Process for treating odor generated in organic industry by direct absorption method

Abstract

The invention relates to the technical field of air pollution control, and discloses a process for treating odor generated in organic industry by a direct absorption method, which comprises the following steps: S1, feeding odor into cooling and dehumidifying equipment through negative pressure, condensing most of steam in waste gas into water, and recycling condensed water; s2, a fan is arranged on a gas pipeline between cooling and dehumidifying equipment and an absorption tower, the subsequent higher pressure difference can be overcome, and under the low-humidity and low-temperature working condition, the fan feeds gas into the absorption tower; s3, gas enters an absorption tower through a fan, and a gas pipeline arranged at the top of the absorption tower is connected with a chimney for discharging; and S4, discharging the cooling circulating water and the absorption liquid to a sewage pipeline through an overflow port, and sending the cooling circulating water and the absorption liquid to a sewage treatment unit. In the operation process, frequent replacement of adsorption materials or complex equipment maintenance is not needed, the investment of manpower, material resources and financial resources for long-term operation is reduced, and effective treatment of odor can be achieved in the organic industry with low cost.

Description

Technical Field

[0001] The invention relates to the technical field of air pollution control, in particular to a direct absorption treatment process for odor generated in the organic industry. Background Art

[0002] The production and manufacturing process of the organic industry produces a large amount of waste gas, which is often toxic and has a pungent odor. For example, during the rubber drying stage, the emission of odor is particularly significant. These organic waste gases contain a large amount of volatile organic compounds (VOCs), and the main odor-causing components are carbon disulfide (CS2), dimethyl sulfide (C2H6S), methyl mercaptan (CH4S), trimethylamine (C3H9N), olefins and lipids. The overall characteristics of the waste gas are often foul-smelling, highly toxic and difficult to treat.

[0003] After searching, the Chinese patent number CN113368652A discloses a method for treating sulfur-containing organic waste gas in the phosphorus chemical industry. According to the flow direction of the medium, the treatment method adopts (dry tail gas) flue gas cooler + alkali washing tower + water washing tower + high-voltage electric tar collector + dry filter + zeolite rotor + desorption fan + blower + mixing box + factory hot air furnace incineration; the flue gas cooler is connected to the cooling tower through a circulation pump to form a loop; the water washing tower and the water washing pump are connected to form a loop, and a demister is fixedly installed on the top of the water washing tower, and multiple groups of the demisters are assembled together to form a combined high-efficiency demister. This method synergistically controls multiple pollutants and removes SO2, dust, and volatile organic compounds in the waste gas at the same time, solving the process problem of high temperature and high moisture content that is difficult to treat organic waste gas.

[0004] After searching, the Chinese patent number CN114100257A discloses a pharmaceutical industry organic waste gas pretreatment device, including a soaking device, the soaking device includes a cleaning box, a blower located at its left end is fixedly installed on the top surface of the cleaning box, and an intelligent control cabinet located on its top is fixedly installed on the left side of the cleaning box; through the immersion cleaning device, the pharmaceutical industry organic waste gas pretreatment device can automatically clean the mixture of particulate matter and organic matter adhered to the surface of the spherical dust filter, so as to clean up the mixture and achieve the purpose of automatic cleaning.

[0005] It can be seen from the above-mentioned existing technical solutions that in the waste gas treatment technology of the organic industry, the existing processes have the following limitations. Although the ozone oxidation + alkali absorption method can decompose organic matter through plasma and achieve purification in combination with acid-base neutralization, it has extremely high requirements for moisture-proofing of the equipment and is prone to failure under high humidity conditions. In addition, the investment and operating costs increase significantly when treating large amounts of waste gas. Although the COO chemical oxidation method can oxidize organic matter into harmless products, it has poor treatment effects on special components containing sulfur, such as methyl mercaptan and carbon disulfide, and is especially unsuitable for sulfur-containing working conditions such as rubber drying. Although the activated carbon adsorption method is widely used, it faces the problems of low adsorption efficiency of high-humidity waste gas, high cost of hazardous waste treatment after saturation, and frequent replacement. It is difficult to meet the deodorization needs of high-humidity dry waste gas. Based on this, the present invention designs a direct absorption treatment process for odor generated in the organic industry to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a direct absorption method for treating odor generated in the organic industry, which solves the technical problem in the background art of lack of suitable treatment methods for organic odor containing complex components such as carbon disulfide, sulfides, and amines.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] A direct absorption treatment process for odor generated in the organic industry, comprising:

