Reaction unit, system and method for continuous flow photo-thermal catalytic conversion of waste gas

Abstract

The invention discloses a reaction unit, system and method for continuous flow photo-thermal catalytic conversion of waste gas. According to the system, a coaxial double-layer quartz sleeve type reactor is used as a core reaction module, and reliable sealing between a quartz tube and a metal pipeline is realized by adopting a ferrule type three-way pipe joint. The system innovatively constructs the design of a full-continuous flow experimental process and an industrial circulating production process, overcomes the defects that sampling needs to be interrupted and a time blind area exists in the traditional batch reaction, realizes continuous feeding of reactants and immediate removal and on-line analysis of products, and effectively avoids secondary decomposition caused by too long retention of the products. Particularly, the coal chemical waste gas with a certain temperature is directly used as a reactant and a main heat source for maintaining the reaction temperature, process coupling and integrated utilization of waste gas chemical energy and physical sensible heat are achieved, and process energy consumption is remarkably reduced. The system has the functions of rapid evaluation of the catalyst and flexible capacity amplification, and provides an efficient platform for research and development and industrial application of a photo-thermal catalysis technology.

Description

Technical Field

[0001] This invention belongs to the fields of catalytic reaction engineering, process intensification and industrial waste gas resource utilization technology. Specifically, it relates to a modular system and method that can realize continuous flow operation, online product analysis, and direct photothermal catalytic conversion using the chemical energy and physical sensible heat of industrial waste gas. Background Technology

[0002] Photothermal catalysis technology offers a new pathway for converting inert molecules such as carbon dioxide under mild conditions, and has great potential for the resource utilization of coal chemical waste gas. However, the research and industrialization of this technology currently face severe challenges.

[0003] First, at the laboratory research level, the vast majority of work uses batch reactors. This model has fundamental drawbacks: 1) Poor time resolution: The reaction needs to be completely terminated at a preset time point and sampled and analyzed offline, making it impossible to track the dynamic process of the reaction in real time and continuously, resulting in a serious "time blind spot." 2) Products are prone to secondary reactions: During the sampling and analysis delay, the target products that have been generated may undergo reversible decomposition or deep reactions under high temperature and in the presence of catalysts, causing the measured product distribution to deviate significantly from the instantaneous true situation in the reactor, distorting the obtained kinetic data, and affecting the intrinsic performance evaluation and mechanism study of the catalyst.

[0004] Secondly, at the industrial scale-up level, existing technologies lack a smooth transition from laboratory to factory. Laboratory equipment is small-scale and has limited functionality, resulting in poor reproducibility of catalyst data in industrial equipment with continuous flow and varying heat and mass transfer conditions. Traditional industrial fixed-bed reactors are ill-suited to the specific lighting requirements of photothermal catalysis and generally suffer from the following problems: 1) Inefficient energy utilization: External electric heating is typically required to provide reaction heat, failing to utilize the substantial sensible heat (typically above 200°C) carried by coal chemical waste gases (such as Fischer-Tropsch synthesis tail gas and shift gas), leading to high energy consumption and poor economic efficiency. 2) Lack of flexibility and integration: Once the equipment is built, the process is fixed, making it difficult to adjust the catalyst loading scheme and flexibly achieve capacity scaling, multi-product production, and rapid parallel catalyst screening on the same equipment. 3) Low carbon atom economy: The recycling of unreacted feedstocks (such as CO2) often lacks precise intelligent control based on real-time component analysis, resulting in limited single-pass conversion rates or excessively high recycling energy consumption. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a reaction unit, system, and method for continuous flow photothermal catalytic conversion of coal chemical waste gas. This system aims to fundamentally solve the time blind spots and secondary product reactions problems of traditional batch reactions, achieving a seamless transition from precise laboratory mechanism research to flexible industrial production. Through process integration and innovation, it maximizes the utilization of the chemical and physical thermal energy of the waste gas, achieving the dual goals of energy conservation, carbon reduction, and resource recovery.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A reaction unit for continuous flow photothermal catalytic conversion of waste gas, the reaction unit includes an inner quartz tube (1) and an outer quartz tube (2) coaxially mounted, the outer wall of the middle part of the inner quartz tube (1) has a surface roughening zone (3), a catalyst layer (4) is loaded on the surface roughening zone (3), and an annular reaction chamber (5) is formed between the inner quartz tube (1) and the outer quartz tube (2); the reaction unit is provided with a compression fitting tee connector as a sealing component at both the upper and lower ends, the compression fitting tee connector at the upper end is provided with a reaction gas inlet (8), and the compression fitting tee connector at the lower end is provided with a product outlet (9).

