Miniature fixed bed reaction device for combined degradation of VOCs (Volatile Organic Compounds) and NOx

Abstract

The utility model discloses a miniature fixed bed reaction device for combined degradation of VOCs and NOx. The miniature fixed bed reaction device is used for solving the problems that an existing device for treating VOCs and NOx is insufficient in synergistic degradation capacity, complex in structure and low in experimental control precision. The device comprises a gas supply module, a mixing module, a fixed bed reaction module and a tail gas detection module, the gas supply module is used for adjusting the flow of each gas, the mixing module is used for uniformly mixing each gas, and the mixed gas is guided into a reactor main body; the tail gas detection module is used for detecting the conversion rate of VOCs and NOx and the type and concentration of main intermediate products; the device is compact in structure, small in occupied area and suitable for a laboratory environment, and has relatively high reaction efficiency; each part is modularly designed and is easy to maintain and upgrade, a catalyst can be quickly replaced or experimental conditions can be quickly adjusted, and various research requirements can be met; the integrated reaction system achieves synchronous and efficient degradation of VOCs and NOx, and the synergistic degradation capacity is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas phase catalysis and environmental pollution control technology, in particular to a micro fixed bed reaction device for jointly degrading VOCs and NOx. BACKGROUND

[0002] VOCs (volatile organic compounds) and NOx (nitrogen oxides) are two main types of atmospheric pollutants commonly emitted by industry and daily life, which not only pose a threat to human health, but also exacerbate air pollution by generating ozone and secondary organic aerosols (SOA) through photochemical reactions. At present, the treatment technology of VOCs and NOx has become a research hotspot in the field of environmental science and engineering. In the prior art, the treatment devices for VOCs and NOx often use independent reaction systems, such as selective catalytic reduction (SCR) devices for treating NOx, and catalytic oxidation devices for oxidizing and degrading VOCs.

[0003] However, these independent systems have the following problems:

[0004] (1) unable to achieve the synergistic removal of VOCs and NOx, making it difficult to meet the demand for efficient treatment of pollutants at the same time;

[0005] (2) the device is large in size and complex in structure, and is not suitable for laboratory-scale performance research or precise control of reaction conditions;

[0006] (3) the existing fixed bed reaction device has deficiencies in the mixing and uniform mass transfer of multiple reaction gases, affecting the reaction efficiency. CONTENT OF THE INVENTION

[0007] Therefore, the present application provides a micro fixed bed reaction device for jointly degrading VOCs and NOx, to solve the problems of insufficient synergistic degradation capacity, complex structure, and low experimental control precision of existing devices for treating VOCs and NOx.

[0008] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] A micro fixed bed reaction device for jointly degrading VOCs and NOx, comprising:

[0010] A gas supply module, the gas supply module comprising a VOCs gas generating device, a nitrogen oxide supply unit, an oxygen supply unit, and an inert gas control unit, and each gas unit is equipped with a flow controller; the VOCs gas generating device is used to generate VOCs gas; the nitrogen oxide supply unit is used to generate NO gas and / or NO2 gas; the oxygen supply unit is used to provide oxygen to support the oxidation reaction; the inert gas control unit is used to provide inert gas to dilute the reaction gas;

[0011] a mixing module for uniformly mixing the VOCs gas, the NO gas and / or the NO2 gas, the oxygen gas and the inert gas;

[0012] a fixed bed reaction module, the fixed bed reaction module comprising a reactor body fixedly installed in a reaction furnace and a temperature control device arranged on the reactor body, the reactor body being a cylindrical tubular structure, an inside of the reactor body being filled with catalyst particles, and an inlet of the reactor body being further connected with an ammonia gas reaction module, the ammonia gas reaction module being used for reducing the NO gas and / or the NO2 gas;

[0013] a tail gas detection module for detecting tail gas generated in the fixed bed reaction module.

[0014] Optionally, the VOCs gas comprises benzene, toluene, chlorobenzene, ethylene gas.

[0015] The flow controller is a gas mass flow meter.

[0016] Optionally, the mixing module comprises a first gas mixer and a second gas mixer, and the oxygen gas supply unit comprises a first oxygen gas supply unit and a second oxygen gas supply unit.

[0017] When the VOCs gas is toluene gas, the VOCs gas generating device comprises a first pipeline, a first end of the first pipeline being connected with the first oxygen gas supply unit for introducing air, a last end of the first pipeline being connected with an inlet of the first gas mixer, an outlet of the first gas mixer being connected with an inlet of the reactor body, a middle part of the first pipeline being a first branch pipeline and a second branch pipeline, the first branch pipeline being sequentially provided with a first switch valve, a first gas mass flow meter, a first buffer tank, a second switch valve, the first buffer tank being stored with toluene liquid, the second branch pipeline being sequentially provided with a third switch valve and a second gas mass flow meter.