[0009] In step S1, the odor is sent to the cooling and dehumidification equipment through negative pressure, and most of the steam in the exhaust gas is condensed into water, which can be reused;

[0010] Among them, the cooling and dehumidification equipment is equipped with a gas pipeline connected to the bottom of the absorption tower, and the cooling and dehumidification equipment is connected to the heat exchanger and the condensation water tank. The final cooling temperature is 28-38℃;

[0011] Step S2: A fan is installed on the gas pipeline between the cooling and dehumidifying equipment and the absorption tower to overcome the subsequent higher pressure difference. Under low humidity and low temperature conditions, the fan sends the gas into the absorption tower;

[0012] In step S3, the gas enters the absorption tower through a blower. A gas pipe is provided at the top of the absorption tower, which is connected to a chimney for external discharge. A circulation pump, a defoaming layer, and a dosing tank are provided inside the absorption tower. A high-efficiency heteroatom compound capture agent and a lipid absorbent are added or supplemented in the dosing tank. Through the circulation of the composite absorbent, organic substances such as dimethyl sulfide, methyl alcohol, carbon disulfide, olefins, trimethylamine, and lipids in the exhaust gas are chelated, captured, and absorbed, and the exhaust gas is discharged through the chimney after meeting the emission requirements.

[0013] In step S4, the cooling circulating water and the absorption liquid can be discharged to the sewage pipe through the overflow port and sent to the sewage treatment unit.

[0014] Preferably, in the formula of the composite absorbent, betaine is 1-5 parts, which is used to reduce the surface tension of the solution and improve the adsorption capacity of VOCs molecules through surface active chemistry and stability;

[0015] 1-5 parts of sodium dodecyl sulfate, used to adsorb VOCs molecules and increase their solubility in water by forming micelle structures, while synergistically working with betaine to further improve the removal efficiency of VOCs;

[0016] 5-10 parts of zinc acetate, used to react with mercaptans, sulfides, organic acids and other compounds in VOCs molecules through the chelating ability of zinc ions to produce precipitation reactions;

[0017] 800-1000 parts of ethanol or isopropyl alcohol are used in combination to defoam and activate the organic surfactant;

[0018] The concentration of the mixed agent of the composite absorbent ranges from 3% to 25%, and is dynamically adjusted according to the concentration of VOCs in the odor.

[0019] Preferably, the cooling and dehumidification equipment recovers condensed water through a condensed water tank and reuses it as washing water. A circulating pump is provided in the absorption tower to maintain the circulating spraying of the absorbent, and the absorbent is replenished in real time through a dosing tank.

[0020] Preferably, the condensate tank is provided with a two-stage filtration device, the first stage is a 20μm stainless steel filter mesh, and the second stage is an activated carbon adsorption layer. The COD value of the condensate after treatment is ≤50mg / L; the dosing tank is equipped with an online concentration monitor. When the absorbent concentration is lower than the set value, fresh absorbent is automatically added, and the replenishment rate is 0.1%-2% / min of the circulating liquid flow rate.

[0021] Preferably, the defoaming layer in the absorption tower is arranged near the upper air outlet of the absorption tower.

[0022] Preferably, a real-time temperature detector is provided on the side of the cooling and dehumidifying equipment for monitoring the odor cooling temperature and dynamically adjusting the cooling water flow of the heat exchanger.

[0023] Preferably, the defoaming layer of the absorption tower adopts a multi-stage baffle structure and is arranged 10-50 cm below the air outlet at the top of the absorption tower; the packing layer of the absorption tower adopts PP material structured packing, the packing specific surface area is 200-350m² / m³, and the gas-liquid contact time is 1.5-3.5 seconds.

[0024] Preferably, the liquid-gas ratio of the absorption tower is controlled at 3-8 L / m³, the spray density is 8-15 m³ / (m2·h), and the superficial gas velocity is 0.6-1.2 m / s.

[0025] Preferably, the fan is a corrosion-resistant fiberglass centrifugal fan with an operating pressure range of -5kPa to +10kPa and an air volume adjustment accuracy of ±5%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention uses a small amount of high-efficiency composite absorbent, and its raw materials are easily available on the market at a relatively reasonable price, with low procurement costs, thereby reducing the cost of using the absorbent. In addition, the present application does not require frequent replacement of adsorption materials or complex equipment maintenance during operation, reducing the human, material and financial investment in long-term operation, enabling the organic industry to achieve effective odor control at a lower cost.

