Dibutyl phthalate recovery alcohol treatment unit
By combining multi-stage separation in a water distillation tower with the synergistic effect of a condenser and cooler, the problem of poor quality of recovered alcohol in the production of dibutyl phthalate was solved. This achieved efficient separation and purification, improved the recovery rate, ensured product quality and resource utilization, and reduced environmental pollution.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-22
- Publication Date
- 2026-06-30
AI Technical Summary
In the current dibutyl phthalate production process, the quality of the recovered alcohol is poor, which leads to a decline in product quality, waste of resources and environmental pollution. Traditional treatment methods are difficult to achieve efficient separation of alcohol, water and impurities, resulting in low recovery rates and substandard wastewater after separation.
The method employs a multi-stage separation process using a water distillation tower, in conjunction with a condenser and cooler. It leverages the difference in volatility of components to achieve efficient separation of alcohol and water, while removing byproducts such as ethers and heavy components. An azeotrope is formed by heating the water distillation vessel, and liquid-liquid separation is achieved by utilizing the density difference between alcohol and water. Combined with condensation and cooling to treat non-condensable gases, the method achieves efficient separation and purification.
It significantly improved the purity and recovery rate of recovered alcohol, reduced processing costs, ensured the stability of DBP product quality, reduced environmental pollution risks, and realized the recycling of resources.
Smart Images
Figure CN224421954U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of dibutyl phthalate production technology, specifically to a dibutyl phthalate recovery alcohol treatment device. Background Technology
[0002] Dibutyl phthalate (DBP), an indispensable chemical raw material in plastics, coatings, inks, and other fields, is produced through a typical esterification process. In an esterification reactor, phthalic anhydride and butanol react at 120–150°C under the catalysis of concentrated sulfuric acid to produce DBP and water. During this production process, the esterification system and the water distillation system generate a large amount of alcohol-containing waste liquid. This waste liquid needs to be preliminarily recovered through its respective alcohol-water separators to form recovered alcohol.
[0003] During normal production, the existing equipment in the workshop presents numerous problems. The initially recovered alcohol has a dark color, failing to meet the requirements for reuse in production; direct discharge would cause visual pollution. The recovered alcohol contains byproducts such as ethers and heavy components. These impurities are chemically stable and difficult to remove using conventional simple treatment methods. Direct reuse without treatment would contaminate subsequent production processes, leading to decreased purity and performance of DBP products, affecting product quality stability. Separate treatment requires additional equipment and reagents, increasing processing costs. The recovered alcohol has a high butanol content; direct disposal would waste significant resources and increase raw material procurement costs. Furthermore, direct discharge of alcohol-containing wastewater without effective treatment would pollute water bodies and soil. Traditional treatment methods often employ single distillation or simple filtration, which are insufficient for efficient separation of alcohol, water, and impurities. The alcohol recovery rate after treatment is low, and the separated wastewater may still contain excessive impurities, failing to meet recycling or discharge standards. This results in low resource recycling efficiency in the production process, hindering the company's green production transformation. Utility Model Content
[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a device for recovering dibutyl phthalate (DBP) alcohol. Through multi-stage separation of water distillation tower and the synergistic effect of condenser and cooler, the device utilizes the difference in volatility of components to achieve efficient separation of alcohol and water. At the same time, it removes by-product ethers and heavy components. The color of the recovered alcohol is significantly reduced and the purity can reach the production reuse standard. This effectively solves the problem of poor quality of traditional recovered alcohol and avoids the impact of alcohol quality problems on the quality of DBP products.
[0005] This utility model is achieved using the following technical solution:
[0006] The dibutyl phthalate recovery alcohol treatment device includes an alcohol storage tank, which is connected to a water distillation kettle via an alcohol storage tank pump. The top of the water distillation kettle is connected to a condenser via a water distillation tower. The condenser is connected to an alcohol-water separation tank via a cooler A. The bottom of the water distillation kettle is connected to a cooler B via a water distillation kettle waste alcohol pump. Cooler B is connected to the alcohol separation tank via a cooler-to-alcohol separation tank pipeline.
