A single fluidized bed reaction system for methane calcium chain reforming and its reaction method

Abstract

The present invention discloses a methane calcium chain reforming single fluidized bed reaction system and reaction method, comprising a cylindrical quartz tube filled with reaction particles, an adjustable light source located beside the cylindrical quartz tube with its radiation focus located at the top center of the reaction particles, a thermal insulation layer wrapped around the outside of the cylindrical quartz tube, a position adjustment device for driving the cylindrical quartz tube to move and rotate, thermocouples uniformly distributed within the cylindrical quartz tube, a gas distribution system for supplying reaction gas into the cylindrical quartz tube, a mass spectrometer connected to the gas outlet of the cylindrical quartz tube via a drying tube, and a control system connected to the thermocouple, the gas distribution system, and the mass spectrometer, respectively. The thermal insulation layer is provided with an inlet on the side facing the adjustable light source. The present invention aims to achieve efficient energy absorption and conversion while reducing heat dissipation, capturing CO2 while obtaining high-value-added hydrocarbon fuels.

Description

Technical Field

[0001] The present invention relates to the technical field of fluidized bed reactions, and in particular to a methane calcium chain reforming single fluidized bed reaction system and a reaction method thereof. Background Art

[0002] Photothermal methane calcium chain reforming combines solar-driven calcium cycle thermochemical heat storage technology with methane dry reforming. It can use solar-driven calcium cycle to capture CO2 and achieve CH4 dry reforming, rationally utilizing renewable energy while reducing carbon emissions and alleviating the carbon deposition problem during the reaction process.

[0003] However, most of the existing technical routes used in calcium chain methane dry reforming place the reverse reaction of methane dry reforming reaction and CaO carbonation reaction in two different fluidized bed reactors, connect the two with pipes, and the calcium-based heat transfer medium moves and stays in different areas to produce corresponding reactions. The frequent flow of particles will lead to high heat loss, and the two independent fluidized bed reactors require two light sources or other forms of heat sources to drive the reaction. Therefore, there are extremely high requirements for system design aspects such as pipeline layout, heat source matching, and thermal insulation performance. Moreover, due to the particularity of unilateral solar energy illumination, the light source it provides can often only converge on a single focus. Therefore, the dual fluidized bed solution requires one solar-heated fluidized bed and one electrically heated fluidized bed, and the electric heating method deviates from the original intention of achieving clean energy utilization.

[0004] Therefore, the above problems need to be solved urgently. Summary of the Invention

[0005] Purpose of the invention: The first purpose of the present invention is to provide a single fluidized bed reaction system for methane calcium chain reforming, which aims to achieve efficient absorption and conversion of energy on the basis of reducing heat dissipation, capture CO2 and obtain high-value-added hydrocarbon fuels.

[0006] The second object of the present invention is to provide a reaction method of a single fluidized bed reaction system for methane calcium chain reforming.

[0007] Technical solution: To achieve the above objectives, the present invention discloses a methane calcium chain reforming single fluidized bed reaction system, comprising a cylindrical quartz tube filled with reaction particles, an adjustable light source located beside the cylindrical quartz tube and with the radiation focus located at the top center of the reaction particles, an insulation layer wrapped around the outside of the cylindrical quartz tube, a position adjustment device for driving the cylindrical quartz tube to move, thermocouples evenly distributed in the cylindrical quartz tube, a gas distribution system for supplying reaction gas into the cylindrical quartz tube, a mass spectrometer connected to the gas outlet of the cylindrical quartz tube through a drying tube, and a control system respectively connected to the thermocouple, the gas distribution system and the mass spectrometer, wherein the insulation layer is provided with an inlet on the side facing the adjustable light source.

[0008] Optionally, the shape of the incident port is formed by overlapping several cones whose center lines are located in the same plane. The initial center line of the cone is perpendicular to the plane where the opening side is located, and the vertex of the cone is located on the central axis of the cylindrical quartz tube. The cone is rotated clockwise by a certain angle, and the overlapping part of the cone and the insulation layer is cut to obtain the incident port.

