Electric auxiliary heating ventilation air methane catalytic oxidation device and method

Abstract

The invention relates to an electric auxiliary heating ventilation air methane catalytic oxidation device and method, and belongs to the technical field of methane treatment. Comprising two heat storage chambers communicated with the oxidation chamber, one heat storage chamber is used for oxidation preheating, and the other heat storage chamber is used for heat storage and works alternately; the catalyst layer and the electric heating layer are arranged in the heat storage chamber, clean energy is used for supplying power to the electric heating layer, carbon emission is reduced, heat energy loss when the ventilation air methane concentration is lower than 0.2% is made up, the methane temperature of the catalyst layer is increased, and low-cost destruction of ultralow-concentration ventilation air methane is achieved. The third heat storage chamber is additionally arranged and enters a waiting state after being preheated, unoxidized ventilation air methane left in heat storage ceramics is blown into the oxidation chamber through the purging fan for catalytic oxidation, the three heat storage chambers are alternately carried out, and therefore the oxidation rate of the ventilation air methane is overall improved. The method solves the problems that continuous and stable oxidation of the ventilation air methane cannot be achieved, and carbon emission can be increased when the ventilation air methane is mixed with extracted gas to be subjected to oxidative destruction.

Description

Technical Field

[0001] This invention belongs to the field of gas treatment technology and relates to an electrically assisted heating exhaust gas catalytic oxidation device and method. Background Technology

[0002] In the coal mining industry, the treatment of exhaust gas (ultra-low concentration gas) is a pressing problem. The concentration of this type of gas is typically below 0.3%. Large quantities of exhaust gas, due to its inherent characteristics, are difficult to utilize effectively and are almost entirely vented, causing not only serious resource waste but also significant negative environmental impacts, becoming one of the main sources of methane emissions.

[0003] From a technical perspective, the core problem in treating spent gas lies in its low methane content. Under normal conditions, the heat generated by methane oxidation is insufficient to sustain continuous combustion. While methane oxidation is an exothermic reaction, it requires specific temperature and concentration conditions to maintain itself. When the methane concentration in the spent gas is too low, the heat released by the oxidation reaction is insufficient to maintain the required temperature, causing the reaction to gradually cease. This renders the spent gas unsuitable for treatment using conventional oxidation combustion methods.

[0004] Currently, traditional regenerative thermal oxidation (RTO) technology is a common method for treating methane gas. However, this technology has strict requirements on methane concentration, with a self-heating equilibrium concentration of 0.3%. When the exhaust gas methane concentration falls below this threshold, the RTO unit cannot maintain normal operation relying solely on the heat generated by the oxidation of methane itself. Therefore, auxiliary fuels such as diesel fuel are needed to provide additional heat to ensure the oxidation reaction continues. However, adding diesel fuel significantly increases treatment costs, making this method economically unfeasible, especially given the current increasing demands for energy costs and environmental benefits. This high-cost method is difficult to promote on a large scale.

[0005] To address this issue, the current mainstream approach relies on the mixed oxidation of high-concentration extracted gas and exhaust gas. By mixing high-concentration gas with exhaust gas in a specific ratio, the overall methane concentration in the mixed gas is increased, reaching the self-heating equilibrium concentration requirements of traditional regenerative thermal oxidation technology, thus achieving low-cost exhaust gas destruction. However, this mixed oxidation method also has significant limitations in practical applications. Some coal mines, due to geographical location, mining conditions, and other factors, lack nearby sources of high-concentration gas, making it impossible to obtain sufficient extracted gas for mixing with exhaust gas, and therefore unable to achieve the goal of low-cost exhaust gas destruction.

[0006] In summary, the field of exhaust gas treatment faces numerous technical challenges. The key issues that urgently need to be addressed in this field are: how to overcome the concentration limitations of traditional regenerative thermal oxidation technology, develop a technology capable of achieving self-heating oxidation combustion of exhaust gas under ultra-low concentration conditions, or find a low-cost treatment method that does not rely on high-concentration gas mixing. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide an electrically assisted heating catalytic oxidation device and method for exhaust gas, which solves the problem that exhaust gas cannot achieve continuous and stable oxidation on its own.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An electrically assisted heating exhaust gas catalytic oxidation device includes at least two heat storage chambers, the tops of which are connected to an oxidation chamber; the bottoms of the first heat storage chamber are respectively connected to a first air inlet pipe and a first air outlet pipe, and the bottoms of the second heat storage chamber are respectively connected to a second air inlet pipe and a second air outlet pipe; the first air inlet pipe and the second air inlet pipe are respectively connected to a main air inlet pipe, and the first air outlet pipe and the second air outlet pipe are respectively connected to a main air outlet pipe, and a straight exhaust pipe is also connected between the main air inlet pipe and the main air outlet pipe;

