A photoreactor and its application

Abstract

The present invention provides a photoreactor and its application, belonging to the technical field of light-driven reaction device design, wherein the photoreactor comprises a light-transmitting window, a light-reflecting curved inner cavity, a catalyst support and a gas path; the light-reflecting curved inner cavity is arranged below the light-transmitting window; the light-transmitting window and the light-reflecting curved inner cavity form a closed reaction cavity; the catalyst support is arranged in the reaction cavity; the gas path is connected to the light-reflecting curved inner cavity, and then connected to the reaction cavity. The photocatalytic reactor designed by the present invention, which includes a light-receiving surface of a curved reactor inner cavity, improves the light utilization rate by changing the light path, and the incident photon utilization rate is higher under the same light intensity conditions, so that the catalytic effect is more excellent, and at the same time overcomes the problem that the concentration of reactants is reduced and light scattering is caused by the retention of condensed water, so that the reaction cannot continue to proceed in the positive direction, and the gas in the reaction cavity can circulate spontaneously, thereby improving the mass transfer efficiency of the reactants and promoting the forward reaction.

Description

Technical Field

[0001] The present invention belongs to the technical field of light-driven reaction device design, and relates to a photoreactor and its application, and in particular to a solar photoreactor with high light utilization rate and high mass transfer efficiency and its application in photoreaction. Background Art

[0002] Photocatalytic technology is an environmentally friendly green technology. It can be used in the energy field to convert low-density solar energy into storable, high-density clean energy hydrogen; it can also be used in the environmental field to use light energy to degrade and mineralize organic and inorganic pollutants in the environment. Therefore, it can be said that photocatalytic technology is a green technology with important application prospects in the fields of energy and environment. Currently, the photocatalytic reactors on the market can be divided into flat-plate reactors, shallow pool reactors, tubular reactors, and ring reactors according to the structure and shape of the reactor.

[0003] However, the current application of photocatalytic technology has long been constrained by its low energy conversion efficiency, which has become a shackle restricting the further development of photocatalytic technology.

[0004] Therefore, how to design a more suitable photocatalytic reactor and improve the photocatalytic reaction efficiency has become one of the technical problems that many forward-looking researchers in this technical field need to solve urgently. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a photoreactor and its application, in particular, a solar photoreactor with high light utilization rate and high mass transfer efficiency. The solar photoreactor provided by the present invention, which includes a curved reactor inner cavity light receiving surface, solves the key problems of poor light focusing effect of ordinary catalytic reactors, low mass transfer efficiency of reactants on the catalyst surface, reduced reactant concentration and light scattering caused by condensation during the reaction.

[0006] The present invention provides a photoreactor, comprising:

[0007] Light-transmitting window, light-reflecting curved inner cavity, catalyst support and gas path;

[0008] The light-reflecting curved inner cavity is arranged below the light-transmitting window;

[0009] The light-transmitting window sheet and the light-reflecting curved inner cavity form a closed reaction cavity;

[0010] The catalyst support is arranged in the reaction chamber;

[0011] The gas path is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity.

[0012] Preferably, the light-transmitting window sheet comprises a high-light-transmitting window sheet;

[0013] The light transmittance of the light-transmitting window sheet is 50% to 100%;

[0014] The material of the light-transmitting window sheet includes quartz and / or barium fluoride;

[0015] The light-transmitting window sheet is specifically a light-incident light-transmitting window sheet.

[0016] Preferably, the thickness of the light-transmitting window sheet is 2-10 mm;

[0017] The light-reflecting curved surface inner cavity is specifically a light-receiving curved surface inner cavity;

[0018] The curved surface of the light-reflecting curved surface inner cavity includes a continuous smooth curved surface, a splicing of multi-directional curved surfaces or a special-shaped single curved surface.

[0019] Preferably, the light-receiving curved surface of the light-reflective curved surface inner cavity is made of one or more of stainless steel, carbon-manganese steel, nickel-based alloy and zirconium;

[0020] The curved surface of the reflective curved cavity satisfies the following parabola formula: y=x 2 / p; x and y are the horizontal and vertical coordinates respectively, and p is 35~73;

[0021] The catalyst support is provided with a catalyst tray for holding catalyst sheets;

[0022] The front side of the catalyst tray faces the light-transmitting window sheet, and the back side has an annular hollow arrangement for exposing the catalyst sheet.

