A VOCs waste gas recovery and treatment device and method

Abstract

This invention relates to the field of VOCs waste gas treatment technology, specifically to a VOCs waste gas recovery and treatment device and method. The device includes a buffer tank, a compressor, a gas-liquid separator, a primary heat exchanger, a deep dehumidification device, a secondary cryogenic heat exchanger, and an adsorption device connected in sequence. A compressor heat exchanger connects an output end of the gas-liquid separator to an input end of the compressor. Output ends of both the primary and secondary cryogenic heat exchangers are connected to a condensate tank, which is connected to the buffer tank via an adsorption storage tank. Using this device, VOCs waste gas is first pressurized and condensed by the compressor and the primary heat exchanger, then deeply dehumidified and condensed by the deep dehumidification device and the secondary cryogenic heat exchanger, and finally adsorbed by the adsorption device. This effectively recovers various light hydrocarbon components from VOCs waste gas, offering advantages such as good recovery and treatment effect, low cost, and high stability.

Description

Technical Field

[0001] This invention relates to the field of VOCs waste gas treatment technology, specifically to a VOCs waste gas recovery and treatment device and method. Background Technology

[0002] Recently, the in-depth treatment and near-zero emissions of VOCs (volatile organic compounds) have received increasing attention from society. Currently, the emission requirements for VOCs are very strict; specifically, the emission limit for the recovery method is 60 mg / m³. 3 The emission limit for the destruction method is 20 mg / m³. 3 However, most destruction methods require safety pretreatment or supplemental oxygen for destruction. Therefore, these methods need to be converted according to a baseline oxygen content conversion formula. This means that most existing destruction processes require outlet oxygen content conversion, and the significantly increased converted data cannot meet the 20 mg / m³ requirement. 3 The emission requirements are limited. Furthermore, most destruction methods require natural gas combustion or high-power electric heating to maintain the reaction temperature. Therefore, at present, for VOCs waste gas, the use of recycling methods for in-depth treatment is encouraged.

[0003] Currently, there is a lack of near-zero emission devices and processes for VOCs waste gas with a high proportion of light hydrocarbons (i.e., ethane and propane with a volume concentration exceeding 10% VOL), especially for VOCs waste gas from oil fields. Specifically, in the oil field gathering and transportation process, crude oil volatilizes a large amount of associated dissolved gases due to temperature and pressure changes. These associated dissolved gases are mainly high-concentration VOCs waste gas, which typically contains large amounts of light hydrocarbons such as ethane and propane, with light hydrocarbons accounting for 10-50% of VOL. Current recovery methods, primarily based on adsorption combinations, generally have low recovery efficiency for light hydrocarbons (mainly ethane and propane components), thus failing to achieve near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons.

[0004] Therefore, there is an urgent need for a VOCs waste gas recovery and treatment device and method. Summary of the Invention

[0005] To address the lack of near-zero emission devices for VOCs waste gas with a high proportion of light hydrocarbons in the prior art, and the poor recovery and treatment effect of existing recovery-based devices on light hydrocarbons in VOCs waste gas, which cannot meet the requirements of practical applications, this invention provides a VOCs waste gas recovery and treatment device and method.

[0006] To achieve the above objectives, the present invention provides a VOCs waste gas recovery and treatment device, which includes a buffer tank, a compressor, a gas-liquid separator, a primary heat exchanger, a deep dehumidification device, a secondary cryogenic heat exchanger, and an adsorption device connected in sequence.

[0007] A compressor heat exchanger is connected between one output end of the gas-liquid separator and one input end of the compressor. One output end of both the primary heat exchanger and the secondary cryogenic heat exchanger is connected to a condensate tank. The condensate tank is connected to the buffer tank through an adsorption storage tank.

[0008] Preferably, the deep dehumidification device includes a first deep dehumidification tank and a second deep dehumidification tank;

[0009] The output end of the primary heat exchanger is connected to the first deep dehumidification tank and the second deep dehumidification tank respectively via pipes, and the output ends of the first deep dehumidification tank and the second deep dehumidification tank are both connected to the secondary cryogenic heat exchanger via pipes.

[0010] Preferably, a first valve is provided on the connecting pipe between the primary heat exchanger and the first deep dehumidification tank; a second valve is provided on the connecting pipe between the primary heat exchanger and the second deep dehumidification tank; a third valve is provided on the connecting pipe between the first deep dehumidification tank and the secondary cryogenic heat exchanger; and a fourth valve is provided on the connecting pipe between the second deep dehumidification tank and the secondary cryogenic heat exchanger.

[0011] Preferably, one output end of the first deep dehumidification tank and the second deep dehumidification tank are respectively connected to the buffer tank and the first vacuum pump via pipes, and the first vacuum pump is connected to the buffer tank.

[0012] Preferably, a fifth valve is provided on the connecting pipe between the first deep dehumidification tank and the buffer tank, and a sixth valve is provided on the connecting pipe between the first deep dehumidification tank and the first vacuum pump;

[0013] A seventh valve is installed on the connecting pipe between the second deep dehumidification tank and the buffer tank, and an eighth valve is installed on the connecting pipe between the first deep dehumidification tank and the first vacuum pump.

[0014] Preferably, the first deep dehumidification tank and the second deep dehumidification tank are connected by a pipe, and a ninth valve is provided on the pipe.

[0015] Preferably, both the first and second deep dehumidification tanks are filled with dehumidifying material, which is selected from one or more of activated alumina, 4A molecular sieve, and 3A molecular sieve.

[0016] Preferably, the dehumidifying material is a combination of activated alumina and 4A molecular sieve, and the mass filling ratio of activated alumina to 4A molecular sieve is 1:(2-3).

[0017] Preferably, the adsorption device includes a first adsorption tank and a second adsorption tank;

[0018] The output end of the secondary cryogenic heat exchanger is connected to the first adsorption tank and the second adsorption tank respectively via pipes.