[0007] The alcohol storage tank adopts a vertical cylindrical structure with a designed volume of 5-10 m³. 3 It meets the 24-hour alcohol recovery storage requirements and avoids system fluctuations caused by frequent feeding; the top of the tank is equipped with a breather valve to balance the pressure inside the tank and prevent positive or negative pressure from occurring inside the tank due to temperature changes or feeding / discharging, which could damage the tank. The distillation kettle adopts a jacketed heating structure, with 0.6MPa saturated steam introduced into the jacket layer. This provides a large heating area and high heat transfer efficiency, quickly heating the recovered alcohol to 90-100℃ and shortening heating time. An internal stirring device (20-30 r / min) ensures uniform heating of the recovered alcohol, preventing localized overheating that could lead to alcohol decomposition or localized underheating that could affect the azeotropic effect. A steam outlet and pressure gauge are located at the top of the kettle. The steam outlet connects to the steam pipeline at the top of the kettle, ensuring the generated azeotropic steam smoothly enters the distillation tower. The pressure gauge monitors the pressure inside the kettle in real time to prevent overpressure and potential safety accidents. A slag discharge port and a waste alcohol pump inlet pipeline are located at the bottom of the kettle. The slag discharge port facilitates regular cleaning of stubborn impurities deposited inside the kettle, while the waste alcohol pump inlet pipeline enables rapid discharge of byproducts such as ethers and heavy components from the bottom of the kettle.
[0008] The alcohol storage tank is connected to a recovery alcohol pipeline from a self-distilled water alcohol-water separator, and the recovery alcohol pipeline from the self-distilled water alcohol-water separator is connected to a recovery alcohol pipeline from an esterification alcohol-water separator. An alcohol storage tank pump inlet pipeline is provided between the alcohol storage tank and the alcohol storage tank pump.
[0009] The alcohol storage tank pump is connected to the distillation kettle via an outlet pipeline, the top of the distillation kettle is connected to the distillation tower via a steam pipeline, and the distillation tower is connected to the condenser via a steam pipeline. The distillation tower adopts a plate tower structure with 15-20 layers of sieve plates inside, with an opening rate of 10%-15%, which increases the gas-liquid contact area and contact time, improving separation efficiency. The tower top has a steam inlet (connecting to the steam pipeline at the top of the distillation tower) and a reflux outlet (connecting to the reflux pipeline from the alcohol-water separator to the distillation tower), while the bottom has a liquid outlet (connecting to the liquid reflux pipeline from the bottom of the distillation tower), forming a complete gas-liquid circulation separation process. The tower body is equipped with an external insulation layer (rock wool, 50-80mm thick) to reduce heat loss and maintain stable internal temperature, ensuring that the separation operation is not affected by external temperature changes. A temperature monitoring point is located in the middle of the tower to monitor the temperature distribution at different heights in real time, providing data for adjusting the reflux ratio and optimizing the separation effect.
[0010] A liquid inlet pipeline connects the condenser and cooler A. The bottom of the water distillation tower is connected to the water distillation kettle via a liquid return pipeline from the bottom of the water distillation tower. A liquid inlet pipeline connects cooler A and alcohol-water separator.
[0011] The condenser and the alcohol-water separator are connected by a non-condensable gas inlet pipeline. The top of the alcohol-water separator is connected to an alcohol-water separator exhaust gas pipeline. A qualified alcohol pipeline is connected to the alcohol-water separator. The alcohol-water separator is connected to the distillation tower via an alcohol-to-distillation tower return pipeline.
[0012] The alcohol-spinning tank is connected to a non-conforming material discharge pipeline. The liquid at the bottom of the distillation tower flows back to the distillation tower pipeline and is connected to the non-conforming material discharge pipeline via the water-to-distillation kettle pipeline at the bottom of the alcohol-water separator. The alcohol-water separator is connected to the water-to-distillation kettle pipeline at the bottom of the alcohol-water separator via a pipeline.
[0013] The water distillation kettle and the waste alcohol pump of the water distillation kettle are connected by an inlet pipeline of the waste alcohol pump of the water distillation kettle, and the outlet pipeline of the waste alcohol pump of the water distillation kettle to the cooler B is connected between the waste alcohol pump of the water distillation kettle and the cooler B. The alcohol transfer tank is connected by a material outlet pipeline of the alcohol transfer tank.