[0009] Optionally, the gas distribution system includes an argon cylinder, a carbon dioxide cylinder and a methane cylinder, each with a flow meter, wherein the argon cylinder, the carbon dioxide cylinder and the methane cylinder are respectively connected to the gas inlet of the columnar quartz tube through a pipe with a heating belt, and the heating belt is connected to the control system.

[0010] Optionally, the reaction particles are Ca-Ni based composite particles.

[0011] Optionally, the stacking height of the reaction particles exceeds the lower end of the incident port of the insulation layer by 3 to 5 mm.

[0012] Optionally, the power of the adjustable light source is adjustable, and the rated power is 1000w.

[0013] Optionally, the adjustable light source is placed on a positioning platform, a pair of support rods are connected between the front side of the positioning platform and the ground, and a pair of electric push rods that can change the illumination angle of the light source are connected between the rear side of the positioning platform and the ground.

[0014] Optionally, the position adjustment device includes a horizontal slide, a vertical slide connected to the slider of the horizontal slide, and an angle-tilted slide connected to the slider of the vertical slide, wherein the working surface of the angle-tilted slide is connected to the columnar quartz tube, and the base of the angle-tilted slide is connected to the slider of the vertical slide.

[0015] Optionally, the drying pipe is also connected to an exhaust pipe.

[0016] Based on the same technical concept, the present invention discloses a reaction method of a single fluidized bed reaction system for methane calcium chain reforming, comprising the following steps:

[0017] By adjusting the position adjustment device and the inclination angle of the adjustable light source, the radiation focus of the adjustable light source is located at the top center of the reaction particle; by rotating the tilt slide, the inclination angle of the columnar quartz tube can be adjusted so that the heat transfer medium inside the quartz tube moves to the radiation irradiation surface under the action of gravity;

[0018] Turn on the heating belt and control the gas distribution system to introduce 3000-5000 mL / min of Ar. From the entrance of the insulation layer, it can be observed that the reaction particles in the cylindrical quartz tube remain stationary. Turn on the adjustable light source and set its power to 800-1000 W. The gas inside the cylindrical quartz tube expands due to the heat, and the particles begin to move and enter the fluidization stage early.

[0019] The gas distribution system is controlled to introduce 2400mL / min of Ar and 600mL / min of CO2. The temperature inside the cylindrical quartz tube is measured by a thermocouple and transmitted to the control system. The reaction particles in the cylindrical quartz tube are continuously fluidized. When the temperature reaches 600℃~650℃, the reaction is controlled to enter the CH4 dry reforming stage.

[0020] The gas distribution system was controlled to introduce 2400 mL / min of Ar and 600 mL / min of CH4, causing CaCO3 decomposition and CH4 dry reforming reactions to occur within the cylindrical quartz tube. The CaCO3 in the reaction particles decomposed into CaO and CO2, and CO2 and CH4 underwent dry reforming. When the mass spectrometer detected that the volume flow rate of CO2 in the exhaust gas was less than 2%, the reaction was controlled to enter the CaO carbonation stage.

[0021] The power of the adjustable light source was adjusted to 600-700W, and the gas distribution system was controlled to introduce 2400mL / min of Ar and 600mL / min of CO2 to remove coke and carbonate CaO. When the mass spectrometer monitored that the volume flow rate of CO2 in the exhaust gas reached 18-22%, the conversion of CaO to CaCO3 was completed.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0023] (1) The present invention uses a laboratory-scale controllable light source to provide radiation energy for the reaction system, realizing photothermal energy conversion and avoiding the carbon emission problem caused by traditional energy input. It has a guiding role in large-scale solar energy utilization and can realize the coordinated utilization and energy storage of solar energy and chemical energy.