[0019] Preferably, a tenth valve is provided on the connecting pipe between the secondary cryogenic heat exchanger and the first adsorption tank, and an eleventh valve is provided on the connecting pipe between the secondary cryogenic heat exchanger and the second adsorption tank.

[0020] Preferably, one output end of the first adsorption tank and the second adsorption tank are respectively connected to the buffer tank and the second vacuum pump via pipes, and the second vacuum pump is connected to the buffer tank.

[0021] Preferably, a twelfth valve is provided on the connecting pipe between the first adsorption tank and the buffer tank, and a thirteenth valve is provided on the connecting pipe between the first adsorption tank and the second vacuum pump;

[0022] A fourteenth valve is installed on the connecting pipe between the second adsorption tank and the buffer tank, and a fifteenth valve is installed on the connecting pipe between the second adsorption tank and the second vacuum pump.

[0023] Preferably, the first adsorption tank and the second adsorption tank are connected by a pipeline, and a sixteenth valve is provided on the pipeline.

[0024] Preferably, the interiors of the first adsorption tank and the second adsorption tank are sequentially provided with a first adsorption material, a second adsorption material, and a third adsorption material from bottom to top; the filling ratio of the first adsorption material, the second adsorption material, and the third adsorption material is (0.1~2):(0.1~2):(6~10);

[0025] The specific surface areas of the first adsorbent material, the second adsorbent material, and the third adsorbent material are 1000-1150 m², respectively. 2 / g、1180-1300m 2 / g and 1300-1600m 2 / g;

[0026] The first adsorbent, the second adsorbent, and the third adsorbent are activated carbon.

[0027] Preferably, the gas-liquid separator is connected to the primary heat exchanger via a pipeline, and the pipeline is equipped with seventeen valves.

[0028] Preferably, the adsorption storage tank is provided with a mixed adsorption material;

[0029] The mixed adsorbent material contains carbon-based activated carbon and water, wherein the weight ratio of water to carbon-based activated carbon is (1-10):10, and the proportions of mesopores and micropores in the carbon-based activated carbon are 30-55% and 45-70%, respectively.

[0030] A second aspect of the present invention provides a method for recovering and treating VOCs waste gas, implemented using the aforementioned VOCs waste gas recovery and treatment device, the method comprising:

[0031] The VOCs waste gas to be treated is introduced into the compressor through the buffer tank. Then the compressor pressurizes the introduced VOCs waste gas to a set pressure and introduces the VOCs waste gas after pressurizing to the set pressure into the gas-liquid separator.

[0032] The gas-liquid separator performs gas-liquid separation treatment on the incoming VOCs waste gas, and the liquid separated from the VOCs waste gas is transported to the compressor heat exchanger for heat exchange and cooling, and then transported to the compressor for cooling; at the same time, the gas separated from the VOCs waste gas is transported to the first-stage heat exchanger.

[0033] The primary heat exchanger cools the incoming VOCs waste gas to a first set temperature and performs a first absorption of the VOCs waste gas. Then, the VOCs waste gas after the first absorption is transported to the deep dehumidification equipment for deep dehumidification.

[0034] The deep dehumidification equipment cools and dehumidifies the incoming VOCs exhaust gas to a second set temperature, and then transports the VOCs exhaust gas after cooling and dehumidifying to the second set temperature to the secondary cryogenic heat exchanger.

[0035] The secondary cryogenic heat exchanger cools the incoming VOCs waste gas to a third set temperature and performs secondary absorption on the VOCs waste gas. Then, the VOCs waste gas after secondary absorption is transported to the adsorption device for adsorption and then discharged into the atmosphere.

[0036] Preferably, the set pressure is 0.5 to 1.0 MPa, the first set temperature is 1 to 7°C, the second set temperature is -30 to -50°C, and the third set temperature is -30 to -60°C.

[0037] According to the above technical solution, based on this VOCs waste gas recovery and treatment device, in actual application, the VOCs waste gas is first pressurized and condensed by a compressor and a primary heat exchanger to achieve primary absorption. Then, the VOCs waste gas is deeply dehumidified and condensed by a deep dehumidification device and a secondary cryogenic heat exchanger to achieve secondary absorption. Finally, the VOCs waste gas is adsorbed by an adsorption device. This can effectively recover various light hydrocarbon components in the VOCs waste gas, and has the advantages of good recovery and treatment effect, low cost, and high stability. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a VOCs waste gas recovery and treatment device;

[0039] Figure 2 This is a schematic diagram of the deep dehumidification equipment in a VOCs waste gas recovery and treatment device;

[0040] Figure 3 This is a schematic diagram of the adsorption equipment in a VOCs waste gas recovery and treatment device.

[0041] Figure 4 This is a diagram showing the specific arrangement of the first, second, and third adsorption materials inside the first and second adsorption tanks of the adsorption equipment.

[0042] Figure 5 This is a pore size distribution diagram of the first adsorbent material;

[0043] Figure 6 This is a pore size distribution diagram of the second adsorbent material;

[0044] Figure 7 This is a pore size distribution diagram of the third adsorbent material.

[0045] Explanation of reference numerals in the attached figures

[0046] 1. Inlet valve; 2. Buffer tank; 3. Compressor; 4. Compressor heat exchanger; 5. Gas-liquid separator;

[0047] Seventeenth valve 6; First stage heat exchanger 7; First valve 8a; Second valve 8b;

[0048] Deep dehumidification equipment 9; First deep dehumidification tank 9a; Second deep dehumidification tank 9b;

[0049] Third valve 10a; Fourth valve 10b; First depth dehumidifier tank valve 11a;

[0050] Second-stage deep dehumidification tank valve 11b; Ninth valve 12; Second-stage cryogenic heat exchanger 13;

[0051] Pressure reducing valve 14; tenth valve 15a; eleventh valve 15b; first adsorption tank valve 16a;

[0052] Second adsorption tank valve 16b; Adsorption equipment 17; First adsorption tank 17a; Second adsorption tank 17b;

[0053] Valve 18a; Valve 18b; Valve 19; Valve 19; Valve 20;

[0054] Valve 21 (21); Vacuum pump 22; Valve 23 (22); Valve 24 (23);

[0055] Condensate tank 25; Adsorption storage tank 26; Twenty-fourth valve 27. Detailed Implementation

[0056] The specific embodiments of the present invention 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 the present invention.