[0014] The working principle of this utility model is as follows:
[0015] The recovered alcohol from the self-esterification system's alcohol-water separator is transported through the recovered alcohol pipeline of the self-esterification alcohol-water separator, and the recovered alcohol from the self-distilled water system's alcohol-water separator is transported through the recovered alcohol pipeline of the self-distilled water alcohol-water separator. The two streams of recovered alcohol enter the alcohol storage tank together, where they are initially collected and buffered to ensure stable feed for subsequent processing.
[0016] Start the alcohol storage tank pump and extract the recovered alcohol from the alcohol storage tank through the inlet pipeline of the alcohol storage tank pump. Then, transport it to the water distillation kettle through the outlet pipeline of the alcohol storage tank pump. The water distillation kettle is heated with 0.6MPa steam to control the temperature of the recovered alcohol in the tank at 90-100℃, so that the alcohol and water in the recovered alcohol form an azeotrope, which is ready for subsequent separation.
[0017] The alcohol-water azeotropic vapor generated at the top of the distillation kettle enters the distillation tower through the steam pipeline at the top of the kettle. Multi-stage separation occurs within the distillation tower: utilizing the difference in volatility between alcohol and water, alcohol vapor is enriched at the top of the tower, while water is enriched at the bottom. Water at the bottom of the distillation tower is returned to the distillation kettle via the bottom liquid return pipeline, achieving water circulation separation and improving alcohol separation efficiency. Alcohol vapor at the top of the distillation tower enters the condenser through the steam pipeline at the top of the tower. The condenser is circulated with circulating water for condensation, turning the alcohol vapor into liquid. The condensed liquid enters cooler A through the liquid inlet cooler pipeline. Cooler A continues to circulate water, cooling the liquid temperature to 30-40℃ to prevent high-temperature liquid from affecting subsequent separation effects. Uncondensed non-condensable gases (mainly small amounts of low-boiling-point impurities) in the condenser enter the alcohol-water separator through the non-condensable gas inlet alcohol-water separator pipeline. The liquid in the alcohol-water separator further dissolves the soluble components in the non-condensable gases, reducing the content of harmful substances in the waste gas.
[0018] The liquid cooled by cooler A enters the alcohol-water separator through the liquid inlet pipeline. Due to the density difference between alcohol and water, stratification occurs within the separator, with the alcohol phase on top and the water phase on the bottom. Initially, the alcohol-to-distillation tower reflux pipeline is opened, and all the liquid in the separator is returned to the distillation tower for a total reflux operation, lasting 30-60 minutes to ensure stable separation conditions within the distillation tower. After the total reflux is completed, a sample is taken to analyze the color and purity of the upper alcohol phase in the separator. If the color is still unacceptable, the liquid is first passed through the water inlet at the bottom of the separator to... The lower aqueous phase is discharged to the distillation kettle for reprocessing via the distillation kettle pipeline, while the upper unqualified alcohol phase is discharged to the alcohol removal tank via the unqualified material discharge pipeline. If the sample analysis is qualified (color number ≤30APHA, purity ≥95%), the reflux flow rate is reduced, and the reflux ratio is adjusted to 3:1-5:1 (reflux flow rate: output flow rate). Qualified alcohol is extracted through the qualified alcohol pipeline and transported to the recovery alcohol settling tank for subsequent DBP production recycling. The tail gas at the top of the alcohol-water separator is discharged to the tail gas pipeline through the alcohol-water separator tail gas pipeline and is incinerated to meet emission standards.
[0019] The by-products ethers and heavy components deposited at the bottom of the distillation kettle are extracted by the waste alcohol pump through the inlet pipeline of the waste alcohol pump in the distillation kettle, and then transported to cooler B through the outlet pipeline of the waste alcohol pump in the distillation kettle. Cooler B is circulated with water to cool them to 40-50℃ to prevent the volatilization or pipeline blockage of high-temperature impurities during transportation. The cooled impurities enter the alcohol separation tank through the cooler pipeline. After the impurities in the alcohol separation tank reach a certain liquid level, they are transported to the hazardous waste treatment unit through the material outlet pipeline of the alcohol separation tank for standardized disposal.