[0018] The nitrogen oxide supply unit comprises a second pipeline, a first end of the second pipeline being connected with the NO gas and / or the NO2 gas, a last end of the second pipeline being connected with an inlet of the second gas mixer, and the second pipeline being sequentially provided with a sixth switch valve and a fourth gas mass flow meter.

[0019] The second oxygen gas supply unit comprises a third pipeline, a first end of the third pipeline being connected with air, a last end of the third pipeline being connected with an inlet of the second gas mixer, and the third pipeline being sequentially provided with a seventh switch valve and a fifth gas mass flow meter.

[0020] The inert gas control unit comprises a fourth pipeline, a first end of the fourth pipeline is connected with the inert gas, a second end of the fourth pipeline is connected with an inlet of the second gas mixer, and an eighth switch valve and a sixth gas mass flow meter are sequentially arranged on the fourth pipeline;

[0021] The ammonia gas reaction module comprises a fifth pipeline, a first end of the fifth pipeline is connected with the ammonia gas, a second end of the fifth pipeline is connected with an inlet of the reactor body, and a ninth switch valve and a seventh gas mass flow meter are sequentially arranged on the fifth pipeline;

[0022] When the VOCs gas is ethylene gas, a sixth pipeline is further arranged, a first end of the sixth pipeline is connected with the ethylene gas, a second end of the sixth pipeline is connected with an inlet of the second gas mixer, and a tenth switch valve and an eighth gas mass flow meter are sequentially arranged on the sixth pipeline, and an outlet of the second gas mixer is connected with an inlet of the reactor body.

[0023] Optionally, the outlet of the first gas mixer and the outlet of the second gas mixer are connected with a first end of a manifold through a seventh pipeline and an eighth pipeline respectively, and a second end of the manifold is connected with an inlet of the reactor body.

[0024] A three-way pipe is arranged at the inlet of the reactor body, a first interface, a second interface and a third interface of the three-way pipe are connected with a second end of the fifth pipeline, a second end of the manifold and an inlet end of the reactor body respectively.

[0025] Optionally, the tail gas detection module comprises a tail gas pipeline, a gas chromatograph and a flue gas analyzer, and the gas chromatograph and the flue gas analyzer are used for detecting concentrations of VOCs, NOx and intermediate products in the reaction tail gas.

[0026] One end of the tail gas pipeline is connected with an outlet of the reactor body, and the other end is connected with the gas chromatograph and the flue gas analyzer, and a three-way valve A and a three-way valve B are sequentially arranged on the tail gas pipeline, a first interface and a second interface of the three-way valve A are connected with the gas chromatograph and the flue gas analyzer respectively, a third interface of the three-way valve A is connected to an outlet end of the reactor body through the three-way valve B, and the three-way valve B is further connected with the manifold through a ninth pipeline.

[0027] Optionally, a three-way valve C is arranged at a connection position of the ninth pipeline and the manifold.

[0028] The first branch pipeline is divided into a front section and a rear section, a second end of the front section of the first branch pipeline extends into the toluene liquid in the first buffer tank, and a first end of the rear section of the first branch pipeline is connected with a top pipe opening of the first buffer tank.

[0029] The third branch pipe is sequentially provided with a fourth switch valve, a third gas mass flow meter, a second buffer tank, and a fifth switch valve, the second buffer tank stores water, the third branch pipe is divided into a front section and a rear section, the end of the front section of the third branch pipe extends into the water in the second buffer tank, and the first end of the rear section of the third branch pipe is connected to the top pipe of the second buffer tank.

[0030] Optionally, the first gas mixer and the second gas mixer are internally provided with a porous structure or a spiral guide plate.

[0031] Optionally, the material of the reactor body is quartz.

[0032] The inside of the reactor body adopts a uniform distribution of fixed bed structure.

[0033] Optionally, the reaction furnace is an electric heating furnace, and the temperature control device comprises a temperature sensor and a temperature controller, the temperature sensor is used for detecting the reaction temperature inside the reactor body, and the temperature controller is used for receiving the signal of the temperature sensor to adjust the heating temperature of the electric heating furnace.

[0034] Optionally, the reactor body is provided with a filter screen at both ends for fixing catalyst particles.

