An ethoxylated pre-treatment off-gas treatment device

Abstract

The utility model discloses an ethoxylation pretreatment tail gas treatment device, including first condenser, condensate tank, second condenser, oil -water separator, the top of first condenser is provided gas phase entrance, and the bottom is provided liquid phase export, gas phase entrance and pretreatment kettle are linked together through tail gas pipeline intercommunication, and liquid phase export is linked together with condensate tank through first condensate pipeline intercommunication, condensate tank is linked together with second condenser through first gas phase pipeline intercommunication, second condenser top is provided second gas phase pipeline, and condensate tank is linked together with pretreatment kettle, second condenser bottom is linked together with oil -water separator through second condensate pipeline intercommunication, oil -water separator is linked together with pretreatment kettle. The utility model improves the separation effect, and through the recovery fatty alcohol reaches the purpose of reducing raw material loss, reduces waste water pollution, and can also guarantee dehydration effect, stabilizes the follow -up production.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to an ethoxylation pretreatment tail gas treatment device. Background Technology

[0002] Ethoxylation is an important organic synthesis reaction. It refers to the addition reaction between ethylene oxide (EO) and compounds containing active hydrogen (such as alcohols, phenols, amines, and carboxylic acids) under the action of a catalyst, producing a product containing an ethoxy group (-CH2CH2O-). The active hydrogen in the compound attacks the three-membered ring of ethylene oxide, causing the ring to open and bond, forming an ethoxy chain. Ethoxylation is a core reaction in the preparation of nonionic surfactants. For example, fatty alcohols react with ethylene oxide to produce fatty alcohol polyoxyethylene ethers (AEO), which are widely used in detergents and emulsifiers.

[0003] The main function of the ethoxylation pretreatment vessel is to separate the trace amounts of water contained in fatty alcohols, reduce the impact of water on subsequent reactions, and ensure product quality.

[0004] However, in existing technologies, a small amount of fatty alcohols are separated along with water during the dehydration process in the pretreatment vessel and enter the wastewater treatment system, increasing the burden on the system and causing the following adverse environmental impacts: Some fatty alcohols have poor biodegradability in the natural environment. When these alcohols enter water bodies or soil, they can persist for a long time, potentially affecting the living environment of aquatic microorganisms and disrupting the aquatic ecological balance. Furthermore, the direct discharge of industrial wastewater containing fatty alcohols into the ocean without effective treatment may interfere with the physiological functions of marine organisms, affecting fish respiration and reproduction, and threatening marine biodiversity. Utility Model Content

[0005] This invention relates to a tail gas treatment device for ethoxylation pretreatment. While ensuring the dehydration effect of ethoxylation pretreatment, it can recover and reuse a small amount of fatty alcohols in the tail gas, reducing the environmental impact of fatty alcohol-containing wastewater. The specific technical solution is as follows: An ethoxylation pretreatment tail gas treatment device, which is connected to a pretreatment vessel, includes a first condenser, a condensate tank, a second condenser, and an oil-water separator. The first condenser has a gas phase inlet at the top and a liquid phase outlet at the bottom; the gas phase inlet is connected to the pretreatment vessel through a tail gas pipeline, and the liquid phase outlet is connected to the condensate tank through a first condensate pipeline. The condensate tank is connected to the second condenser via a first vapor phase pipeline; a second vapor phase pipeline is installed at the top of the second condenser, and the condensate tank is connected to the pretreatment vessel; the bottom of the second condenser is connected to the oil-water separator via a second condensate pipeline; the oil-water separator is connected to the pretreatment vessel.

[0006] Preferably, the first condenser is equipped with a first thermometer and a first outlet valve.

[0007] Preferably, the second condenser is equipped with a second thermometer and a second outlet valve.

[0008] Preferably, the length of the second condensate pipeline is greater than 10 meters, and the outlet end of the second condensate pipeline extends below the liquid surface inside the oil-water separator.

[0009] Preferably, the condensate tank is provided with an outer jacket, and the jacket is provided with a steam inlet and a condensate outlet.

[0010] Preferably, the oil-water separator is equipped with a steam heating device, which has a steam inlet and a condensate outlet.

[0011] The beneficial effects of this utility model are: 1. Recovering fatty alcohols and reducing raw material loss. This invention recovers fatty alcohols through preliminary condensation in a first condenser and deep condensation in a second condenser, combined with precise separation by an oil-water separator. The recovered fatty alcohols can be returned to the pretreatment reactor for production, reducing raw material waste and lowering production costs for enterprises.

