Purification and heat recovery system for gas containing volatile organic compounds

Abstract

The utility model relates to the technical field of industrial gas purification and heat energy recovery, and discloses a volatile organic compound-containing gas purification and heat recovery system, which comprises an oxygen supply element, an oxygen dilution device, a raw material gas mixing tank, a heat storage type thermal oxidation furnace, a waste heat recovery device and a purified gas mixing device which are communicated in sequence, wherein the raw material gas mixing tank is provided with an inlet of gas containing volatile organic compounds; and an outlet of the heat accumulating type thermal oxidation furnace is connected with an inlet of the oxygen diluting device and an inlet of the purified gas mixing device. According to the purification and heat recovery system for the gas containing the volatile organic compounds, the gas containing the volatile organic compounds is removed, heat exchange is carried out on cold water in the waste heat recovery device through high-temperature purified gas generated by the heat storage type thermal oxidation furnace, and the energy recovery utilization rate is increased; meanwhile, part of purified gas is returned to the oxygen dilution device, so that the utilization rate of oxygen is increased.

Description

Technical Field

[0001] This utility model relates to the field of industrial gas purification and heat recovery technology, specifically to a purification and heat recovery system for gases containing volatile organic compounds. Background Technology

[0002] In industrial production processes such as petroleum, chemical, natural gas, and environmental protection, large quantities of combustible carbon and hydrogen components are generated. These gases are volatile organic compounds (VOCs) and significant gaseous pollutants, directly impacting human health and the ecological environment. They can also generate secondary pollutants through atmospheric photochemical reactions. In certain specific processes, such as low-temperature methanol washing and polyoxymethylene (POM) processes in coal chemical industries, the total CO2 and N2 content of the off-gas exceeds 97%, and it contains certain amounts of combustible carbon and hydrogen, but these cannot be directly burned in air. The combustible component concentration is above 500 mg / Nm³. 3 The above-mentioned regenerative thermal oxidation technology can be used to treat volatile organic compounds. After purification, the emissions can be discharged after meeting the emission standards.

[0003] Current methods for treating volatile organic compounds (VOCs) mainly involve supplementing the air with oxygen, which has been initially applied in some large-scale coal chemical projects. However, there are significant shortcomings in terms of heat recovery and resource utilization of the recovered gases: First, the large amount of supplemented air carries away a significant amount of heat energy due to temperature rise, reducing heat recovery efficiency; second, the high N2 content in the air results in a higher N2 content and lower CO2 content in the gas being treated, making low-cost utilization difficult; and third, it may increase the "pollution" of the purified gas by adding smoke and other components. Currently, there is no feasible solution that can technically adapt to the fields of VOC treatment, heat recovery, and resource utilization of recovered gases. Utility Model Content

[0004] The purpose of this invention is to overcome the problems of low energy recovery rate and high cost of waste gas resource utilization in the existing technology, and to provide a purification and heat recovery system for gases containing volatile organic compounds.

[0005] To achieve the above objectives, this utility model provides a purification and heat recovery system for gases containing volatile organic compounds. The system includes an oxygen supply element, an oxygen dilution device, a raw material gas mixing tank, a regenerative thermal oxidizer, a waste heat recovery device, and a purified gas mixing device, which are connected in sequence. The raw material gas mixing tank is provided with an inlet for the gas containing volatile organic compounds. The outlet of the regenerative thermal oxidizer is connected to the inlet of the oxygen dilution device and the inlet of the purified gas mixing device.

[0006] Preferably, the regenerative thermal oxidizer is provided with an oxidation chamber and at least one regenerative chamber, and the outlet of the regenerative chamber is connected to the inlet of the oxygen dilution device through a low-temperature purified gas main pipeline, a low-temperature purified gas circulation pipeline and a circulation replenishment gas pipeline.

[0007] Preferably, the outlet of the heat storage chamber is connected to the inlet of the purified gas mixing device through a low-temperature purified gas main pipeline and a low-temperature purified gas first discharge pipeline.

[0008] Preferably, the system further includes a purge gas pipeline, the two ends of which are connected to the outlet of the low-temperature purified gas main pipeline and the inlet of the heat storage chamber, respectively.

[0009] Preferably, the system further includes a combustion device that provides heat to the regenerative thermal oxidizer.

[0010] Preferably, the system further includes a combustion-supporting mixing device, the inlet of which is connected to an oxygen supply element; the outlet of which is connected to the inlet of the combustion device via a combustion-supporting pipeline.