[0028] 2. The present invention does not generate new pollutants during the treatment process, avoids harmful by-products that may be produced by certain chemical treatment methods, and is more environmentally friendly. The small amount of absorbed liquid discharged does not require special treatment and can be directly sent to the existing sewage treatment station for treatment, which simplifies the sewage treatment process and reduces the complexity and cost of sewage treatment. In addition, the condensed water is reused as washing water, realizing the recycling of water resources.

[0029] 3. The process equipment of the present invention is relatively simple in structure, requires minimal equipment investment, and has low construction costs. It is particularly suitable for achieving effective odor control within a limited budget in the organic industry. At the same time, the process improves the treatment efficiency of odors containing large amounts of carbon disulfide (CS2), dimethyl sulfide (C2H6S), methyl mercaptan (CH4S), trimethylamine (C3H9N), olefins, and lipids, and can significantly reduce the concentration of VOCs in waste gas to meet emission standards, effectively reducing odor pollution to the atmospheric environment during the production process of the organic industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the odor treatment process of the present invention;

[0031] Figure 2 Schematic diagram of the absorption tower structure and internal components of the present invention;

[0032] Figure 3 This is a composition diagram of the composite absorbent of the present invention;

[0033] Figure 4 This is a flow chart of the condensed water recovery process of the present invention;

[0034] Figure 5 This is a flow chart for the treatment of malodorous gases according to the present invention.

[0035] Among them: 1. Cooling and dehumidification equipment; 2. Heat exchanger; 3. Fan; 4. Absorption tower; 5. Chimney; 6. Sewage pipe; 12. Condensate tank; 15. Real-time temperature detector; 42. Packing layer; 43. Circulation pump; 44. Defoaming layer; 45. Dosing tank. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Example 1;

[0038] See also Figure 1-Figure 5 In an embodiment of the present invention, a direct absorption method for treating odor generated in an organic industry is provided, which is characterized by comprising:

[0039] Step S1: The odor is sent to the cooling and dehumidifying equipment 1 by negative pressure, and most of the steam in the exhaust gas is condensed into water, which can be reused;

[0040] Among them, the cooling and dehumidifying equipment 1 is provided with a gas pipeline connected to the bottom of the absorption tower 4, and the cooling and dehumidifying equipment 1 is connected to the heat exchanger 2 and the condensation water tank 12, and the final cooling temperature is 28-38°C;

[0041] In step S2, the fan 3 is installed on the gas pipeline between the cooling and dehumidifying equipment 1 and the absorption tower 4 to overcome the subsequent higher pressure difference. Under low humidity and low temperature working conditions, the fan sends the gas into the absorption tower 4;

[0042] In step S3, the gas enters the absorption tower 4 through the fan 3. A gas pipe is provided at the top of the absorption tower 4, which is connected to a chimney 5 for external discharge. A circulation pump 43, a defoaming layer 44, and a dosing tank 45 are provided inside the absorption tower 4. A high-efficiency heteroatom compound capture agent and a lipid absorbent are added or supplemented in the dosing tank 45. Through the circulation of the composite absorbent, organic substances such as dimethyl sulfide, methyl alcohol, carbon disulfide, olefins, trimethylamine, and lipids in the exhaust gas are chelated, captured, and absorbed. After the exhaust gas meets the emission requirements, it is discharged through the chimney 5.

[0043] In step S4, the cooling circulating water and the absorption liquid can be discharged to the sewage pipe 6 through the overflow port and sent to the sewage treatment unit.

[0044] In the formula of the composite absorbent, 1-5 parts of betaine are used to reduce the surface tension of the solution and improve the adsorption capacity of VOCs molecules through surfactant chemistry and stability; 1-5 parts of sodium dodecyl sulfate are used to adsorb VOCs molecules and increase their solubility in water by forming micelle structures, and at the same time synergize with betaine to further improve the removal efficiency of VOCs; 5-10 parts of zinc acetate are used to react with thiols, sulfides and organic acids in VOCs molecules through the chelating ability of zinc ions to produce precipitation reactions; 800-1000 parts of ethanol or isopropanol are used in combination as defoaming and activating organic surfactants; the concentration of the mixed agent of the composite absorbent ranges from 3% to 25%, and is dynamically adjusted according to the concentration of VOCs in the odor.