[0020] Specifically, the recovered alcohols (including butanol, water, ethers, and heavy components) from the esterification and distillation systems are first collected in an alcohol storage tank and then pumped to a distillation kettle. The distillation kettle is heated with steam, causing the alcohol and water to form an azeotrope and evaporate. The azeotropic steam rises to a distillation tower for multi-stage distillation separation. Utilizing the difference in volatility of the components, the alcohol vapor is enriched at the top of the tower, while the aqueous phase and some heavy components are refluxed to the bottom of the distillation kettle. The alcohol vapor at the top of the tower is condensed by a condenser and further cooled by cooler A before entering the alcohol-water separator. In the alcohol-water separator, the density difference between alcohol and water is used to separate the liquid into layers: a high-purity alcohol phase on top and an aqueous phase on the bottom. Alcohol that passes sampling analysis is collected and reused through the qualified alcohol pipeline, while unqualified alcohols and ethers and heavy components enriched at the bottom of the distillation kettle are discharged into a waste alcohol tank through corresponding pipelines for centralized treatment. The small amount of non-condensable gas and tail gas generated in the alcohol-water separator are treated and discharged in compliance with standards. This process efficiently separates alcohol, water, and impurities, significantly improving the quality and recovery rate of the recovered alcohol.
[0021] Compared with the prior art, the beneficial effects of this utility model are:
[0022] (1) This device achieves efficient separation of alcohol and water by using the multi-stage separation of the water distillation tower and the synergistic effect of the condenser and cooler, taking advantage of the difference in volatility of the components. At the same time, it removes by-product ethers and heavy components. The color of the recovered alcohol after treatment is significantly reduced, and the purity can reach the production reuse standard. This effectively solves the problem of poor quality of traditional recovered alcohol and avoids the impact of alcohol quality problems on the quality of DBP products.
[0023] (2) The device has a recovery rate of over 90% for alcohol. The alcohol-containing waste liquid that was originally to be discarded can be recycled back into the DBP production process after treatment, reducing the amount of butanol raw material purchased and lowering the raw material cost of the enterprise. At the same time, the separated wastewater can be partially reused in the production auxiliary process after passing the test, further saving water resources and realizing resource recycling.
[0024] (3) The water distillation kettle is heated to induce an azeotropic reaction between alcohol and water. Multi-stage separation in the water distillation tower allows heavy components to accumulate at the bottom of the tower. Finally, the waste alcohol from the water distillation kettle is pumped to the alcohol transfer tank for centralized treatment. This effectively removes byproducts such as ethers and heavy components from the recovered alcohol, avoiding product quality fluctuations caused by impurities entering subsequent production. This ensures the stability and continuity of the DBP production process and reduces rework and scrap losses due to product defects. The qualified alcohol after treatment is reused, wastewater is discharged in compliance with standards, and impurities are centrally treated as hazardous waste. This reduces the amount of alcohol-containing waste liquid and impurities discharged from the source, thus lowering the risk of environmental pollution. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the alcohol recovery device for dibutyl phthalate of this invention.
[0026] In the diagram: 1. Alcohol storage tank; 2. Alcohol storage tank pump; 3. Distillation kettle; 4. Distillation tower; 5. Condenser; 6. Cooler A; 7. Alcohol-water separator; 8. Waste alcohol pump from the distillation kettle; 9. Cooler B; 10. Alcohol transfer tank; 11. Alcohol recovery pipeline from the esterification alcohol-water separator; 12. Alcohol recovery pipeline from the distillation alcohol-water separator; 13. Inlet pipeline of the alcohol storage tank pump; 14. Outlet pipeline of the alcohol storage tank pump; 15. Steam pipeline at the top of the distillation kettle; 16. Steam pipeline at the top of the distillation tower; 17. Liquid reflux from the bottom of the distillation tower to the steam... 18. Water tower pipeline; 19. Liquid inlet cooler pipeline; 20. Non-condensable gas inlet alcohol-water separator pipeline; 21. Liquid inlet alcohol-water separator pipeline; 22. Alcohol inlet to distillation tower return pipeline from alcohol-water separator; 23. Bottom water in alcohol-water separator pipeline to distillation kettle pipeline; 24. Non-conforming material discharge pipeline; 25. Alcohol-water separator tail gas pipeline; 26. Conforming alcohol pipeline; 27. Distillation kettle waste alcohol pump inlet pipeline; 28. Distillation kettle waste alcohol pump outlet to cooler pipeline; 29. Cooler to alcohol removal tank pipeline; 20. Alcohol removal tank material outlet pipeline. Detailed Implementation
[0027] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.