[0011] Preferably, the outlet of the heat storage chamber is connected to the inlet of the combustion-supporting gas mixing device via a low-temperature purified gas main pipeline, a low-temperature purified gas circulation pipeline, and a circulation combustion-supporting gas pipeline.

[0012] Preferably, the waste heat recovery device is provided with a cold water inlet, a hot water outlet, or a steam outlet.

[0013] Preferably, the purified gas mixing device is equipped with a gas-liquid separator.

[0014] Preferably, the raw material gas mixing tank is provided with a first gas concentration regulating device, which is used to regulate the flow rate of the raw material gas and the mixed gas from the oxygen dilution device into the raw material gas mixing tank, thereby realizing the regulation of the oxygen concentration in the raw material gas mixing tank.

[0015] Preferably, the oxygen dilution device is provided with a second gas concentration regulating device, which is used to regulate the flow rate of oxygen and purified gas entering the oxygen dilution device, thereby realizing the regulation of the oxygen concentration in the oxygen dilution device.

[0016] Preferably, the combustion-supporting gas mixing device is provided with a third gas concentration regulating device, which is used to regulate the flow rate of oxygen and purified gas entering the combustion-supporting gas mixing device, thereby realizing the regulation of the oxygen concentration in the combustion-supporting gas mixing device.

[0017] Through the above technical solution, the present invention has achieved the following beneficial effects:

[0018] (1) The gas purification and heat recovery system containing volatile organic compounds of this utility model not only removes the volatile organic compounds from the gas, but also improves the energy recovery efficiency by using the high-temperature purified gas generated by the regenerative thermal oxidizer to exchange heat with the cold water in the waste heat recovery device; at the same time, returning part of the purified gas to the oxygen dilution device improves the oxygen utilization rate. The system of this utility model has a small footprint, is easy to control, and is convenient to maintain.

[0019] (2) In a preferred embodiment of the present invention, the high-temperature purified gas generated by the regenerative thermal oxidizer is used to exchange heat with the regenerative chamber to preheat the gas containing volatile organic compounds, thereby further improving the energy recovery and utilization rate.

[0020] (3) In the preferred embodiment of this utility model, the purification rate of combustible components in the gas containing volatile organic compounds exceeds 99.7% by volume, and the oxygen content in the purified gas can be reduced to 2-4% by volume, and the purified gas can be directly used by downstream processes.

[0021] (4) In the preferred embodiment of this utility model, by using purified gas to dilute high-concentration oxygen, the content of impurities (such as nitrogen, dust, etc.) in the purified gas can be reduced, and the purified gas obtained can be directly used by downstream processes, simplifying the process flow and achieving zero carbon emissions.

[0022] (5) In the preferred embodiment of the present invention, compared with directly using air as the combustion-supporting gas containing volatile organic compounds, under the same processing capacity, the present invention reduces equipment investment by more than 20% and increases energy recovery rate by more than 20% by using high concentration oxygen as the combustion-supporting gas containing volatile organic compounds.

[0023] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof.

[0025] Figure 1 This is a schematic diagram of the structure of a gas purification and heat recovery system containing volatile organic compounds according to this utility model.

[0026] Explanation of reference numerals in the attached figures

[0027] 1-Raw gas mixing tank; 2-Regenerative thermal oxidizer; 3-Combustion device; 4-Oxygen dilution device; 5-Combustion-supporting gas mixing device; 6-Waste heat recovery device; 7-Purified gas mixing device; 8-First pipeline; 9-Second pipeline; 10-Combustion-supporting gas pipeline; 11-High-temperature purified gas pipeline; 12-Oxygen replenishment pipeline; 13-Circulating gas replenishment pipeline; 14-Low-temperature purified gas first discharge pipeline; 15-Combustion-supporting oxygen pipeline; 16-Third pipeline; 17-Circulating combustion-supporting gas pipeline; 18-Purge gas pipeline; 19-Low-temperature purified gas main pipeline; 20-Fourth pipeline; 21-Low-temperature purified gas circulation pipeline; 22-Oxygen supply element. Detailed Implementation

[0028] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0029] This utility model provides a purification and heat recovery system for gas containing volatile organic compounds. The system includes an oxygen supply element 22, an oxygen dilution device 4, a raw material gas mixing tank 1, a regenerative thermal oxidizer 2, a waste heat recovery device 6, and a purified gas mixing device 7 connected in sequence. The raw material gas mixing tank 1 is provided with an inlet for the gas containing volatile organic compounds. The outlet of the regenerative thermal oxidizer 2 is connected to the inlet of the oxygen dilution device 4 and the inlet of the purified gas mixing device 7.