[0012] 2. Reduce wastewater pollution and alleviate environmental pressure. After two-stage condensation and oil-water separation, the content of fatty alcohols in the wastewater discharged into the sewage treatment system is reduced. Low-concentration alcohol-containing wastewater can reduce the load on the sewage treatment system, while avoiding the long-term retention of fatty alcohols in water bodies and soil, which can disrupt the ecological balance, reduce interference with the physiological functions of marine organisms, and lower environmental risks.

[0013] 3. Ensure effective dehydration and stable subsequent production. The first condenser, through precise temperature control (condensation temperature slightly higher than the boiling point of water under system pressure but lower than the boiling point of fatty alcohols), can recover fatty alcohols while preventing moisture from affecting catalyst activity and product quality, thus ensuring production stability.

[0014] 4. The rational structural design enhances separation reliability. The design of a second condensate pipeline longer than 10 meters with its outlet extending below the oil-water separator surface creates a stable water seal, reducing the impact of gas phase disturbances on the static separation effect of the oil-water separator. Simultaneously, the design of the condensate tank jacket and the steam heating device of the oil-water separator prevents the fatty alcohol solution from solidifying, further ensuring a stable and efficient separation process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an ethoxylation pretreatment tail gas treatment device according to the present invention.

[0016] The diagram is labeled as follows: 1 is the pretreatment vessel; 2 is the tail gas pipeline; 3 is the first condenser; 4 is the first condensate pipeline; 5 is the second condensate pipeline; 6 is the first gas phase pipeline; 7 is the second gas phase pipeline; 8 is the second condenser; 9 is the oil-water separator; 10 is the condensate tank; 11 is the vacuum system; 12 is the water tank; 13 is the water jet vacuum pump; 14 is the first outlet valve; 15 is the first thermometer; 16 is the second thermometer; 17 is the second outlet valve; 18 is the wastewater treatment system; 19 is the steam inlet; 20 is the condensate outlet; 21 is the circulating water inlet; 22 is the circulating water outlet. Detailed Implementation

[0017] To make the technical problems solved, the technical solutions, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0018] Combination Figure 1 As shown, the ethoxylation pretreatment tail gas treatment device of this utility model is connected to the pretreatment vessel 1 and includes a first condenser 3, a condensate tank 10, a second condenser 8, and an oil-water separator 9. The first condenser 3 is provided with a gas phase inlet at the top and a liquid phase outlet at the bottom. The first condenser 3 is provided with a circulating water inlet 21 and a circulating water outlet 22. Cooling water enters through the circulating water inlet 21 and flows out from the circulating water outlet 22 to achieve the purpose of cooling.

[0019] The gas phase inlet is connected to the pretreatment vessel 1 via the tail gas pipeline 2, and the liquid phase outlet is connected to the condensate tank 10 via the first condensate pipeline 4.

[0020] The condensate tank 10 is connected to the second condenser 8 via the first gas phase pipeline 6; the second condenser 8 is equipped with a second gas phase pipeline 7 at its top, and the condensate tank 10 is connected to the pretreatment vessel 1; the bottom of the second condenser 8 is connected to the oil-water separator 9 via the second condensate pipeline 5; the oil-water separator 9 is connected to the pretreatment vessel 1.

[0021] Specifically, this invention also includes a first thermometer 15 and a first outlet valve 14. The first thermometer 15 is used to monitor the condensation temperature inside the first condenser 3. The first thermometer 15 is located near the liquid phase outlet of the first condenser 3. The first outlet valve 14 is located at the circulating water outlet 22 of the first condenser 3. The first outlet valve 14 is controlled by the first thermometer 15 to regulate the cooling circulating water flow rate. The condensation temperature inside the first condenser 3 is slightly higher than the boiling point of water under system pressure (vacuum conditions provided by vacuum system 11) and lower than the boiling point of fatty alcohols under system pressure. Some fatty alcohol vapor is condensed into liquid in the first condenser 3, and the condensed fatty alcohol is recovered and reused in production.

[0022] Specifically, this invention also includes a second thermometer 16 and a second outlet valve 17. The second thermometer 16 is used to monitor the condensation temperature inside the second condenser 8, ensuring that its temperature is much lower than the boiling points of water and fatty alcohols under the system pressure.

[0023] The second gas phase pipeline 7 of this invention is connected to the vacuum system 11, which includes a water tank 12 and a water jet vacuum pump 13. The function of the vacuum system 11 is to provide vacuum conditions.

[0024] Specifically, the second condensate line 5 is longer than 10 meters, and its outlet end extends below the liquid surface inside the oil-water separator 9. This arrangement forms a water seal and reduces the impact of gas phase disturbances on the static separation effect inside the oil-water separator 9.