[0023] Preferably, the catalyst tray is located between the light reflection focus formed by the light-transmitting window and the light-receiving curved surface in the height direction;

[0024] The radial dimension of the catalyst tray and / or catalyst sheet is 1 / 3 to 5 / 6 of the radial dimension of the light-transmitting portion of the light-transmitting window sheet;

[0025] The annular hollowing on the back of the catalyst tray is arranged to overlap with the light ring formed by the secondary light reflection of the light receiving curved surface;

[0026] The gas circuit includes a plurality of gas circuits.

[0027] Preferably, the photoreactor further comprises one or more of a reactor cover, a positioning device, a sealing ring, a sampling port and a reactor base;

[0028] The reactor base is fixed to the periphery of the light-reflecting curved surface inner cavity;

[0029] The reactor cover is stacked on the light-transmitting window sheet;

[0030] The gas circuit includes an air inlet circuit and an air outlet circuit.

[0031] Preferably, the reactor cover and the reactor base are fixed by a positioning device to achieve sealing between the light-transmitting window and the light-reflecting curved inner cavity, thereby forming a sealed reaction cavity;

[0032] The sealing ring is arranged on one side or both sides of the light-transmitting window sheet;

[0033] The sampling port is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity;

[0034] The photoreactor further comprises one or more of an air inlet valve, an air outlet valve, a pressure gauge, a thermocouple, a circulating condensed water pipeline, a pressurizing device and a heating device.

[0035] The present invention also provides the use of the photoreactor in photoreaction;

[0036] The photoreactor comprises:

[0037] Light-transmitting window, light-reflecting curved inner cavity, catalyst support and gas path;

[0038] The light-reflecting curved inner cavity is arranged below the light-transmitting window;

[0039] The light-transmitting window sheet and the light-reflecting curved inner cavity form a closed reaction cavity;

[0040] The catalyst support is arranged in the reaction chamber;

[0041] The gas path is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity.

[0042] Preferably, the photoreaction comprises utilizing sunlight and / or other light sources to drive a gas-solid two-phase chemical reaction or a gas-liquid-solid three-phase chemical reaction;

[0043] The applications include applications in improving light utilization and / or mass transfer efficiency in light reaction processes;

[0044] Specifically, the light utilization rate in the light reaction process is improved by uniformly focusing the parallel incident light on the front and back sides of the catalyst sheet to improve the light utilization rate.

[0045] The method of improving the mass transfer efficiency during the photoreaction process specifically comprises that the airflow circulates spontaneously in the reaction chamber of the photoreactor, thereby promoting uniform mixing of the reaction gas and improving the mass transfer efficiency.

[0046] Preferably, the photoreaction includes one or more of a photochemical reaction, a photodecomposition reaction, a photooxidation reaction and a photoreduction reaction;

[0047] The method of improving the mass transfer efficiency during the photoreaction process specifically comprises that the reaction condensate spontaneously circulates in the reaction chamber of the photoreactor to avoid the retention of the condensate and improve the mass transfer efficiency;

[0048] The light-reflective curved surface inner cavity comprises a light-reflective curved surface inner cavity with a coating.

[0049] The present invention provides a photoreactor, the photoreactor comprising: a light-transmitting window, a light-reflecting curved inner cavity, a catalyst support and a gas path; the light-reflecting curved inner cavity is arranged below the light-transmitting window; the light-transmitting window and the light-reflecting curved inner cavity form a closed reaction cavity; the catalyst support is arranged in the reaction cavity; the gas path is connected to the light-reflecting curved inner cavity, and then connected to the reaction cavity. Compared with the prior art, the present invention aims at the problem of low energy conversion efficiency of the existing photocatalytic reaction. The research believes that in addition to the low conversion efficiency of the photocatalyst itself to photons, there are also key problems such as poor light focusing effect of the catalytic reactor, low mass transfer efficiency of reactants on the catalyst surface, reduced reactant concentration and light scattering caused by condensation during the reaction. The present invention is based on the shortcoming of the existing reactors on the market, that is, insufficient light utilization rate. In particular, the light-receiving surface of the inner cavity of the reactor is improved to change the light path, thereby improving the light utilization rate. At the same time, further improvements are made so that the reactor light entrance window and the catalyst sheet have a certain temperature to improve the mass transfer efficiency and prevent the occurrence of condensation. Finally, a solar reactor with high light utilization rate and high mass transfer efficiency is obtained.