[0030] According to this utility model, preferably, the regenerative thermal oxidizer 2 is provided with an oxidation chamber and at least one regenerator chamber. The outlet of the regenerator chamber is connected to the inlet of the oxygen dilution device 4 through a low-temperature purified gas main pipeline 19, a low-temperature purified gas circulation pipeline 21, and a circulation replenishment pipeline 13. The combustible components (i.e., volatile organic compounds) in the gas containing volatile organic compounds undergo an oxidation reaction in the oxidation chamber to produce high-temperature purified gas. A portion of the produced high-temperature purified gas exchanges heat with the gas containing volatile organic compounds in the regenerator chamber to produce low-temperature purified gas. The remaining portion of the high-temperature purified gas enters the waste heat recovery device 6 for heat exchange to produce low-temperature purified gas. Understandably, during system operation, the gas containing volatile organic compounds first exchanges heat with the high-temperature purified gas in the heat storage chamber to obtain preheated gas containing volatile organic compounds and low-temperature purified gas. The low-temperature purified gas enters the low-temperature purified gas main pipeline 19, and the preheated gas containing volatile organic compounds enters the oxidation chamber for oxidation reaction. The high-temperature purified gas produced by the oxidation reaction returns to the heat storage chamber to exchange heat with the gas containing volatile organic compounds, thereby realizing the recycling of energy.

[0031] In this invention, "low temperature" or "high temperature" refers to the state of the gas before and after a heat exchange process. For example, the purified gas obtained by the oxidation-reduction reaction in the oxidation chamber can be called "high temperature purified gas"; the purified gas obtained by the "high temperature purified gas" after the temperature decreases after the heat exchange process can be called "low temperature purified gas"; "low temperature" or "high temperature" is only relative in the heat exchange process.

[0032] According to this invention, preferably, a gas-liquid separator is also provided on the main low-temperature purified gas pipeline 19. The gas-liquid separator is used to remove moisture from the low-temperature purified gas in the main low-temperature purified gas pipeline 19 to avoid the influence of moisture on the oxidation reaction. The gas-liquid separator in this invention can be a commonly used gas-liquid separator in the art, as long as it can separate the moisture from the low-temperature purified gas.

[0033] In this invention, the temperature of the low-temperature purified gas in the low-temperature purified gas main pipeline 19 is below 60°C.

[0034] In this invention, the oxygen content of the low-temperature purified gas in the low-temperature purified gas main pipeline 19 is stably maintained at 2-4% by volume.

[0035] According to this utility model, preferably, the outlet of the heat storage chamber is connected to the inlet of the purified gas mixing device 7 through the low-temperature purified gas main pipeline 19 and the low-temperature purified gas first discharge pipeline 14.

[0036] According to this utility model, preferably, the number of heat storage chambers is 1-5. When multiple heat storage chambers are provided, they are arranged in parallel. Preferably, by providing multiple heat storage chambers, the operational stability and operational flexibility of the device can be further improved.

[0037] According to this utility model, preferably, the system further includes a purge gas pipeline 18, the two ends of which are connected to the outlet of the low-temperature purified gas main pipeline 19 and the inlet of the heat storage chamber, respectively. By using low-temperature purified gas to purge the heat storage chamber, the introduction of other impurities can be avoided.

[0038] According to this invention, when the system is started, heat needs to be provided to the oxidation chamber to ensure that the combustible components in the gas containing volatile organic compounds meet the conditions for complete oxidation. Preferably, the system further includes a combustion device 3, which provides heat to the regenerative thermal oxidizer 2. Simultaneously, when the heat in the oxidation chamber is insufficient to meet the heat required for complete oxidation of the combustible components in the gas containing volatile organic compounds, the combustion device 3 can also be activated to provide heat to the regenerative thermal oxidizer 2. Normally, when the system is running stably, the combustion device 3 is in the off state.

[0039] According to this utility model, the combustion device 3 can use hydrocarbons, such as alkanes (e.g., methane, natural gas), olefins, etc., as fuel gas.

