A VOCs treatment system and application method thereof

Abstract

The present application relates to the VOCs treatment technical field, disclose a kind of VOCs processing system and its application method, VOCs processing system includes first processing module, second processing module and catalytic oxidation processing module;The oil washing tower of first processing module is set to the upstream of first water washing tower and is communicated with first water washing tower;Catalytic oxidation processing module is set to the downstream of first processing module and second processing module, and respectively with the first outlet of oil washing tower and the second outlet of second processing module is communicated.The present application corresponds to the processing of lipophilic VOCs, hydrophilic VOCs by first processing module, second processing module respectively, two types of exhaust gas complete pretreatment, exhaust gas concentration is controlled within the lower limit of explosion safety threshold, avoid catalytic oxidation process deflagration safety hazard, then again convergence unified and sent into downstream catalytic oxidation processing module, reduce system equipment configuration quantity, reduce equipment investment, land space and subsequent operation and maintenance cost.

Description

Technical Field

[0001] This invention relates to the technical field of VOCs treatment, specifically to a VOCs treatment system and its application method. Background Technology

[0002] To enhance the risk resistance of petrochemical enterprises, the planning of chemical products is becoming increasingly diversified. Coastal tank farms also have a greater number of tanks storing flammable liquid chemicals. Correspondingly, raw materials and auxiliary materials are also becoming more diversified, leading to a trend of increased variety in tank farms supplying flammable liquid raw materials and products. In recent years, people have paid increasing attention to air pollution, especially incorporating in-depth VOCs treatment in tank farms into key emission reduction tasks, placing higher demands on VOCs treatment in multi-category integrated tank farms.

[0003] Petrochemical enterprises need to install VOCs tail gas recovery and treatment facilities in their raw material and product storage tank areas and warehouses. In related technologies, different production lines are set up to treat a single type of VOCs. However, given the characteristics of large-scale integrated tank areas with a wide variety of VOCs, multiple production lines need to be established, resulting in a complex overall system structure and high costs. Summary of the Invention

[0004] This invention provides a VOCs treatment system and its application method to solve the problem that when dealing with multiple types of VOCs, it is necessary to establish multiple production lines, resulting in a complex overall system structure and high cost.

[0005] In a first aspect, the present invention provides a VOCs treatment system, comprising a first treatment module, a second treatment module, and a catalytic oxidation treatment module; the first treatment module includes an oil washing tower and a first water washing tower, the oil washing tower having a first inlet adapted to feed oleophilic VOCs, the oil washing tower being disposed upstream of and connected to the first water washing tower, the first water washing tower having a first outlet; the second treatment module having a second inlet and a second outlet, the second inlet being adapted to feed hydrophilic VOCs; the catalytic oxidation treatment module being disposed downstream of the first treatment module and the second treatment module, and connected to the first outlet and the second outlet respectively.

[0006] Beneficial effects: The first and second treatment modules respectively treat oleophilic VOCs and hydrophilic VOCs, pre-treating both types of exhaust gases and controlling their concentrations within the lower explosive limit, thus avoiding the risk of deflagration during catalytic oxidation. The gases are then combined and sent to the downstream catalytic oxidation module. Unlike related technologies, this significantly reduces the number of system devices, lowering equipment investment, floor space requirements, and subsequent operation and maintenance costs. The first treatment module uses an oil wash followed by a water wash. The water wash effectively removes small amounts of VOCs and their associated washing oil and gas from the exhaust gas, while also ensuring safe and effective isolation between the oil wash tower and the catalytic oxidation module, guaranteeing the safe operation of both modules.

[0007] In one optional embodiment, the oil washing tower includes a first coarse washing section and a first fine washing section, the first coarse washing section is connected to the first fine washing section, the first coarse washing section is located upstream of the first fine washing section, the first coarse washing section has a first inlet, and the first fine washing section is connected to the first water washing tower.

[0008] Beneficial effects: The oil washing tower is divided into two absorption sections: a first coarse washing section and a first fine washing section. Oleophilic VOCs first enter the first coarse washing section to complete the absorption and removal of most VOCs. The remaining low-concentration VOCs then enter the first fine washing section for further deep absorption and purification. The washing oil enriched with a small amount of VOCs after fine washing can overflow back to the first coarse washing section to continue to participate in absorption, reducing the frequency of fresh washing oil replenishment, reducing washing oil consumption, and reducing the hazardous waste disposal costs caused by the discharge of sludge and oil.