[0050] The photocatalytic reactor designed in the present invention has a specific structure and includes a curved reactor inner cavity light-receiving surface. Its advantage is that the light path is changed to improve the light utilization rate. Under the same light intensity conditions, the incident photon utilization rate is higher, so the catalytic effect is better. At the same time, due to the heating of the light window above, condensation is avoided, thereby overcoming the problems of reduced reactant concentration and light scattering caused by condensed water retention, which makes the reaction unable to continue in the positive direction. The laminar flow of the reactor is simulated, and it is found that the gas in the reaction chamber can circulate spontaneously during the reaction to make the catalyst sheet fully contact with the gas, improve the mass transfer efficiency of the reactants on the catalyst surface, and promote the forward reaction.

[0051] The solar photoreactor has a high light utilization rate. The curved reactor cavity can reflect the incident light from the light inlet through the light receiving surface of the curved reactor cavity and converge it at the focus. After converging at the focus, it hits the light receiving surface of the reactor cavity again, and converges on the back of the catalyst sheet after reflection. At this time, all parallel incident light is basically converged on the front and back sides of the catalyst sheet. Compared with ordinary catalytic reactors, the utilization rate of incident photons is greatly improved; and the gas in the reaction chamber can circulate spontaneously during the reaction: the airflow in the reaction chamber circulates spontaneously to mix the reaction gas evenly. With the air inlet slightly cut from the inner wall of the reactor, the reaction gas is fully in contact with the catalyst sheet, which improves the mass transfer efficiency of the reactants on the catalyst surface and promotes the forward reaction; at the same time, it also has the characteristics of participating in and improving the circulation efficiency of the catalytic reaction condensate. After the reaction starts, under the irradiation of light, the catalyst sheet will be heated to a temperature higher than the condensation temperature, so that the liquid begins to evaporate to the light entrance window. Therefore, when the temperature in the reaction chamber is high, the temperature at the light-entering window is also higher than the condensation temperature, so there will be no condensate on the light-entering window, and the vapor form will fully contact the catalyst to improve the mass transfer efficiency. When the temperature in the reaction chamber is low, the condensate will also appear at the edge of the light-transmitting window, and then drip into the inner cavity of the catalytic reactor, reducing the impact on the reaction process. At the same time, it can also be heated to the gas phase with the help of the circulating high-temperature airflow, forming a spontaneous circulation flow. Therefore, the above two steps are circulated back and forth to improve the mass transfer efficiency, thereby overcoming the problem that the condensate retention causes the catalysis to be unable to continue in the positive reaction direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of the 3D structural disassembly of a solar photoreactor with high light utilization and high mass transfer efficiency provided by the present invention;

[0053] Figure 2 This is a temperature simulation diagram when parallel light irradiates the reactor in Example 2 of the present invention;

[0054] Figure 3 This is a light path diagram of the light in the inner cavity of the curved reactor when parallel light is incident on the reactor in Example 2 of the present invention;

[0055] Figure 4 This is a light spot diagram when parallel incident light hits both the front and back sides of the catalyst sheet in Example 2 of the present invention; wherein, Figure 4 (a) is the front side of the catalyst sheet. Figure 4 (b) is the back side of the catalyst sheet;

[0056] Figure 5 Schematic diagram of reaction gas flow in a reactor simulated in Example 2 of the present invention.

[0057] In the figure, 1 is the reactor cover, 2 is the high light transmittance window, 3 is the positioning bolt, 4 is the sealing ring, 5 is the reflective reaction cavity, 6 is the reactor base, 7 is the gas inlet / outlet 1 (which can be connected to a pressure gauge or other measuring device), 8 is the gas inlet / outlet 2 (which can be connected to a pressure gauge or other measuring device), 9 is the gas inlet / outlet 3 (which can be connected to a pressure gauge or other measuring device), 10 is the catalyst holder, 11 is the sampling port; 12 is the focus of the reflected light; 13 and 14 are the two endpoints of the catalyst sheet; 15 is the incident light; 16 is the reflected light. DETAILED DESCRIPTION

[0058] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention rather than limiting the patent claims of the present invention.

[0059] The raw materials involved in the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0060] The raw materials involved in the present invention have no particular limitation on their purity. The present invention preferably uses the conventional purity in the field of photocatalytic reaction.

[0061] All process and device names and their abbreviations in the present invention are conventional abbreviations in the field. Each name is clear and unambiguous in the field of its relevant use. Those skilled in the art can understand its conventional process steps and device structures based on the names.