[0010] The first air inlet pipe, the first air outlet pipe, the second air inlet pipe, the second air outlet pipe, and the direct exhaust pipe are respectively equipped with valves V1, V2, V4, V3, and V5; when valve V1 is open, valve V3 is open, and valves V2, V4, and V5 are closed; when valve V4 is open, valve V2 is open, and valves V1, V3, and V5 are closed; when valve V5 is open, valves V1, V2, V3, and V4 are closed.

[0011] The heat storage chamber is sequentially provided with a first heat storage layer, a catalytic layer, an electric heating layer, and a second heat storage layer; when the exhaust gas concentration is less than a, the electric heating layer is activated; 1.5% ≤ a ≤ 2.5%.

[0012] Optionally, the oxidation chamber is equipped with a burner; the burner is connected to a diesel storage tank for fuel supply.

[0013] Optionally, the electric heating layer is electrically connected to a solar panel and / or a wind turbine via an inverter.

[0014] Optionally, an air intake fan and a collection hood are sequentially connected to the end of the main air intake pipe away from the heat storage chamber.

[0015] Optionally, a third heat storage chamber is also provided, arranged in parallel with the first and second heat storage chambers, wherein the top of the third heat storage chamber is connected to the oxidation chamber; and the bottom of the third heat storage chamber is connected to a third air inlet pipe and a third air outlet pipe.

[0016] The third air inlet pipe and the third air outlet pipe are respectively equipped with valves V7 and V6. When valve V1, V4 or V5 is opened, valve V7 is closed; when valve V6 is opened, valves V1, V4 and V5 are closed.

[0017] Optionally, the bottom of the first heat storage chamber, the second heat storage chamber, and the third heat storage chamber are respectively provided with a first purge air duct, a second purge air duct, and a third purge air duct. The first purge air duct, the second purge air duct, and the third purge air duct are respectively provided with a V8 valve, a V9 valve, and a V10 valve. The V8 valve, along with the V4 valve and the V6 valve, is opened simultaneously, while the other valves are closed. The V9 valve, along with the V2 valve and the V7 valve, is opened simultaneously, while the other valves are closed. The V10 valve, along with the V1 valve and the V3 valve, is opened simultaneously, while the other valves are closed.

[0018] Optionally, the first purge duct, the second purge duct, and the third purge duct are respectively connected to the purge main duct, and a purge fan is connected to the end of the purge main duct away from the heat storage chamber.

[0019] A catalytic oxidation method for a waste gas catalytic oxidation device utilizing any of the above-mentioned electrically auxiliary heating methods includes the following steps:

[0020] In the nth cycle, valve V1 is opened and valves V2, V4, and V5 are closed. Exhaust gas enters the first heat storage chamber through the first air inlet pipe for preheating, and then enters the oxidation chamber for oxidation and combustion. The high-temperature flue gas produced enters the second heat storage chamber for heat storage, and then is discharged from the second air outlet pipe.

[0021] In the (n+1)th cycle, valve V4 is opened and valves V1, V3, and V5 are closed. Exhaust gas enters the second heat storage chamber through the second air inlet pipe for preheating, and then enters the oxidation chamber for oxidation and combustion. The high-temperature flue gas produced enters the first heat storage chamber for heat storage, and then is discharged from the first air outlet pipe; where n is a natural number.

[0022] One preheating-heat storage cycle takes 85 to 95 seconds;

[0023] In case of emergency, open valve V5 and close valves V1, V2, V3 and V4. Exhaust gas will be discharged sequentially through the main inlet pipe, the direct exhaust pipe and the main outlet pipe.

[0024] When the concentration of exhaust gas is less than a, the electric heating layer is turned on for electric auxiliary heating.

