Photothermal synergistic methane-carbon dioxide dry reforming device

Abstract

The utility model relates to a kind of methane-carbon dioxide dry reforming device of photo-thermal cooperation, including gas distribution tank, tubular reactor, electric heating furnace, light beam generator and gas chromatograph;The upper portion of the tubular reactor is placed in electric heating furnace, and the lower portion side wall is provided with the raw material gas inlet of connecting gas distribution tank, and the bottom is provided with the reforming gas outlet of connecting gas chromatograph;The tubular reactor is provided with photocatalyst reservoir, the light beam generator generates specific wavelength light beam according to the property of photocatalyst, and makes the raw material gas of methane and carbon dioxide composition occur reaction in photocatalyst reservoir, and generates reforming gas, and the composition of reforming gas is monitored and analyzed by gas chromatograph in real time.The device of the utility model has the advantages of high light utilization, short reaction time, high reforming conversion efficiency, low energy consumption, good safety and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of chemical reaction device, especially, a kind of high-efficiency methane-carbon dioxide dry reforming experimental device in combination with photocatalysis and thermal catalysis synergistic effect belongs to new energy conversion and catalytic reaction engineering technical field. BACKGROUND

[0002] In 1928, Fischer and Tropsch et al. first studied the methane carbon dioxide reforming reaction (Dry reforming of methane, DRM, CH4+CO2→2CO+2H2), and after that, DRM gradually became an important research direction in the academic field. With the advancement of industrialization, the consumption of fossil energy produces a large amount of greenhouse gases, of which CH4 and CO2 account for more than 98% of greenhouse gas emissions, leading to increasingly serious environmental problems such as global warming. Since the methane dry gas reforming reaction can convert CH4 and CO2, two greenhouse gases, into CO and H2, the product is more suitable for the Fischer-Tropsch synthesis to produce gasoline, aviation kerosene, ethanol, and other oxygen-containing compounds and artificial fuels, etc. high value-added chemicals, therefore, methane carbon dioxide reforming has again become a research hotspot widely concerned by the industry and academia.

[0003] It was found that most of the Group VIII metals have good DRM catalytic performance. Among them, noble metal (Rh, Ru, Pt, Ir, Pd) catalysts exhibit excellent carbon deposition resistance and high catalytic activity, but their high cost limits their large-scale industrial application; non-noble metal catalysts (Ni, Co, Fe) also have relatively good catalytic activity and are inexpensive and easy to obtain, making them suitable substitutes for industrial applications. However, the methane carbon dioxide reforming reaction is a strong endothermic reaction, and the reaction process is limited by thermodynamics, requiring high energy input, which is prone to high-temperature carbon deposition sintering and rapid deactivation, thereby affecting the conversion rate of methane dry gas reforming. For example, the reforming activity of Ni / Al2O3 catalyst is very good at 770°C, but the carbon deposition rate increases as the reaction continues. After that, researchers have also tried to use bimetallic catalysts, but the problem is that under long-term high-temperature reaction conditions, bimetallic catalysts are prone to deactivation due to metal element agglomeration. Therefore, developing new catalysts and corresponding supporting reaction devices has become the direction of researchers' efforts.

[0004] In recent years, with the continuous development of clean energy technologies such as solar thermal technology and nuclear energy technology, solar energy as a heat source has made it possible to apply green chemical technology. Researchers have found that green and environmentally friendly photocatalytic technology can make the methane dry reforming reaction proceed under mild conditions, but there are problems such as low solar energy utilization rate due to unreasonable reaction device, thereby causing low reaction conversion rate. SUMMARY

[0005] The utility model mainly aims at the unreasonable reaction device setting of the existing methane dry reforming reaction under the photocatalytic condition, thereby causing the low solar energy utilization rate, leading to the low reaction conversion rate and other problems, provides a kind of methane-carbon dioxide dry reforming experimental device based on photo-thermal cooperation, by optimizing the reactor structure and photo-thermal coupling mode, realize the efficient collaborative use of light energy and heat energy, improve catalytic reaction efficiency.

[0006] The specific scheme adopted by the utility model is as follows.