[0028] Example 1
[0029] like Figure 1As shown, the dibutyl phthalate recovery alcohol treatment device includes an alcohol storage tank 1. The alcohol storage tank 1 is connected to a water distillation kettle 3 via an alcohol storage tank pump 2. The top of the water distillation kettle 3 is connected to a condenser 5 via a water distillation tower 4. The condenser 5 is connected to an alcohol-water separation tank 7 via a cooler A6. The bottom of the water distillation kettle 3 is connected to a cooler B9 via a water distillation kettle waste alcohol pump 8. The cooler B9 is connected to an alcohol-spinning tank 10 via a cooler-to-alcohol-spinning tank pipeline 28. An alcohol recovery pipeline 12 from the water distillation alcohol-water separation tank is connected to the alcohol recovery pipeline 12 from the water distillation alcohol-water separation tank, and an alcohol recovery pipeline 11 from the esterification alcohol-water separation tank is connected to the alcohol storage tank 1. An alcohol storage tank pump inlet pipeline 13 is provided between the alcohol storage tank 1 and the alcohol storage tank pump 2. An outlet pipeline 14 connects the alcohol storage tank pump 2 to the distillation kettle 3. A steam pipeline 15 connects the top of the distillation kettle 3 to the distillation tower 4. A steam pipeline 16 connects the top of the distillation tower 4 to the condenser 5. A liquid inlet pipeline 18 connects the condenser 5 to the cooler A6. The bottom of the distillation tower 4 is connected to the distillation kettle 3 via a liquid return pipeline 17. A liquid inlet pipeline 20 connects the cooler A6 to the alcohol-water separator 7. A non-condensable gas inlet pipeline 19 connects the condenser 5 to the alcohol-water separator 7. An exhaust gas pipeline 24 connects the top of the alcohol-water separator 7. A qualified alcohol pipeline 25 connects to the alcohol-water separator 7. The alcohol-water separator 7 is connected to the distillation tower 4 via a return pipeline 21. The alcohol-scraping tank 10 is connected to a non-conforming material discharge pipeline 23. Liquid from the bottom of the distillation tower flows back to the distillation tower pipeline 17, which is connected to the non-conforming material discharge pipeline 23 via the bottom water to the distillation vessel pipeline 22 of the alcohol-water separator. The alcohol-water separator 7 is connected to the bottom water to the distillation vessel pipeline 22 via a pipeline. The distillation vessel 3 and the waste alcohol pump 8 are connected by the waste alcohol pump inlet pipeline 26. The waste alcohol pump 8 and the cooler B9 are connected by the waste alcohol pump outlet pipeline 27. The alcohol-scraping tank 10 is connected to the alcohol-scraping tank material outlet pipeline 29.
[0030] In this embodiment, a batch of mixed recovered alcohol from the DBP production workshop is processed, with a total feed volume of 5.0 cubic meters. The initial composition of the recovered alcohol is: approximately 75% butanol, approximately 20% water, and approximately 5% ethers and heavy components (including DBP and other esters); the initial color number is 180APHA.