[0040] According to this utility model, preferably, the system further includes a combustion-supporting gas mixing device 5, the inlet of which is connected to the oxygen supply element 22; the outlet of the combustion-supporting gas mixing device 5 is connected to the inlet of the combustion device 3 via a combustion-supporting gas pipeline 10. The combustion-supporting gas mixing device 5 mainly provides the combustion-supporting gas required for combustion in the combustion device 3. It is understood that when the combustion device 3 is in the off state, the combustion-supporting gas mixing device 5 is also in the off state.

[0041] According to this utility model, the combustion-supporting gas in the combustion-supporting gas mixing device 5 can be provided by the oxygen supply element 22, or the oxygen in the oxygen supply element 22 can be mixed with the low-temperature purified gas to serve as the combustion-supporting gas. Preferably, the outlet of the heat storage chamber is connected to the inlet of the combustion-supporting gas mixing device 5 through the low-temperature purified gas main pipeline 19, the low-temperature purified gas circulation pipeline 21, and the circulating combustion-supporting gas pipeline 17.

[0042] According to this utility model, preferably, the waste heat recovery device 6 is provided with a cold water inlet, a hot water outlet, or a steam outlet. The waste heat recovery device can be a preheating recovery device commonly used in the art, as long as it can realize the heat exchange between hot water and high-temperature purified gas.

[0043] According to this invention, the high-temperature purified gas enters the purified gas mixing device 7 after heat exchange in the waste heat recovery device 6. Simultaneously, the remaining portion of the low-temperature purified gas in the low-temperature purified gas main pipeline 19 also enters the purified gas mixing device 7, where they are mixed evenly. Preferably, the purified gas mixing device 7 is equipped with a gas-liquid separator. The gas-liquid separator is used to separate moisture from the low-temperature purified gas.

[0044] In this invention, the oxygen content in the oxygen-containing gas provided by the oxygen supply element 22 can be any volume of oxygen sufficient to fully oxidize the combustible components in a gas containing volatile organic compounds. Preferably, the oxygen concentration in the oxygen-containing gas is greater than 30% by volume, more preferably 90-100% by volume. Other gases in the oxygen-containing gas besides oxygen can be any non-flammable gas available in the prior art, such as carbon dioxide or inert gases (e.g., nitrogen, argon, neon, etc.). The oxygen-containing gas can also be oxygen, specifically oxygen that can be supplied or purchased from an upstream plant, for example, oxygen with a purity greater than 99% by volume. Typically, when the main gas in the oxygen-containing gas besides oxygen is carbon dioxide, and the proportion of other gases besides oxygen and carbon dioxide in the volume of the oxygen-containing gas does not exceed 1% by volume, a high-concentration carbon dioxide purified gas can be obtained. The flow rate of oxygen and purified gas entering the oxygen dilution device 4 is adjusted by the second gas concentration adjustment device, thereby adjusting the oxygen concentration in the oxygen dilution device 4 and thus achieving the purity of the purified gas.

[0045] According to this invention, when the raw material gas and oxygen-containing gas do not contain nitrogen, the temperature of the oxidation chamber can operate stably at a temperature above 1000°C without producing NOx (nitrogen oxides).

[0046] According to this utility model, preferably, the raw material gas mixing tank 1 is provided with a first gas concentration regulating device. The first gas concentration regulating device is used to regulate the flow rate of the raw material gas and the mixed gas from the oxygen dilution device 4 into the raw material gas mixing tank 1, thereby regulating the oxygen concentration in the raw material gas mixing tank 1. More preferably, the first gas concentration regulating device regulates the volume concentration of oxygen in the mixed gas in the raw material gas mixing tank 1 to the range of 2.5-5%.

[0047] According to this utility model, preferably, the oxygen dilution device 4 is provided with a second gas concentration regulating device, which is used to regulate the flow rate of oxygen and purified gas entering the oxygen dilution device 4, thereby realizing the regulation of the oxygen concentration in the oxygen dilution device 4.

[0048] In this invention, the proportion of low-temperature purified gas returned to the oxygen dilution device 4 can be selected as needed, as long as the requirement of sufficient oxidation of volatile organic compounds is met. Preferably, the volume ratio of low-temperature purified gas and oxygen-containing gas entering the oxygen dilution device 4 is controlled by the second gas concentration regulating device so that the volume concentration of oxygen in the resulting mixed gas is 21-30%.

[0049] According to this utility model, preferably, the combustion-supporting gas mixing device 5 is provided with a third gas concentration regulating device, which is used to regulate the flow rate of oxygen and purified gas entering the combustion-supporting gas mixing device 5, thereby realizing the regulation of the oxygen concentration in the combustion-supporting gas mixing device 5.