[0007] A kind of photo-thermal cooperation's methane-carbon dioxide dry reforming experimental device, comprising: gas distribution system, photoelectricity collaborative reaction system and reforming gas real-time monitoring system;The gas distribution system is prepared into uniform mixed gas after methane and carbon dioxide are prepared according to preset proportion, is transported to photoelectricity collaborative reaction system;Methane and carbon dioxide mixed gas is reacted in the photoelectricity collaborative reaction system, and the reforming gas obtained is transported to reforming gas real-time monitoring system and carries out gas component detection, obtains the required methane-carbon dioxide dry reforming experimental data.

[0008] A specific technical scheme is that, in the photo-thermal cooperation's methane-carbon dioxide dry reforming experimental device, the gas distribution system is by methane gas cylinder, carbon dioxide gas cylinder, gas flow meter and gas distribution tank, the upper portion gas pipeline of the methane gas cylinder, carbon dioxide gas cylinder is independently provided with gas flow meter;By adjusting the gas flow meter, the raw material gas obtained after methane and carbon dioxide are inputted into gas distribution tank and mixed uniformly according to preset proportion is transported to the tubular reactor of the photoelectricity collaborative reaction system;Photo-thermal collaborative reaction system is composed of tubular reactor, electric heating furnace and light beam generator;The electric heating furnace is sleeved on the upper portion of tubular reactor, and the reaction temperature in the tubular reactor is accurately adjusted by temperature controller;The tubular reactor is provided with photocatalyst reservoir, and the light beam generator emits light beam of specific wavelength according to light response characteristic and is vertically irradiated on the surface of the photocatalyst reservoir;Monitoring system includes thermocouple, temperature controller and gas chromatograph;The thermocouple is embedded in the photocatalyst reservoir, and the reaction temperature in the tubular reactor is monitored in real time and is fed back to temperature controller.

[0009] Preferably, the tubular reactor is in the form of a double-pipe structure, and the photocatalyst reservoir is located at one end of the double-pipe structure that receives the light beam generated by the light beam generator; the raw material gas enters from the bottom of the outer pipe and flows upwards through the photocatalyst reservoir, and the generated reforming gas is discharged from the bottom of the inner pipe.

[0010] More preferably, the inner pipe of the double-pipe structure is made of quartz, and the outer pipe is made of high-temperature-resistant stainless steel, to ensure the light transmittance and thermal stability.

[0011] More preferably, the photocatalyst reservoir uses a porous ceramic carrier to load metal catalysts, enhancing gas diffusion and light absorption efficiency.

[0012] More preferably, the light beam generator is a tunable wavelength LED light source or a xenon lamp, matched with a filter to match the light response range of the catalyst.

[0013] Compared with the prior art, the present application has the following advantages and effects:

[0014] (1) The tubular reactor of the present application has a double-tube structure, and the double-tube reactor design prolongs the gas residence time and enhances the contact efficiency of the photocatalyst and the reaction gas.

[0015] (2) The device of the present application has the advantage of photocatalytic and thermal catalysis, and through the synergistic effect of the electric heating furnace and the light beam generator, the photocatalyst activity temperature window is widened, and the reaction kinetics is improved.

[0016] (3) The device of the present application is provided with a temperature controller at the electric heater and a thermocouple at the photocatalyst reservoir, which can monitor and adjust the reaction temperature in real time, and through the combination of the thermocouple and the gas chromatograph, the reaction condition is accurately controlled and the product is rapidly analyzed, which is suitable for laboratory research and process optimization.

[0017] (4) The device of the present application has the advantages of high light utilization rate, short reaction time, high reforming conversion efficiency, low energy consumption, good safety, etc. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the light-heat synergistic methane-carbon dioxide reforming device of the present application;

[0019] Figure 2 is Figure 1 is a cross-sectional structure diagram of the tubular reactor, showing the double-tube design and the position of the photocatalyst reservoir;

[0020] Figure 1 , 2 In the present application, 1 is a light beam generator; 2 is an electric heating furnace; 3 is a thermocouple; 4 is a photocatalyst reservoir; 5 is a tubular reactor; 6 is a gas chromatograph; 7 is a gas distribution box; 8 is a carbon dioxide cylinder; 9 is a methane cylinder; 10 is a temperature controller; 11 is an outer sleeve; 12 is an inner sleeve. DETAILED DESCRIPTION

[0021] A light-heat synergistic methane-carbon dioxide dry reforming experimental device, comprising: a gas distribution system, a photoelectric synergistic reaction system and a reforming gas real-time monitoring system.