[0025] Optionally, the device further includes a third heat storage chamber arranged in parallel with the first heat storage chamber and the second heat storage chamber, the top of the third heat storage chamber being connected to the oxidation chamber; the bottom of the third heat storage chamber is connected to a third air inlet pipe and a third air outlet pipe;

[0026] The method includes the following steps:

[0027] S1, in the m-th cycle, the third regenerator has just finished preheating in the previous cycle. Valves V10, V1, and V3 are opened, other valves are closed, and the purge fan is turned on to purge the third regenerator through the third purge duct. The residual exhaust gas in the heat storage layer of the third regenerator is blown into the oxidation chamber for combustion and oxidation. The exhaust gas enters the first regenerator through the first inlet duct for preheating, and then enters the oxidation chamber for oxidation and combustion. The high-temperature flue gas produced enters the second regenerator for heat storage, and then is discharged from the second outlet duct.

[0028] S2, in the (m+1)th cycle, the first regenerator chamber has just finished preheating in the previous cycle. Valve V8, valve V4, and valve V6 are opened, other valves are closed, and the purge fan is turned on to purge the first regenerator chamber through the first purge duct. The residual exhaust gas in the heat storage layer of the first regenerator chamber is blown into the oxidation chamber for combustion and oxidation. The exhaust gas enters the second regenerator chamber through the second inlet duct for preheating, and then enters the oxidation chamber for oxidation and combustion. The high-temperature flue gas produced enters the third regenerator chamber for heat storage, and then is discharged from the third outlet duct.

[0029] S3, in the (m+2)th cycle, the second regenerator chamber has just finished preheating in the previous cycle. Valve V9, valve V2, and valve V7 are opened, other valves are closed, and the purge fan is turned on to purge the second regenerator chamber through the second purge duct. The residual exhaust gas in the heat storage layer of the second regenerator chamber is blown into the oxidation chamber for combustion and oxidation. The exhaust gas enters the third regenerator chamber through the third inlet duct for preheating, and then enters the oxidation chamber for oxidation and combustion. The high-temperature flue gas generated enters the first regenerator chamber for heat storage, and then is discharged from the first outlet duct.

[0030] Repeat steps S1 to S3 to make the three heat storage chambers work alternately in turn; where m is a natural number;

[0031] One purging cycle of the purging blower is less than one preheating-heat storage cycle.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention solves the problem that waste gas cannot achieve continuous and stable oxidation on its own, and that the oxidation and destruction of waste gas mixed with extracted gas increases carbon emissions. It utilizes electrically assisted heating catalytic oxidation technology to directly oxidize waste gas with a concentration of approximately 0.2% or higher. When the concentration is below approximately 0.2%, catalytic oxidation is performed using electric auxiliary heating. Through the combined action of electric auxiliary heat and catalyst, ultra-low concentration waste gas below approximately 0.2% can be destroyed at low cost without adding additional fuel, thereby reducing overall carbon emissions, promoting near-zero emissions of coal mine gas, and contributing to the achievement of the national dual-carbon goals.

[0034] Specifically, a low-cost catalyst is placed between the two regenerable ceramic layers, lowering the minimum oxidation temperature of exhaust gas and reducing heat loss in the unit, thus achieving self-heating equilibrium for oxidation of lower concentrations of exhaust gas. An electric heating layer is installed below the catalyst layer. When the exhaust gas concentration is below approximately 0.2%, the electric heating layer is activated to preheat the exhaust gas, increasing the temperature of the gas entering the catalyst layer. This also compensates for heat loss in the unit, further reducing the gas concentration required for heat balance in the entire oxidation unit, enabling the destruction of even lower concentrations (approximately <0.2%) of exhaust gas. Renewable energy sources such as wind and solar power are used to generate electricity to power the electric heating layer, thereby reducing carbon emissions.

[0035] The invention also adds a heat storage chamber, which enters a waiting state after the preheating process. The unoxidized exhaust gas remaining in the heat storage ceramic is blown into the oxidation chamber by the bottom blower for catalytic oxidation. The three heat storage chambers take turns to perform the oxidation process, thereby improving the overall oxidation rate of exhaust gas.

[0036] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0038] Figure 1 This is a schematic diagram of the overall device of the present invention. Figure 1 ;

[0039] Figure 2 This is a schematic diagram of the overall device of the present invention. Figure 2 .