[0024] (2) The present invention utilizes measures such as improving the insulation layer and adjusting the relative position of the space to enable the fluidized bed reaction system to fully receive and utilize the radiant heat from the light source. Specifically, the tilt angle of the light source can be flexibly adjusted, and the fluidized bed system is provided with an insulation layer, and the insulation layer has an opening to receive radiation, the shape of the opening matching the radiation characteristics. The vertical and horizontal positions of the fluidized bed can be adjusted very conveniently, and the tilt angle of the fluidized bed can be adjusted so that the working fluid inside the fluidized bed moves toward the radiation irradiation point under the action of gravity, thereby achieving a higher light-to-heat conversion efficiency. The angle adjustment of the integrated light source can obtain the most suitable light source-reactor spatial distribution. In addition, the light source power can also be adjusted in time according to the reaction situation to avoid problems such as uneven temperature field inside the reactor and particle corrosion of the wall.

[0025] (3) The present invention adopts a single fluidized bed to integrate all the reactions involved into a single fluidized bed reactor, which greatly simplifies the design. Only a single heat source is needed to supply heat to the entire system, which is in line with the characteristics of relatively concentrated solar radiation distribution. Compared with the traditional dual fluidized bed structure that separates dry reforming and carbonation, the single fluidized bed solution can avoid the movement of particles in different reactors and utilize the heat generated by the previous reaction to reduce heat loss, thereby having higher energy storage efficiency.

[0026] (4) The present invention utilizes Ca-Ni based composite solid particles as a reaction medium, which simultaneously possesses high energy storage density and high catalytic efficiency; doping with other metal elements is beneficial to improving the spectral absorption capacity, anti-sintering performance and cycle stability of the particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the system of the present invention;

[0028] Figure 2 Schematic diagram of the shape of the thermal insulation layer in the present invention;

[0029] Figure 3 Schematic diagram of the formation of the incident port of the thermal insulation layer in the present invention;

[0030] Figure 4 Schematic diagram of particle movement inside the columnar quartz tube of the present invention;

[0031] Figure 5 This is a graph showing the volume flow rate of each gas-producing component changing with time in the present invention;

[0032] Figure 6 This is a graph showing the temperature inside the columnar quartz tube changing with time in the present invention. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0034] like Figure 1 As shown, a methane calcium chain reforming single fluidized bed reaction system of the present invention includes a columnar quartz tube 1, an adjustable light source 2, an insulation layer 3, a position adjustment device 4, a thermocouple 5, a gas distribution system 6, a drying tube 7, a mass spectrometer 8, a control system 9, a flow meter 10, a positioning platform 11, a support rod 12, an electric push rod 13, an exhaust pipe 14 and a data acquisition system 16.

[0035] The cylindrical quartz tube 1 is filled with reaction particles, and the stacking height of the reaction particles exceeds the lower end of the insulation layer entrance by 3mm to 5mm to ensure that the particles can fully receive the radiant heat released by the adjustable light source 2 and react; the reaction particles are Ca-Ni based composite particles, which are dual-functional particles that integrate high-efficiency energy storage and catalysis. That is, while having high energy storage density and catalytic properties, they also have high spectral absorptivity and cyclic stability; specifically, the CaCO3 / CaO components in the Ca-Ni based composite particles realize thermochemical energy storage, absorb and convert the radiant heat released by the adjustable light source 2, and the Ni element can be used to catalyze the methane dry reforming reaction. The particles are appropriately doped with dark metal elements and stabilizers to improve the spectral absorptivity and cyclic stability of the reaction material. Ca-Ni based composite particles are used as the reaction medium of the methane calcium chain reforming system. During its preparation process, they are also doped with Ce and Al elements, and have excellent energy storage properties, catalytic activity, spectral absorptivity and cyclic stability. The present invention adopts an extrusion spheronization method to prepare particles, wherein the ratio of Ca-Al-Ce-Ni is 100-10-4-12. In the entire photothermal energy storage process of the present invention, all reactions occur inside the columnar quartz tube 1, that is, calcium circulation, methane dry reforming reaction and reverse Boudouard reaction occur in the columnar quartz tube 1. The selected columnar quartz tube 1 has an inner diameter of 26 mm, an outer diameter of 30 mm, and a tube length of 210 mm, and an air distribution plate is installed 70 mm away from the bottom end of the quartz tube. An air distribution plate is provided in the columnar quartz tube 1 to carry the reaction particles and evenly distribute the intake air; Ca-Ni-based composite particles are deposited above the air distribution plate, which has excellent energy storage-catalytic effect. An air inlet is provided at the bottom of the columnar quartz tube 1, and an air outlet is provided at the top of the columnar quartz tube 1. Calcium circulation and methane dry reforming reactions occur within the cylindrical quartz tube 1. Using data from the control system as a reference, the gas distribution system 6 adjusts the intake air, thereby achieving the desired reaction within the cylindrical quartz tube 1. CH4 is first introduced into the tube 1, where CaCO3 decomposes and stores radiant heat, producing CO2 that undergoes a dry reforming reaction with CH4. Once the CaCO3 has completely reacted, meaning the reforming reaction is complete, CO2 is introduced, recarbonating the CaO to form CaCO3, ready for the next cycle. The tube 1 receives radiation and undergoes all relevant reactions, reaching internal temperatures of up to 800°C during the process, ensuring efficient and stable reaction.