[0022] The gas distribution system comprises a methane gas cylinder, a carbon dioxide gas cylinder, a gas flow meter and a gas distribution tank, and the methane and the carbon dioxide are mixed at a preset ratio by adjusting the gas flow meter and then are delivered to the reactor.

[0023] The photoelectric synergistic reaction system comprises an electric heating furnace, which is sleeved on the upper portion of the tubular reactor and is used for accurately adjusting the reaction temperature (200-600 DEG C) through a temperature controller, and a light beam generator, which emits a light beam with a specific wavelength according to the light response characteristics (such as ultraviolet light, visible light or infrared light) of the photocatalyst and vertically irradiates the photocatalyst reservoir.

[0024] The reforming gas real-time monitoring system comprises a thermocouple, which is embedded in the photocatalyst reservoir, is used for monitoring the reaction temperature in real time and feeds back to the temperature controller, and a gas chromatograph, which is connected with the reforming gas outlet and is used for analyzing the product composition (including the H2 and CO contents and the CH4 / CO2 conversion rate) online.

[0025] In the device, the gas flow path is as follows: the raw gas enters from the bottom of the outer sleeve, flows upwards through the photocatalyst reservoir and is subjected to a reforming reaction under the synergistic action of light and heat; the generated reforming gas is transferred into the inner sleeve and is discharged from the bottom gas outlet to the gas chromatograph.

[0026] The device will be further described in detail below with reference to the drawings.

[0027] As shown in Figure 1 The photo-thermal synergistic methane-carbon dioxide dry reforming device comprises a gas distribution tank 7, a tubular reactor 5, an electric heating furnace 2, a light beam generator 1 and a gas chromatograph 6; the upper portion of the tubular reactor 5 is arranged in the electric heating furnace 2, the lower portion is provided with a raw gas inlet connected with the gas distribution tank 7, and the bottom is provided with a reforming gas outlet connected with the gas chromatograph 6; the tubular reactor 5 is provided with a photocatalyst reservoir 4; the light beam generator 1 generates a light beam with a specific wavelength according to the properties of the photocatalyst, and makes the raw gas composed of methane and carbon dioxide react in the photocatalyst reservoir 4 to generate reforming gas, which is monitored and analyzed in real time by the gas chromatograph 6.

[0028] In a preferred embodiment, the light beam generator is an adjustable wavelength LED light source or a xenon lamp, which is matched with a filter to match the light response range of the catalyst.

[0029] As shown in Figure 2As shown, the dry reforming device of the light-heat synergistic methane-carbon dioxide is characterized in that the tubular reactor adopts a sleeve structure arranged vertically, comprising an outer sleeve 11 and an inner sleeve 12.

[0030] The photocatalyst storage layer 4 is located at one end of the sleeve structure receiving the light beam generated by the light beam generator 1, and can receive the light beam, the photocatalyst storage layer 4 adopts a porous ceramic carrier to load a metal catalyst (such as a Ni-based or Co-based catalyst), so as to enhance the gas diffusion and light absorption efficiency. The raw gas passes through the outer sleeve 11 of the sleeve structure from bottom to top, passes through the photocatalyst storage layer 4, and is discharged from the inner sleeve 12 of the sleeve structure through the reforming gas outlet; the photocatalyst storage layer 4 is provided with a thermocouple 3 for monitoring the temperature of the methane-carbon dioxide dry reforming reaction process; the electric heating furnace 2 is connected with the temperature controller 10, and the heating temperature of the tubular reactor 5 is controlled through the temperature controller 10; the gas distribution tank 7 is connected with the carbon dioxide cylinder 8 and the methane cylinder 9, and the carbon dioxide cylinder 8 and the methane cylinder 9 are both provided with a gas flow meter, and the carbon dioxide gas and the methane gas with different flow rates are mixed into a certain proportion of carbon dioxide / methane mixed gas through the gas distribution tank 7.

[0031] In a preferred embodiment, the inner sleeve of the sleeve structure is made of quartz, and the outer sleeve is made of high-temperature-resistant stainless steel, so as to ensure the light transmittance and thermal stability.

[0032] Taking Ni / Al2O3 as the photocatalyst as an example, the operation process of the device is described as follows:

[0033] (1) Gas distribution: open the methane and carbon dioxide cylinders, adjust the mixed gas ratio to CH4:CO2=1:1 through the flow meter, the total flow rate is 50 mL / min, and the mixed gas is introduced into the tubular reactor after being mixed in the gas distribution tank.