[0040] Figure label:

[0041] 1 First heat storage chamber, 101 First heat storage layer, 102 Electric heating layer, 103 Catalytic layer, 104 Second heat storage layer, 105 First air inlet pipe, 106 First air outlet pipe, 2 Second heat storage chamber, 201 Second air inlet pipe, 202 Second air outlet pipe, 3 Third heat storage chamber, 301 Third air inlet pipe, 302 Third air outlet pipe, 4 Main air inlet pipe, 5 Main air outlet pipe, 6 Direct exhaust pipe, 7 Main purging pipe, 701 First purging pipe, 702 Second purging pipe, 703 Third purging pipe, 8 Purging fan, 9 Oxidation chamber, 901 Burner, 10 Diffusion tower, 11 Collection hood, 12 Air inlet fan, 13 Solar panel, 14 Wind turbine, 15 Inverter, 16 Chimney, 17 Diesel storage tank. Detailed Implementation

[0042] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0043] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0044] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0045] Please see Figures 1-2 This is an electrically assisted heating catalytic oxidation device for exhaust gas, comprising at least two heat storage chambers, the tops of which are connected to an oxidation chamber 9; the bottoms of the first heat storage chamber 1 are respectively connected to a first air inlet pipe 105 and a first air outlet pipe 106, and the bottoms of the second heat storage chamber 2 are respectively connected to a second air inlet pipe 201 and a second air outlet pipe 202; the first air inlet pipe 105 and the second air inlet pipe 201 are respectively connected to a main air inlet pipe 4, and the first air outlet pipe 106 and the second air outlet pipe 202 are respectively connected to a main air outlet pipe 5, and a direct exhaust pipe 6 is also connected between the main air inlet pipe 4 and the main air outlet pipe 5.

[0046] The first air inlet pipe 105, the first air outlet pipe 106, the second air inlet pipe 201, the second air outlet pipe 202, and the direct exhaust pipe 6 are respectively equipped with valves V1, V2, V4, V3, and V5. When valve V1 is open, valve V3 is open, and valves V2, V4, and V5 are closed. When valve V4 is open, valve V2 is open, and valves V1, V3, and V5 are closed. When valve V5 is open, valves V1, V2, V3, and V4 are closed. The heat storage chamber is provided with a first heat storage layer 101, a catalytic layer 103, an electric heating layer 102, and a second heat storage layer 104, arranged sequentially from top to bottom. When the exhaust gas concentration is less than a, the electric heating layer 102 is activated; 1.5% ≤ a ≤ 2.5%. In some embodiments of the present invention, the concentration a is preferably 2%. The electric heating layer 102 is electrically connected to the solar panel 13 and / or the wind turbine generator 14 via an inverter 15.

[0047] In some embodiments of the present invention, the heat storage layer is preferably a heat storage ceramic.

[0048] An oxidization chamber 9 is equipped with a burner 901; the burner 901 is connected to a diesel storage tank 17 for fuel supply. The end of the main air inlet duct 4 furthest from the regenerator is connected in sequence to an air inlet fan 12 and a collection hood 11. Under the action of the air inlet fan 12, the exhaust gas generated in the exhaust gas diffuser tower 10 is collected by the collection hood 11 and enters the main air inlet duct 4 for catalytic oxidation. The end of the main exhaust duct 5 furthest from the regenerator is connected to a chimney 16. The high-temperature flue gas after catalytic oxidation is completed is discharged from the chimney 16 through the main exhaust duct 5.

[0049] Example 1

[0050] A catalytic oxidation method for a waste gas catalytic oxidation device using the above-mentioned electric auxiliary heating, wherein the first heat storage chamber 1 and the second heat storage chamber 2 alternately perform preheating and heat storage processes.

[0051] Specifically, the following steps are included:

[0052] In the nth cycle, valve V1 is opened, and valves V2, V4, and V5 are closed. The collection hood 11 collects the exhaust gas discharged from the diffusion tower 10, and the exhaust gas is then sent to the first heat storage chamber 1 via the first air inlet pipe 105 by the air inlet fan 12. After passing through the heat storage ceramic, electric heating layer 102, catalytic layer 103, and heat storage ceramic layer for preheating, it enters the oxidation chamber 9 for oxidation combustion. In the oxidation chamber 9, diesel fuel is injected from the burner 901, and the exhaust gas mixes with the diesel fuel for oxidation. The resulting high-temperature flue gas enters the second heat storage chamber 2, heating the heat storage ceramic in the second heat storage chamber 2 from top to bottom, and then discharges low-temperature exhaust gas from the second air outlet pipe 202. After the entire device establishes thermal balance, the diesel fuel supply is automatically shut off. During this cycle, the electric heating layer 102 of the first heat storage chamber 1 is opened to preheat the exhaust gas; the electric heating layer 102 of the second heat storage chamber 2 is closed to recover heat, and the temperature of the heat storage ceramic gradually increases.