[0036] The adjustable light source 2 is located next to the cylindrical quartz tube. It simulates thermal radiation to achieve unilateral illumination, providing heat for the chemical reaction. The radiation focus of the adjustable light source 2 is located at the top center of the reaction particles to prevent particle sintering or corrosion of the wall due to reaction with the components of the quartz tube. The power of the adjustable light source 2 is adjustable, with a rated power of 1000W. The internal program can be set to switch the power from 1000W to 600W every 15 minutes, and then from 600W to 1000W after 15 minutes, for a total of three cycles. As a radiant heat source, the adjustable light source 2 can provide heat and the required high temperature environment for the calcium cycle and methane dry reforming reaction. The introduction of light can reduce the activation energy of the reaction, promoting the reaction to proceed at 600℃-700℃. The adjustable light source 2 is placed on a positioning platform 11. A pair of support rods 12 are connected between the front side of the positioning platform 11 and the ground, and a pair of electric push rods 13 are connected between the rear side of the positioning platform and the ground. The support rod 12 can be a support rod of fixed length or a support rod of adjustable length; the length of the electric push rod 13 is adjustable. By adjusting the length of the electric push rod 13, the inclination angle of the positioning platform is adjusted, and the horizontal inclination angle of the adjustable light source 2 is changed. At the same time, the position adjustment device 4 can drive the columnar quartz tube 1 to move. The position adjustment device 4 includes a horizontal slide, a vertical slide connected to the slider of the horizontal slide, and an angle-tilted slide connected to the slider of the vertical slide, wherein the working surface of the angle-tilted slide 17 is connected to the columnar quartz tube, and the base of the angle-tilted slide 17 is connected to the slider of the vertical slide. The angle-tilted slide 17 can control the vertical inclination angle of the columnar quartz tube 1 to adjust between 0° and 20°. As Figure 4 As shown, the cylindrical quartz tube 1 rotates counterclockwise by a certain angle, causing the particles inside to rise from the inlet due to gas fluidization and then move to the radiation irradiation surface under the action of gravity. By adjusting the position of the cylindrical quartz tube 1, the relative position of the adjustable light source 2 and the cylindrical quartz tube 1 is changed, ensuring that the radiation focus of the adjustable light source 2 is located at the top center of the reaction particles. The optimal distance between the adjustable light source 2 and the cylindrical quartz tube 1 is 12 to 15 cm, and the horizontal tilt angle of the adjustable light source 2 is 20°, which effectively alleviates the problems of light attenuation and reactor corrosion and significantly improves radiation uniformity. The adjustable light source 2 can flexibly adjust the illumination angle, relative distance from the cylindrical quartz tube 1, and operating power to adapt to different reaction conditions within the fluidized bed reactor. The position of the adjustable light source 2 on the positioning platform 11 can change its relative distance from the cylindrical quartz tube 1. Controlling the extension length of the electric push rod 13 on the positioning platform 11 can change the radiation angle of the adjustable light source 2. Changing the power of the adjustable light source 2 at different stages can further control the temperature within the reaction system by varying the illumination intensity. During the dry reforming process, the power of the adjustable light source 2 is changed to control the temperature inside the cylindrical quartz tube 1 to reach 800° C. During the CaO carbonation process, the power of the adjustable light source 2 is changed to control the temperature inside the cylindrical quartz tube 1 to drop to 600° C.