[0045] The cooling and dehumidifying equipment 1 recovers condensed water through the condensed water tank 12 and reuses it as washing water. A circulating pump 43 is provided in the absorption tower 4 to maintain the circulating spray of the absorbent, and the absorbent is replenished in real time through the dosing tank 45.

[0046] The condensate tank 12 is equipped with a two-stage filtration device, the first stage is a 20μm stainless steel filter mesh, and the second stage is an activated carbon adsorption layer. The COD value of the condensate after treatment is ≤50mg / L; the dosing tank 45 is equipped with an online concentration monitor. When the absorbent concentration is lower than the set value, fresh absorbent is automatically added at a replenishment rate of 0.1%-2% / min of the circulating liquid flow rate.

[0047] The defoaming layer 44 in the absorption tower 4 is arranged near the upper air outlet of the absorption tower 4 .

[0048] A real-time temperature detector 15 is provided on the side of the cooling and dehumidifying device 1 for monitoring the odor cooling temperature and dynamically adjusting the cooling water flow of the heat exchanger 2 .

[0049] The defoaming layer 44 of the absorption tower 4 adopts a multi-stage baffle structure and is arranged 10-50 cm below the air outlet at the top of the absorption tower; the packing layer 42 of the absorption tower 4 adopts PP material structured packing with a packing specific surface area of ​​200-350m² / m³ and a gas-liquid contact time of 1.5-3.5 seconds.

[0050] The liquid-gas ratio of the absorption tower 4 is controlled at 3-8 L / m³, the spray density is 8-15 m³ / (m2·h), and the superficial gas velocity is 0.6-1.2 m / s.

[0051] Fan 3 uses a corrosion-resistant fiberglass centrifugal fan with an operating pressure range of -5kPa to +10kPa and an air volume adjustment accuracy of ±5%.

[0052] The working principle of the embodiment of the present invention is as follows: organic odor first enters the cooling and dehumidification equipment 1 under the action of negative pressure, and undergoes heat exchange with the circulating cooling water through the plate heat exchanger 2, accurately controlling the gas temperature in the range of 28-38°C. This temperature range has been experimentally verified to maximize the efficiency of water vapor condensation, while preventing the liquid phase precipitation of VOCs components due to supercooling, which affects subsequent absorption. The real-time temperature detector 15 is linked to the PLC control system to dynamically maintain stable operating conditions by adjusting the cooling water flow rate. After the condensed water is treated by the two-stage filtration device (20μm stainless steel filter + activated carbon adsorption layer) in the condensation water tank 12, the COD value is reduced to below 50mg / L and can be directly reused in the production washing process.

[0053] The dehumidified, low-temperature gas is transported to absorption tower 4 by a corrosion-resistant fiberglass centrifugal fan 3, located between the cooling and dehumidifying equipment 1 and absorption tower 4. Its operating pressure range of -5 kPa to +10 kPa effectively mitigates system pressure drops, and its air volume regulation accuracy of ±5% ensures airflow stability. The gas enters absorption tower 4 through absorption tower inlet 41, where it comes into countercurrent contact with the composite absorbent. The packing layer 42 within absorption tower 4 utilizes structured PP packing (specific surface area 200-350 m² / m³). A circulating pump 43 maintains a liquid-to-gas ratio of 3-8 L / m³ and a spray density of 8-15 m³ / (m²·h) within a gas-liquid contact time of 1.5-3.5 seconds, achieving efficient material transfer. The composite absorbent is prepared in the dosing tank 45 and includes a compound system of betaine (1-5 parts), sodium dodecyl sulfate (1-5 parts), zinc acetate (5-10 parts) and isopropyl alcohol (800-1000 parts). Betaine reduces the surface tension of the liquid membrane through its zwitterionic properties, sodium dodecyl sulfate forms a micellar structure to enhance the dissolution and capture of hydrophobic VOCs, zinc acetate undergoes a chelating precipitation reaction with sulfur-containing and amine substances, and isopropyl alcohol acts as a co-solvent to simultaneously exert a defoaming effect.