[0007] The reaction unit has a surface roughening zone 3 with a width of about 50-200mm formed by fine sandblasting on the outer wall of the inner quartz tube 1, and the surface roughness is controlled between 1.6μm and 6.3μm.

[0008] The reaction unit is obtained by loading the catalyst into the roughening zone 3 through equal-volume impregnation or coating, followed by drying and programmed temperature calcination.

[0009] The reaction unit has a rollable reflector 11 attached to the outside of the outer quartz tube 2. The reflector can reflect light incident from one side and focus it onto the catalyst layer 4 in the annular reaction chamber 5.

[0010] The aforementioned reaction unit, the ferrule-type tee fitting includes a stainless steel body, a double ferrule sealing assembly, a compression nut, and a polytetrafluoroethylene sealing gasket. By tightening the compression nut, the double ferrule is forced to cut into the quartz tube wall and the fitting body, forming a reliable metal-quartz sealed connection.

[0011] A laboratory online analysis system comprising any of the aforementioned reaction units includes: a reaction unit placed in a sealed reaction chamber with a quartz glass light window; a cold trap (17) whose inlet is connected to the product outlet (9) via a pipe; a low-temperature bath (18) in which the cold trap (17) is placed to maintain a low-temperature environment; the gas phase outlet of the cold trap (17) is connected to a gas chromatograph via a pipe for online analysis of the composition of uncondensed gases; and the liquid phase outlet of the cold trap (17) is connected to a liquid chromatograph via a pipe for online analysis of the composition of condensed liquids. In the aforementioned laboratory online analysis system, the reaction unit is placed in a sealed reaction chamber equipped with a quartz glass light window. A 300W~1000W full-spectrum xenon lamp light source 21 is used to simulate sunlight. After being focused by a rollable reflector 11, the light is vertically irradiated onto the reactor through the light window.

[0012] The aforementioned laboratory online analysis system uses a type K thermocouple inserted and fixed through temperature measurement channel 10 to monitor the catalyst bed temperature in real time, and the data is connected to a temperature controller.

[0013] According to the laboratory online analysis method of any of the systems described, the following steps are included: after the reaction is started, coal chemical waste gas is sent in from the reaction gas inlet 8, and the reaction product is discharged from the product outlet 9. The product is then immediately sent through the heat-insulated pipe into the cold trap 17 immersed in the low-temperature bath 18 for deep condensation. The condensed non-condensable gas is directly connected to an online gas chromatograph equipped with a thermal conductivity detector and a flame ionization detector through the pipeline 19 for real-time analysis. The condensed liquid is periodically sampled by a micro-metering pump or directly sent to an online liquid chromatograph for analysis through the pipeline 20.

[0014] An industrialized circular production system comprising any of the aforementioned reaction units includes: an industrial tubular reactor 24, in which multiple reaction units can be connected in series or in parallel, and the industrial tubular reactor 24 is provided with an inlet and an outlet; coal chemical waste gas is fed into the industrial tubular reactor 24 from the inlet, undergoes photothermal catalytic conversion, and is discharged from the outlet; a gas compressor (25) is connected to the outlet of the industrial tubular reactor (24); a heat exchanger (26) is connected downstream of the gas compressor (25); a gas-liquid separator (27) is connected downstream of the heat exchanger (26); a liquid phase outlet valve (28) is connected to the liquid phase outlet of the gas-liquid separator (27), and the liquid phase outlet valve (28) is connected to a liquid phase product storage tank through a pipeline; a gas phase outlet valve (29) is connected to the gas phase outlet of the gas-liquid separator (27); and a circulating compressor (30) whose inlet is connected to the outlet of the gas phase outlet valve (29), and whose outlet is connected upstream of the inlet regulating valve (23).