[0050] According to this utility model, the proportion of low-temperature purified gas returned to the combustion-supporting gas mixing device 5 can be selected as needed, as long as the combustion requirements are met. Preferably, the volume concentration of oxygen in the combustion-supporting gas in the combustion-supporting gas pipeline 10 is controlled to be 21-30% by the third gas concentration regulating device.

[0051] According to this utility model, preferably, the first gas concentration regulating device, the second gas concentration regulating device and the third gas concentration regulating device each independently mainly include an oxygen concentration monitor, a flow meter and a regulating valve.

[0052] According to a particularly preferred embodiment of the present invention, such as Figure 1As shown, the system includes, in sequence, an oxygen supply element 22, an oxygen dilution device 4, a raw gas mixing tank 1, a regenerative thermal oxidizer 2, a waste heat recovery device 6, and a purified gas mixing device 7; the system also includes a purge gas pipeline 18, a combustion device 3, and a combustion-supporting gas mixing device 5. The raw gas mixing tank 1 is provided with an inlet for gas containing volatile organic compounds; the regenerative thermal oxidizer 2 is provided with an oxidation chamber and three regenerator chambers (not shown in the figure). The outlet of the regenerator chamber is connected to the inlet of the oxygen dilution device 4 through a low-temperature purified gas main pipeline 19, a low-temperature purified gas circulation pipeline 21, and a circulation replenishment pipeline 13; the outlet of the regenerator chamber is also connected to the inlet of the purified gas mixing device 7 through the low-temperature purified gas main pipeline 19 and a low-temperature purified gas first discharge pipeline 14. A gas-liquid separator is also provided on the low-temperature purified gas main pipeline 19. The outlet of the low-temperature purified gas main pipeline 19 is also connected to the inlet of the regenerator chamber through the purge gas pipeline 18. The inlet of the combustion-supporting gas mixing device 5 is connected to the oxygen supply element 22; the outlet of the combustion-supporting gas mixing device 5 is connected to the inlet of the combustion device 3 through the combustion-supporting gas pipeline 10; the outlet of the regenerator is also connected to the inlet of the combustion-supporting gas mixing device 5 through the low-temperature purified gas main pipeline 19, the low-temperature purified gas circulation pipeline 21, and the circulating combustion-supporting gas pipeline 17. The combustion device 3 provides heat to the regenerative thermal oxidizer 2. The waste heat recovery device 6 is provided with a cold water inlet, a hot water outlet, or a steam outlet. The purified gas mixing device 7 is provided with a gas-liquid separator. The raw material gas mixing tank 1 is provided with a first gas concentration regulating device, the oxygen dilution device 4 is provided with a second gas concentration regulating device, and the combustion-supporting gas mixing device 5 is provided with a third gas concentration regulating device. Each of the first, second, and third gas concentration regulating devices independently includes an oxygen concentration monitor, a flow meter, and a regulating valve.

[0053] The method using the system of a particularly preferred embodiment of this utility model may include:

[0054] When the system is started, air is sent to the raw material gas mixing tank 1 and the combustion-supporting gas mixing device 5 respectively, and methane is sent to the combustion device 3. After the methane is mixed with the air, it is burned to provide heat to the oxidation chamber of the regenerative thermal oxidizer 2. After the air is mixed with the gas containing volatile organic compounds in the oxygen dilution device 4, it enters the oxidation chamber of the regenerative thermal oxidizer 2 to carry out a full oxidation reaction to obtain high-temperature purified gas. The system is then started. Then, the amount of air can be replaced by the low-temperature purified gas in the low-temperature purified gas main pipeline 19 to gradually reduce the amount of air used. At the same time, the amount of methane used can also be reduced until the system is running stably.