[0037] like Figure 3 and Figure 5 As shown, the insulation layer 3 is wrapped around the outside of the cylindrical quartz tube. The insulation layer 3 has an inlet on the side facing the adjustable light source to receive simulated radiant heat. The simulated solar radiation can be considered as a cone. The volume of the cone depends on the parameters of the lampshade inside the adjustable light source 2. The insulation layer is cut accordingly based on its characteristics. To ensure efficient reaction, the lampshade opening diameter is selected to be 150 to 170 mm, and the focal length is 140 to 170 mm. The shape of the insulation layer inlet is formed by overlapping several cones whose centerlines are located in the same plane. The initial centerline of the cone is perpendicular to the plane of the opening side, and the cone vertex is located on the central axis of the cylindrical quartz tube 1. The cone is rotated 40° clockwise and the overlapping portion of the cone and the insulation layer is cut to obtain the desired insulation layer inlet, which is conducive to fully receiving the radiant heat released by the adjustable light source 2. The spatial distribution can be regarded as the radiant heat of the cone entering the cylindrical quartz tube through the inlet. The radiation generated by the light source lampshade can be regarded as a cone with a bottom side length of 162mm and a height of 15mm. The opening of the insulation layer is cut accordingly according to its characteristics. The main raw material of the insulation layer 3 is aluminum silicate. Its shape and its arrangement with the cylindrical quartz tube 1 are as follows Figure 3 While ensuring the airtightness of the entire columnar quartz tube, the exposed quartz tubes above and below the insulation layer 3 are wrapped with insulation materials such as quartz wool to alleviate the problem of heat loss during system operation.

[0038] Thermocouples 5 are distributed uniformly within the cylindrical quartz tube 1 and connected to a control system. These thermocouples are spaced 2 cm apart along the central axis of the tube, enabling real-time monitoring of temperature changes at different particle heights within the tube, providing accurate thermal distribution data for research. The thermocouples 5 monitor the internal temperature of the tube 1 in real time, and the data is transmitted to the control system, providing a reference for regulating the gas distribution system 6.

[0039] The gas distribution system 6 supplies Ar, CO2, and CH4 into the cylindrical quartz tube. The gas distribution system 6 includes argon, carbon dioxide, and methane cylinders, each equipped with a flowmeter 10. The argon, carbon dioxide, and methane cylinders are each connected to the gas inlet of the cylindrical quartz tube 1 via a pipe with a heating tape 15. The gas distribution system 6 is connected to a control system, which is connected to the control system via a data acquisition system 16. The control system reads the temperature of the gas and particles at different locations in the cylindrical quartz tube 1 to evaluate heat transfer performance and reaction efficiency. The gas distribution system 6 regulates the composition and flow rate of the gas during the reaction. Before entering the cylindrical quartz tube 1, the gas is preheated by the heating tape 15 to improve reaction efficiency. To increase the overall reaction rate, the heating tape 15 is installed in the gas transport channel before entering the cylindrical quartz tube, ensuring that the gas enters the cylindrical quartz tube at a higher temperature and participates in the reaction. The gas flow rate is regulated by the flowmeter 10. By changing reaction parameters such as gas flow rate and radiation intensity, the specific reaction inside the cylindrical quartz tube is determined. The control system can regulate the gas distribution system 6 to change the components and proportions of the gas distribution, and control the internal reaction of the columnar quartz tube to switch between methane dry reforming and calcium oxide carbonation.