[0009] In one optional embodiment, the oil washing tower further includes a first coarse washing pump and a first fine washing pump. The first coarse washing section is provided with a first coarse packing. The first inlet is located upstream of the first coarse packing. The inlet of the first coarse washing pump is connected to the upstream of the first coarse packing, and the outlet of the first coarse washing pump is connected to the downstream of the first coarse packing. The first fine washing section is provided with a first fine packing. The inlet of the first fine washing pump is connected to the upstream of the first fine packing, and the outlet of the first fine washing pump is connected to the downstream of the first fine packing.

[0010] Beneficial effects: The first coarse wash pump and the first fine wash pump provide circulation power for the coarse wash circulation loop and the fine wash circulation loop, respectively, forming a closed-loop spray in the coarse wash section and the fine wash section. This allows the exhaust gas and washing oil to fully come into countercurrent contact in the packing area, improving the gas-liquid mass transfer absorption efficiency and ensuring the stable absorption effect of each section of the coarse wash and fine wash.

[0011] In one optional embodiment, the first water washing tower includes a tower body and a water circulation pump. The tower body is provided with water washing packing. The upstream of the water washing packing is connected to the inlet of the oil washing tower and the inlet of the water circulation pump, respectively. The downstream of the water washing packing is connected to the outlet of the water circulation pump. The tower body has a first outlet, which is located downstream of the water washing packing.

[0012] Beneficial effects: The water circulation pump delivers the washing water from the bottom of the tower to the upper part of the water washing packing for spraying and falling. It comes into full contact with the exhaust gas flowing upward from the oil washing tower in a countercurrent, which can efficiently capture the oil mist and oil gas carried by the exhaust gas, reduce the risk of oil and gas being carried into the downstream catalytic oxidation module, and protect the catalyst from being covered and deactivated by oil.

[0013] In one optional embodiment, the second processing module includes a second rough washing section and a second fine washing section, the second rough washing section is connected to the second fine washing section, the second rough washing section is located upstream of the second fine washing section, the second rough washing section has a second inlet, and the second fine washing section has a second outlet.

[0014] Beneficial effects: By setting up two-stage water washing and absorption sections, namely the second coarse washing section and the second fine washing section, the hydrophilic VOCs exhaust gas first enters the second coarse washing section, where most of the hydrophilic organic components are absorbed by the washing water. The remaining small amount of low-concentration hydrophilic VOCs then enters the second fine washing section for deep absorption and purification. The low-concentration VOCs washing water after fine washing can be reused from the coarse washing section, effectively reducing washing water consumption and wastewater discharge.

[0015] In one optional embodiment, the second processing module further includes a second coarse washing pump and a second fine washing pump. The second coarse washing section is provided with a second coarse packing. The second inlet is located upstream of the second coarse packing. The inlet of the second coarse washing pump is connected to the upstream of the second coarse packing, and the outlet of the second coarse washing pump is connected to the downstream of the second coarse packing. The second fine washing section is provided with a second fine packing. The inlet of the second fine washing pump is connected to the upstream of the second fine packing, and the outlet of the second fine washing pump is connected to the downstream of the second fine packing.

[0016] Beneficial effects: The second coarse wash pump and the second fine wash pump provide circulation power for the coarse wash circulation loop and the fine wash circulation loop, respectively, forming a closed circulation spray inside the coarse wash section and the fine wash section. This allows the exhaust gas and washing oil to fully come into countercurrent contact in the packing area, improving the gas-liquid mass transfer absorption efficiency and ensuring the stable absorption effect of each section of the coarse wash and fine wash.

[0017] In one optional embodiment, the catalytic oxidation treatment module further includes a mixing and separating tank, a first blower, a preheater, a heater, a catalytic oxidation reactor, and an exhaust structure. The mixing and separating tank is connected to the first outlet and the second outlet, respectively. The mixing and separating tank is connected upstream of the first blower. The preheater has a preheating channel and a cooling channel. The downstream of the first blower is connected to the first end of the preheating channel. The second end of the preheating channel is connected upstream of the heater. The downstream of the heater is connected upstream of the catalytic oxidation reactor. The downstream of the catalytic oxidation reactor is connected to the first end of the cooling channel. The second end of the cooling channel is connected to the exhaust structure.