[0057] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of indicated technical features. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean a non-exclusive inclusion, the possibility of the presence or addition of one or more other features, units, components, and / or combinations thereof.

[0058] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] The first aspect of this invention provides a VOCs waste gas recovery and treatment device, such as... Figure 1-4 As shown, the VOCs waste gas recovery and treatment device includes a buffer tank 2, a compressor 3, a gas-liquid separator 5, a primary heat exchanger 7, a deep dehumidification device 9, a secondary cryogenic heat exchanger 13, and an adsorption device 17 connected in sequence.

[0060] A compressor heat exchanger 4 is connected between one output end of the gas-liquid separator 5 and one input end of the compressor 3. One output end of the primary heat exchanger 7 and the secondary cryogenic heat exchanger 13 are both connected to the condensate tank 25. The condensate tank 25 is connected to the buffer tank 2 through an adsorption storage tank 26.

[0061] According to the above technical solution, based on this VOCs waste gas recovery and treatment device, in actual application, the VOCs waste gas is first pressurized and condensed by a compressor and a primary heat exchanger to achieve primary absorption. Then, the VOCs waste gas is deeply dehumidified and condensed by a deep dehumidification device and a secondary cryogenic heat exchanger to achieve secondary absorption. Finally, the VOCs waste gas is adsorbed by an adsorption device. This can effectively recover various light hydrocarbon components in the VOCs waste gas, and has the advantages of good recovery and treatment effect, low cost, and high stability.

[0062] In a preferred embodiment of the VOCs waste gas recovery and treatment device of the present invention, the deep dehumidification device 9 includes a first deep dehumidification tank 9a and a second deep dehumidification tank 9b.

[0063] The output end of the primary heat exchanger 7 is connected to the first deep dehumidification tank 9a and the second deep dehumidification tank 9b respectively through pipes. The output ends of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are both connected to the secondary cryogenic heat exchanger 13 through pipes.

[0064] In one specific embodiment, a first valve 8a is provided on the connecting pipe between the primary heat exchanger 7 and the first deep dehumidification tank 9a; a second valve 8b is provided on the connecting pipe between the primary heat exchanger 7 and the second deep dehumidification tank 9b; a third valve 10a is provided on the connecting pipe between the first deep dehumidification tank 9a and the secondary cryogenic heat exchanger 13; and a fourth valve 10b is provided on the connecting pipe between the second deep dehumidification tank 9b and the secondary cryogenic heat exchanger 13.

[0065] In this embodiment of the invention, by providing the deep dehumidification device 9 including a first deep dehumidification tank 9a and a second deep dehumidification tank 9b, one or more can be selected for use as needed during actual application. Preferably, one of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b is kept in reserve, thereby facilitating the replacement of either the first deep dehumidification tank 9a or the second deep dehumidification tank 9b while ensuring dehumidification efficiency. Preferably, the linear velocity of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b is controlled between 0.1 and 0.5 m / s, i.e., the residence time is more than 6 seconds, and the height-to-diameter ratio of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b is between 2 and 6.

[0066] In this invention, to further ensure that the first deep dehumidification tank 9a and the second deep dehumidification tank 9b can operate stably for a long time without frequent replacement, thereby reducing costs, in another specific embodiment, one output end of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are respectively connected to the buffer tank 2 and the first vacuum pump via pipes, and the first vacuum pump is connected to the buffer tank 2.

[0067] A fifth valve is provided on the connecting pipe between the first deep dehumidification tank 9a and the buffer tank 2, and a sixth valve is provided on the connecting pipe between the first deep dehumidification tank 9a and the first vacuum pump.

[0068] A seventh valve is installed on the connecting pipe between the second deep dehumidification tank 9b and the buffer tank 2, and an eighth valve is installed on the connecting pipe between the first deep dehumidification tank 9b and the first vacuum pump. The arrangement of the valves on the pipes between the first deep dehumidification tank 9a and the buffer tank 2 and the first vacuum pump, as well as the arrangement of the valves on the pipes between the second deep dehumidification tank 9b and the buffer tank 2 and the first vacuum pump, can also be as follows: Figure 1 As shown, other settings with the same effect can also be used, which will not be elaborated here.

[0069] In this embodiment of the invention, the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are respectively connected to the buffer tank 2 and the first vacuum pump. In practical applications, one can be used as a backup, that is, the second deep dehumidification tank 9b can be regenerated while the first deep dehumidification tank 9a is being used. This effectively improves the overall efficiency of the device in recovering and treating VOCs waste gas, and avoids the frequent replacement of the deep dehumidification equipment 9, which affects efficiency and increases dehumidification costs.

[0070] Specifically, taking the regeneration of the second deep dehumidifier 9b using the first deep dehumidifier 9a as an example, the regeneration process is described below. The regeneration process includes two stages: depressurization regeneration and deep regeneration. During the depressurization regeneration stage, the seventh valve is opened and the eighth valve is closed. The second deep dehumidifier 9b is depressurized to atmospheric pressure through the buffer tank 2. When the pressure reaches atmospheric pressure, the seventh valve is closed, completing the depressurization regeneration stage. During the deep regeneration stage, the eighth valve is opened and the first vacuum pump is started. The first vacuum pump further reduces the pressure of the second deep dehumidifier 9b. The pressure inside the first deep dehumidifier 9a is increased until the pressure inside the second deep dehumidifier 9b reaches -80 kPa to -90 kPa. In a preferred embodiment, to further improve the desorption and regeneration effect of the second deep dehumidifier 9b, the first deep dehumidifier 9a and the second deep dehumidifier 9b are connected by a pipeline, and a ninth valve 12 is provided on the pipeline. When the pressure inside the second deep dehumidifier 9b reaches -80 kPa to -90 kPa, the ninth valve 12 is opened to purge the second deep dehumidifier 9b for a period of time and then closed, thereby further improving the desorption and regeneration effect.