[0015] In the industrialized circular production system, when the core photothermal catalytic reaction unit is arranged in series in the industrialized tubular reaction equipment (24), each unit is filled with the same catalyst for continuous production of the same product; when arranged in parallel, each unit is filled with different catalysts for parallel production of different products or for comparison of catalyst performance.

[0016] The industrialized circular production system further includes an online detection unit and an intelligent control system. The online detection unit is installed on the outlet pipeline of the gas phase outlet valve (29) or the outlet pipeline of the circulating compressor (30) for real-time analysis of carbon dioxide concentration in the gas. The intelligent control system controls the operation of the inlet regulating valve (23), liquid phase outlet valve (28), gas phase outlet valve (29) and circulating compressor (30) according to the detection results of the online detection unit.

[0017] An industrial circular production method according to any of the described industrial circular production systems includes the following steps: B1: After pretreatment, the coal chemical waste gas enters the system through the process gas inlet manifold 22. After the total inlet flow and pressure are adjusted by the inlet regulating valve 23, it enters the industrial tubular reaction equipment 24 for photothermal catalytic conversion. The waste gas is used as both a reactant and a heating medium in the system. B2: After the reaction, the gas is discharged from the outlet of the industrial tubular reaction equipment 24. It is first pressurized by the gas compressor 25, and then enters the heat exchanger 26 to exchange heat with the feed waste gas or cooling medium to recover the waste heat and cool the gas. The cooled gas enters the gas-liquid separator 27, where most of the liquid phase products are separated. B3: The separated liquid phase product is output and collected under the control of the liquid phase outlet valve 28. The separated gas phase is discharged from the upper end of the gas-liquid separator 27 and flows through the gas phase outlet valve 29; the outlet pipeline of the gas phase outlet valve 29 is connected to an online detection unit for real-time analysis of the CO2 concentration; the detection signal is transmitted to the PLC or DCS intelligent control system; the system presets the CO2 concentration threshold. B4: If the detected value is higher than the threshold, it indicates that there is a lot of unreacted CO2. The intelligent control system will automatically open the gas phase outlet valve 29 and start the circulating compressor 30 to pressurize most of the gas phase material and return it to the upstream of the process gas inlet manifold 22. After mixing with the fresh feed gas, the reaction will continue to form a circulation loop, thereby improving the total utilization rate of carbon atoms. B5: If the detected value is lower than the threshold, it indicates that the reaction is relatively complete. The intelligent control system will then close the gas phase outlet valve 29, stop the circulation, and deliver the qualified tail gas to the downstream section, where it can be used as fuel gas.

[0018] Firstly, this invention provides a modular system, the foundation and core of which is a core reaction unit specifically designed for continuous flow photothermal catalysis. This unit employs a coaxial double-layer quartz tube structure. The outer wall of the inner quartz tube (1) is roughened by sandblasting or chemical etching to form a surface roughening zone (3), significantly increasing the specific surface area and surface energy. The catalyst is loaded onto it through impregnation, coating, or other methods to form a uniform catalyst layer (4). An annular reaction chamber (5) is formed between the inner and outer tubes, where the reaction gas flows and reacts with the catalyst. One of its key innovations lies in the sealing structure: specially designed compression fitting tee connectors (6, 7) are used at the upper and lower ends to achieve a high-pressure, high-airtightness, and reliable connection between the brittle quartz tube and the metal pipeline. This connector uses double compression fittings and PTFE gaskets to form a multi-stage seal between the metal connector and the quartz tube, laying the equipment foundation for constructing a stable, leak-free continuous flow system.