[0040] The mass spectrometer 8 is connected to the gas outlet of the columnar quartz tube through the drying tube 7. The drying tube 7 is also connected to an exhaust pipe 14. The mass spectrometer 8 is connected to the control system 9. The interior of the drying tube 7 is filled with color-changing silica gel. The gas discharged from the columnar quartz tube first passes through the drying tube 7 to avoid the interference of moisture and fine dust on subsequent processing. A part of the dry gas is discharged from the exhaust pipe 14, and the remaining dry gas enters the mass spectrometer 8. The data collected by the mass spectrometer 8 is entered into the control system. The mass spectrometer 8 can show the composition and changes of the gas at different times. By connecting the mass spectrometer 8 to the control system, the control system 9 can obtain real-time gas content change images, which has a guiding role in the analysis of the reaction mechanism and can cooperate with the control system to achieve more reasonable and timely regulation of the reaction. Specifically, when the CO2 volume fraction monitored by the control system is 0 and the monitored internal temperature of the system is the highest, the methane dry reforming reaction is basically completed, and the control system can be controlled to enter the calcium oxide carbonation reaction; when the CO2 volume fraction reaches a stable peak value and the internal temperature of the system is the lowest, the calcium oxide carbonation reaction is basically completed, and the control system can re-enter the methane dry reforming reaction.

[0041] The columnar reaction tube involved in the present invention adopts the form of a fluidized bed, and the internal fluid is in full contact with the reaction medium, resulting in less heat loss, higher heat and mass transfer efficiency and more uniform temperature distribution. At the same time, the fluidized bed reaction system has strong operability. It can operate in a continuous processing state and continuously introduce new gas, eliminating the startup conditions in the intermittent process and improving the overall efficiency. Specifically, the reaction gas provided by the gas distribution system can be switched between CH4 and CO2, and the two gases participate in the CH4 dry reforming and CaO carbonation processes respectively. There is no need to restart the reaction system when switching the gas, and the particles are always in a fluidized state during the complete reaction process, which greatly improves the reaction efficiency and reduces the time cost.

[0042] The reaction system involved in the present invention integrates solar radiation absorption, CO2 capture and fuel conversion, realizing the in-situ conversion and utilization of solar energy and CO2; heat is provided to the system in the form of thermal radiation, and the calcium cycle energy storage and methane dry reforming processes occur in the same fluidized bed reactor. The easy operation of the fluidized bed is utilized to timely regulate reaction parameters such as gas flow and incident radiation, and the reaction occurring inside the bed is flexibly regulated according to demand; due to the characteristics of calcium cycle heat storage, the fluidized bed can undergo multiple cycles, and at the same time, the Ca-Ni-based composite material has high energy storage density and high catalytic efficiency, and the entire system has high energy storage efficiency and stability.

[0043] The present invention provides a reaction method of a single fluidized bed reaction system for methane calcium chain reforming, comprising the following steps:

[0044] By adjusting the position adjustment device and the inclination angle of the adjustable light source, the radiation focus of the adjustable light source is located at the top center of the reaction particles, and the fluidized bed is rotated 5° to 10° counterclockwise. Under the action of gravity, the particles inside the fluidized bed receive more radiation heat without sintering;

[0045] The heating belt was turned on and set to 270°C. The gas distribution system was controlled to introduce 4700mL / min of Ar. From the entrance of the insulation layer, it was observed that the reaction particles in the cylindrical quartz tube remained stationary. The adjustable light source was turned on and its power was set to 1000W. The gas inside the cylindrical quartz tube expanded due to the heat, and the particles began to move violently at a high speed, that is, the particles entered the fluidization process. This allowed the particles to enter the fluidization stage earlier and match the radiation characteristics, allowing subsequent reactions to proceed more stably and efficiently. Premature fluidization of the particles can also alleviate the sintering problem caused by continuous radiation exposure to stationary particles.