[0062] The present invention provides a photoreactor, comprising:

[0063] Light-transmitting window, light-reflecting curved inner cavity, catalyst support and gas path;

[0064] The light-reflecting curved inner cavity is arranged below the light-transmitting window;

[0065] The light-transmitting window sheet and the light-reflecting curved inner cavity form a closed reaction cavity;

[0066] The catalyst support is arranged in the reaction chamber;

[0067] The gas path is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity.

[0068] In the present invention, the light-transmitting window sheet preferably includes a high-light-transmitting window sheet.

[0069] In the present invention, the light transmittance of the light-transmitting window sheet is preferably 50% to 100%, more preferably 60% to 90%, and more preferably 70% to 80%.

[0070] In the present invention, the material of the light-transmitting window sheet preferably includes quartz and / or barium fluoride, and more preferably quartz or barium fluoride.

[0071] In the present invention, the light-transmitting window sheet is preferably a light-incident light-transmitting window sheet.

[0072] In the present invention, the thickness of the light-transmitting window sheet is preferably 2-10 mm, more preferably 3.5-8.5 mm, and more preferably 5-7 mm.

[0073] In the present invention, the radius of the light-transmitting window sheet is preferably 20-60 mm, more preferably 25-55 mm, more preferably 30-50 mm, and more preferably 35-45 mm.

[0074] In the present invention, the light-reflecting curved surface inner cavity is preferably a light-receiving curved surface inner cavity.

[0075] In the present invention, the curved surface of the light-reflective curved surface inner cavity preferably includes a continuous smooth curved surface, a splicing of multi-directional curved surfaces or a special-shaped single curved surface.

[0076] In the present invention, the light receiving curved surface of the light reflective curved inner cavity is preferably made of one or more of stainless steel, carbon manganese steel, nickel-based alloy and zirconium, more preferably stainless steel, carbon manganese steel, nickel-based alloy or zirconium. Specifically, the nickel-based alloy is Hastelloy alloy or Monel alloy.

[0077] In the present invention, the curved surface of the reflective curved surface cavity preferably satisfies the following parabola formula: y=x 2 / p; wherein x and y are the horizontal and vertical coordinates respectively, and p is preferably 35-73, more preferably 40-70, more preferably 45-65, and more preferably 50-60.

[0078] In the present invention, the catalyst support is preferably provided with a catalyst tray for holding catalyst sheets.

[0079] In the present invention, the catalyst tray preferably has its front side facing the light-transmitting window sheet, and its back side has an annular hollow arrangement through which the catalyst sheet can be exposed.

[0080] In the present invention, the catalyst tray is preferably located between the light-transmitting window and the light-reflecting focus formed by the light-receiving curved surface in the height direction.

[0081] The radial dimension of the catalyst tray and / or catalyst sheet is preferably 1 / 3 to 5 / 6 of the radial dimension of the light-transmitting portion of the light-transmitting window sheet, more preferably 5 / 12 to 11 / 12, more preferably 1 / 2 to 4 / 6, more preferably 7 / 12 to 3 / 4.

[0082] In the present invention, the annular hollowing on the back of the catalyst tray is preferably arranged to coincide with the light ring formed by the secondary light reflection of the light receiving curved surface;

[0083] In the present invention, the gas path preferably includes a plurality of gas paths.

[0084] In the present invention, the photoreactor preferably also includes one or more of a reactor cover, a positioning device, a sealing ring, a sampling port and a reactor base, more preferably a reactor cover, a positioning device, a sealing ring, a sampling port or a reactor base.

[0085] In the present invention, the reactor base is preferably fixed to the periphery of the light-reflecting curved surface inner cavity;

[0086] In the present invention, the reactor cover is preferably laminated on the light-transmitting window sheet.

[0087] In the present invention, the gas path preferably includes an inlet path and an outlet path. Further, in the present invention, the positions of the inlet and outlet ports can be adjusted to increase the overall flow rate in the reaction chamber.

[0088] In the present invention, the reactor cover and the reactor base are preferably fixed by a positioning device to achieve sealing between the light-transmitting window and the light-reflecting curved inner cavity to form a sealed reaction cavity.

[0089] In the present invention, the sealing ring is preferably arranged on one side or both sides of the light-transmitting window sheet.

[0090] In the present invention, the sampling port is preferably connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity;

[0091] In the present invention, the photoreactor preferably also includes one or more of an air inlet valve, an air outlet valve, a pressure gauge, a thermocouple, a circulating condensed water pipeline, a pressurizing device and a heating device, and more preferably an air inlet valve, an air outlet valve, a pressure gauge, a thermocouple, a circulating condensed water pipeline, a pressurizing device or a heating device.