[0019] Secondly, based on this core unit, this invention constructs two complementary and freely configurable operating modes: Model A (Laboratory Online Analysis System): The core reaction unit is directly connected to the cold trap (17) and the low-temperature bath (18), and the product pipeline is coupled with online gas chromatography and liquid chromatography. This system constructs a fully continuous closed flow path of "reaction-instant removal-deep condensation-online analysis". Its core innovation is that once the reaction product is generated on the catalyst surface, it is carried away from the high-temperature reaction zone by the carrier gas and immediately enters deep condensation, thereby blocking the secondary decomposition, reverse reaction or isomerization of the product caused by sampling, transfer and waiting for analysis in the traditional batch method. This ensures that the analysis results reflect the activity, selectivity and stability of the catalyst in real time and accurately, which is beneficial for the evaluation of the intrinsic performance of the catalyst and the study of the reaction mechanism.

[0020] Model B (Energy-Saving Industrial Circular Production System): Multiple core reaction units are integrated into a single industrial tubular reaction device (24) as standardized modules. It can be flexibly configured as a series or parallel flow path according to production needs. In series arrangement, each unit is filled with the same catalyst, and the reaction gas passes through sequentially, with the reaction depth accumulating step by step. It is suitable for large-scale continuous production and capacity expansion of a single product. In parallel arrangement, each unit can be filled with different catalysts, and the reaction gas is evenly distributed. It is suitable for multi-product production or high-throughput catalyst screening. Its core innovation lies in the energy utilization method: the waste gas generated by the upstream coal chemical process is used to enter the system. This not only provides reactants, but more importantly, it makes full use of the physical sensible heat of the waste gas itself as the main heat source for reactor start-up and temperature maintenance, replacing or significantly reducing the traditional external electric heating load, and realizing process thermal energy integration and energy saving. The system further integrates a circulation control unit for compression, heat exchange, separation, and detection, forming a highly efficient and energy-saving waste gas resource production system.

[0021] Thirdly, the present invention provides detailed operating methods corresponding to the above two modes. Beneficial effects

[0022] Compared with the prior art, the present invention has the following outstanding advantages: (1) Overcoming the shortcomings of traditional analytical methods: By constructing a fully continuous flow and real-time online analytical system, the problems of "time blind zone" and "secondary reaction of products" in batch experiments are solved, providing real and dynamic reaction data that can be obtained for basic research on photothermal catalysis.

[0023] (2) Energy saving and consumption reduction and process integration were achieved: Coal chemical waste gas was innovatively used as both a reactant and a heat source, realizing process coupling between the reaction process and the upstream process waste heat recovery. The independent raw material preheater and most of the external heating facilities of the reactor were eliminated, which greatly reduced the consumption of public works such as steam and electricity, and improved the thermodynamic efficiency and economic benefits of the whole process.

[0024] (3) It bridges the gap between R&D and production, improving R&D and scale-up efficiency: The modular design allows the same core hardware concept to be flexibly extended to both laboratory precision analysis and industrial scale-up production scenarios. Series connection is used for large-scale production, while parallel connection is used for parallel screening or flexible production, which greatly improves the efficiency of catalyst R&D and reduces the technical risks and investment costs in the pilot-scale scale-up process.

[0025] (4) Improved process economy and carbon atom efficiency: Based on real-time online component detection and circulation control system, the circulation ratio can be dynamically adjusted according to the concentration of key components such as unreacted CO2, so as to maximize the utilization of raw material carbon atoms and ensure that the exhaust gas meets emission standards. Attached Figure Description

[0026] Figure 1 This is an axial structural cross-sectional view of the core photothermal catalytic reaction unit of this invention.

[0027] Figure 2 A schematic diagram of the logistics process for multiple core reaction units arranged in series inside a tubular device.

[0028] Figure 3 A schematic diagram of the logistics process for multiple core reaction units configured in parallel within a tubular device.

[0029] Figure 4 This is a schematic diagram of the overall structure and process of the laboratory online analysis system described in this invention.

[0030] Figure 5 This is a process flow diagram of the industrialized circular production system described in this invention.