[0053] In the (n+1)th cycle, the flow direction of the exhaust gas is changed, and the valves automatically switch, opening valve V4 and closing valves V1, V3, and V5. The exhaust gas enters the second heat storage chamber 2 through the second air inlet duct 201 for preheating. At this time, the electric heating layer 102 of the second heat storage chamber 2 is energized for heating. The exhaust gas passes through the heat storage ceramic, the electric heating layer 102, the catalytic layer 103, and the heat storage ceramic layer for preheating. During this process, the temperature gradually increases and oxidation begins. It then enters the oxidation chamber 9 for complete oxidation. The resulting high-temperature flue gas enters the first heat storage chamber 1 for heat storage. At this time, the electric heating layer 102 in the first heat storage chamber 1 is turned off and energized, and the low-temperature exhaust gas is discharged from the first air outlet duct 106, achieving continuous combustion of ultra-low concentration gas. This cycle is the opposite of the previous cycle. The electric heating layer 102 of the second heat storage chamber 2 is turned on to preheat the exhaust gas; the electric heating layer 102 of the first heat storage chamber 1 is turned off to recover heat, and the temperature of the heat storage ceramic slowly increases.

[0054] Where n is a natural number.

[0055] A preheating-heat storage cycle lasts 85 to 95 seconds; in some embodiments of the present invention, the duration of a preheating-heat storage cycle is preferably 90 seconds.

[0056] By adding a catalytic layer 103 in the middle of the traditional heat storage ceramic layer, the exhaust gas (ultra-low concentration gas) is oxidized in a lower temperature range using an inexpensive catalyst. Then, heat is generated to maintain the continuous oxidation process. This embodiment can reduce the minimum oxidation concentration of gas and achieve the oxidation and destruction of exhaust gas with a minimum concentration of 0.2%.

[0057] In case of emergency, open valve V5 and close valves V1, V2, V3, and V4. Exhaust gas will be discharged sequentially through the main air inlet duct 4, the direct exhaust duct 6, and the main air outlet duct 5. When the exhaust gas concentration is less than 2%, the electric heating layer 102 is turned on for electric auxiliary heating to preheat the exhaust gas with electricity and maintain thermal balance. The electricity is obtained through solar power generation or wind power generation, thereby reducing carbon emissions and enabling catalytic oxidation of exhaust gas with a concentration of less than 2%.

[0058] Example 2

[0059] Based on the above embodiment 2, the device of this embodiment also includes a third heat storage chamber 3 arranged in parallel with the first heat storage chamber 1 and the second heat storage chamber 2. The top of the third heat storage chamber 3 is connected to the oxidation chamber 9. The bottom of the third heat storage chamber 3 is connected to a third air inlet pipe 301 and a third air outlet pipe 302. The third air inlet pipe 301 and the third air outlet pipe 302 are respectively provided with a V7 valve and a V6 valve. When the V1 valve, V4 valve, or V5 valve is opened, the V7 valve is closed. When the V6 valve is opened, the V1 valve, V4 valve, and V5 valve are closed.

[0060] The bottom of the first heat storage chamber 1, the second heat storage chamber 2, and the third heat storage chamber 3 are respectively provided with a first purge air duct 701, a second purge air duct 702, and a third purge air duct 703. The first purge air duct 701, the second purge air duct 702, and the third purge air duct 703 are respectively provided with a V8 valve, a V9 valve, and a V10 valve. The V8 valve, along with the V4 and V6 valves, opens simultaneously, while the other valves are closed. The V9 valve, along with the V2 and V7 valves, opens simultaneously, while the other valves are closed. The V10 valve, along with the V1 and V3 valves, opens simultaneously, while the other valves are closed.