[0071] In this invention, to further improve the cooling and dehumidification effect and regeneration efficiency of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b, in a preferred embodiment, both the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are filled with dehumidifying material. The dehumidifying material is selected from one or more of activated alumina, 4A molecular sieve, and 3A molecular sieve. Preferably, the dehumidifying material is a combination of activated alumina and 4A molecular sieve, and the mass filling ratio of activated alumina to 4A molecular sieve is 1:(2-3). In an optional embodiment, the dehumidifying material is a combination of activated alumina, 4A molecular sieve, and 3A molecular sieve, and the mass filling ratio of activated alumina, 4A molecular sieve, and 3A molecular sieve is 1:(2-3):(1.8-2.2). Preferably, the mass filling ratio of the three can be 1:(2-3):2. In practical applications, it is preferable to select one or more of the activated alumina, 4A molecular sieve, and 3A molecular sieve as the filling material according to their mass filling ratio.

[0072] In a preferred embodiment of the VOCs waste gas recovery and treatment device of the present invention, the adsorption device 17 includes a first adsorption tank 17a and a second adsorption tank 17b; the output end of the secondary cryogenic heat exchanger 13 is connected to the first adsorption tank 17a and the second adsorption tank 17b respectively through pipes.

[0073] In one specific embodiment, a tenth valve 15a is provided on the connecting pipe between the secondary cryogenic heat exchanger 13 and the first adsorption tank 17a, and an eleventh valve 15b is provided on the connecting pipe between the secondary cryogenic heat exchanger 13 and the second adsorption tank 17b.

[0074] In this embodiment of the invention, by providing the adsorption device 17 with a first adsorption tank 17a and a second adsorption tank 17b, one or more can be selected for use as needed during practical applications. Preferably, the first adsorption tank 17a and the second adsorption tank 17b are used interchangeably, thereby facilitating the replacement of either the first adsorption tank 17a or the second adsorption tank 17b while ensuring adsorption efficiency.

[0075] In this invention, to further ensure that the first adsorption tank 17a and the second adsorption tank 17b can operate stably for a long time without frequent replacement, thereby reducing costs, in another specific embodiment, one output end of the first adsorption tank 17a and the second adsorption tank 17b are respectively connected to the buffer tank 2 and the second vacuum pump via pipes, and the second vacuum pump is connected to the buffer tank 2.

[0076] A twelfth valve is provided on the connecting pipe between the first adsorption tank 17a and the buffer tank 2, and a thirteenth valve is provided on the connecting pipe between the first adsorption tank 17a and the second vacuum pump.

[0077] A fourteenth valve is installed on the connecting pipe between the second adsorption tank 17b and the buffer tank 2, and a fifteenth valve is installed on the connecting pipe between the second adsorption tank 17b and the second vacuum pump. The arrangement of the valves on the pipes between the first adsorption tank 17a and the buffer tank 2 and the second vacuum pump, as well as the arrangement of the valves on the pipes between the second adsorption tank 17b and the buffer tank 2 and the second vacuum pump, can also be as follows: Figure 1 As shown, other settings with the same effect can also be used, which will not be elaborated here.

[0078] In this embodiment of the invention, the first adsorption tank 17a and the second adsorption tank 17b are respectively connected to the buffer tank 2 and the second vacuum pump. In practical applications, one can be used as a backup, that is, the second adsorption tank 17b can be regenerated while the first adsorption tank 17a is being used. This effectively improves the overall efficiency of the device in recovering and treating VOCs waste gas, and avoids the frequent replacement of the adsorption equipment 17, which affects efficiency and increases adsorption costs.

[0079] Specifically, taking the regeneration of the second adsorption tank 17b using the first adsorption tank 17a as an example, the regeneration process is described below. The regeneration process includes two stages: depressurization regeneration and deep regeneration. During the depressurization regeneration stage, the fourteenth valve is opened and the fifteenth valve is closed. The second adsorption tank 17b is depressurized to atmospheric pressure through the buffer tank 2. When the pressure reaches atmospheric pressure, the fourteenth valve is closed, completing the depressurization regeneration stage. During the deep regeneration stage, the fifteenth valve and the second vacuum pump are opened, and the pressure in the second adsorption tank 17b is further reduced by the second vacuum pump. The pressure inside the first adsorption tank 17a is increased until the pressure inside the second adsorption tank 17b reaches -80 kPa to -90 kPa. In a preferred embodiment, to further improve the desorption and regeneration effect of the second adsorption tank 17b, the first adsorption tank 17a and the second adsorption tank 17b are connected by a pipeline, and a sixteenth valve 19 is provided on the pipeline. When the pressure inside the second adsorption tank 17b reaches -80 kPa to -90 kPa, the sixteenth valve 19 is further opened to purge the second adsorption tank 17b for a period of time and then closed, thereby further improving the desorption and regeneration effect.

[0080] In this invention, in order to further improve the adsorption effect and regeneration efficiency of the first adsorption tank 17a and the second adsorption tank 17b, in a preferred embodiment, the first adsorption tank 17a and the second adsorption tank 17b are respectively provided with a first adsorption material, a second adsorption material and a third adsorption material from bottom to top; the filling ratio of the first adsorption material, the second adsorption material and the third adsorption material is (0.1~2):(0.1~2):(6~10);

[0081] Preferably, the specific surface areas of the first adsorbent material, the second adsorbent material, and the third adsorbent material are each 1000-1150 m². 2 / g、1180-1300m 2 / g and 1300-1600m 2 / g. Preferably, the specific surface areas of the first adsorbent material, the second adsorbent material, and the third adsorbent material are each 1100 m² / g. 2 / g、1200m 2 / g and 1500m 2 / g. Further, the pore size distribution of the first adsorbent material is as follows: Figure 5 As shown, the dv / dlogD (ml / g / nm) reaches above 0.6 between 0.5nm and 1nm, and above 0.189 between 1nm and 2nm; the pore size distribution of the second adsorbent material is as follows. Figure 6As shown, the dv / dlogD (ml / g / nm) reaches a maximum of 1.13 between 0.5 nm and 0.8 nm; the pore size distribution of the third adsorbent material is as follows. Figure 7 As shown, the dv / dlogD (ml / g / nm) reaches a maximum of over 2.4 in the range of 0.5nm to 0.8nm.