[0031] 1-Inner quartz tube; 2-Outer quartz tube; 3-Surface roughening zone; 4-Catalyst layer; 5-Annular reaction chamber; 6-Upper end compression fitting tee; 7-Lower end compression fitting tee; 8-Reaction gas inlet; 9-Product outlet; 10-Temperature measuring channel; 11-Reflector; 12-Inlet manifold of series reactor; 13-Product outlet manifold of series reactor; 14-Parallel inlet gas splitter; 15-Inlet pipe of parallel reactor; 16-Product outlet pipe of parallel reactor; 17-Cold trap; 18-Cryogenic bath; 19-Gas chromatography pipeline; 20-Liquid chromatography pipeline; 21-Xenon lamp light source; 11-Reflector; 22-Process gas inlet main pipe; 23-Inlet regulating valve; 24-Industrial tubular reaction equipment; 25-Gas compressor; 26-Heat exchanger; 27-Gas-liquid separator; 28-Liquid phase outlet valve; 29-Gas phase outlet valve; 30-Circulating compressor. Detailed Implementation

[0032] The present invention will be described in detail below with reference to specific embodiments.

[0033] Example 1: Detailed structure of the photothermal catalytic reaction unit ( Figure 1 ) like Figure 1 As shown, the photothermal catalytic reaction unit is the foundation of all systems in this invention. Its main body consists of an inner quartz tube 1 and an outer quartz tube 2, both made of high-transmittance quartz material, coaxially mounted and held concentrically by a high-temperature resistant quartz support. The outer wall of the inner quartz tube 1 is finely sandblasted to form a surface roughening zone 3 approximately 50-200 mm wide, with a surface roughness controlled between 1.6 μm and 6.3 μm, significantly increasing the catalyst adhesion area and bonding strength. The catalyst is loaded onto the roughening zone 3 through equal-volume impregnation or coating, followed by drying and programmed temperature calcination (e.g., heating to 400°C in air at 2°C / min and holding for 4 hours) to form a uniformly thick and firmly bonded catalyst layer 4. A uniformly annular reaction chamber 5 is formed between the inner and outer tubes, with the gap width designed according to fluid dynamics and mass transfer requirements, typically 2 mm to 10 mm. The upper end uses a compression fitting tee connector 6, and the lower end uses a compression fitting tee connector 7 as the sealing assembly. The main body of the compression fitting tee connector 6 is made of 316 stainless steel, and internally includes two precision-machined metal ferrules, a brass clamping nut, and a high-temperature resistant PTFE sealing gasket. During installation, the end of the quartz tube is inserted into the connector body, and the clamping nut is tightened. At the same time, the PTFE gasket fills the microscopic gaps, together forming a seal that can withstand a pressure of at least 1.0 MPa and meet the airtightness requirements (helium leak detection rate <1×10⁻). 9A reliable seal (Pa·m³ / s) is achieved. The upper ferrule-type tee connector 6 has a reaction gas inlet 8, and the lower ferrule-type tee connector 7 has a product outlet 9. The lower extension of the inner quartz tube 1 forms a temperature measuring channel 10, into which a heating jacket and thermocouple can be inserted. Its temperature measuring endpoint can be precisely placed at the corresponding inner tube wall in the middle of the catalyst layer 4 to monitor the reaction temperature in real time.

[0034] A rollable reflector 11 can be attached to the outside of the outer quartz tube 2. The reflector is made of polished aluminum foil or silver-plated polyester film, which can reflect light incident from one side and focus it onto the catalyst layer 4 in the annular reaction chamber 5, effectively improving the light energy utilization efficiency.

[0035] Example 2: Series configuration for capacity scaling ( Figure 2 ) Reference Figure 2 This demonstrates a series connection of multiple core reaction units within an industrial-scale tubular reactor. Pre-treated coal chemical waste gas enters the system through the inlet manifold 12 of the series reactors, flowing sequentially through each of the connected reaction units. The sensible heat carried by the waste gas is directly used to maintain the reactor temperature, achieving energy integration. The final reaction products are discharged through the product outlet manifold 13 of the series reactors. In this configuration, each unit is filled with the same catalyst (e.g., a Cu-ZnO-Al2O3 composite catalyst), suitable for the large-scale hydrogenation of CO2 from coal chemical waste gas to produce single products such as methanol. As the gas flows through each reactor stage, the reactant concentration decreases progressively while the product concentration increases progressively. Increasing the reaction path length (number of stages) effectively improves the overall conversion rate of the reactants.