[0092] The present invention provides the application of a photoreactor in a photoreaction;

[0093] The photoreactor comprises:

[0094] Light-transmitting window, light-reflecting curved inner cavity, catalyst support and gas path;

[0095] The light-reflecting curved inner cavity is arranged below the light-transmitting window;

[0096] The light-transmitting window sheet and the light-reflecting curved inner cavity form a closed reaction cavity;

[0097] The catalyst support is arranged in the reaction chamber;

[0098] The gas path is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity.

[0099] In the present invention, the photoreaction preferably includes utilizing sunlight and / or other light sources to drive a gas-solid two-phase chemical reaction or a gas-liquid-solid three-phase chemical reaction, and more preferably utilizing sunlight or other light sources to drive a gas-solid two-phase chemical reaction or a gas-liquid-solid three-phase chemical reaction.

[0100] In the present invention, the application preferably includes the application of improving the light utilization rate and / or mass transfer efficiency in the photoreaction process, and more preferably the application of improving the light utilization rate or mass transfer efficiency in the photoreaction process.

[0101] In the present invention, the method of improving the light utilization rate in the photoreaction process is preferably that the photoreactor improves the light utilization rate by uniformly converging parallel incident light on the front and back sides of the catalyst sheet.

[0102] In the present invention, the mass transfer efficiency in the photoreaction process is improved preferably by spontaneously circulating the airflow in the reaction chamber of the photoreactor to promote uniform mixing of the reaction gases and improve the mass transfer efficiency.

[0103] In the present invention, the photoreaction preferably includes one or more of a photochemical reaction, a photodecomposition reaction, a photooxidation reaction and a photoreduction reaction, and more preferably includes a photochemical reaction, a photodecomposition reaction, a photooxidation reaction or a photoreduction reaction.

[0104] In the present invention, the mass transfer efficiency in the light reaction process is preferably improved by spontaneously circulating the reaction condensate in the reaction chamber of the photoreactor to avoid condensate retention and improve the mass transfer efficiency. When the temperature in the reaction chamber is high enough and there is no condensate, the steam form is in full contact with the catalyst to improve the mass transfer efficiency. When the temperature in the reaction chamber is low, the condensate formed by water at the edge of the light-transmitting window sheet will also form a spontaneous circulation flow.

[0105] In the present invention, the light-reflective curved surface inner cavity preferably includes a light-reflective curved surface inner cavity with a coating.

[0106] The present invention is a complete and detailed overall technical solution to better improve the light utilization rate and mass transfer efficiency of the photoreactor during the photoreaction process. The above-mentioned solar photoreactor with high light utilization rate and high mass transfer efficiency and its application in the photoreaction may specifically include the following contents:

[0107] A solar photoreactor with high light utilization and high mass transfer efficiency comprises a high light transmittance window, a specially made curved reflective reaction cavity, a catalyst support, a gas path and other accessories.

[0108] Specifically, the light incident window can be a quartz window, a barium fluoride window, etc., and its material, transmittance and transmission band, surface shape, smoothness, radius, thickness, pressure resistance, parallelism difference and other parameters can be adjusted according to the reaction conditions.

[0109] Specifically, the light-receiving surface of the inner cavity of the reactor is a curved surface, which can reflect part of the incident light and converge it on the back side where the catalyst is located.

[0110] Specifically, the light-receiving surface of the inner cavity of the reactor may be a continuous smooth curved surface, or may be transformed into a splicing of multi-directional curved surfaces, a special-shaped single curved surface, or the like.

[0111] Specifically, the light reflectivity, water absorption, material and other parameters of the curved surface can be adjusted by changing the coating on the light-receiving surface of the reactor cavity.

[0112] Specifically, the catalyst support is hollowed out, and the shape of the central support sheet and the connection method with the outer frame are adjustable.

[0113] Specifically, the radius of the catalyst support portion is preferably 1 / 3 to 5 / 6 of the radius of the light incident window.

[0114] Specifically, the catalyst support height is preferably close to the light incident window.

[0115] Specifically, the catalyst sheet is placed on a hollow support. The catalyst sheet refers to a sheet on which the catalyst is evenly coated or dripped, and the sheet can be made of quartz fiber, glass fiber, etc., but is not limited thereto.