[0018] Beneficial effects: The pre-treated exhaust gas from the first and second processing modules enters the mixing and separating tank. The mixing and separating tank can remove liquid droplets entrained in the exhaust gas. After separation, the exhaust gas is pressurized and transported by the first fan. It then passes through the preheating channel of the preheater to recover the waste heat of the flue gas after oxidation, and the heater to supplement the heat and raise the temperature. After reaching the reaction temperature, it is sent to the catalytic oxidation reactor. The high-temperature flue gas after the reaction enters the cooling channel of the preheater to realize heat recovery and utilization, reduce the heating energy consumption of the heater, and discharge the exhaust gas after heat recovery is completed.

[0019] In one optional embodiment, the VOCs treatment system further includes a solvent regeneration module, the first end of which is connected to the oil washing tower, and the second end of which is connected to the second end of the cooling channel.

[0020] Beneficial effects: Through the solvent regeneration module, when oleophilic VOCs are not being fed in large quantities such as during unloading from ships or trucks, and when the storage tank itself is operating under conditions of low VOCs treatment capacity, a portion of the flue gas is extracted and used for oil washing tower oil and gas regeneration via the solvent regeneration module. By utilizing the characteristics of the operating conditions, the washing sludge is recycled, effectively reducing washing oil consumption, reducing sludge emissions, and effectively saving operating costs.

[0021] In one optional embodiment, the solvent regeneration module includes a second fan and a flue gas cooler, the second fan being connected to the flue gas cooler and the second end of the cooling channel being connected to the oil washing tower.

[0022] Beneficial effects: The second fan provides the power to transport and pressurize the regenerated flue gas. The flue gas with a high temperature after catalytic oxidation is drawn from the second end of the cooling channel. After being cooled by the flue gas cooler, it is sent into the oil washing tower, which avoids the high-temperature regenerated flue gas entering the oil washing tower and causing the overall temperature inside the oil washing tower to rise.

[0023] Secondly, the present invention also provides an application method for a VOCs treatment system, applied to the aforementioned VOCs treatment system, comprising the following steps: S1. Differentiate the exhaust gases to be treated; S2. The oleophilic VOCs exhaust gas is sent into the first inlet of the first treatment module, and the hydrophilic VOCs exhaust gas is sent into the second inlet of the second treatment module. S3. The exhaust gas is pretreated by the first processing module and the second processing module respectively. After the pretreatment is completed, the exhaust gas is fed into the catalytic oxidation treatment module for further treatment to obtain qualified flue gas.

[0024] Beneficial effects: First, the exhaust gases to be treated are distinguished, and oleophilic VOCs and hydrophilic VOCs are sent to the corresponding first treatment module and second treatment module for targeted pretreatment. After separate pretreatment, the VOCs concentration of the two exhaust gases can be controlled separately, which makes it easier to control the mixed gas entering the catalytic oxidation unit within the lower explosion limit safety threshold and improve the safety of process operation. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the system structure of a VOCs processing system according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures: 10. First processing module; 11. Oil washing tower; 111. First coarse washing section; 1111. First coarse packing; 112. First fine washing section; 1121. First fine packing; 113. First coarse washing pump; 114. First fine washing pump; 12. First water washing tower; 121. Tower body; 1211. Water washing packing; 122. Water circulation pump; 20. Second processing module; 21. Second coarse washing section; 211. Second coarse packing; 22. Second fine washing section; 221. Second fine packing; 23. Second coarse washing pump; 24. Second fine washing pump; 30. Catalytic oxidation treatment module; 31. Mixing and separating tank; 32. First blower; 33. Preheater; 34. Heater; 35. Catalytic oxidation reactor; 36. Exhaust structure; 40. Solvent regeneration module; 41. Second blower; 42. Flue gas cooler. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] The following is combined Figure 1 The following describes embodiments of the present invention.

[0032] According to an embodiment of the present invention, in a first aspect, a VOCs treatment system is provided, including a first treatment module 10, a second treatment module 20, and a catalytic oxidation treatment module 30; the first treatment module 10 includes an oil washing tower 11 and a first water washing tower 12, the oil washing tower 11 having a first inlet adapted to feed oleophilic VOCs, the oil washing tower 11 being disposed upstream of and connected to the first water washing tower 12, the first water washing tower 12 having a first outlet; the second treatment module 20 having a second inlet and a second outlet, the second inlet being adapted to feed hydrophilic VOCs; the catalytic oxidation treatment module 30 being disposed downstream of the first treatment module 10 and the second treatment module 20, and connected to the first outlet and the second outlet respectively.