[0036] Example 3: Parallel configuration for multi-product production or catalyst screening ( Figure 3 ) Reference Figure 3 This demonstrates a parallel flow configuration of multiple core reaction units within a tubular reactor. Pre-treated coal chemical waste gas is distributed to each parallel reactor unit via a parallel feed gas distributor 14. This configuration also fully utilizes waste heat from the waste gas to heat each reaction unit, ensuring that each branch operates under the same optimized temperature conditions. After reaction in each independent unit, the products are collected via product outlet pipes 16 of each parallel reactor. Different catalysts can be loaded into each branch; for example, one branch can be loaded with a catalyst for methanol synthesis, while another can be loaded with a catalyst for low-carbon olefin synthesis, thus enabling the parallel production of different high-value chemicals using the same feed gas.

[0037] Another important application is rapid catalyst screening: different candidate catalysts are loaded into each branch and reacted in parallel under the same temperature conditions maintained by the waste heat of the exhaust gas. By analyzing the composition and yield of the products in each branch, performance comparison data of multiple catalysts can be obtained efficiently in a single experiment.

[0038] Example 4: Application of the Laboratory Online Analysis System ( Figure 4 ) Reference Figure 4 This demonstrates the laboratory online analysis system of the present invention. The core reaction unit (structured similarly to...) Figure 1 The catalyst bed is placed vertically in a sealed reaction chamber equipped with a quartz glass light window. A 300W~1000W full-spectrum xenon lamp light source 21 is used to simulate sunlight. The light is focused by a cylindrical reflector 11 and then shines vertically onto the reactor through the light window. A gas distribution system is used to mix high-purity CO2, H2, and inert gases in a certain proportion to simulate coal chemical waste gas with a certain temperature and composition as the reaction gas source. A K-type thermocouple is inserted and fixed through a temperature measuring channel 10 to monitor the catalyst bed temperature in real time, and the data is connected to a temperature controller. After the reaction starts, the coal chemical waste gas is sent in through the reaction gas inlet 8, and the reaction products are discharged through the product outlet 9. The products immediately enter the cold trap 17, which is immersed in a low-temperature bath 18 (such as an ethanol-liquid nitrogen bath, temperature -50℃), through an insulated short pipe (<30 cm) for deep condensation. The condensed non-condensable gases (such as unreacted H2, CO, CH4, etc.) are directly connected to an online gas chromatograph equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID) via pipeline 19 for real-time analysis; the condensed liquids (such as methanol, water, etc.) are sampled periodically via a micro-metering pump or directly sent to an online liquid chromatograph for analysis via pipeline 20. This system can achieve continuous and stable operation, obtaining a complete set of reaction data every minute, completely avoiding the data distortion caused by the time delay (usually several hours) of traditional batch sampling analysis.

[0039] Example 5: Energy Integration and Intelligent Cyclic Process in Industrial Systems ( Figure 5 ) Figure 5This invention demonstrates an energy-saving industrial circular production system. Coal chemical waste gas, at approximately 300°C and 0.5 MPa, originating from the previous stage (such as a coal gasification or conversion unit), undergoes pretreatment including dust removal and desulfurization. The treated waste gas enters the system through the process gas inlet manifold 22, and after the total inlet flow rate and pressure are regulated by the inlet regulating valve 23, it enters an industrial tubular reactor 24 for photothermal catalytic conversion. Multiple reaction units in the industrial tubular reactor 24 can be connected in series or parallel. The waste gas serves simultaneously as a reactant and a heating medium within the system. After the reaction, the gas exits from the outlet of the industrial tubular reactor 24, first being pressurized to approximately 1.2 MPa by a gas compressor 25 to promote subsequent separation and compensate for system pressure drop. It then enters a heat exchanger 26 to exchange heat with the feed waste gas or cooling medium, recovering residual heat and cooling the gas. The cooled gas then enters a gas-liquid separator 27, where most of the liquid phase products, such as methanol and water, are separated.