[0025] Specifically, the condensate tank 10 is provided with an outer jacket, and the jacket is provided with a steam inlet 19 and a condensate outlet 20. The oil-water separator 9 is provided with a steam heating device, which is preferably a jacket sleeved on the outer wall of the oil-water separator 9 or a steam coil provided inside the oil-water separator 9. The steam heating device is provided with a steam inlet 19 and a condensate outlet 20.

[0026] In this invention, the steam inlet 19 and the condensate outlet 20 are used independently for the condensate tank 10 and the oil-water separator, respectively.

[0027] The working principle of this utility model: During dehydration in pretreatment vessel 1, a water vapor mixture containing a small amount of fatty alcohol enters the first condenser 3 through pretreatment tail gas pipeline 2. The cooling medium in the first condenser 3 is circulating cooling water. The temperature reflected in real time by the first thermometer 15 of the first condenser 3 controls the flow rate of the circulating cooling water through the first outlet valve 14, ensuring that the temperature inside the first condenser 3 is slightly higher than the boiling point of water under this system pressure, but lower than the boiling point of fatty alcohol under this system pressure. Therefore, some fatty alcohol vapor is condensed into liquid in the first condenser 3 and flows into the condensate tank through the first condensate pipeline 4 for temporary storage, and is then returned to the pretreatment vessel 1 as needed. "As needed" is used because production is intermittent, allowing the vapor to be discharged into the pretreatment vessel 1 before the next batch of production.

[0028] Uncondensed water vapor and a small amount of uncondensed fatty alcohol vapor in the first condenser 3 enter the second condenser 8 through the first vapor phase pipeline 6 above the condensate tank 10. The cooling medium of the second condenser 8 is cooling circulating water. The temperature is detected by the second thermometer 16 and the second outlet valve 17 is controlled so that the temperature in the second condenser 8 is much lower than the boiling point of water and fatty alcohol under this system pressure. Most of the water vapor and the remaining fatty alcohol vapor are condensed into liquid and flow into the oil-water separator 9 through the condensate pipeline with a length of more than 10 meters.

[0029] The oil-water separator 9 is equipped with a steam heating device to prevent the fatty alcohol aqueous solution from solidifying, thus facilitating better separation. The fatty alcohol oil phase is further separated and stored in the oil-water separator 9 and sent back to the pretreatment vessel, while the wastewater is discharged into the sewage treatment system 18. A small amount of uncondensed water vapor in the second condenser 8 enters the vacuum system 11.

[0030] It is understood that the above specific description of this utility model is only used to illustrate this utility model and is not limited to the technical solutions described in the embodiments of this utility model. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to this utility model to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of this utility model.

Claims

1. A tail gas treatment device for ethoxylation pretreatment, characterized in that, Connected to the pretreatment vessel (1), it includes a first condenser (3), a condensate tank (10), a second condenser (8), and an oil-water separator (9); The first condenser (3) has a gas inlet at the top and a liquid outlet at the bottom. The gas inlet is connected to the pretreatment vessel (1) via a tail gas pipeline (2), and the liquid outlet is connected to the condensate tank (10) via a first condensate pipeline (4). The condensate tank (10) is connected to the second condenser (8) through the first gas phase pipeline (6); the second condenser (8) is provided with a second gas phase pipeline (7) at the top, and the condensate tank (10) is connected to the pretreatment vessel (1); the bottom of the second condenser (8) is connected to the oil-water separator (9) through the second condensate pipeline (5); the oil-water separator (9) is connected to the pretreatment vessel (1).

2. The ethoxylation pretreatment tail gas treatment device according to claim 1, characterized in that, The first condenser (3) is equipped with a first thermometer (15) and a first outlet valve (14).

3. The ethoxylation pretreatment tail gas treatment device according to claim 1, characterized in that, The second condenser (8) is equipped with a second thermometer (16) and a second outlet valve (17).

4. The ethoxylation pretreatment tail gas treatment device according to claim 1, characterized in that, The length of the second condensate pipeline (5) is greater than 10 meters, and the outlet end of the second condensate pipeline (5) extends below the liquid surface inside the oil-water separator (9).

5. The ethoxylation pretreatment tail gas treatment device according to claim 1, characterized in that, The condensate tank (10) has an outer jacket, which has a steam inlet (19) and a condensate outlet.

6. The ethoxylation pretreatment tail gas treatment device according to claim 1, characterized in that, The oil-water separator (9) is equipped with a steam heating device, which has a steam inlet (19) and a condensate outlet.

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