[0034] (2) Start light-heat synergy: start the electric heating furnace and set the temperature to 400℃; start the light beam generator (wavelength 450nm) to irradiate the photocatalyst storage layer.

[0035] (3) Reaction and monitoring: the raw gas is reformed on the surface of the photocatalyst, the thermocouple monitors the temperature fluctuation in real time (within ±5℃), and the temperature controller automatically adjusts the heating power. The reforming gas is analyzed by the gas chromatograph, and the CH4 conversion rate reaches 85% and the CO2 conversion rate reaches 78%.

[0036] The utility model discloses a kind of, only be the preferred specific implementation of the utility model, but the protection scope of the utility model is not limited to this, any familiar with the technical field of the technology technician in the utility model disclosed technical range, according to the technical scheme and utility model conception of the utility model, it is equivalent to replace or change, it should be covered in the protection scope of the utility model.

Claims

1. A photothermal synergistic methane-carbon dioxide dry reforming device, characterized in that, include: The system includes a gas mixing system, a photoelectric synergistic reaction system, and a real-time reforming gas monitoring system. The gas mixing system mixes methane and carbon dioxide in a preset ratio to form a uniform gas mixture, which is then transported to the photoelectric synergistic reaction system. After the methane and carbon dioxide mixture reacts in the photoelectric synergistic reaction system, the resulting reforming gas is transported to the real-time reforming gas monitoring system for gas component detection to obtain the required methane-carbon dioxide dry reforming experimental data.

2. The photothermal synergistic methane-carbon dioxide dry reforming apparatus as described in claim 1, characterized in that, The gas distribution system consists of a methane cylinder (9), a carbon dioxide cylinder (8), a gas flow meter, and a gas distribution box (7). Gas flow meters are independently installed on the upper gas pipelines of the methane cylinder (9) and the carbon dioxide cylinder (8). By adjusting the gas flow meter, the raw material gas obtained by mixing methane and carbon dioxide in the gas distribution box (7) according to a preset ratio is transported to the tubular reactor (5) of the photoelectric synergistic reaction system. The photothermal synergistic reaction system consists of a tubular reactor (5), an electric heating furnace (2), and a beam generator (1); the electric heating furnace (2) is installed on the upper part of the tubular reactor (5), and the reaction temperature inside the tubular reactor (5) is precisely adjusted by a temperature controller (10); a photocatalyst reservoir (4) is provided inside the tubular reactor (5), and the beam generator (1) emits a beam of a specific wavelength according to the photoresponse characteristics and vertically irradiates the surface of the photocatalyst reservoir (4); The monitoring system includes a thermocouple (3), a temperature controller (10), and a gas chromatograph (6); the thermocouple (3) is embedded in the photocatalyst reservoir to monitor the reaction temperature in the tubular reactor (5) in real time and feed it back to the temperature controller (10).

3. The photothermal synergistic methane-carbon dioxide dry reforming apparatus as described in claim 2, characterized in that, The tubular reactor (5) has a sleeve-like structure inside. The photocatalyst reservoir (4) is located at one end of the sleeve-like structure that receives the light beam generated by the light beam generator (1). The raw material gas enters from the bottom of the outer sleeve and flows upward through the photocatalyst reservoir (4). Under the synergistic effect of photothermal reaction, a reforming reaction occurs. The generated reformed gas is transferred into the inner sleeve and discharged through the bottom outlet.

4. The photothermal synergistic methane-carbon dioxide dry reforming apparatus according to claim 3, characterized in that, The inner sleeve of the tubular structure is made of quartz, while the outer sleeve is made of high-temperature resistant stainless steel, ensuring light transmittance and thermal stability.

5. The photothermal synergistic methane-carbon dioxide dry reforming apparatus according to claim 2 or 3, characterized in that, The photocatalyst reservoir (4) uses a porous ceramic support to support the metal catalyst, thereby enhancing gas diffusion and light absorption efficiency.

6. The photothermal synergistic methane-carbon dioxide dry reforming apparatus according to claim 2 or 3, characterized in that, The beam generator (1) is an adjustable wavelength LED light source or a xenon lamp, which is matched with a filter to match the photoresponse range of the catalyst.

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