[0040] The separated liquid phase product is output and collected under the control of the liquid phase outlet valve 28. The separated gas phase (mainly containing H2, unreacted CO, CO2, CH4, and a small amount of light components) is discharged from the top of the gas-liquid separator 27 and flows through the gas phase outlet valve 29. The outlet pipeline of the gas phase outlet valve 29 is connected to an online detection unit (such as an infrared CO2 analyzer using the NDIR principle, not shown in the figure) for real-time analysis of the CO2 concentration. The detection signal is transmitted to the PLC or DCS intelligent control system. The system presets the CO2 concentration threshold to 8% (volume fraction).

[0041] If the detected value is higher than the threshold, it indicates that there is a lot of unreacted CO2. The intelligent control system will automatically open the gas phase outlet valve 29 and start the circulating compressor 30 to pressurize most of the gas phase material and return it to the upstream of the process gas inlet manifold 22. After mixing with the fresh feed gas, the reaction will continue to form a circulation loop, thereby improving the total utilization rate of carbon atoms.

[0042] If the detected value is below the threshold, indicating that the reaction is relatively complete, the intelligent control system will close the gas phase outlet valve 29 to stop the circulation and deliver the qualified tail gas (mainly composed of H2, CH4, etc.) to the downstream section for use as fuel gas. The coordinated control of the inlet regulating valve 23, liquid phase outlet valve 28, and gas phase outlet valve 29 enables the management of system feed, liquid phase product output, and gas phase circulation loop.

[0043] In summary, this invention solves the construction challenge of continuous flow photothermal catalytic reactors through an innovative sealed structure, overcomes the shortcomings of traditional research methods through fully continuous flow and online analysis technology, achieves energy saving in the process by utilizing the physical sensible heat of coal chemical waste gas, and provides a set of technical solutions from basic mechanism research to flexible industrial production through modular and flexible configuration (series connection for scale-up, parallel connection for screening or multi-production).

[0044] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A reaction unit for continuous flow photothermal catalytic conversion of waste gas, characterized in that, The reaction unit includes an inner quartz tube (1) and an outer quartz tube (2) coaxially mounted. The outer wall of the middle part of the inner quartz tube (1) has a surface roughening zone (3). The catalyst layer (4) is loaded on the surface roughening zone (3). An annular reaction chamber (5) is formed between the inner quartz tube (1) and the outer quartz tube (2). The reaction unit is provided with a compression fitting tee connector as a sealing component at both ends. The compression fitting tee connector at the upper end is provided with a reaction gas inlet (8), and the compression fitting tee connector at the lower end is provided with a product outlet (9).

2. The reaction unit according to claim 1, characterized in that, The outer wall of the middle part of the inner quartz tube 1 is finely sandblasted to form a surface roughening zone (3) with a width of about 50-200mm, and its surface roughness is controlled between 1.6μm and 6.3μm.

3. The reaction unit according to claim 1, characterized in that, An outer quartz tube (2) has a rollable reflector (11) attached to its outer side. This reflector can reflect light incident from one side and focus it onto the catalyst layer (4) inside the annular reaction chamber (5).

4. A laboratory online analysis system comprising any one of the reaction units described in claims 1-3, characterized in that, include: The reaction unit is placed in a sealed reaction chamber with a quartz glass light window; a cold trap (17) whose inlet is connected to the product outlet (9) via a pipe; a low-temperature bath (18) in which the cold trap (17) is placed to maintain a low-temperature environment; the gas phase outlet of the cold trap (17) is connected to a gas chromatograph via a pipe for online analysis of the composition of uncondensed gas; the liquid phase outlet of the cold trap (17) is connected to a liquid chromatograph via a pipe for online analysis of the composition of condensed liquid.

5. The laboratory online analysis system according to claim 4, characterized in that, The reaction unit is placed in a sealed reaction chamber with a quartz glass light window. A 300W~1000W full-spectrum xenon lamp light source (21) is used to simulate sunlight. After the light is focused by a rollable reflector (11), it shines vertically onto the reactor through the light window.