[0054] The treated clean gas passes through the defoaming layer 44 (a multi-stage baffle structure located 10-50 cm below the air outlet) installed at the top of the absorption tower 4 to remove entrained droplets. The air velocity in the empty tower is controlled at 0.6-1.2 m / s to prevent mist entrainment, and is finally discharged through the chimney 5 to meet the emission standards. The absorption liquid circulation system is dynamically regulated by the online concentration monitor equipped with the dosing tank 45. When the active ingredient is detected to be below the set threshold, fresh absorbent is automatically added at a rate of 0.1%-2% / min to maintain the working concentration within the dynamic range of 3%-25%. The saturated absorption liquid is discharged into the sewage pipe 6 through the absorption tower overflow 47 and sent to the sewage treatment unit. The entire system is coordinated through the temperature detector 15, the dosing tank 45 adjustment module, and the fan 3 to optimize energy consumption and operating costs while ensuring a VOC removal rate of over 90%.

[0055] Example 2;

[0056] See also Figure 1-Figure 5 In an embodiment of the present invention, a solution is provided for treating a large amount of high-temperature and high-humidity malodorous gases generated during the drying process of a natural rubber plant. The process of the present invention is applied and a 5% concentration absorption liquid is used for absorption treatment, including the following steps:

[0057] Due to the negative pressure, the exhaust gas enters the condensation tower 1 through the condensation tower air inlet 11. Cooling water is introduced through the cooling water addition port 16 to cool the high-temperature and high-humidity exhaust gas to 28-38°C. The temperature of the entire system is monitored in real time by the temperature detection system 15. Most of the steam in the exhaust gas condenses into water. The cooling water circulates in the tower through the cooling water circulation pump 13. During the circulation process, it is cooled by the plate heat exchanger 2. The condensed water flows into the reuse water tank 12 through the condensation tower overflow port 14 and is used as rubber washing water.

[0058] The fan 3 is installed between the condensation tower and the absorption tower. The exhaust gas after cooling and dehumidification is drawn to the absorption tower air inlet 41 through the fan. The filler layer 42 in the absorption tower is made of PP material to increase the gas-liquid contact area. A defoaming layer 44 is provided to prevent reaction droplets from entering the exhaust gas pipe. The high-efficiency absorbent is prepared through the dosing tank 45 and added to the absorption tower from the dosing port 46 for circulation spraying. The circulating liquid containing the high-efficiency absorbent absorbs and elutes the VOCs in the exhaust gas. The concentration of the high-efficiency absorbent in the circulating liquid is controlled at about 5%. The circulating liquid after absorption is discharged into the sewage pipe network 6 through the overflow port 47 of the absorption tower and sent to the wastewater treatment station for treatment.

[0059] During the treatment process, the absorbent concentration increases with the increase of VOCs concentration or gas volume, and the circulating liquid absorbent concentration is adjusted through the dosing tank 45; the clean flue gas that meets the standards after treatment is discharged from the chimney 5. Since the fan is set in the middle section, it has a strong ability to overcome the pressure head and can be discharged smoothly without additional power equipment.

[0060] The working principle of the embodiment of the present invention is as follows: the removal effect of dimethyl disulfide, methyl sulfide, methyl mercaptan, and hydrogen sulfide in the treated odor is excellent, with a removal rate of up to 99.99%. The removal efficiency of 1-decene, the compound with the highest content in the odor component, reaches 94.85%. At the same time, the removal efficiency of 2-heptanone, propylene glycol monomethyl ether acetate, hexamethyldisiloxane, 1-dodecene, benzaldehyde, ethyl acetate, and 3-pentanone reaches more than 90%.

[0061] Example 3;

[0062] See also Figure 1-Figure 5 In an embodiment of the present invention, a method for treating high-concentration VOCs waste gas generated during the production process of an organic industry is provided, wherein the process of the present invention is applied and a 20% concentration absorption liquid is used for absorption treatment, including the following steps:

[0063] Under the guidance of the fan 3, the exhaust gas enters the condensation tower 1 through the condensation tower air inlet 11, and the cooling water is added to the condensation tower through the addition port 16 and circulated in the tower through the cooling water circulation pump 13; the cooling water in the condensation tower 1 cools the exhaust gas to 28-38°C. During the circulation process, the cooling water is cooled by the heat exchanger 2, and most of the steam in the exhaust gas is condensed into water. The condensed water flows into the reuse water tank 12 through the condensation tower overflow port 14 as washing water; the temperature of the condensation system is monitored in real time by the temperature detection system 15.