[0033] The VOCs treatment system of this embodiment treats oleophilic VOCs and hydrophilic VOCs respectively through the first treatment module 10 and the second treatment module 20. The two types of exhaust gases are pretreated to control the concentration of exhaust gases within the lower explosive limit safety threshold, avoiding the safety hazard of deflagration in the catalytic oxidation process. Then, they are combined and sent to the downstream catalytic oxidation treatment module 30. Unlike related technologies, this system significantly reduces the number of equipment configurations, lowers equipment investment, floor space, and subsequent operation and maintenance costs. The first treatment module 10 adopts oil washing followed by water washing. Water washing can wash and absorb a small amount of VOCs and the washing oil and gas carried in the exhaust gas. At the same time, it can also achieve safe and effective isolation between the oil washing tower 11 and the catalytic oxidation treatment module 30, ensuring the safe operation of the first treatment module 10 and the catalytic oxidation treatment module 30.

[0034] It should be noted that the upstream and downstream references in this embodiment refer to the VOCs processing flow direction within each module.

[0035] It should be noted that VOCs (Volatile Organic Compounds) are process waste gases containing volatile organic compounds emitted during industrial production, storage tank transportation, and other processes. They are key precursor pollutants for atmospheric ozone and secondary PM2.5. Therefore, in-depth treatment of VOCs in tank farms needs to be included in key emission reduction tasks. Among them, hydrophilic VOCs include alcohols, ethers, ketones, acids, and other flammable organic gases such as methanol, ethanol, acetone, and acetic acid; lipophilic VOCs include benzene, toluene, xylene, gasoline and other benzene series compounds, hydrocarbons, and other flammable organic gases.

[0036] It should be noted that in the relevant technologies, different production lines are set up to treat a single type of VOCs. However, given the characteristics of large-scale integrated tank farms with a wide variety of VOCs, multiple production lines need to be established, resulting in a complex overall system structure and high costs.

[0037] Therefore, in this embodiment, by combining the exhaust gases of the first processing module 10 and the second processing module 20, the number of system equipment configurations is reduced, thereby reducing equipment investment, floor space, and subsequent operation and maintenance costs.

[0038] It should be noted that in this embodiment, the concentration of VOCs exhaust gas after treatment by the first treatment module 10 and the second treatment module 20 needs to be reduced to below 25% of its lower explosive limit (LEL) in order to meet the safety treatment requirements of the downstream catalytic oxidation treatment module 30.

[0039] In one embodiment, refer to Figure 1As shown, the oil washing tower 11 includes a first coarse washing section 111 and a first fine washing section 112. The first coarse washing section 111 is connected to the first fine washing section 112. The first coarse washing section 111 is located upstream of the first fine washing section 112. The first coarse washing section 111 has a first inlet. The first fine washing section 112 is connected to the first water washing tower 12.

[0040] Specifically, refer to Figure 1 As shown, based on the characteristic of gas moving upward in the oil washing tower 11, the first coarse washing section 111 is located below the first fine washing section 112.

[0041] It should be noted that in other alternative implementations, the oil washing tower 11 can be divided into multiple cleaning stages, such as three stages or four stages, according to actual needs, in order to improve the absorption and removal effect of VOCs.

[0042] It is worth noting that the oil washing tower 11 is divided into two absorption sections: the first coarse washing section 111 and the first fine washing section 112. The oleophilic VOCs first enter the first coarse washing section 111 to complete the absorption and removal of most of the VOCs. The remaining low-concentration VOCs then enter the first fine washing section 112 for further deep absorption and purification. The washing oil enriched with a small amount of VOCs after fine washing can overflow back to the first coarse washing section 111 to continue to participate in absorption, reducing the frequency of fresh washing oil replenishment, reducing washing oil consumption, and reducing the hazardous waste disposal costs caused by the discharge of waste oil.

[0043] In one embodiment, refer to Figure 1 As shown, the oil washing tower 11 also includes a first coarse washing pump 113 and a first fine washing pump 114. The first coarse washing section 111 is provided with a first coarse packing 1111. The first inlet is located upstream of the first coarse packing 1111. The inlet of the first coarse washing pump 113 is connected to the upstream of the first coarse packing 1111, and the outlet of the first coarse washing pump 113 is connected to the downstream of the first coarse packing 1111. The first fine washing section 112 is provided with a first fine packing 1121. The inlet of the first fine washing pump 114 is connected to the upstream of the first fine packing 1121, and the outlet of the first fine washing pump 114 is connected to the downstream of the first fine packing 1121.

