large-scale scaling and continuous operation.

[0013] Through engineering units such as pressure stabilization, back pressure and gas-liquid separation, pressure control and low pressure drop operation can be achieved under target working conditions, reducing pumping energy consumption and sealing safety risks.

[0014] The wide range of light sources and materials available facilitates engineering configuration based on reaction wavelength requirements, temperature and corrosion resistance requirements, and cost.

[0015] It can be flexibly adopted in a cycle or series to adapt to different reaction kinetics and capacity requirements, and is easy to integrate into industrial processes. Attached Figure Description

[0016] The invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of the spray / spray-enhanced tubular photocatalytic reactor of the present invention.

[0018] Figure 2 This is a schematic diagram of the cyclic operation process of the present invention.

[0019] Figure 3 This is a schematic diagram of the multi-stage series operation process of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto. For those skilled in the art, various modifications or substitutions can be made without departing from the concept of the present invention, and all such modifications or substitutions should fall within the scope of protection of the present invention.

[0021] 5.1 Overall Structure of the Reactor The reactor is a light-transmitting and pressure-resistant tubular reaction chamber (1), inside which a spray / spray unit (2) is installed. An illumination unit (3) is installed on the outside of the reaction chamber, including a light source and an optional reflective / focusing structure. A gas-liquid separation unit (4) is installed at the bottom of the reaction chamber to achieve gas-liquid separation and demisting. The liquid phase is returned to the liquid supply tank (6) by a circulation pump (5) to achieve circulation, or enters the next reactor section through the discharge port to achieve series connection. The system can be equipped with a back pressure valve or a pressure stabilizing tank (7) for pressure regulation.

[0022] 5.2 Spraying / Sprinkling Method The spray / sprinkler unit can be: a) High-pressure nozzle: Atomization is achieved through liquid pump pressure; b) Venturi spray / two-fluid jet: Atomization is achieved through gas ejection or compressed gas, reducing dependence on high-pressure liquid pumps; c) Ultrasonic atomization: micron-sized droplets are generated through ultrasonic vibration; d) Rotary atomization: Atomization is achieved through a turntable / rotor. e) Any combination of the above methods.

[0023] 5.3 Reaction Chamber Materials and Structure The reaction chamber material can be selected according to wavelength requirements and operating conditions, such as: quartz glass (suitable for ultraviolet and visible light), borosilicate glass or tempered glass (suitable for the visible light region and higher mechanical strength requirements), sapphire or transparent ceramic (suitable for high temperature / wear-resistant scenarios), etc. To improve pressure resistance, a composite structure of "transparent inner tube + pressure-bearing outer tube" can be adopted: the inner tube provides light transmission, the outer tube bears the system pressure, and an air layer or cooling jacket can be set between the two to control the temperature.

[0024] 5.4 Light Source and Light Field Configuration The light source is not limited to LEDs, xenon lamps, halogen lamps, mercury lamps, lasers, or sunlight simulators; monochromatic or broadband light sources can be selected according to the catalyst absorption band, and the light intensity can be controlled by changing the filter or adjusting the driving current. The light source can be arranged in a circular, segmented, or multi-faceted reflective cavity to achieve uniform illumination.

[0025] 5.5 Pressure Regulation and Safety The system can achieve pressure control through back pressure valves, pressure stabilizing tanks, throttling valves, and safety valves. For volatile solvents or gas-generating reactions, a condensation recovery and tail gas treatment unit can be installed after the gas-liquid separator. When the risk of droplet entrainment is high, a demister or cyclone separator can be installed to reduce droplet escape.

[0026] 5.6 Cyclic and Serial Operation Modes Circulation mode: After the reaction, the liquid phase is returned to the supply tank, and the target residence time and pressure are achieved by adjusting the circulation flow rate and the back pressure valve.

[0027] Series mode: Multiple reactors are connected in series according to the process sequence to improve the conversion rate step by step; intermediate separation or feeding units can also be set between some stages.

[0028] Cyclic-Serial Mode: The front end uses a cyclic process to achieve rapid photoactivation, while the back end uses a serial process to achieve deep conversion.