[0061] The first purge duct 701, the second purge duct 702, and the third purge duct 703 are respectively connected to the purge main duct 7, and the purge main duct 7 is connected to a purge fan 8 at the end away from the heat storage chamber.

[0062] The method for catalytic oxidation of exhaust gas in this embodiment involves the first regenerator 1, the second regenerator 2, and the third regenerator 3 alternately undergoing preheating, heat storage, and waiting (purging) processes, specifically including the following steps:

[0063] S1, in the m-th cycle, the third regenerator 3 has just finished preheating in the previous cycle and enters the purging (waiting) state, while the first regenerator 1 is about to enter the preheating (oxidation) state (airflow from bottom to top), and the second regenerator 2 is about to enter the heat storage state (high-temperature flue gas from top to bottom). This is because after the previous oxidation process cycle is completed, some exhaust gas will remain in the heat storage ceramic of the third regenerator 3. Open valves V10, V1, and V3, and close other valves. Use the purge fan 8 to purge the third heat storage chamber 3 through the third purge duct 703. The purge fan 8 blows the third heat storage chamber 3 through the third purge duct 703, blowing the residual exhaust gas in the heat storage layer of the third heat storage chamber 3 into the oxidation chamber 9 for combustion and oxidation, thereby increasing the oxidation rate. The exhaust gas enters the first heat storage chamber 1 through the first air inlet duct 105 for preheating, and then enters the oxidation chamber 9 for oxidation and combustion. The high-temperature flue gas generated enters the second heat storage chamber 2 for heat storage, and then is discharged from the second air outlet duct 202.

[0064] S2, in the (m+1)th cycle, the first regenerator 1 has just finished preheating in the previous cycle and enters the purging (waiting) state, while the second regenerator 2 is about to enter the preheating (oxidation) state (airflow from bottom to top), and the third regenerator 3 is about to enter the heat storage state (high-temperature flue gas from top to bottom); open valves V8, V4, and V6, close other valves, and turn on the purging fan 8 to purge the first regenerator 1 through the first purging duct 701, blowing the residual exhaust gas in the heat storage layer of the first regenerator 1 into the oxidation chamber 9 for combustion and oxidation; the exhaust gas enters the second regenerator 2 through the second inlet duct 201 for preheating, and then enters the oxidation chamber 9 for oxidation and combustion, and the generated high-temperature flue gas enters the third regenerator 3 for heat storage, and then is discharged from the third outlet duct 302.

[0065] S3, in the (m+2)th cycle, the second heat storage chamber 2 has just finished preheating in the previous cycle. Valves V9, V2, and V7 are opened, other valves are closed, and the purge fan 8 is turned on to purge the second heat storage chamber 2 through the second purge duct 702. The residual exhaust gas in the heat storage layer of the second heat storage chamber 2 is blown into the oxidation chamber 9 for combustion and oxidation. The exhaust gas enters the third heat storage chamber 3 through the third inlet duct 301 for preheating, and then enters the oxidation chamber 9 for oxidation and combustion. The high-temperature flue gas generated enters the first heat storage chamber 1 for heat storage, and then is discharged from the first outlet duct 106.

[0066] The S1 to S3 steps are repeated to allow the three regenerators to work alternately in turn, thereby improving the overall oxidation rate of exhaust gas; where m is a natural number.

[0067] One purging cycle of the purging blower 8 is less than one preheating-heat storage cycle. In some embodiments of the present invention, the duration of one purging cycle is preferably 10 seconds.

[0068] This invention solves the problem that waste gas cannot achieve continuous and stable oxidation on its own, and that the oxidation and destruction of waste gas mixed with extracted gas increases carbon emissions. It utilizes electrically assisted heating catalytic oxidation technology to directly oxidize waste gas with a concentration of approximately 0.2% or higher. When the concentration is below approximately 0.2%, catalytic oxidation is performed using electric auxiliary heating. Through the combined action of electric auxiliary heat and catalyst, ultra-low concentration waste gas below approximately 0.2% can be destroyed at low cost without adding additional fuel, thereby reducing overall carbon emissions, promoting near-zero emissions of coal mine gas, and contributing to the achievement of the national dual-carbon goals.