[0044] It is worth noting that the first coarse wash pump 113 and the first fine wash pump 114 provide circulation power for the coarse wash circulation loop and the fine wash circulation loop, respectively, forming a closed circulation spray inside the coarse wash section and the fine wash section, so that the exhaust gas and the washing oil can fully come into countercurrent contact in the packing area, improve the gas-liquid mass transfer absorption efficiency, and ensure the stable absorption effect of each section of coarse wash and fine wash.

[0045] Specifically, a detection device is provided in the first rough washing section 111 to detect the concentration of VOCs in the circulating oil.

[0046] It should be noted that as the absorbed VOCs accumulate in the oil, the concentration of VOCs in the circulating oil gradually increases. In order to avoid the concentration of dissolved and absorbed VOCs in the circulating washing oil being too high and affecting the absorption effect, the coarse circulating washing oil of the first coarse washing section 111 is periodically discharged, the fine circulating washing oil of the first fine washing section 112 is discharged to the first coarse washing section 111, and fresh oil is added to the first fine washing section 112.

[0047] In one embodiment, refer to Figure 1 As shown, the first water washing tower 12 includes a tower body 121 and a water circulation pump 122. Water washing packing 1211 is installed inside the tower body 121. The upstream of the water washing packing 1211 is connected to the inlet of the oil washing tower 11 and the inlet of the water circulation pump 122, respectively. The downstream of the water washing packing 1211 is connected to the outlet of the water circulation pump 122. The tower body 121 has a first outlet, which is located downstream of the water washing packing 1211.

[0048] Specifically, refer to Figure 1 As shown, the first outlet is located near the top of the tower body 121, and the lower end of the tower body 121 is connected to the oil washing tower 11.

[0049] It is worth noting that the water circulation pump 122 delivers the bottom washing water to the upper part of the water washing packing 1211 for spraying and falling, which fully contacts the exhaust gas flowing upward from the oil washing tower 11 in a countercurrent. This can efficiently capture the oil mist and oil gas carried by the exhaust gas, reduce the risk of oil gas being carried into the downstream catalytic oxidation module, and protect the catalyst from being covered and deactivated by oil.

[0050] In one embodiment, refer to Figure 1 As shown, the second processing module 20 includes a second coarse washing section 21 and a second fine washing section 22. The second coarse washing section 21 is connected to the second fine washing section 22. The second coarse washing section 21 is located upstream of the second fine washing section 22. The second coarse washing section 21 has a second inlet, and the second fine washing section 22 has a second outlet.

[0051] Specifically, refer to Figure 1 As shown, based on the characteristic of gas moving upward in the oil washing tower 11, the second coarse washing section 21 is located below the second fine washing section 22.

[0052] It should be noted that in other alternative implementations, the second processing module 20 can be divided into multiple cleaning stages, such as three stages or four stages, according to actual needs, in order to improve the absorption and removal effect of VOCs.

[0053] It is worth noting that by setting up two-stage water washing and absorption sections, namely the second coarse washing section 21 and the second fine washing section 22, the hydrophilic VOCs exhaust gas first enters the second coarse washing section 21. Most of the hydrophilic organic components are absorbed by the washing water in the coarse washing section. The remaining small amount of low-concentration hydrophilic VOCs then enters the second fine washing section 22 for deep absorption and purification. The low-concentration VOCs washing water after fine washing can be reused for coarse washing, effectively reducing washing water consumption and sewage discharge.

[0054] In one embodiment, refer to Figure 1 As shown, the second processing module 20 also includes a second coarse washing pump 23 and a second fine washing pump 24. A second coarse packing 211 is provided in the second coarse washing section 21. A second inlet is provided upstream of the second coarse packing 211. The inlet of the second coarse washing pump 23 is connected to the upstream of the second coarse packing 211, and the outlet of the second coarse washing pump 23 is connected to the downstream of the second coarse packing 211. A second fine packing 221 is provided in the second fine washing section 22. The inlet of the second fine washing pump 24 is connected to the upstream of the second fine packing 221, and the outlet of the second fine washing pump 24 is connected to the downstream of the second fine packing 221.

[0055] It is worth noting that the second coarse wash pump 23 and the second fine wash pump 24 provide circulation power for the coarse wash circulation loop and the fine wash circulation loop, respectively, forming a closed-loop spray in the coarse wash section and the fine wash section, so that the exhaust gas and washing oil can fully come into countercurrent contact in the packing area, improve the gas-liquid mass transfer absorption efficiency, and ensure the stable absorption effect of each section of coarse wash and fine wash.