[0116] Specifically, the solar reactor can be equipped with other accessories, such as three reserved external pipes, to which any accessories can be added, such as an air inlet valve, an air outlet valve, a pressure gauge, a thermocouple, circulating condensed water, etc. The reactor can also be pressurized and heated.

[0117] Specifically, the provided reactor can utilize sunlight or other light sources to efficiently drive gas-solid two-phase or gas-liquid-solid three-phase chemical reactions.

[0118] Specifically, the reactor can be used in all applicable light-adding reactions, such as photosynthesis, photodecomposition, photooxidation, photoreduction, etc.

[0119] Specifically, for gas-solid phase reaction, the catalyst sheet can be placed on a hollow bracket, and for gas-liquid-solid three-phase reaction, a liquid-holding vessel similar to a watch glass can be directly placed above the bracket in the reaction chamber, and the catalyst can be added therein. Such solutions are not limited to these.

[0120] Specifically, the material of the reactor can be any one, including but not limited to stainless steel, PTFE and the like.

[0121] See also Figure 1 , Figure 1 A schematic diagram of the 3D structural disassembly of a solar photoreactor with high light utilization and high mass transfer efficiency provided by the present invention.

[0122] The above content of the present invention provides a solar photoreactor with high light utilization rate and high mass transfer efficiency and its application in photoreaction. The photocatalytic reactor designed by the present invention has a specific structure and includes a curved reactor inner cavity light-receiving surface. Its advantage is that it changes the light path to improve the light utilization rate. Under the same light intensity conditions, the incident photon utilization rate is higher, making the catalytic effect more excellent. At the same time, due to the heating of the upper light window to avoid the occurrence of condensation, the concentration of reactants is reduced and the light scattering problem caused by the retention of condensed water is overcome, which makes the reaction unable to continue in the positive direction. The laminar flow of the reactor is simulated to obtain that the gas in the reaction chamber can spontaneously circulate during the reaction so that the catalyst sheet is fully in contact with the gas, improving the mass transfer efficiency of the reactants on the catalyst surface and promoting the reaction to proceed in the positive direction.

[0123] The solar photoreactor has a high light utilization rate. The curved reactor cavity can reflect the incident light from the light inlet through the light receiving surface of the curved reactor cavity and converge it at the focus. After converging at the focus, it hits the light receiving surface of the reactor cavity again, and converges on the back of the catalyst sheet after reflection. At this time, all parallel incident light is basically converged on the front and back sides of the catalyst sheet. Compared with ordinary catalytic reactors, the utilization rate of incident photons is greatly improved; and the gas in the reaction chamber can circulate spontaneously during the reaction: the airflow in the reaction chamber circulates spontaneously to mix the reaction gas evenly. With the air inlet slightly cut from the inner wall of the reactor, the reaction gas is fully in contact with the catalyst sheet, which improves the mass transfer efficiency of the reactants on the catalyst surface and promotes the forward reaction; at the same time, it also has the characteristics of participating in and improving the circulation efficiency of the catalytic reaction condensate. After the reaction starts, under the irradiation of light, the catalyst sheet will be heated to a temperature higher than the condensation temperature, so that the liquid begins to evaporate to the light entrance window. Therefore, when the temperature in the reaction chamber is high, the temperature at the light-entering window is also higher than the condensation temperature, so there will be no condensate on the light-entering window, and the vapor form will fully contact the catalyst to improve the mass transfer efficiency. When the temperature in the reaction chamber is low, the condensate will also appear at the edge of the light-transmitting window, and then drip into the inner cavity of the catalytic reactor, reducing the impact on the reaction process. At the same time, it can also be heated to the gas phase with the help of the circulating high-temperature airflow, forming a spontaneous circulation flow. Therefore, the above two steps are circulated back and forth to improve the mass transfer efficiency, thereby overcoming the problem that the condensate retention causes the catalysis to be unable to continue in the positive reaction direction.

[0124] In order to further illustrate the present invention, a photoreactor and its application provided by the present invention are described in detail in combination with embodiments below. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The protection scope of the present invention is not limited to the following embodiments.

[0125] Example 1

[0126] Specific parameter settings of solar photoreactor

[0127] The invention provides a solar photoreactor with high light utilization rate and high mass transfer efficiency, which is made of stainless steel.

[0128] It includes a reactor cover with screw holes (compatible with positioning bolts for reactor fastening and sealing), a high light transmittance window, and the lower part of the reactor includes a specially made reflective reaction cavity, a catalyst holder placed in the center of the cavity, a gas path and a pressure gauge.