[0055] When the system is running stably, the oxygen-containing gas (98% by volume) supplied by the oxygen supply element 22 is mixed with the low-temperature purified gas from the low-temperature purified gas main pipeline 19 in the oxygen dilution device 4 to obtain a first mixed gas (21% by volume). The first mixed gas enters the raw material gas mixing tank 1 through pipeline 16 and is mixed with the gas containing volatile organic compounds entering the raw material gas mixing tank 1 to obtain a second mixed gas (4.5% by volume). The second mixed gas enters the oxidation chamber of the regenerative thermal oxidizer 2 for a full oxidation reaction to obtain high-temperature purified gas. A portion of the high-temperature purified gas enters the regenerative chamber to preheat the gas containing volatile organic compounds to obtain low-temperature purified gas and preheated gas containing volatile organic compounds. The preheated gas containing volatile organic compounds enters the oxidation chamber for a full oxidation reaction, while the low-temperature purified gas enters the low-temperature purified gas main pipeline 19. The low-temperature purified gas in the main low-temperature purified gas pipeline 19 is divided into three parts. The first part returns to the inlet of the heat storage chamber through the purge gas pipeline 18 to purge the heat storage chamber. The second part enters the oxygen dilution device 4 through the low-temperature purified gas circulation pipeline 21 and the circulation replenishment pipeline 13. The third part enters the purified gas mixing device 7 through the first low-temperature purified gas discharge pipeline 14. The remaining high-temperature purified gas enters the waste heat recovery device 6 to exchange heat with cold water to obtain low-temperature purified gas. The obtained low-temperature purified gas enters the purified gas mixing device 7 and is mixed with the low-temperature purified gas that enters the purified gas mixing device 7 through the first low-temperature purified gas discharge pipeline 14. The water content is then separated to obtain a third mixed gas (oxygen content of 4% by volume). The third mixed gas can be directly sent to the downstream purified gas processing section.

[0056] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A system for purifying and recovering heat from gases containing volatile organic compounds, characterized in that: The system comprises an oxygen supply element (22), an oxygen dilution device (4), a raw gas mixing tank (1), a regenerative thermal oxidation furnace (2), a waste heat recovery device (6) and a purified gas mixing device (7) which are connected in sequence; wherein the raw gas mixing tank (1) is provided with an inlet for gas containing volatile organic matter; and the outlet of the regenerative thermal oxidation furnace (2) is connected to the inlet of the oxygen dilution device (4) and the inlet of the purified gas mixing device (7).

2. The system according to claim 1, wherein: The regenerative thermal oxidation furnace (2) is provided with an oxidation chamber and at least one regenerative chamber, the outlet of the regenerative chamber being connected to the inlet of the oxygen dilution device (4) via a low-temperature purified gas main pipeline (19), a low-temperature purified gas circulation pipeline (21) and a circulation air supply pipeline (13).

3. The system according to claim 2, wherein: The outlet of the heat storage chamber is connected to the inlet of the purified gas mixing device (7) via a low-temperature purified gas main pipeline (19) and a low-temperature purified gas first discharge pipeline (14).

4. The system according to claim 2, wherein: The system further comprises a purge gas pipeline (18), the two ends of which are respectively connected to the outlet of the low-temperature purified gas main pipeline (19) and the inlet of the heat storage chamber.

5. The system according to claim 2, wherein: The system further comprises a combustion device (3), wherein the combustion device (3) provides heat for the regenerative thermal oxidation furnace (2).

6. The system according to claim 5, wherein: The system further comprises a combustion-supporting gas mixing device (5), the inlet of which is connected to an oxygen supply element (22); the outlet of which is connected to an inlet of the combustion device (3) via a combustion-supporting gas pipeline (10); The outlet of the heat storage chamber is connected to the inlet of the combustion-supporting gas mixing device (5) via a low-temperature purified gas main pipeline (19), a low-temperature purified gas circulation pipeline (21) and a circulating combustion-supporting gas pipeline (17).

7. The system according to claim 1, wherein: The waste heat recovery device (6) is provided with a cold water inlet, a hot water outlet or a steam outlet.

8. The system according to claim 1, wherein: A gas-liquid separator is provided in the purified gas mixing device (7).

9. The system according to claim 1, wherein: The raw gas mixing tank (1) is provided with a first gas concentration regulating device, which is used to regulate the flow rate of the raw gas and the mixed gas from the oxygen dilution device (4) entering the raw gas mixing tank (1), thereby achieving the regulation of the oxygen concentration in the raw gas mixing tank (1); The oxygen dilution device (4) is provided with a second gas concentration regulating device, which is used to regulate the flow rate of oxygen and purified gas entering the oxygen dilution device (4), thereby achieving regulation of the oxygen concentration in the oxygen dilution device (4).

10. The system according to claim 6, wherein: The combustion-supporting gas mixing device (5) is provided with a third gas concentration regulating device, and the third gas concentration regulating device is used to regulate the flow rate of oxygen and purified gas entering the combustion-supporting gas mixing device (5), thereby achieving regulation of the oxygen concentration in the combustion-supporting gas mixing device (5).

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