[0035] Compared with the prior art, the present application has at least the following beneficial effects:

[0036] 1. Based on further analysis and research on the problems of the prior art, the present application provides a micro fixed bed reaction device for jointly degrading VOCs and NOx, which comprises a gas supply module, a mixing module, a fixed bed reaction module, and a tail gas detection module, the gas supply module is used for adjusting the flow of each gas, the mixing module is used for uniformly mixing each gas, the mixed gas is introduced into the fixed bed reactor body, and the reaction temperature is controlled through a temperature control device, and the tail gas detection module is used for detecting the conversion rate of VOCs (such as toluene) and NOx and the types and concentrations of main intermediate products; the present application has a compact structure, a small footprint, is suitable for laboratory environment, and has a high reaction efficiency; each part is modularly designed, is easy to maintain and upgrade, can quickly replace catalysts or adjust experimental conditions, and is suitable for various research needs; through an integrated reaction system, synchronous and efficient degradation of VOCs and NOx is realized, and the synergistic degradation capacity is strong; the gas flow control unit and the temperature control device are provided, the mixed ratio of VOCs and NOx, the reaction temperature, and the like can be accurately controlled, the reaction performance of different catalysts is facilitated to be explored, the fixed bed structure is uniformly distributed inside the reactor body, the gas flow resistance is reduced, and the full contact between the reaction gas and the catalyst is ensured; through the device, synchronous and efficient degradation of VOCs and NOx can be realized under laboratory conditions, and technical support is provided for the collaborative management of multiple pollutants.

[0037] 2. The gas mixer of the present application is internally provided with a porous structure or spiral guide vane, so that the gas mixing efficiency is improved;

[0038] 3. The internal part of the reactor body adopts a uniform distribution of fixed bed structure, so as to reduce the gas flow resistance, ensure the full contact of the reaction gas and the catalyst, and improve the reaction efficiency and conversion rate;

[0039] 4. High-temperature corrosion-resistant filter screen is arranged at both ends of the reactor body, so as to fix the catalyst particles and prevent the loss of particles. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more directly illustrate the prior art and the present application, the following exemplary drawings are given. It should be understood that the specific shape, structure shown in the drawings should not be regarded as the limitation condition for realizing the present application; for example, based on the technical concept and exemplary drawings disclosed in the present application, those skilled in the art can easily make routine adjustments or further optimization on the increase / decrease / attribute division of certain units (components), specific shape, positional relationship, connection mode, size ratio relationship, etc.

[0041] Figure 1 The structural schematic diagram of the micro fixed bed reaction device for jointly degrading VOCs and NOx provided for an embodiment of the present application is shown in the figure;

[0042] Figure 2 The structural schematic diagram of the micro fixed bed reaction device for jointly degrading VOCs and NOx provided for an embodiment of the present application is shown in the figure; Figure 1 The partial schematic diagram of the gas supply module in the figure; Figure 1 ;

[0043] Figure 3 The partial schematic diagram of the gas supply module in the figure; Figure 1 The partial schematic diagram of the gas supply module in the figure; Figure 2 ;

[0044] Figure 4 The partial schematic diagram of the tail gas detection module in the figure; Figure 1 The partial schematic diagram of the tail gas detection module in the figure;

[0045] Figure 5 The partial schematic diagram of the ammonia gas reaction module in the figure; Figure 1 The partial schematic diagram of the ammonia gas reaction module in the figure;

[0046] Figure 6 The partial schematic diagram of the fixed bed reaction module in the figure; Figure 1 The partial schematic diagram of the fixed bed reaction module in the figure;

[0047] Figure 7 The catalytic performance schematic diagram of the Ce-Ti-S catalyst for jointly removing NOx and toluene provided for an embodiment of the present application is shown in the figure.

[0048] Explanation of reference signs:

[0049] 1. VOCs gas generating device; 101, first pipeline; 1011, first branch pipeline; 1012, second branch pipeline; 1013, third branch pipeline; 102, first switch valve; 103, first gas mass flow meter; 104, first buffer tank; 105, second switch valve; 106, third switch valve; 107, second gas mass flow meter; 108, fourth switch valve; 109, third gas mass flow meter; 110, second buffer tank; 111, fifth switch valve; 112, sixth pipeline; 113, tenth switch valve; 114, eighth gas mass flow meter;