[0056] Specifically, a detection device is installed in the second coarse washing section 21 to detect the concentration of VOCs in the circulating water.

[0057] It should be noted that as the absorbed VOCs accumulate in the water, the concentration of VOCs in the circulating water gradually increases. In order to avoid the concentration of dissolved and absorbed VOCs in the circulating washing water being too high and affecting the absorption effect, the coarse circulating washing wastewater of the second coarse washing section 21 is periodically discharged, and the fine circulating washing wastewater of the second fine washing section 22 is discharged to the second coarse washing section 21, and fresh circulating water is added to the second fine washing section.

[0058] In one embodiment, refer to Figure 1As shown, the catalytic oxidation treatment module 30 also includes a mixing and separating tank 31, a first blower 32, a preheater 33, a heater 34, a catalytic oxidation reactor 35, and an exhaust structure 36. The mixing and separating tank 31 is connected to the first outlet and the second outlet, respectively. The mixing and separating tank 31 is connected to the upstream of the first blower 32. The preheater 33 has a preheating channel and a cooling channel. The downstream of the first blower 32 is connected to the first end of the preheating channel. The second end of the preheating channel is connected to the upstream of the heater 34. The downstream of the heater 34 is connected to the upstream of the catalytic oxidation reactor 35. The downstream of the catalytic oxidation reactor 35 is connected to the first end of the cooling channel. The second end of the cooling channel is connected to the exhaust structure 36.

[0059] Specifically, in this embodiment, the heater 34 is an electric heater 34, and the exhaust structure 36 is a flue gas chimney.

[0060] Specifically, after being processed by the first processing module 10 and the second processing module 20, the VOCs exhaust gas is mixed and separated in the mixing and separating tank 31, then pressurized by the first fan 32 and sent to the preheater 33 for preheating. It then enters the heater 34 and is heated to the temperature required for the catalytic oxidation reaction. The reaction takes place in the catalytic oxidation reactor 35, where the VOCs in the exhaust gas are oxidized into CO2 and H2O. After the qualified flue gas recovers heat through the preheater 33, it is directly discharged into the atmosphere through the flue gas chimney.

[0061] It is worth noting that the pre-treated exhaust gas from the first processing module 10 and the second processing module 20 enters the mixing and separating tank 31. The mixing and separating tank 31 can remove liquid droplets entrained in the exhaust gas. After separation, the exhaust gas is pressurized and transported by the first fan 32. It then passes through the preheating channel of the preheater 33 to recover the waste heat of the flue gas after oxidation, and the heater 34 to supplement the heat and raise the temperature. After reaching the reaction temperature, it is sent to the catalytic oxidation reactor 35. The high-temperature flue gas after the reaction enters the cooling channel of the preheater 33 to realize heat recovery and utilization, and reduce the heating energy consumption of the heater 34.

[0062] In one embodiment, refer to Figure 1 As shown, the VOCs treatment system also includes a solvent regeneration module 40. The first end of the solvent regeneration module 40 is connected to the oil washing tower 11, and the second end of the solvent regeneration module 40 is connected to the second end of the cooling channel.

[0063] In one embodiment, refer to Figure 1 As shown, the solvent regeneration module 40 includes a second fan 41 and a flue gas cooler 42. The second fan 41 is connected to the flue gas cooler 42 and the second end of the cooling channel is connected to the second end of the cooling channel. The flue gas cooler 42 is connected to the oil washing tower 11.

[0064] Specifically, the second fan 41 provides the power to transport and pressurize the regenerated flue gas. The flue gas after catalytic oxidation, which is drawn from the second end of the cooling channel, is at a high temperature. After being cooled by the flue gas cooler 42, it is sent into the oil washing tower 11 to prevent the high-temperature regenerated flue gas from entering the oil washing tower 11 and causing the overall temperature inside the oil washing tower 11 to rise.

[0065] It is worth noting that, through the solvent regeneration module 40, when a large amount of oleophilic VOCs are fed in, such as when unloading ships or trucks, and when the storage tank itself is in a low VOCs processing condition, a portion of the flue gas is extracted and used by the solvent regeneration module 40 for the washing oil and gas regeneration of the oil washing tower 11. By utilizing the characteristics of the operating conditions, the washing sludge is regenerated and reused, effectively reducing washing oil consumption, reducing sludge discharge, and effectively saving operating costs.