[0082] More preferably, the first adsorbent, the second adsorbent, and the third adsorbent are activated carbon, but other adsorbents may also be used, or different materials may be selected for the first adsorbent, the second adsorbent, and the third adsorbent.

[0083] In a preferred embodiment of the VOCs waste gas recovery and treatment device of the present invention, the gas-liquid separator 5 and the primary heat exchanger 7 are connected by a pipeline, and the pipeline is equipped with seventeen valves 6.

[0084] In this embodiment of the invention, by setting the seventeenth valve 6, it can be ensured that the VOCs waste gas entering the first-stage heat exchanger 7 is pressurized to the set pressure during actual application. Furthermore, the gas-liquid separator 5 not only effectively separates the liquid from the VOCs waste gas, but also allows the liquid to be used to cool the compressor 3 via the compressor heat exchanger 4, thereby ensuring that the compressor 3 can operate efficiently and stably for a long time, and thus improving the VOCs waste gas recovery and treatment effect of subsequent devices.

[0085] In a preferred embodiment of the VOCs waste gas recovery and treatment device of the present invention, the adsorption storage tank 26 is provided with a mixed adsorption material.

[0086] The mixed adsorbent material contains carbon-based activated carbon and water, wherein the weight ratio of water to carbon-based activated carbon is (1-10):10, and the proportions of mesopores and micropores in the carbon-based activated carbon are 30-55% and 45-70%, respectively.

[0087] In this embodiment of the invention, by providing a mixed adsorption material in the adsorption storage tank 26, light hydrocarbon molecules such as ethane and propane in VOCs waste gas can be first adsorbed by carbon-based activated carbon under the set pressure, and then further formed with water molecules to form ethane hydrate and propane hydrate, thereby ensuring that the gas entering the buffer tank 2 is air, while light hydrocarbon molecules such as ethane and propane are effectively absorbed.

[0088] A second aspect of the present invention also provides a method for VOCs waste gas recovery and treatment, implemented using the above-mentioned VOCs waste gas recovery and treatment device, the method comprising:

[0089] The VOCs waste gas to be treated is introduced into the compressor 3 through the buffer tank 2. Then, the compressor 3 pressurizes the introduced VOCs waste gas to a set pressure and introduces the VOCs waste gas after pressurizing to the set pressure into the gas-liquid separator 5.

[0090] The gas-liquid separator 5 performs gas-liquid separation treatment on the incoming VOCs waste gas, and the liquid separated from the VOCs waste gas is transported to the compressor heat exchanger 4 for heat exchange and cooling, and then transported to the compressor 3 for cooling the compressor 3; at the same time, the gas separated from the VOCs waste gas is transported to the first-stage heat exchanger 7.

[0091] The primary heat exchanger 7 cools the incoming VOCs waste gas to a first set temperature and performs a first absorption of the VOCs waste gas. Then, the VOCs waste gas after the first absorption is transported to the deep dehumidification device 9 for deep dehumidification.

[0092] The deep dehumidification device 9 cools and dehumidifies the incoming VOCs exhaust gas to a second set temperature, and then transports the VOCs exhaust gas after cooling and dehumidifying to the second set temperature to the secondary cryogenic heat exchanger 13.

[0093] The secondary cryogenic heat exchanger 13 cools the incoming VOCs waste gas to a third set temperature and performs secondary absorption on the VOCs waste gas. Then, the VOCs waste gas after secondary absorption is transported to the adsorption device 17 for adsorption and then discharged into the atmosphere.

[0094] The VOCs waste gas recovery and treatment method described in this invention, in practical application, firstly uses a compressor and a primary heat exchanger to pressurize and condense the VOCs waste gas to achieve primary absorption, then uses a deep dehumidification device and a secondary cryogenic heat exchanger to perform deep dehumidification and condensation of the VOCs waste gas to achieve secondary absorption, and finally uses an adsorption device to adsorb the VOCs waste gas. This method can effectively recover various light hydrocarbon components in VOCs waste gas and has the advantages of good recovery and treatment effect, low cost, and high stability.

[0095] In a preferred embodiment of the VOCs waste gas recovery and treatment method of the present invention, the set pressure is 0.5 to 1.0 MPa, the first set temperature is 1 to 7°C, the second set temperature is -30 to -50°C, and the third set temperature is -30 to -60°C, thereby further ensuring the recovery and treatment effect of VOCs waste gas.

[0096] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0097] Example 1

[0098] The specific composition of the VOCs waste gas to be recovered and treated is as follows: ethane 5.37% VOL, propane 5.38% VOL, butane 11.72% VOL, pentane 17.11% VOL, hexane 3.67% VOL, and the remainder is air; the humidity of the VOCs waste gas to be recovered and treated is 10-50% RH, and the temperature is room temperature. Figure 1 As shown, the VOCs waste gas recovery and treatment device of the present invention is used for implementation. Specifically, the device includes a buffer tank 2, a compressor 3, a gas-liquid separator 5, a primary heat exchanger 7, a deep dehumidification device 9, a secondary cryogenic heat exchanger 13, and an adsorption device 17 connected in sequence.