[0050] 2. Nitrogen oxide supply unit; 21, second pipeline; 22, sixth switch valve; 23, fourth gas mass flow meter; 3, second oxygen supply unit; 31, third pipeline; 32, seventh switch valve; 33, fifth gas mass flow meter; 4, inert gas control unit; 41, fourth pipeline; 42, eighth switch valve; 43, sixth gas mass flow meter; 5, first gas mixer; 6, second gas mixer; 7, fixed bed reaction module; 71, reactor main body; 72, tee; 73, reaction furnace; 8, tail gas detection module; 81, tail gas pipeline; 82, gas chromatograph; 83, flue gas analyzer; 84, tee valve A; 85, tee valve B; 9, ammonia gas reaction module; 91, fifth pipeline; 92, ninth switch valve; 93, seventh gas mass flow meter;

[0051] 10. Seventh pipeline; 11, eighth pipeline; 12, manifold; 13, ninth pipeline; 14, tee valve C. DETAILED DESCRIPTION

[0052] The present application will be further described in conjunction with the accompanying drawings and specific embodiments.

[0053] In the description of the present application: unless otherwise specified, the meaning of "a plurality of" is two or more. The terms "first", "second", "third" and the like in the present application are intended to distinguish the objects referred to, and do not have a special meaning in the technical connotation aspect (for example, it should not be understood as emphasizing the importance or order, etc.). The expressions "include", "contain", "have" and the like also mean "not limited to" (certain units, components, materials, steps, etc.).

[0054] The terms such as "upper", "lower", "left", "right", "intermediate" and the like referred to in the present application are generally made for the purpose of intuitive understanding by referring to the relative position relationship in the drawings, and are not an absolute limitation of the position relationship in the actual product.

[0055] One embodiment of the present application is a micro fixed bed reaction device for jointly degrading VOCs and NOx, as shown in the accompanying drawings. Figures 1-6As shown, the device comprises a gas supply module, a mixing module, a fixed bed reaction module 7 and a tail gas detection module 8 connected in sequence;

[0056] The gas supply module comprises a VOCs gas generating device 1, a nitrogen oxide supply unit 2, an oxygen supply unit, an inert gas control unit 4, and each gas unit is equipped with a flow controller for accurately adjusting the gas flow; the VOCs gas generating device 1 is used to generate VOCs gas; the nitrogen oxide supply unit 2 is used to generate NO gas and / or NO2 gas; the oxygen supply unit is used to provide oxygen to support the oxidation reaction; the inert gas control unit 4 is used to provide inert gas (balance gas, such as nitrogen) to dilute the reaction gas, thereby regulating the mixing ratio of VOCs gas and NOx;

[0057] The mixing module is used to uniformly mix VOCs gas, NO gas and / or NO2 gas, oxygen and inert gas;

[0058] The fixed bed reaction module 7 comprises a reactor body 71 fixedly installed in a reaction furnace 73 and a temperature control device arranged on the reactor body 71, the reactor body 71 is a cylindrical tubular structure, the inside of the reactor body 71 is filled with catalyst particles, and the inlet of the reactor body 71 is also connected with an ammonia gas reaction module 9 for reducing NO gas and / or NO2 gas;

[0059] The tail gas detection module 8 is used to detect the tail gas generated in the fixed bed reaction module 7.

[0060] Preferably, the flow controller is a gas mass flow meter; the mixing module comprises a first gas mixer 5 and a second gas mixer 6, the oxygen supply unit comprises a first oxygen supply unit and a second oxygen supply unit 3; the VOCs gas comprises benzene, toluene, chlorobenzene, ethylene gas, etc.;

[0061] As Figure 1 , Figure 2As shown, when the VOCs gas is toluene gas, the VOCs gas generating device 1 comprises a first pipeline 101, a first end of the first pipeline 101 is connected with a first oxygen supply unit for introducing air, a tail end of the first pipeline 101 is connected with an inlet of a first gas mixer 5, an outlet of the first gas mixer 5 is connected with an inlet of a reactor main body 71, a middle part of the first pipeline 101 is a first branch pipeline 1011 and a second branch pipeline 1012, the first branch pipeline 1011 is sequentially provided with a first switch valve 102, a first gas mass flow meter 103, a first buffer tank 104, and a second switch valve 105, the first buffer tank 104 stores toluene liquid, the second branch pipeline 1012 is sequentially provided with a third switch valve 106 and a second gas mass flow meter 107; the first branch pipeline 1011 is divided into a front section and a rear section, a tail end of the front section of the first branch pipeline 1011 extends into the toluene liquid in the first buffer tank 104, a first end of the rear section of the first branch pipeline 1011 is connected with a top pipe opening of the first buffer tank 104, the first switch valve 102 and the first gas mass flow meter 103 are arranged in the front section of the first branch pipeline 1011, and the second switch valve 105 is arranged in the rear section of the first branch pipeline 1011; after the air enters the first buffer tank 104 storing the toluene liquid, toluene gas is generated, and then the toluene gas enters the first gas mixer 5;