[0129] A sealing ring and a quartz high-transmittance window with a radius of 47mm and a thickness of 5mm are provided between the upper cover of the reactor and the lower part of the reactor. The high-transmittance window is 30.19mm away from the bottom of the reactor cavity. The lower part of the reactor uses a parabola as the light-receiving surface of the reflective reaction cavity of the reactor. The focal position is 13.25mm away from the bottom of the reflective reaction cavity of the reactor, and the radius of the light-transmitting part of the reactor is 40mm. The lower part of the reactor includes a hollow catalyst sheet bracket with a height of 27mm and a radius of 30mm, and glass fiber is used as the catalyst sheet. A septum is placed at the sampling port for easy sampling.

[0130] Three inlet / outlet external pipes are reserved outside the reactor, which are connected to the inlet valve, outlet valve and pressure gauge respectively. Thus, a cylindrical reactor is formed with a volume of 73.154 ml.

[0131] The schematic diagram of the solar reactor structure processed according to the parameters is as follows: Figure 1 shown.

[0132] Example 2

[0133] Application of solar photoreactor in CO2 catalytic conversion to methane

[0134] First, 5 mg of CuPt-loaded nano-Au catalyst was evenly coated on both sides of the glass fiber, and 3 mL of deionized water was added to wet the catalyst sheet and placed on the hollow reactor support. The reactor was sealed and CO2 reaction gas was introduced until the gas filled the reactor cavity. The reaction was carried out under a light intensity of 1000 mW / cm 2The reaction was carried out for 3 h under the irradiation of xenon lamp. After the reaction was completed, a needle was used to take a sample from the sampling port to the gas chromatograph to quantitatively measure the CH4 production.

[0135] When the solar reactor is in stable operation, the temperature of the light-entering window rises to 190 degrees, which is higher than the boiling point of water. This can effectively avoid the problem of reduced reactant concentration and light scattering caused by condensation of water vapor on the upper light window. Figure 2 shown.

[0136] See also Figure 2 , Figure 2 This is a temperature simulation diagram when parallel light irradiates the reactor in Example 2 of the present invention.

[0137] See also Figure 3 , Figure 3 This is a light path diagram of the light in the inner cavity of the curved reactor when parallel light enters the reactor in Example 2 of the present invention.

[0138] See also Figure 4 , Figure 4 This is the spot diagram when the parallel incident light hits the front and back sides of the catalyst sheet in Example 2 of the present invention. Figure 4 (a) is the front side of the catalyst sheet. Figure 4 (b) is the back side of the catalyst sheet.

[0139] See also Figure 5 , Figure 5 Schematic diagram of reaction gas flow in a reactor simulated in Example 2 of the present invention.

[0140] Light path simulation diagram of this solar photoreactor ( Figure 3 ) shows that part of the incident light is directly absorbed by the front side of the catalyst sheet (see Figure 4 (a)), the remaining part is reflected by the light-receiving surface of the inner cavity of the parabolic reactor and converges at the focus 12 of the reflected light, and is reflected again to the ring on the back of the catalyst sheet. The two ends 13 and 14 of the catalyst sheet are the two ends of the outer ring (see Figure 4 (b)). At this time, theoretically, all incident light is basically focused on the front and back sides of the catalyst sheet. Compared with ordinary catalytic reactors, the utilization rate of incident photons is greatly improved.

[0141] The reaction gas in the solar reactor will circulate spontaneously due to the thermal convection effect, so that the CO2 reaction gas is fully in contact with the catalyst sheet, improving the mass transfer efficiency of the reactants on the catalyst surface. The simulated laminar flow diagram is shown in Figure 5.

[0142] The CO2 catalytic conversion efficiency of the solar photoreactor is 1~1.5 mmol·g -1 ·h -1 .

[0143] Comparative Example 1

[0144] A flat-plate reactor is used as a photocatalytic reactor.

[0145] The reaction materials and reaction conditions were the same as those in Example 2, and the light intensity was 1000 mW / cm 2 The reaction was carried out for 3 hours under the irradiation of a xenon lamp. After the reaction was completed, a sample was taken into a gas chromatograph to quantitatively measure the CH4 production.

[0146] The CO2 catalytic conversion efficiency of the flat-plate reactor is 0.1~0.2 mmol·g -1 ·h -1 .