[0064] The condensed waste gas enters the absorption tower 4 through the absorption tower air inlet 41. The absorption tower is provided with a defoaming layer 44 and a packing layer 42. A high-efficiency absorbent is added through a dosing tank 45 and a dosing port 46. After entering the absorption system, the liquid phase is circulated and sprayed through an absorption liquid circulation pump 43 to absorb part of the VOCs in the waste gas. The concentration of the high-efficiency absorbent in the circulating liquid is controlled at 18-20%. The circulating liquid after absorption is discharged into the sewage pipe network 6 through the absorption tower overflow port 47 and sent to the wastewater treatment station for treatment. After treatment, the flue gas meets the standards once and is discharged through the chimney 5.

[0065] The working principle of the embodiment of the present invention is as follows: using this device system and adding a 20% concentration of absorption liquid, the ultimate effect on dimethyl disulfide, methyl sulfide, methyl mercaptan, and hydrogen sulfide is excellent, with a removal rate of 99.99%. The removal efficiency of anisole, 1-dodecene, acetone, isopropyl alcohol, 2-heptanone, propylene glycol monomethyl ether acetate, and n-hexane in odor is greater than 90%, and the exhaust gas meets emission standards after single-stage absorption treatment. The cooling and dehumidification system ensures dehumidification effectiveness through temperature detection, high-efficiency absorbents ensure removal efficiency, and the provision of a defoaming layer ensures the cleanliness of the outlet flue gas, pipes, and chimneys.

[0066] Working principle: The present invention has made innovative improvements to the cooling and dehumidification equipment 1. By introducing an advanced temperature detection system, the operating temperature of the equipment is monitored in real time to ensure the stability and reliability of the cooling and dehumidification effect; at the same time, the position of the fan 3 is carefully set between the cooling and dehumidification equipment 1 and the absorption tower 4, which effectively avoids high humidity, high temperature, and high VOCs concentration of organic odor directly passing through the fan 3, thereby extending the service life of the fan. Through the negative pressure generated by the flue gas inlet, the gas is sucked into the cooling and dehumidification equipment 1 for preliminary treatment. At this time, the fan 3 is in the middle position and can overcome a higher pressure difference. Compared with the traditional layout, the system energy consumption of the present invention is significantly reduced, and the operation is more stable.

[0067] The internal structure of the absorption tower 4 has been optimized and a defoaming layer 44 is provided, which effectively prevents impurities such as foam and bubbles generated during the chemical reaction from entering the chimney 5, thereby reducing the additional investment and operation and maintenance costs brought about by multi-stage absorption; at the same time, by utilizing the recycling effect of the high-efficiency composite absorbent, on the basis of simplifying the process flow, efficient treatment of organic odor is achieved, thereby improving the treatment efficiency and economy of the entire system.

[0068] The absorbent proposed by the present invention has various components that play a unique and synergistic role in the odor treatment process. Betaine is a natural quaternary ammonium base with excellent surface active chemistry and stability. It can significantly reduce the surface tension of the solution, thereby enhancing the adsorption capacity for VOCs and improving the enrichment efficiency of VOCs molecules in the liquid phase. Sodium dodecyl sulfate, as an anionic surfactant, can efficiently adsorb VOCs molecules by virtue of its hydrophobic groups and transfer them from the gas phase to the liquid phase. By forming a micellar structure, sodium dodecyl sulfate can encapsulate VOCs inside the micelles, further improving the solubility of VOCs in water, and synergizing with betaine to significantly improve the removal efficiency of VOCs. The zinc ions of zinc acetate have strong chelating ability and can undergo precipitation reactions with compounds such as thiols, sulfides and organic acids in VOCs, thereby effectively removing VOCs and reducing odor concentration. Ethanol or isopropyl alcohol mainly plays the role of defoaming and activating organic surfactants, ensuring that the absorbent maintains good performance and stability during the circulation process.