[0066] According to an embodiment of the present invention, in a second aspect, a method for applying a VOCs treatment system is also provided, which is applied to the aforementioned VOCs treatment system, comprising the steps of: S1. Differentiate the exhaust gases to be treated; S2. The oleophilic VOCs exhaust gas is sent into the first inlet of the first treatment module 10, and the hydrophilic VOCs exhaust gas is sent into the second inlet of the second treatment module 20. S3. The exhaust gas is pretreated by the first processing module 10 and the second processing module 20 respectively. After the pretreatment is completed, the exhaust gas is fed into the catalytic oxidation treatment module 30 for further treatment to obtain qualified flue gas.

[0067] Specifically, in step S2: After separation, the oleophilic VOCs tail gas from the tank area tail gas collection system is externally pressurized and sent to the lower layer of the first coarse packing 1111 in the first coarse washing section 111. The high-concentration VOCs coarse washing oil is pressurized by the first coarse washing pump 113 and sent to the upper layer of the first coarse packing 1111. The washing oil comes into countercurrent contact with the VOCs tail gas through the packing inside the tower, washing and absorbing the VOCs in the tail gas into the coarse washing oil. The coarse washing oil system is circulated and absorbed through the first coarse washing pump 113. The tail gas that has absorbed most of the VOCs in the first coarse washing section 111 enters the first fine washing section 112, where it is further washed and absorbed by the low-concentration VOCs fine washing oil. The fine washing oil at the bottom of the tower is pressurized by the first fine washing pump 114 and returned to the upper part of the first fine packing 1121 of the first fine washing pump 114, realizing the circulation and absorption of the fine washing section. After separation, the hydrophilic VOCs tail gas from the tank area tail gas collection system is pressurized externally and sent to the lower layer of the second coarse packing 211 in the second coarse washing section 21. The high-concentration VOCs coarse washing water is pressurized by the second coarse washing pump 23 and sent to the upper layer of the second coarse packing 211. The washing water comes into countercurrent contact with the VOCs in the packing inside the tower, and the VOCs are washed and absorbed into the coarse washing water. The coarse washing water system is circulated and absorbed by the second coarse washing pump 23. The tail gas that has absorbed most of the VOCs in the second coarse washing section 21 enters the second fine washing section 22, where it is further washed and absorbed by the low-concentration VOCs fine washing water to achieve "fine washing". The fine washing water at the bottom of the tower is pressurized by the second fine washing pump 24 and returned to the upper part of the second fine packing 221 in the second fine washing section 22 to achieve circulated washing and absorption in the fine washing section.

[0068] The application method of the VOCs treatment system in this embodiment first distinguishes the exhaust gas to be treated, and sends the oleophilic VOCs and hydrophilic VOCs to the corresponding first treatment module 10 and second treatment module 20 for targeted pretreatment. After the separate pretreatment, the VOCs concentration of the two exhaust gases can be controlled separately, which makes it easier to control the mixed gas entering the catalytic oxidation unit within the lower explosion limit safety threshold and improve the safety of process operation.

[0069] In one embodiment, the application method of the VOCs treatment system further includes the following steps: S4. When a large amount of oil-loving VOCs are fed in, such as when unloading ships or trucks, and when the storage tank itself is in a low-VOCs processing condition, the second fan 41 provides the power to transport and pressurize the regenerated flue gas. The flue gas after catalytic oxidation drawn from the second end of the cooling channel is cooled by the flue gas cooler 42 and then sent to the oil washing tower 11.

[0070] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A VOCs treatment system, characterized in that, include: The first processing module (10) includes an oil washing tower (11) and a first water washing tower (12). The oil washing tower (11) has a first inlet adapted to feed oleophilic VOCs. The oil washing tower (11) is located upstream of the first water washing tower (12) and is connected to the first water washing tower (12). The first water washing tower (12) has a first outlet. The second processing module (20) has a second inlet and a second outlet, the second inlet being adapted to feed hydrophilic VOCs; A catalytic oxidation treatment module (30) is located downstream of the first treatment module (10) and the second treatment module (20), and is connected to the first outlet and the second outlet, respectively.