[0029] 5.7 Typical Implementation Examples Example 1: Taking a visible light-driven organic photo-oxidation reaction as an example, a borosilicate glass inner tube is used, with an external annular LED array for irradiation. A Venturi two-fluid nozzle is installed at the top to atomize the reaction liquid, forming a droplet reaction zone along the inside of the tube. After gas-liquid separation at the bottom, the liquid phase is circulated back. By adjusting the gas-liquid ratio and the back pressure valve, stable atomization and a high conversion rate can be obtained at a lower liquid pump pressure.

[0030] Example 2: Taking ultraviolet light-driven photocatalysis for water treatment as an example, a quartz glass reaction chamber and an external xenon / mercury lamp light source are used. The spray unit is a high-pressure nozzle or an ultrasonic atomizer. The reaction liquid forms a thin film / droplet in the tube to improve the utilization of light flux. Multiple reactors are connected in series to meet the high processing capacity requirements.

Claims

1. An industrial photocatalytic reactor, characterized in that, include: A light-transmitting and pressure-resistant reaction chamber; A spray / spray unit disposed within or at the inlet of the reaction chamber is used to disperse the liquid to be reacted into micro-droplet clusters and / or form a thin liquid film flowing along the inner wall. The illumination unit, located on the outside and / or inside the reaction chamber, is used to provide illumination to the microdroplet clusters and / or thin liquid film for photocatalytic reaction. A gas-liquid separation unit connected to the reaction chamber; A pressure control unit connected to the reaction chamber and / or the gas-liquid separation unit; The spray / spray unit shortens the equivalent optical path of the liquid phase to improve light penetration and photon utilization, and the pressure control unit enables pressure control during continuous operation.

2. The industrial photocatalytic reactor according to claim 1, characterized in that, The reaction chamber is a tubular or cylindrical structure, and the material is selected from quartz glass, borosilicate glass, tempered glass, transparent ceramics, sapphire, or a combination thereof.

3. The industrial photocatalytic reactor according to claim 1 or 2, characterized in that, The reaction chamber adopts a composite structure of a light-transmitting inner tube and a pressure-bearing outer tube, wherein the pressure-bearing outer tube is made of metal or composite material.

4. The industrial photocatalytic reactor according to claim 1, characterized in that, The atomization method of the spray / spray unit is selected from high-pressure nozzle atomization, venturi spray / two-fluid jet atomization, ultrasonic atomization, rotary atomization, capillary atomization, or a combination thereof.

5. The industrial photocatalytic reactor according to claim 1, characterized in that, The light source of the illumination unit is selected from LED arrays, xenon lamps, halogen lamps, mercury lamps, lasers, sunlight simulators, or combinations thereof.

6. The industrial photocatalytic reactor according to claim 1, characterized in that, The pressure control unit includes a back pressure valve and / or a pressure stabilizing tank and / or a throttle valve and / or a pressure relief valve and / or a safety valve.

7. The industrial photocatalytic reactor according to claim 1, characterized in that, The gas-liquid separation unit includes a demister and / or a cyclone separator and / or a gravity separator.

8. The industrial photocatalytic reactor according to claim 1, characterized in that, The industrial photocatalytic reactor is configured for cyclic operation, with the liquid phase after the reaction flowing back to the supply tank and then re-entering the spray / spray unit.

9. The industrial photocatalytic reactor according to claim 1, characterized in that, The industrial photocatalytic reactor is configured to operate in a multi-stage series, with the reacted material entering the next stage reactor to improve the overall conversion rate.

10. An industrial photocatalysis method, characterized in that, The industrial photocatalytic reactor according to any one of claims 1-9 comprises the following steps: The liquid to be reacted is delivered to the spray / spray unit and atomized / sprayed to form microdroplet clusters and / or thin liquid films; Under the illumination provided by the illumination unit, the microdroplet clusters and / or thin liquid films undergo photocatalytic reactions; The two-phase mixture after the reaction flows out and is then subjected to gas-liquid separation. The system pressure is regulated by a pressure control unit; The liquid phase can be circulated back or the reactor can be connected in multiple stages in series, depending on the needs.

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