[0099] A compressor heat exchanger 4 is connected between one output end of the gas-liquid separator 5 and one input end of the compressor 3. One output end of the primary heat exchanger 7 and the secondary cryogenic heat exchanger 13 are both connected to the condensate tank 25. The condensate tank 25 is connected to the buffer tank 2 through an adsorption storage tank 26.

[0100] Specifically, the gas-liquid separator 5 is connected to the first-stage heat exchanger 7 via a pipeline, and the pipeline is equipped with seventeen valves 6; the deep dehumidification device 9 includes a first deep dehumidification tank 9a and a second deep dehumidification tank 9b; the output end of the first-stage heat exchanger 7 is connected to the first deep dehumidification tank 9a and the second deep dehumidification tank 9b via pipelines respectively, and the output ends of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are both connected to the second-stage cryogenic heat exchanger 13 via pipelines.

[0101] A first valve 8a is installed on the connecting pipe between the primary heat exchanger 7 and the first deep dehumidification tank 9a; a second valve 8b is installed on the connecting pipe between the primary heat exchanger 7 and the second deep dehumidification tank 9b; a third valve 10a is installed on the connecting pipe between the first deep dehumidification tank 9a and the secondary cryogenic heat exchanger 13; and a fourth valve 10b is installed on the connecting pipe between the second deep dehumidification tank 9b and the secondary cryogenic heat exchanger 13.

[0102] In practical application, the inlet valve 1 is first opened to allow the VOCs waste gas to be treated to be introduced into the compressor 3 through the buffer tank 2. The compressor 3 then pressurizes the introduced VOCs waste gas to 0.8 MPa (while pressurizing, the temperature of the VOCs waste gas rises to 40–60°C), and then introduces the pressurized VOCs waste gas into the gas-liquid separator 5. The gas-liquid separator 5 then performs gas-liquid separation treatment on the introduced VOCs waste gas, and the liquid separated from the VOCs waste gas is transported to the compressor heat exchanger 4 for heat exchange and cooling. After being heated, the gas is then fed into compressor 3 to cool it down. Simultaneously, the seventeenth valve 6 is opened, allowing the gas separated from the VOCs waste gas to be fed into the primary heat exchanger 7. The primary heat exchanger 7 then cools the incoming VOCs waste gas to a first set temperature and performs a primary absorption of the VOCs. The VOCs waste gas after primary absorption is then fed into the deep dehumidification device 9 for deep dehumidification. Specifically, the primary heat exchanger 7 cools the incoming VOCs waste gas to 2°C to remove large amounts of VOCs. Some moisture is absorbed, along with a small amount of ethane and propane, and most butane, pentane, and hexane molecules. The condensate is transported to condensate tank 25, while a small amount of gas is absorbed in adsorption storage tank 26. Next, the deep dehumidification equipment 9 cools and dehumidifies the incoming VOCs waste gas to -40°C, and then transports the dehumidified VOCs waste gas to the secondary cryogenic heat exchanger 13. Finally, the secondary cryogenic heat exchanger 13 cools the incoming VOCs waste gas to -60°C and performs secondary absorption of the VOCs waste gas, specifically targeting ethane and propane. The absorption process involves transporting the condensate to the condensate tank 25, while a small amount of gas is absorbed in the adsorption storage tank 26. Then, the opening of the pressure reducing valve 14 is controlled to maintain the gas pressure in the primary heat exchanger 7, the deep dehumidification device 9, and the secondary cryogenic heat exchanger 13 at 0.8 MPa. The VOCs waste gas after secondary absorption is then transported to the adsorption device 17 for adsorption. Finally, by controlling the opening of the twentieth valve 20, the recovered VOCs waste gas is discharged into the atmosphere while the gas pressure in the adsorption device 17 is maintained between 0.1 and 0.5 MPa.

[0103] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.00042% VOL, the propane component for 0.00028% VOL, and the proportions of butane, pentane, and hexane components were considered to be 0. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the system has the advantages of good recycling and treatment effect, low cost, high efficiency and high stability.

[0104] Example 2

[0105] The implementation follows the same procedure as Embodiment 1, except that an output end of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b is connected to the buffer tank 2 and the first vacuum pump respectively via pipes, and the first vacuum pump is connected to the buffer tank 2; the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are connected by pipes, and a ninth valve 12 is provided on the pipes.

[0106] By setting up the first deep dehumidifier tank 9a and the second deep dehumidifier tank 9b, one can be used as a backup. Specifically, taking the use of the first deep dehumidifier tank 9a to regenerate the second deep dehumidifier tank 9b as an example, in actual application, valves 11a, 8b, 10b, and 12 of the first deep dehumidifier tank are closed, while valves 8a and 10a are open. During the pressure relief and regeneration stage, valves 11b and 21 of the second deep dehumidifier tank are opened. When the pressure inside the second deep dehumidifier tank 9b drops from 0.8 MPa to atmospheric pressure, valve 21 is closed. During the deep regeneration stage, vacuum pump 22 is turned on to extract the gas inside the second deep dehumidifier tank 9b, reducing its pressure to below atmospheric pressure and gradually transitioning to a vacuum state. When its pressure drops to -80 kPa to -90 kPa, valve 12 is opened, allowing a small amount of gas to enter the second deep dehumidifier tank 9b from the first deep dehumidifier tank 9a, thereby further assisting in the removal of water molecules from the surface of the dehumidifying material.

[0107] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.00042% VOL, the propane component for 0.00028% VOL, and the proportions of butane, pentane, and hexane components were considered to be 0. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the system has the advantages of good recycling and treatment effect, low cost, high efficiency and high stability.

[0108] Example 3

[0109] The implementation follows the same procedure as Example 2, except that the interiors of the first deep dehumidification tank 9a and the second deep dehumidification tank 9b are filled with dehumidifying material, which is a combination of activated alumina and 4A molecular sieve, and the mass ratio of activated alumina to 4A molecular sieve is 1:2.

[0110] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0003% VOL, the propane component for 0.00016% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the system has the advantages of good recycling and treatment effect, low cost, high efficiency and high stability.