[0062] As shown in Figure 1 , Figure 3 , the nitrogen oxide supply unit 2 comprises a second pipeline 21, a first end of the second pipeline 21 is connected with NO gas and / or NO2 gas, a tail end of the second pipeline 21 is connected with an inlet of a second gas mixer 6, and the second pipeline 21 is sequentially provided with a sixth switch valve 22 and a fourth gas mass flow meter 23;

[0063] As shown in Figure 1 , Figure 3 , the second oxygen supply unit 3 comprises a third pipeline 31, a first end of the third pipeline 31 is connected with air, a tail end of the third pipeline 31 is connected with an inlet of the second gas mixer 6, and the third pipeline 31 is sequentially provided with a seventh switch valve 32 and a fifth gas mass flow meter 33;

[0064] As shown in Figure 1 , Figure 3 , the inert gas control unit 4 comprises a fourth pipeline 41, a first end of the fourth pipeline 41 is connected with inert gas, a tail end of the fourth pipeline 41 is connected with an inlet of the second gas mixer 6, and the fourth pipeline 41 is sequentially provided with an eighth switch valve 42 and a sixth gas mass flow meter 43;

[0065] As shown in Figure 1 , Figure 5As shown, the ammonia gas reaction module 9 includes a fifth pipeline 91, the first end of which is connected to ammonia gas, the second end of which is connected to the inlet of the reactor body 71, and the fifth pipeline 91 is sequentially provided with a ninth switch valve 92 and a seventh gas mass flow meter 93;

[0066] As shown in the drawings, Figure 1 , Figure 3 When the VOCs gas is ethylene gas, a sixth pipeline 112 is further included, the first end of which is connected to ethylene gas, the second end of which is connected to the inlet of the second gas mixer 6, and the sixth pipeline 112 is sequentially provided with a tenth switch valve 113 and an eighth gas mass flow meter 114, and the outlet of the second gas mixer 6 is connected to the inlet of the reactor body 71.

[0067] Further preferably, a manifold 12 is provided between the first gas mixer 5 and the reactor body 71, and the outlet of the first gas mixer 5 and the outlet of the second gas mixer 6 are respectively connected to the first end of the manifold 12 through a seventh pipeline 10 and an eighth pipeline 11, and the second end of the manifold 12 is connected to the inlet of the reactor body 71;

[0068] A three-way pipe 72 is further provided at the inlet of the reactor body 71, and the first interface, the second interface and the third interface of the three-way pipe 72 are respectively connected to the second end of the fifth pipeline 91, the second end of the manifold 12 and the inlet end of the reactor body 71.

[0069] Further preferably, as shown in the drawings, Figure 1 , Figure 4 The tail gas detection module 8 includes a tail gas pipeline 81, a gas chromatograph 82 and a flue gas analyzer 83, which are used to detect the concentrations of VOCs, NOx and intermediate products in the reaction tail gas, so as to ensure that the tail gas emission meets the standards;

[0070] One end of the tail gas pipeline 81 is connected to the outlet of the reactor body 71, and the other end is connected to the gas chromatograph 82 and the flue gas analyzer 83, and the tail gas pipeline 81 is sequentially provided with a three-way valve A 84 and a three-way valve B 85, the first interface and the second interface of the three-way valve A 84 are respectively connected to the gas chromatograph 82 and the flue gas analyzer 83, the third interface of the three-way valve A 84 is connected to the outlet end of the reactor body 71 through the three-way valve B 85, and the three-way valve B 85 is further connected to the manifold 12 through a ninth pipeline 13; wherein the ninth pipeline 13 is used to test the concentration of the reaction gas that does not pass through the reaction furnace 73, i.e. to test the initial reaction gas concentration; the three-way valve A 84 can also be directly provided as a three-way pipe, when the tail gas is introduced into the three-way valve A 84 through the tail gas pipeline 81, it is directly divided into two paths, and the gas chromatograph 82 and the flue gas analyzer 83 are used to determine the concentration of the tail gas.

[0071] Further preferably, a three-way valve C14 is arranged at the connection between the ninth pipeline 13 and the manifold 12.