6. The laboratory online analysis method of the system according to claim 4 or 5, characterized in that, The process includes the following steps: After the reaction is started, coal chemical waste gas is sent in through the reaction gas inlet (8), and the reaction products are discharged through the product outlet (9). The products are then immediately sent through the insulation pipe into the cold trap (17) immersed in the low temperature bath (18) for deep condensation. The condensed non-condensable gas is directly connected to an online gas chromatograph equipped with a thermal conductivity detector and a flame ionization detector through the pipeline (19) for real-time analysis. The condensed liquid is periodically sampled by a micro metering pump or directly sent to an online liquid chromatograph for analysis through the pipeline (20).

7. An industrialized circular production system comprising any one of the reaction units described in claims 1-3, characterized in that, include: An industrial tubular reactor (24) is provided, in which multiple reaction units can be connected in series or in parallel. The industrial tubular reactor (24) is provided with an inlet and an outlet. Coal chemical waste gas is sent into the industrial tubular reactor (24) from the inlet, undergoes photothermal catalytic conversion, and is discharged from the outlet. A gas compressor (25) is connected to the outlet of the industrial tubular reactor (24). A heat exchanger (26) is connected downstream of the gas compressor (25). A gas-liquid separator (27) is connected downstream of the heat exchanger (26). A liquid phase outlet valve (28) is connected to the liquid phase outlet of the gas-liquid separator (27). The liquid phase outlet valve (28) is connected to the liquid phase product storage tank through a pipeline. A gas phase outlet valve (29) is connected to the gas phase outlet of the gas-liquid separator (27). A circulating compressor (30) is connected to the outlet of the gas phase outlet valve (29) at its inlet and to the upstream of the inlet regulating valve (23) at its outlet.

8. The industrialized circular production system according to claim 7, characterized in that, When the core photothermal catalytic reaction units are arranged in series in the industrial tubular reaction equipment (24), each unit is filled with the same catalyst for continuous production of the same product; when arranged in parallel, each unit is filled with different catalysts for parallel production of different products or for comparison of catalyst performance.

9. The industrialized circular production system according to claim 7, characterized in that, It also includes an online detection unit and an intelligent control system. The online detection unit is set on the outlet pipeline of the gas phase outlet valve (29) or the outlet pipeline of the circulating compressor (30) for real-time analysis of carbon dioxide concentration in the gas. The intelligent control system controls the operation of the inlet regulating valve (23), liquid phase outlet valve (28), gas phase outlet valve (29) and circulating compressor (30) according to the detection results of the online detection unit.

10. An industrialized circular production method for the system according to any one of claims 7-9, characterized in that, Includes the following steps: B1: After pretreatment, the coal chemical waste gas enters the system through the process gas inlet manifold (22), and after the total inlet flow and pressure are adjusted by the inlet regulating valve (23), it enters the industrial tubular reaction equipment (24) for photothermal catalytic conversion. The waste gas is used as both reactant and heating medium in the system. B2: After the reaction, the gas is discharged from the outlet of the industrial tubular reaction equipment (24), first pressurized by the gas compressor (25), and then enters the heat exchanger (26) to exchange heat with the feed waste gas or cooling medium, recovering the waste heat and cooling the gas; the cooled gas enters the gas-liquid separator (27), where most of the liquid phase products are separated; B3: The separated liquid phase product is output and collected under the control of the liquid phase outlet valve (28); the separated gas phase is discharged from the upper end of the gas-liquid separator (27) and flows through the gas phase outlet valve (29); the outlet pipeline of the gas phase outlet valve (29) is connected to an online detection unit for real-time analysis of the CO2 concentration; the detection signal is transmitted to the PLC or DCS intelligent control system; the system presets the CO2 concentration threshold; B4: If the detected value is higher than the threshold, it indicates that there is a lot of unreacted CO2. The intelligent control system will automatically open the gas phase outlet valve (29) and start the circulating compressor (30) to pressurize most of the gas phase material and return it to the upstream of the process gas inlet manifold (22). After mixing with the fresh feed gas, it will continue to react and form a circulation loop, thereby improving the total utilization rate of carbon atoms. B5: If the detected value is lower than the threshold, it indicates that the reaction is relatively complete. The intelligent control system will then close the gas phase outlet valve (29), stop the circulation, and deliver the qualified tail gas to the downstream section, which can be used as fuel gas.

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