[0111] Example 4

[0112] Referring to Embodiment 3, the difference is that the adsorption device 17 includes a first adsorption tank 17a and a second adsorption tank 17b; the output end of the secondary cryogenic heat exchanger 13 is connected to the first adsorption tank 17a and the second adsorption tank 17b respectively through pipes; a tenth valve 15a is provided on the connecting pipe between the secondary cryogenic heat exchanger 13 and the first adsorption tank 17a, and an eleventh valve 15b is provided on the connecting pipe between the secondary cryogenic heat exchanger 13 and the second adsorption tank 17b.

[0113] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0003% VOL, the propane component for 0.00016% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0114] Example 5

[0115] Referring to Embodiment 4, the difference is that one output end of the first adsorption tank 17a and the second adsorption tank 17b are respectively connected to the buffer tank 2 and the second vacuum pump through pipes, and the second vacuum pump is connected to the buffer tank 2; the first adsorption tank 17a and the second adsorption tank 17b are connected by pipes, and a sixteenth valve 19 is provided on the pipes.

[0116] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0003% VOL, the propane component for 0.00016% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0117] Example 6

[0118] The implementation follows the same procedure as in Example 5, except that the first adsorption tank 17a and the second adsorption tank 17b are each provided with a first adsorption material, a second adsorption material and a third adsorption material from bottom to top; the filling ratio of the first adsorption material, the second adsorption material and the third adsorption material is 1:2:6, and the first adsorption material, the second adsorption material and the third adsorption material are activated carbon.

[0119] Testing showed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the gas ultimately discharged into the atmosphere accounted for 0.00023% VOL, the propane component accounted for 0.00011% VOL, and the butane, pentane, and hexane components were considered to be 0%, achieving near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0120] Example 7

[0121] The implementation is the same as in Example 6, except that the specific surface areas of the first adsorbent material, the second adsorbent material, and the third adsorbent material are all 1100 m². 2 / g、1200m 2 / g and 1500m 2 / g.

[0122] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0002% VOL, the propane component for 0.0001% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0123] Example 8

[0124] Referring to Embodiment 7, the difference is that the adsorption storage tank 26 is provided with a mixed adsorption material; the mixed adsorption material contains carbon-based activated carbon and water, wherein the weight ratio of water to carbon-based activated carbon is 1:10, and the proportions of mesopores and micropores in the carbon-based activated carbon are 40% and 50%, respectively.

[0125] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0002% VOL, the propane component for 0.0001% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0126] Example 9

[0127] The same method was implemented as in Example 8, except that the weight ratio of water to carbon-based activated carbon was 3:10, and the proportions of mesopores and micropores in the carbon-based activated carbon were 45% and 55%, respectively.

[0128] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0002% VOL, the propane component for 0.0001% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0129] Example 10

[0130] The same method was implemented as in Example 8, except that the weight ratio of water to carbon-based activated carbon was 7:10, and the proportions of mesopores and micropores in the carbon-based activated carbon were 50% and 60%, respectively.

[0131] Testing revealed that, using the VOCs waste gas recovery and treatment device described in this invention, the ethane component in the final gas discharged into the atmosphere accounted for 0.0002% VOL, the propane component for 0.0001% VOL, and the butane, pentane, and hexane components were considered to be zero. This achieved near-zero emission recovery of VOCs waste gas with a high proportion of light hydrocarbons, i.e., less than 60 mg / m³. 3 The emission limits are met, and the recycling and treatment methods have the advantages of good performance, low cost, higher efficiency, and high stability.

[0132] The VOCs waste gas recovery and treatment device and method provided by the present invention pressurizes and condenses the VOCs waste gas through a compressor and a first-stage heat exchanger to achieve primary absorption, then performs deep dehumidification and condensation of the VOCs waste gas through a deep dehumidification device and a second-stage cryogenic heat exchanger to achieve secondary absorption, and finally adsorbs the VOCs waste gas through an adsorption device. This method can effectively recover various light hydrocarbon components in VOCs waste gas and has the advantages of good recovery and treatment effect, low cost, and high stability.

[0133] 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 thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A VOCs waste gas recovery and treatment device, characterized in that, The device includes a buffer tank (2), a compressor (3), a gas-liquid separator (5), a primary heat exchanger (7), a deep dehumidification device (9), a secondary cryogenic heat exchanger (13), and an adsorption device (17) connected in sequence. A compressor heat exchanger (4) is connected between one output end of the gas-liquid separator (5) and one input end of the compressor (3). One output end of the first-stage heat exchanger (7) and the second-stage cryogenic heat exchanger (13) are both connected to the condensate tank (25). The condensate tank (25) is connected to the buffer tank (2) through the adsorption storage tank (26). The deep dehumidification device (9) includes a first deep dehumidification tank (9a) and a second deep dehumidification tank (9b); The output end of the first-stage heat exchanger (7) is connected to the first deep dehumidification tank (9a) and the second deep dehumidification tank (9b) respectively through pipes. The output ends of the first deep dehumidification tank (9a) and the second deep dehumidification tank (9b) are both connected to the second-stage cryogenic heat exchanger (13) through pipes. A first valve (8a) is provided on the connecting pipe between the primary heat exchanger (7) and the first deep dehumidification tank (9a); a second valve (8b) is provided on the connecting pipe between the primary heat exchanger (7) and the second deep dehumidification tank (9b); a third valve (10a) is provided on the connecting pipe between the first deep dehumidification tank (9a) and the secondary cryogenic heat exchanger (13); and a fourth valve (10b) is provided on the connecting pipe between the second deep dehumidification tank (9b) and the secondary cryogenic heat exchanger (13). The first deep dehumidification tank (9a) and the second deep dehumidification tank (9b) are respectively connected to the buffer tank (2) and the first vacuum pump through pipes. The first vacuum pump is connected to the buffer tank (2).