[0069] Specifically, a low-cost catalyst is placed between the two regenerable ceramic layers, lowering the minimum oxidation temperature of exhaust gas and reducing heat loss in the unit, thereby achieving self-heating balance for oxidation of lower concentrations of exhaust gas. An electric heating layer 102 is installed below the catalyst layer 103. When the exhaust gas concentration is below approximately 0.2%, the electric heating layer 102 is activated to preheat the exhaust gas, increasing the temperature of the exhaust gas entering the catalyst layer 103. This also compensates for heat loss in the unit, further reducing the gas concentration required for heat balance in the entire oxidation unit, enabling the destruction of even lower concentrations (approximately <0.2%) of exhaust gas. Renewable energy sources such as wind and solar power are used to generate electricity to power the electric heating layer 102, thereby reducing carbon emissions.

[0070] The invention also adds a heat storage chamber, which enters a waiting state after the preheating process. The unoxidized exhaust gas remaining in the heat storage ceramic is blown into the oxidation chamber 9 by the bottom blower 8 for catalytic oxidation. The three heat storage chambers take turns to perform the oxidation process, thereby improving the overall oxidation rate of exhaust gas.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A catalytic oxidation device for exhaust gas with electric auxiliary heating, characterized in that: It includes at least two heat storage chambers, the tops of which are connected to the oxidation chamber (9); the bottom of the first heat storage chamber (1) is connected to the first air inlet pipe (105) and the first air outlet pipe (106), respectively; the bottom of the second heat storage chamber (2) is connected to the second air inlet pipe (201) and the second air outlet pipe (202), respectively; the first air inlet pipe (105) and the second air inlet pipe (201) are connected to the main air inlet pipe (4), the first air outlet pipe (106) and the second air outlet pipe (202) are connected to the main air outlet pipe (5), and a straight exhaust pipe (6) is also connected between the main air inlet pipe (4) and the main air outlet pipe (5); The first air inlet pipe (105), the first air outlet pipe (106), the second air inlet pipe (201), the second air outlet pipe (202), and the direct exhaust pipe (6) are respectively equipped with valves V1, V2, V4, V3, and V5; when valve V1 is open, valve V3 is open, and valves V2, V4, and V5 are closed; when valve V4 is open, valve V2 is open, and valves V1, V3, and V5 are closed; when valve V5 is open, valves V1, V2, V3, and V4 are closed. The heat storage chamber is provided with a first heat storage layer (101), a catalytic layer (103), an electric heating layer (102), and a second heat storage layer (104) in sequence; when the exhaust gas concentration is less than a, the electric heating layer (102) is turned on; 1.5% ≤ a ≤ 2.5%.

2. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 1, characterized in that: The oxidation chamber (9) is equipped with a burner (901); the burner (901) is connected to a diesel storage tank (17) for fuel supply.

3. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 1, characterized in that: The electric heating layer (102) is electrically connected to the solar panel (13) and / or the wind turbine (14) via an inverter (15).

4. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 1, characterized in that: The air intake manifold (4) is connected in sequence to an air intake fan (12) and a collection hood (11) at the end away from the heat storage chamber.

5. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 1, characterized in that: It also includes a third heat storage chamber (3) arranged in parallel with the first heat storage chamber (1) and the second heat storage chamber (2), the top of the third heat storage chamber (3) being connected to the oxidation chamber (9); the bottom of the third heat storage chamber (3) is connected to a third air inlet pipe (301) and a third air outlet pipe (302); The third air inlet pipe (301) and the third air outlet pipe (302) are respectively equipped with valves V7 and V6. When valve V1, valve V4 or valve V5 is opened, valve V7 is closed; when valve V6 is opened, valves V1, V4 and V5 are closed.

6. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 5, characterized in that: The bottom of the first heat storage chamber (1), the second heat storage chamber (2), and the third heat storage chamber (3) are respectively provided with a first purge air pipe (701), a second purge air pipe (702), and a third purge air pipe (703). The first purge air pipe (701), the second purge air pipe (702), and the third purge air pipe (703) are respectively provided with a V8 valve, a V9 valve, and a V10 valve. The V8 valve, along with the V4 valve and the V6 valve, is opened simultaneously, while the other valves are closed. The V9 valve, along with the V2 valve and the V7 valve, is opened simultaneously, while the other valves are closed. The V10 valve, along with the V1 valve and the V3 valve, is opened simultaneously, while the other valves are closed.