[0072] Preferably, as shown in Figure 1 、 Figure 2 Further, a third branch pipeline 1013 is arranged, and the fourth switch valve 108, the third gas mass flow meter 109, the second buffer tank 110 and the fifth switch valve 111 are arranged in sequence on the third branch pipeline 1013. The second buffer tank 110 stores water. The third branch pipeline 1013 is divided into a front section and a rear section. The end of the front section of the third branch pipeline 1013 extends into the water in the second buffer tank 110. The first end of the rear section of the third branch pipeline 1013 is connected to the top pipe of the second buffer tank 110. The fourth switch valve 108 and the third gas mass flow meter 109 are arranged on the front section of the third branch pipeline 1013, and the fifth switch valve 111 is arranged on the rear section of the third branch pipeline 1013. When air enters the second buffer tank 110, water vapor is generated, and then the water vapor enters the first gas mixer 5, so as to test the water resistance under specific conditions.

[0073] Meanwhile, sulfur dioxide can also be introduced into the sixth pipeline 112, so as to test the sulfur resistance under specific conditions.

[0074] Preferably, the first gas mixer 5 and the second gas mixer 6 are internally provided with a porous structure or a spiral guide plate to improve the gas mixing efficiency.

[0075] Preferably, the reactor main body 71 is a glass tube microreactor made of high-temperature-resistant and corrosion-resistant materials such as quartz.

[0076] Further preferably, the internal structure of the reactor main body 71 is a fixed bed structure with uniform distribution, so as to reduce the gas flow resistance and ensure sufficient contact between the reaction gas and the catalyst.

[0077] Preferably, the reaction furnace 73 is an electric heating furnace, and the temperature control device includes a temperature sensor and a temperature controller. The temperature sensor is used to detect the reaction temperature inside the reactor main body, and the temperature controller is used to receive the signal of the temperature sensor, so as to adjust the heating temperature of the electric heating furnace, so as to realize accurate control of the reaction temperature.

[0078] Preferably, high-temperature corrosion-resistant filter screens are arranged at both ends of the reactor main body 71, so as to fix the catalyst particles and prevent the loss of particles.

[0079] Further preferably, the catalyst particles can be Ce-Ti-S catalyst.

[0080] The use principle of the above embodiment is as follows:

[0081] The device can be used for degradation treatment of VOCs (for example, toluene gas) or NOx (for example, NO gas) alone, or for synchronous degradation treatment of toluene and NO gas.

[0082] Air from the first pipeline 101 enters the first branch pipeline 1011 and the second branch pipeline 1012, the air in the first branch pipeline 1011 enters the first buffer tank 104 containing toluene liquid in sequence through the first switch valve 102 and the first gas mass flow meter 103, toluene gas is generated by bubbling, and the toluene gas enters the first gas mixer 5; the air in the second branch pipeline 1012 is mixed with the toluene gas in the first gas mixer 5 in sequence through the third switch valve 106 and the second gas mass flow meter 107; in this process, the flow rates of the corresponding gases are adjusted by the gas mass flow meters according to the laboratory research requirements;

[0083] NO gas enters from the inlet of the second pipeline 21 and enters the second gas mixer 6 in sequence through the sixth switch valve 22 and the fourth gas mass flow meter 23; oxygen enters from the inlet of the third pipeline 31 and enters the second gas mixer 6 in sequence through the seventh switch valve 32 and the fifth gas mass flow meter 33; inert gas enters from the inlet of the fourth pipeline 41 and enters the second gas mixer 6 in sequence through the eighth switch valve 42 and the sixth gas mass flow meter 43; in this process, the flow rates of the corresponding gases are adjusted by the gas mass flow meters according to the laboratory research requirements;

[0084] After the toluene gas and the oxygen are fully mixed in the first gas mixer 5, the first mixed gas formed enters the reactor main body 71 through the seventh pipeline 10; after the NO gas and the oxygen are fully mixed in the second gas mixer 6, the second mixed gas formed enters the reactor main body 71 through the eighth pipeline 11; in this process, the first mixed gas or the second mixed gas can be subjected to degradation treatment by the reactor main body 71 alone, or the first mixed gas and the second mixed gas can be combined into the manifold 12, fully mixed, and then introduced into the reactor main body 71 to realize synchronous degradation of toluene gas and NO gas, and the reaction temperature is controlled by the temperature control device; when the NO gas is subjected to degradation treatment, ammonia is introduced from the inlet of the fifth pipeline 91 and introduced into the reactor main body 71 in sequence through the ninth switch valve 92 and the seventh gas mass flow meter 93;

[0085] After the above-mentioned mixed gas, ammonia introduced into the reactor main body 71, and the catalyst particles in the reactor main body 71 fully react for a period of time, the tail gas is collected, and the conversion rates of toluene and NO and the types and concentrations of main intermediate products are detected by the tail gas detection module 8.