2. The VOCs waste gas recovery and treatment device according to claim 1, characterized in that, A fifth valve is provided on the connecting pipe between the first deep dehumidification tank (9a) and the buffer tank (2), and a sixth valve is provided on the connecting pipe between the first deep dehumidification tank (9a) and the first vacuum pump; A seventh valve is provided on the connecting pipe between the second deep dehumidification tank (9b) and the buffer tank (2), and an eighth valve is provided on the connecting pipe between the first deep dehumidification tank (9b) and the first vacuum pump.

3. The VOCs waste gas recovery and treatment device according to claim 1 or 2, characterized in that, The first deep dehumidification tank (9a) and the second deep dehumidification tank (9b) are connected by a pipe, and a ninth valve (12) is provided on the pipe.

4. The VOCs waste gas recovery and treatment device according to claim 1, characterized in that, The interior of both the first deep dehumidification tank (9a) and the second deep dehumidification tank (9b) is filled with dehumidifying material, which is selected from one or more of activated alumina, 4A molecular sieve and 3A molecular sieve.

5. The VOCs waste gas recovery and treatment device according to claim 4, characterized in that, The dehumidifying material is a combination of activated alumina and 4A molecular sieve, and the mass filling ratio of activated alumina to 4A molecular sieve is 1:(2~3).

6. The VOCs waste gas recovery and treatment device according to claim 1, characterized in that, The adsorption device (17) includes a first adsorption tank (17a) and a second adsorption tank (17b). The output end of the secondary cryogenic heat exchanger (13) is connected to the first adsorption tank (17a) and the second adsorption tank (17b) respectively via pipes.

7. The VOCs waste gas recovery and treatment device according to claim 6, characterized in that, A tenth valve (15a) is provided on the connecting pipe between the secondary cryogenic heat exchanger (13) and the first adsorption tank (17a), and an eleventh valve (15b) is provided on the connecting pipe between the secondary cryogenic heat exchanger (13) and the second adsorption tank (17b).

8. The VOCs waste gas recovery and treatment device according to claim 6, characterized in that, The first adsorption tank (17a) and the second adsorption tank (17b) are respectively connected to the buffer tank (2) and the second vacuum pump through pipes. The second vacuum pump is connected to the buffer tank (2).

9. The VOCs waste gas recovery and treatment device according to claim 8, characterized in that, A twelfth valve is provided on the connecting pipe between the first adsorption tank (17a) and the buffer tank (2), and a thirteenth valve is provided on the connecting pipe between the first adsorption tank (17a) and the second vacuum pump; A fourteenth valve is provided on the connecting pipe between the second adsorption tank (17b) and the buffer tank (2), and a fifteenth valve is provided on the connecting pipe between the second adsorption tank (17b) and the second vacuum pump.

10. The VOCs waste gas recovery and treatment device according to claim 8 or 9, characterized in that, The first adsorption tank (17a) and the second adsorption tank (17b) are connected by a pipe, and a sixteenth valve (19) is provided on the pipe.

11. The VOCs waste gas recovery and treatment device according to claim 6, characterized in that, The first adsorption tank (17a) and the second adsorption tank (17b) are each provided with a first adsorption material, a second adsorption material and a third adsorption material from bottom to top; the filling ratio of the first adsorption material, the second adsorption material and the third adsorption material is (0.1~2):(0.1~2):(6~10); The specific surface areas of the first adsorbent material, the second adsorbent material, and the third adsorbent material are 1000-1150 m², respectively. 2 / g、1180-1300m 2 / g and 1300-1600m 2 / g; The first adsorbent, the second adsorbent, and the third adsorbent are activated carbon.

12. The VOCs waste gas recovery and treatment device according to claim 1, characterized in that, The gas-liquid separator (5) is connected to the primary heat exchanger (7) by a pipeline, and the pipeline is equipped with seventeen valves (6).

13. The VOCs waste gas recovery and treatment device according to claim 1, characterized in that, The adsorption storage tank (26) is equipped with a mixed adsorption material; The mixed adsorbent material contains carbon-based activated carbon and water, wherein the weight ratio of water to carbon-based activated carbon is (1~10):10, and the proportions of mesopores and micropores in the carbon-based activated carbon are 30~55% and 45~70%, respectively.

14. A method for recovering and treating VOCs waste gas, implemented using the apparatus described in any one of claims 1-13, characterized in that, The method includes: The VOCs waste gas to be treated is introduced into the compressor (3) through the buffer tank (2). Then the compressor (3) pressurizes the introduced VOCs waste gas to a set pressure and introduces the VOCs waste gas after being pressurized to the set pressure into the gas-liquid separator (5). The gas-liquid separator (5) performs gas-liquid separation treatment on the incoming VOCs waste gas, and transports the liquid separated from the VOCs waste gas to the compressor heat exchanger (4) for heat exchange and cooling, and then to the compressor (3) for cooling the compressor (3); at the same time, the gas separated from the VOCs waste gas is transported to the first-stage heat exchanger (7); The primary heat exchanger (7) cools the incoming VOCs waste gas to the first set temperature and performs a first absorption of the VOCs waste gas. Then, the VOCs waste gas after the first absorption is transported to the deep dehumidification device (9) for deep dehumidification. The deep dehumidification device (9) cools and dehumidifies the incoming VOCs exhaust gas to a second set temperature, and then transports the VOCs exhaust gas after cooling and dehumidifying to the second set temperature to the secondary cryogenic heat exchanger (13). The secondary cryogenic heat exchanger (13) cools the incoming VOCs waste gas to the third set temperature and performs secondary absorption on the VOCs waste gas. Then, the VOCs waste gas after secondary absorption is transported to the adsorption device (17) for adsorption and then discharged into the atmosphere.

15. The VOCs waste gas recovery and treatment method according to claim 14, characterized in that, The set pressure is 0.5~1.0MPa, the first set temperature is 1~7℃, the second set temperature is -30~-50℃, and the third set temperature is -30~-60℃.

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