[0046] The gas distribution system is controlled to introduce 2400mL / min of Ar and 600mL / min of CO2. The CO2-containing gas can prevent the CaCO3 component in the Ca-Ni-based composite material from premature decomposition. The temperature inside the cylindrical quartz tube is measured by a thermocouple and transmitted to the control system. The reaction particles in the cylindrical quartz tube are continuously fluidized and the temperature is raised to 600°C at a high rate. The heating rate then slows and the temperature stabilizes. That is, when the temperature reaches 600°C to 650°C, the reaction is controlled to enter the CH4 dry reforming stage.

[0047] The gas distribution system is controlled to introduce 2400 mL / min of Ar and 600 mL / min of CH4, and a CaCO3 decomposition reaction and a CH4 dry reforming reaction occur in the cylindrical quartz tube. The chemical formula of the reaction is the forward process of formula (1) and formula (2); the CaCO3 in the reaction particles decomposes into CaO and CO2, and CO2 and CH4 undergo a dry reforming reaction; this process is catalyzed by the metal Ni in the composite material, and CO2 as a reaction gas participates in the CH4 dry reforming process, which can reduce the CO2 partial pressure and accelerate the decomposition reaction of CaCO3, so that CH4 dry reforming obtains sufficient reaction gas; the internal temperature of the reactor measured by the thermocouple is as high as 800 ° C. After 15 minutes of the CH4 dry reforming stage, the CaCO3 in the particles reacts completely, the internal temperature of the cylindrical quartz tube tends to be stable, and the mass spectrometer monitors that the CO2 flow rate in the system exhaust is almost 0. That is, when the mass spectrometer monitors that the CO2 volume flow rate in the exhaust is less than 2%, the reaction is controlled to enter the CaO carbonation stage;

[0048] (1)

[0049] (2)

[0050] (3)

[0051] The power of the adjustable light source is adjusted to 600W, and the gas distribution system is controlled to introduce 2400mL / min of Ar and 600mL / min of CO2, so that coke removal and CaO carbonation occur, which is the reverse process of equations (3) and (1). At the beginning of the stage, a small amount of CO can be monitored in the mass spectrometer, which is generated by the reaction of coke and CO2. The CaO generated in the dry reforming stage is converted back into CaCO3 in the carbonation stage and can be used for the next dry reforming reaction. The minimum temperature in this stage is lower than 500℃, but CaO carbonation can be achieved at a higher rate. The conversion of CaO to CaCO3 is completed after 15 minutes. That is, when the mass spectrometer monitors that the volume flow rate of CO2 in the exhaust gas reaches 18~22%, the conversion of CaO to CaCO3 is completed.

[0052] By controlling the different components and flow rates of the gas distribution and switching the power of the adjustable light source, the system is controlled to produce different reactions, with each adjustment interval being 15 minutes. One dry reforming stage and one carbonation stage are called a cycle, and the gas supply is stopped after three cycles. The entire reaction system realizes the synergistic utilization and energy storage of solar energy and chemical energy, integrating the absorption of solar radiation, CO2 capture and fuel conversion, realizing the in-situ conversion and utilization of solar energy and CO2. The reaction medium is recyclable, which can fully utilize the advantages of Ca-Ni-based composite materials and maximize their energy storage performance. The fact that all reactions occur inside the cylindrical quartz tube greatly simplifies the design, facilitates operation and adjustment, and avoids unnecessary medium transportation, reducing heat dissipation while improving energy conversion efficiency.