[0147] The above is a detailed introduction to a solar photoreactor with high light utilization rate and high mass transfer efficiency provided by the present invention and its application in photoreaction. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A photoreactor, characterized in that: The photoreactor comprises: Light-transmitting window, light-reflecting curved inner cavity, catalyst support and gas path; The light-reflecting curved inner cavity is arranged below the light-transmitting window; The light-transmitting window sheet and the light-reflecting curved inner cavity form a closed reaction cavity; The catalyst support is arranged in the reaction chamber; The gas path is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity; The catalyst support is provided with a catalyst tray for holding catalyst sheets; The front side of the catalyst tray faces the light-transmitting window sheet, and the back side has an annular hollow setting for exposing the catalyst sheet; The catalyst tray is located between the light reflection focus formed by the light-transmitting window and the light-receiving curved surface in the height direction; The radial dimension of the catalyst tray and / or catalyst sheet is 1 / 3 to 5 / 6 of the radial dimension of the light-transmitting portion of the light-transmitting window sheet; The annular hollowing on the back side of the catalyst tray is arranged to overlap with the light ring formed after the secondary light reflection of the light receiving curved surface.

2. The photoreactor according to claim 1, characterized in that The light-transmitting window sheet comprises a high-light-transmitting window sheet; The light transmittance of the light-transmitting window sheet is 50% to 100%; The material of the light-transmitting window sheet includes quartz and / or barium fluoride; The light-transmitting window sheet is a light-incident light-transmitting window sheet.

3. The photoreactor according to claim 1, characterized in that: The thickness of the light-transmitting window sheet is 2-10 mm; The light-reflecting curved surface inner cavity is a light-receiving curved surface inner cavity; The curved surface of the light-reflecting curved surface inner cavity includes a continuous smooth curved surface, a splicing of multi-directional curved surfaces or a special-shaped single curved surface.

4. The photoreactor according to claim 3, characterized in that The light-receiving curved surface of the light-reflective curved surface inner cavity is made of one or more of stainless steel, carbon-manganese steel, nickel-based alloy and zirconium; The curved surface of the reflective curved inner cavity satisfies the following parabola formula: y=x 2 / p; where x and y are the horizontal and vertical coordinates respectively, and p is 35~73.

5. The photoreactor according to claim 4, characterized in that: The gas circuit includes a plurality of gas circuits.

6. The photoreactor according to claim 1, characterized in that: The photoreactor further comprises one or more of a reactor cover, a positioning device, a sealing ring, a sampling port and a reactor base; The reactor base is fixed to the periphery of the light-reflecting curved surface inner cavity; The reactor cover is stacked on the light-transmitting window sheet; The gas circuit includes an air inlet circuit and an air outlet circuit.

7. The photoreactor according to claim 6, characterized in that The reactor cover and the reactor base are fixed by a positioning device to achieve sealing between the light-transmitting window and the light-reflecting curved inner cavity, thereby forming a sealed reaction cavity; The sealing ring is arranged on one side or both sides of the light-transmitting window sheet; The sampling port is connected to the light reflective curved surface inner cavity, and further connected to the reaction cavity; The photoreactor further comprises one or more of an air inlet valve, an air outlet valve, a pressure gauge, a thermocouple, a circulating condensed water pipeline, a pressurizing device and a heating device.

8. Use of the photoreactor according to any one of claims 1 to 7 in photoreaction.

9. The use according to claim 8, characterized in that: The photoreaction includes utilizing sunlight and / or other light sources to drive a gas-solid two-phase chemical reaction or a gas-liquid-solid three-phase chemical reaction; The applications include applications in improving light utilization and / or mass transfer efficiency in light reaction processes; The light utilization rate in the light reaction process is improved by the photoreactor uniformly converging parallel incident light on the front and back sides of the catalyst sheet to improve the light utilization rate; The method for improving the mass transfer efficiency in the photoreaction process is that the airflow circulates spontaneously in the reaction chamber of the photoreactor to promote uniform mixing of the reaction gas and improve the mass transfer efficiency.

10. The use according to claim 8, characterized in that: The photoreaction includes one or more of photochemical reaction, photodecomposition reaction, photooxidation reaction and photoreduction reaction; The applications include applications in improving light utilization and / or mass transfer efficiency in light reaction processes; The mass transfer efficiency during the photoreaction process is improved by allowing the reaction condensate to circulate spontaneously in the reaction chamber of the photoreactor to avoid condensate retention and improve the mass transfer efficiency; The light-reflective curved surface inner cavity comprises a light-reflective curved surface inner cavity with a coating.

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