7. The electrically assisted heating exhaust gas catalytic oxidation device according to claim 6, characterized in that: The first purge duct (701), the second purge duct (702), and the third purge duct (703) are respectively connected to the purge main duct (7), and the purge main duct (7) is connected to a purge fan (8) at the end away from the heat storage chamber.

8. A catalytic oxidation method using an electrically auxiliary heating catalytic oxidation device for exhaust gas according to any one of claims 1 to 7, characterized in that: Includes the following steps: In the nth cycle, valve V1 is opened and valves V2, V4 and V5 are closed. Exhaust gas enters the first heat storage chamber (1) through the first air inlet pipe (105) for preheating, and then enters the oxidation chamber (9) for oxidation and combustion. The generated high-temperature flue gas enters the second heat storage chamber (2) for heat storage, and then is discharged from the second air outlet pipe (202). In the (n+1)th cycle, valve V4 is opened and valves V1, V3, and V5 are closed. Exhaust gas enters the second heat storage chamber (2) through the second air inlet pipe (201) for preheating, and then enters the oxidation chamber (9) for oxidation and combustion. The high-temperature flue gas generated enters the first heat storage chamber (1) for heat storage, and then is discharged from the first air outlet pipe (106); where n is a natural number. One preheating-heat storage cycle takes 85 to 95 seconds; In case of emergency, open valve V5 and close valves V1, V2, V3 and V4. Exhaust gas will be discharged through the main inlet pipe (4), the direct exhaust pipe (6) and the main outlet pipe (5) in sequence. When the concentration of exhaust gas is less than a, the electric heating layer (102) is turned on for electric auxiliary heating.

9. The catalytic oxidation method of the electrically assisted heating exhaust gas catalytic oxidation device according to claim 8, characterized in that: The device also includes a third heat storage chamber (3) arranged in parallel with the first heat storage chamber (1) and the second heat storage chamber (2), the top of the third heat storage chamber (3) being connected to the oxidation chamber (9); the bottom of the third heat storage chamber (3) is connected to a third air inlet pipe (301) and a third air outlet pipe (302); The method includes the following steps: S1, in the m-th cycle, the third heat storage chamber (3) has just finished the preheating of the previous cycle. Open valves V10, V1, and V3, close other valves, and turn on the purge fan (8) to purge the third heat storage chamber (3) through the third purge duct (703). Blow the residual exhaust gas in the heat storage layer of the third heat storage chamber (3) into the oxidation chamber (9) for combustion and oxidation. The exhaust gas enters the first heat storage chamber (1) through the first air inlet duct (105) for preheating, and then enters the oxidation chamber (9) for oxidation and combustion. The generated high-temperature flue gas enters the second heat storage chamber (2) for heat storage, and then is discharged from the second air outlet duct (202). S2, in the m+1th cycle, the first heat storage chamber (1) has just finished the preheating of the previous cycle. The V8 valve, V4 valve, and V6 valve are opened, the other valves are closed, and the purge fan (8) is turned on to purge the first heat storage chamber (1) through the first purge air pipe (701). The residual exhaust gas in the heat storage layer of the first heat storage chamber (1) is blown into the oxidation chamber (9) for combustion and oxidation. The exhaust gas enters the second heat storage chamber (2) through the second air inlet pipe (201) for preheating, and then enters the oxidation chamber (9) for oxidation and combustion. The high-temperature flue gas generated enters the third heat storage chamber (3) for heat storage, and then is discharged from the third air outlet pipe (302). S3, in the m+2th cycle, the second heat storage chamber (2) has just finished the preheating of the previous cycle. Open valves V9, V2 and V7, close other valves, and turn on the purge fan (8) to purge the second heat storage chamber (2) through the second purge air pipe (702). Blow the residual exhaust gas in the heat storage layer of the second heat storage chamber (2) into the oxidation chamber (9) for combustion and oxidation. The exhaust gas enters the third heat storage chamber (3) through the third air inlet pipe (301) for preheating, and then enters the oxidation chamber (9) for oxidation and combustion. The generated high-temperature flue gas enters the first heat storage chamber (1) for heat storage, and then is discharged from the first air outlet pipe (106). Repeat steps S1 to S3 to make the three heat storage chambers work alternately in turn; where m is a natural number; One purging cycle of the purging blower (8) is less than one preheating-storage cycle.

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