[0086] Application example (synchronous degradation experiment of toluene and NOx):

[0087] (1) Experimental conditions: reaction gas: toluene (60 ppm), NO (600 ppm), O2 (5 vol.%), and N2 (balance gas); flow rate: 200 mL / min; catalyst: Ce-Ti-S catalyst (0.1 g).

[0088] (2) Experimental steps: adjust the flow rate of each gas through the gas supply module, and uniformly mix through the mixing module; introduce the mixed gas into the fixed bed reactor body, and control the reaction temperature through the temperature control device; collect the tail gas, and detect the conversion rates of toluene and NOx and the types and concentrations of main intermediate products through the tail gas detection module.

[0089] (3) Experimental results: see Table 1 Figure 6 At 300℃, the conversion rates of toluene and NOx reached 95% and 92%, respectively, and the main products were CO2, H2O, and N2.

[0090] In summary, the present application has at least the following advantages:

[0091] The micro fixed bed reaction device provided by the present application is a miniaturized, modularized, and reaction condition precisely controllable combined degradation device, which can realize the synergistic degradation of VOCs and NOx in the same system, and meets the experimental research and industrial application requirements; the fixed bed structure is uniformly distributed inside the reactor body to reduce the gas flow resistance and ensure the full contact of the reaction gas and the catalyst; the modular design realizes the precise control of the key reaction conditions such as gas flow rate, temperature, and pressure; the device is miniaturized as a whole, suitable for laboratory research requirements, and supports the rapid replacement of different catalysts.

[0092] (1) Strong synergistic degradation ability: through the integrated reaction system, the synchronous and efficient degradation of VOCs and NOx is realized, effectively solving the problem of single function of existing devices.

[0093] (2) Precise control of reaction conditions: equipped with a gas flow control unit and a temperature control device, the mixing ratio of toluene and NOx, reaction temperature, and other conditions can be precisely regulated, which is convenient for exploring the reaction performance of different catalysts.

[0094] (3) Modular design: modular design of each part, easy to maintain and upgrade, can quickly replace the catalyst or adjust the experimental conditions, and adapts to various research requirements.

[0095] (4) Miniaturization and high efficiency: the device structure is compact, the floor area is small, suitable for laboratory environment, and has high reaction efficiency.

[0096] Any technical features in the above embodiments can be combined (as long as the combinations of the technical features do not contradict each other), and for the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; the embodiments not explicitly written in the above description should also be considered as the scope of the present disclosure.

Claims

1. A micro fixed bed reactor device for combined degradation of VOCs and NOx, characterized in that, The application relates to a VOCs (volatile organic compounds) reduction device, which comprises the following modules: a gas supply module, which comprises a VOCs gas generating device, a nitrogen oxide supply unit, an oxygen supply unit, an inert gas control unit, and each gas unit is equipped with a flow controller; the VOCs gas generating device is used for generating VOCs gas; the nitrogen oxide supply unit is used for generating NO gas and / or NO2 gas; the oxygen supply unit is used for providing oxygen to support the oxidation reaction; and the inert gas control unit is used for providing inert gas to dilute the reaction gas; a mixing module, which is used for uniformly mixing the VOCs gas, the NO gas and / or NO2 gas, the oxygen and the inert gas; a fixed bed reaction module, which comprises a reactor body fixedly installed in a reaction furnace and a temperature control device arranged on the reactor body; the reactor body is a cylindrical tubular structure, the inside of the reactor body is filled with catalyst particles, and the inlet of the reactor body is further connected with an ammonia gas reaction module, which is used for reducing the NO gas and / or NO2 gas; and a tail gas detection module, which is used for detecting the tail gas generated in the fixed bed reaction module.

2. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 1, wherein, The VOCs gas comprises benzene, toluene, chlorobenzene and ethylene gas. The flow controller is a gas mass flow meter.

3. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 2, characterized in that, The mixing module comprises a first gas mixer and a second gas mixer, and the oxygen supply unit comprises a first oxygen supply unit and a second oxygen supply unit. When the VOCs gas is toluene gas, the VOCs gas generating device comprises a first pipeline, the first end of the first pipeline is connected with the first oxygen supply unit and is used for introducing air, the last end of the first pipeline is connected with the inlet of the first gas mixer, the outlet of the first gas mixer is connected with the inlet of the reactor body, the middle part of the first pipeline is a first branch pipeline and a second branch pipeline, the first branch pipeline is sequentially provided with a first switch valve, a first gas mass flow meter, a first buffer tank and a second switch valve, the first buffer tank stores toluene liquid, and the second branch pipeline is sequentially provided with a third switch valve and a second gas mass flow meter. The nitrogen oxide supply unit comprises a second pipeline, the first end of the second pipeline is connected with NO gas and / or NO2 gas, the last end of the second pipeline is connected with the inlet of the second gas mixer, and the second pipeline is sequentially provided with a sixth switch valve and a fourth gas mass flow meter. The second oxygen supply unit comprises a third pipeline, the first end of the third pipeline is connected with air, the last end of the third pipeline is connected with the inlet of the second gas mixer, and the third pipeline is sequentially provided with a seventh switch valve and a fifth gas mass flow meter. The inert gas control unit comprises a fourth pipeline, the first end of the fourth pipeline is connected with inert gas, the last end of the fourth pipeline is connected with the inlet of the second gas mixer, and the fourth pipeline is sequentially provided with an eighth switch valve and a sixth gas mass flow meter. The ammonia gas reaction module comprises a fifth pipeline, a first end of the fifth pipeline is connected with ammonia gas, a last end of the fifth pipeline is connected with an inlet of the reactor body, and a ninth switch valve and a seventh gas mass flow meter are sequentially arranged on the fifth pipeline; When the VOCs gas is ethylene gas, a sixth pipeline is further arranged, a first end of the sixth pipeline is connected with ethylene gas, a last end of the sixth pipeline is connected with an inlet of the second gas mixer, and a tenth switch valve and an eighth gas mass flow meter are sequentially arranged on the sixth pipeline, and an outlet of the second gas mixer is connected with an inlet of the reactor body.

4. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 3, characterized in that, An outlet of the first gas mixer and an outlet of the second gas mixer are connected with a first end of a manifold through a seventh pipeline and an eighth pipeline respectively, and a last end of the manifold is connected with an inlet of the reactor body. A three-way joint is arranged at the inlet of the reactor body, a first interface, a second interface and a third interface of the three-way joint are connected with a last end of the fifth pipeline, a last end of the manifold and an inlet end of the reactor body respectively.

5. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 4, wherein, The tail gas detection module comprises a tail gas pipeline, a gas chromatograph and a flue gas analyzer, and the gas chromatograph and the flue gas analyzer are used for detecting concentrations of VOCs, NOx and intermediate products in the reaction tail gas. One end of the tail gas pipeline is connected with an outlet of the reactor body, the other end is connected with the gas chromatograph and the flue gas analyzer, and a three-way valve A and a three-way valve B are sequentially arranged on the tail gas pipeline, a first interface and a second interface of the three-way valve A are connected with the gas chromatograph and the flue gas analyzer respectively, a third interface of the three-way valve A is connected to an outlet end of the reactor body through the three-way valve B, and the three-way valve B is further connected with the manifold through a ninth pipeline.

6. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 5, wherein, A three-way valve C is arranged at a connection position of the ninth pipeline and the manifold. The first branch pipeline is divided into a front section and a rear section, a last end of the first branch pipeline front section extends into toluene liquid in the first buffer tank, and a first end of the first branch pipeline rear section is connected with a top pipe opening of the first buffer tank. A third branch pipeline is further arranged, a fourth switch valve, a third gas mass flow meter, a second buffer tank and a fifth switch valve are sequentially arranged on the third branch pipeline, the second buffer tank stores water, the third branch pipeline is divided into a front section and a rear section, a last end of the third branch pipeline front section extends into water in the second buffer tank, and a first end of the third branch pipeline rear section is connected with a top pipe opening of the second buffer tank.

7. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 3, wherein, The first gas mixer and the second gas mixer are internally provided with a porous structure or a spiral guide plate.

8. The micro fixed bed reactor device for combined degradation of VOCs and NOx according to claim 1, wherein, The reactor body is made of quartz material. An internal structure of the reactor body adopts a fixed bed structure which is uniformly distributed.

9. The micro fixed bed reaction device for combined degradation of VOCs and NOx according to claim 1, characterized in that, The reaction furnace is an electric heating furnace, and the temperature control device comprises a temperature sensor and a temperature controller, the temperature sensor is used for detecting a reaction temperature in the reactor body, and the temperature controller is used for receiving a signal of the temperature sensor so as to adjust a heating temperature of the electric heating furnace.

10. The micro fixed bed reaction device for combined degradation of VOCs and NOx according to any one of claims 1 to 9, characterized in that, Filter screens are arranged at two ends of the reactor body and are used for fixing catalyst particles.

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