Claims

1. A methane calcium chain reforming single fluidized bed reaction system, characterized in that: The invention comprises a cylindrical quartz tube filled with reaction particles, an adjustable light source located beside the cylindrical quartz tube and having a radiation focus located at the top center of the reaction particles, a heat preservation layer wrapped around the outside of the cylindrical quartz tube, a position adjustment device for driving the cylindrical quartz tube to move and rotate, thermocouples uniformly distributed in the cylindrical quartz tube, a gas distribution system for supplying reaction gas into the cylindrical quartz tube, a mass spectrometer connected to the gas outlet of the cylindrical quartz tube through a drying tube, and a control system respectively connected to the thermocouple, the gas distribution system and the mass spectrometer, wherein an inlet is provided on the side of the heat preservation layer facing the adjustable light source, and the shape of the inlet is formed by overlapping a plurality of cones whose center lines are located in the same plane, and the initial center lines of the cones are aligned with the center line of the cone. The plane where the opening side is located is vertical, and the apex of the cone is located on the central axis of the cylindrical quartz tube. The cone is rotated clockwise at a certain angle, and the overlapping part of the cone and the insulation layer is cut to obtain the incident port; the adjustable light source is placed on the positioning platform, and a pair of support rods are connected between the front side of the positioning platform and the ground, and a pair of electric push rods that can change the irradiation angle of the light source are connected between the rear side of the positioning platform and the ground, and the power of the adjustable light source is adjustable; the position adjustment device includes a horizontal slide, a vertical slide connected to the slider of the horizontal slide, and an angle tilt slide connected to the slider of the vertical slide, wherein the working surface of the angle tilt slide is connected to the cylindrical quartz tube, and the base of the angle tilt slide is connected to the slider of the vertical slide.

2. The methane calcium chain reforming single fluidized bed reaction system according to claim 1, characterized in that: The gas distribution system includes an argon cylinder, a carbon dioxide cylinder and a methane cylinder, each of which is equipped with a flow meter. The argon cylinder, the carbon dioxide cylinder and the methane cylinder are respectively connected to the gas inlet of the columnar quartz tube through a pipe with a heating belt, and the heating belt is connected to the control system.

3. The methane calcium chain reforming single fluidized bed reaction system according to claim 1, characterized in that: The reaction particles are Ca-Ni based composite particles.

4. The methane calcium chain reforming single fluidized bed reaction system according to claim 1, characterized in that: The stacking height of the reaction particles exceeds the lower end of the incident port of the thermal insulation layer by 3 to 5 mm.

5. The methane calcium chain reforming single fluidized bed reaction system according to claim 1, characterized in that: The rated power of the adjustable light source is 1000w.

6. The methane calcium chain reforming single fluidized bed reaction system according to claim 1, characterized in that: The drying pipe is also connected to an exhaust pipe.

7. A reaction method of a single fluidized bed reaction system for methane calcium chain reforming according to any one of claims 1 to 6, characterized in that: The steps include: By adjusting the position adjustment device and the inclination angle of the adjustable light source, the radiation focus of the adjustable light source is located at the top center of the reaction particle; by rotating the tilt slide, the inclination angle of the columnar quartz tube can be adjusted so that the heat transfer medium inside the quartz tube moves to the radiation irradiation surface under the action of gravity; Turn on the heating belt and control the gas distribution system to introduce 3000-5000 mL / min of Ar. From the entrance of the insulation layer, it can be observed that the reaction particles in the cylindrical quartz tube remain stationary. Turn on the adjustable light source and set its power to 800-1000 W. The gas inside the cylindrical quartz tube expands due to the heat, and the particles begin to move and enter the fluidization stage early. The gas distribution system is controlled to introduce 2400mL / min of Ar and 600mL / min of CO2. The temperature inside the cylindrical quartz tube is measured by a thermocouple and transmitted to the control system. The reaction particles in the cylindrical quartz tube are continuously fluidized. When the temperature reaches 600℃~650℃, the reaction is controlled to enter the CH4 dry reforming stage. The gas distribution system was controlled to introduce 2400 mL / min of Ar and 600 mL / min of CH4, causing CaCO3 decomposition and CH4 dry reforming reactions to occur in the cylindrical quartz tube. The CaCO3 in the reaction particles decomposed into CaO and CO2, and CO2 and CH4 underwent dry reforming. When the mass spectrometer detects that the volume flow of CO2 in the tail gas is less than 2%, the reaction is controlled to enter the CaO carbonation stage; The power of the adjustable light source was adjusted to 600-700W, and the gas distribution system was controlled to introduce 2400mL / min of Ar and 600mL / min of CO2 to remove coke and carbonate CaO. When the mass spectrometer monitored that the volume flow rate of CO2 in the exhaust gas reached 18-22%, the conversion of CaO to CaCO3 was completed.

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