[0069] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A direct absorption treatment process for odor generated in the organic industry, characterized in that: include: Step S1: The odor is sent to the cooling and dehumidifying equipment (1) through negative pressure, and most of the steam in the waste gas is condensed into water, which can be reused; The cooling and dehumidifying equipment (1) is provided with a gas pipeline connected to the bottom of the absorption tower (4), and the cooling and dehumidifying equipment (1) is connected to the heat exchanger (2) and the condensation water tank (12), and the final cooling temperature is 28-38°C; Step S2, a fan (3) is installed on the intermediate gas pipeline between the cooling and dehumidifying equipment (1) and the absorption tower (4), which can overcome the subsequent higher pressure difference. Under low humidity and low temperature working conditions, the fan sends the gas into the absorption tower (4); In step S3, the gas enters the absorption tower (4) through the blower (3). The top of the absorption tower (4) is provided with a gas pipeline connected to the chimney (5) for external discharge. A circulation pump (43), a defoaming layer (44), and a dosing tank (45) are provided inside the absorption tower. A high-efficiency heteroatom compound capture agent and a lipid absorbent are added or supplemented in the dosing tank (45). Through the circulation action of the composite absorbent, organic substances such as dimethyl sulfide, methyl alcohol, carbon disulfide, olefins, trimethylamine and lipids in the exhaust gas are chelated, captured and absorbed, and the exhaust gas meets the emission requirements at one time and is discharged through the chimney (5). In step S4, the cooling circulating water and the absorption liquid can be discharged to the sewage pipe (6) through the overflow port and sent to the sewage treatment unit.

2. The process for treating odor generated in the organic industry by direct absorption method according to claim 1, characterized in that: In the formula of the composite absorbent, 1-5 parts of betaine are used to reduce the surface tension of the solution and improve the adsorption capacity of VOCs molecules through surface active chemistry and stability; 1-5 parts of sodium dodecyl sulfate, used to adsorb VOCs molecules and increase their solubility in water by forming micelle structures, while synergistically working with betaine to further improve the removal efficiency of VOCs; 5-10 parts of zinc acetate, used to react with mercaptans, sulfides, organic acids and other compounds in VOCs molecules through the chelating ability of zinc ions to produce precipitation reactions; 800-1000 parts of ethanol or isopropyl alcohol are used in combination to defoam and activate the organic surfactant; The concentration of the mixed agent of the composite absorbent ranges from 3% to 25%, and is dynamically adjusted according to the concentration of VOCs in the odor.

3. The direct absorption treatment process for odor generated in the organic industry according to claim 1, characterized in that: The cooling and dehumidifying equipment (1) recovers condensed water through the condensed water tank (12) and reuses it as washing water. A circulating pump (43) is provided in the absorption tower (4) to maintain the circulating spraying of the absorbent, and the absorbent is replenished in real time through the dosing tank (45).

4. The direct absorption treatment process for odor generated in the organic industry according to claim 3, characterized in that: The condensate tank (12) is provided with a two-stage filtration device, the first stage is a 20 μm stainless steel filter, and the second stage is an activated carbon adsorption layer. The COD value of the condensate after treatment is ≤50 mg / L; the dosing tank (45) is equipped with an online concentration monitor. When the absorbent concentration is lower than the set value, fresh absorbent is automatically added at a replenishment rate of 0.1%-2% / min of the circulating liquid flow rate.

5. The process for treating odor generated in the organic industry by direct absorption method according to claim 1, characterized in that: The defoaming layer (44) in the absorption tower (4) is arranged near the upper air outlet of the absorption tower (4).

6. The process for treating odor generated in the organic industry by direct absorption method according to claim 1, characterized in that: A real-time temperature detector (15) is provided on the side of the cooling and dehumidifying device (1) for monitoring the odor cooling temperature and dynamically adjusting the cooling water flow of the heat exchanger (2).

7. The direct absorption treatment process for odor generated in the organic industry according to claim 1, characterized in that: The defoaming layer (44) of the absorption tower (4) adopts a multi-stage baffle structure and is arranged 10-50 cm below the air outlet at the top of the absorption tower; the packing layer (42) of the absorption tower (4) adopts PP material structured packing, the packing specific surface area is 200-350 m² / m³, and the gas-liquid contact time is 1.5-3.5 seconds.

8. The direct absorption treatment process for odor generated in the organic industry according to claim 1, characterized in that: The liquid-gas ratio of the absorption tower (4) is controlled at 3-8 L / m³, and the spray density is 8-15 m³ / (m 2 ·h), the superficial gas velocity is 0.6-1.2m / s.

9. The process for treating odor generated in the organic industry by direct absorption method according to claim 1, characterized in that: The fan (3) is a corrosion-resistant glass fiber reinforced plastic centrifugal fan with an operating pressure range of -5kPa to +10kPa and an air volume adjustment accuracy of ±5%.

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