2. The VOCs treatment system according to claim 1, characterized in that, The oil washing tower (11) includes a first coarse washing section (111) and a first fine washing section (112). The first coarse washing section (111) is connected to the first fine washing section (112). The first coarse washing section (111) is located upstream of the first fine washing section (112). The first coarse washing section (111) has a first inlet. The first fine washing section (112) is connected to the first water washing tower (12).

3. The VOCs treatment system according to claim 2, characterized in that, The oil washing tower (11) further includes a first coarse washing pump (113) and a first fine washing pump (114). The first coarse washing section (111) is provided with a first coarse packing (1111). The first inlet is located upstream of the first coarse packing (1111). The inlet of the first coarse washing pump (113) is connected to the upstream of the first coarse packing (1111). The outlet of the first coarse washing pump (113) is connected to the downstream of the first coarse packing (1111). The first fine washing section (112) is provided with a first fine packing (1121). The inlet of the first fine washing pump (114) is connected to the upstream of the first fine packing (1121). The outlet of the first fine washing pump (114) is connected to the downstream of the first fine packing (1121).

4. The VOCs treatment system according to claim 1, characterized in that, The first water washing tower (12) includes a tower body (121) and a water circulation pump (122). The tower body (121) is provided with water washing packing (1211). The upstream of the water washing packing (1211) is connected to the inlet of the oil washing tower (11) and the water circulation pump (122), respectively. The downstream of the water washing packing (1211) is connected to the outlet of the water circulation pump (122). The tower body (121) has a first outlet, which is located downstream of the water washing packing (1211).

5. The VOCs treatment system according to claim 1, characterized in that, The second processing module (20) includes a second coarse washing section (21) and a second fine washing section (22). The second coarse washing section (21) is connected to the second fine washing section (22). The second coarse washing section (21) is located upstream of the second fine washing section (22). The second coarse washing section (21) has a second inlet, and the second fine washing section (22) has a second outlet.

6. The VOCs treatment system according to claim 5, characterized in that, The second processing module (20) further includes a second coarse washing pump (23) and a second fine washing pump (24). The second coarse washing section (21) is provided with a second coarse packing (211). The second inlet is located upstream of the second coarse packing (211). The inlet of the second coarse washing pump (23) is connected to the upstream of the second coarse packing (211). The outlet of the second coarse washing pump (23) is connected to the downstream of the second coarse packing (211). The second fine washing section (22) is provided with a second fine packing (221). The inlet of the second fine washing pump (24) is connected to the upstream of the second fine packing (221). The outlet of the second fine washing pump (24) is connected to the downstream of the second fine packing (221).

7. The VOCs treatment system according to claim 1, characterized in that, The catalytic oxidation treatment module (30) further includes a mixing and separating tank (31), a first blower (32), a preheater (33), a heater (34), a catalytic oxidation reactor (35), and an exhaust structure (36). The mixing and separating tank (31) is connected to the first outlet and the second outlet respectively. The mixing and separating tank (31) is connected to the upstream of the first blower (32). The preheater (33) has a preheating channel and a cooling channel. The downstream of the first blower (32) is connected to the first end of the preheating channel. The second end of the preheating channel is connected to the upstream of the heater (34). The downstream of the heater (34) is connected to the upstream of the catalytic oxidation reactor (35). The downstream of the catalytic oxidation reactor (35) is connected to the first end of the cooling channel. The second end of the cooling channel is connected to the exhaust structure (36).

8. The VOCs treatment system according to claim 7, characterized in that, The VOCs treatment system also includes a solvent regeneration module (40), the first end of which is connected to the oil washing tower (11), and the second end of which is connected to the second end of the cooling channel.

9. The VOCs treatment system according to claim 8, characterized in that, The solvent regeneration module (40) includes a second fan (41) and a flue gas cooler (42). The second fan (41) is connected to the flue gas cooler (42), and the second fan (41) is connected to the second end of the cooling channel. The flue gas cooler (42) is connected to the oil washing tower (11).

10. A method for applying a VOCs treatment system, wherein the VOCs treatment system is described in any one of claims 1 to 9, characterized in that, Including the following steps: S1. Differentiate the exhaust gases to be treated; S2. The oleophilic VOCs exhaust gas is sent to the first inlet of the first treatment module (10), and the hydrophilic VOCs exhaust gas is sent to the second inlet of the second treatment module (20). S3. The exhaust gas is pretreated by the first processing module (10) and the second processing module (20) respectively. After the pretreatment is completed, the exhaust gas is fed into the catalytic oxidation treatment module (30) for further treatment to obtain qualified flue gas.

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