[0031] The specific processing steps are as follows:
[0032] Feeding and Heating: 5.0 cubic meters of recovered alcohol are collected in alcohol storage tank 1 via recovered alcohol pipeline 11 from the esterification alcohol-water separator and recovered alcohol pipeline 12 from the distillation alcohol-water separator. Then, alcohol storage tank pump 2 pumps the alcohol into distillation kettle 3 at a flow rate of 1.5 cubic meters per hour via alcohol storage tank pump outlet pipeline 14. Distillation kettle 3 is heated by 0.6 MPa saturated steam to maintain the temperature inside the kettle at 95°C, causing butanol and water to form an azeotrope and continuously evaporate.
[0033] Distillation and Condensation: The alcohol-water azeotropic vapor generated at the top of the distillation kettle 3 enters the distillation tower 4 through the steam pipeline 15 at the top of the distillation kettle. The distillation tower 4 is equipped with 18 layers of sieve plates. During operation, the liquid at the bottom of the distillation tower is returned to the distillation kettle 3 through the bottom liquid return pipeline 17. The alcohol vapor at the top of the distillation tower 4 enters the condenser 5 through the steam pipeline 16 at the top of the distillation tower. The circulating water temperature is controlled at 25℃, completely condensing the vapor into liquid. The condensed liquid enters the cooler A6 through the liquid inlet cooler pipeline 18, where the cooling water further reduces the liquid temperature to 35℃. A small amount of uncondensed non-condensable gas in the condenser 5 enters the alcohol-water separator 7 through the non-condensable gas inlet alcohol-water separator pipeline 19.
[0034] Alcohol-water separation and impurity separation: The liquid cooled by cooler A6 enters alcohol-water separator 7 through liquid inlet line 20. Initially, the alcohol-to-distillation tower reflux line 21 of the alcohol-water separator is turned on for a full reflux operation for 30 minutes to stabilize the separation conditions in distillation tower 4. After the full reflux is completed, an upper alcohol phase sample is taken from alcohol-water separator 7 for analysis. The color number is 28APHA, and the butanol purity is 95.8%, meeting the qualification standard. Subsequently, the reflux ratio is adjusted to 4:1 (reflux flow rate: outflow rate), and qualified alcohol is collected through qualified alcohol line 25, with a collection volume of approximately 3.6 cubic meters. A small amount of water phase (approximately 0.5 cubic meters) at the bottom of alcohol-water separator 7 is discharged to distillation kettle 3 for reprocessing through bottom water-to-distillation kettle line 22. The tail gas at the top of alcohol-water separator 7 is discharged to the tail gas treatment system for incineration through alcohol-water separator tail gas line 24.
[0035] Waste alcohol treatment: The by-product ethers and heavy components (approximately 0.7 cubic meters) accumulated at the bottom of the distillation kettle 3 are extracted by the waste alcohol pump 8 through the inlet pipeline 26 of the waste alcohol pump in the distillation kettle, and then transported to the cooler B9 through the outlet pipeline 27 of the waste alcohol pump in the distillation kettle, where they are cooled to 45°C. The cooled impurities then enter the alcohol transfer tank 10 through the cooler to the alcohol transfer tank pipeline 28, and are finally transported to the hazardous waste treatment unit through the material outlet pipeline 29 of the alcohol transfer tank.
[0036] After treatment, the color number of the recovered alcohol significantly decreased from 180 APHA to 28 APHA, and the purity increased from 75% to 95.8%, meeting the requirements for production reuse (color number ≤ 30 APHA, purity ≥ 95%). The butanol recovery rate reached approximately 92%. Ethers and heavy components were effectively removed, avoiding any impact on the quality of DBP products.
[0037] Example 2
[0038] This embodiment uses the same apparatus structure as in Example 1. It processes another batch of mixed recovered alcohol with slightly lower initial quality, with a total feed volume of 7.0 cubic meters. The initial composition of this recovered alcohol is: approximately 70% butanol, approximately 25% water, and approximately 5% ethers and heavy components; the initial color number is 220APHA.
[0039] The specific processing steps are as follows:
[0040] Feeding and Heating: 7.0 cubic meters of recovered alcohol are collected in alcohol storage tank 1 via recovered alcohol pipeline 11 from the esterification alcohol-water separator and recovered alcohol pipeline 12 from the distillation alcohol-water separator. Then, alcohol storage tank pump 2 pumps the alcohol into distillation kettle 3 at a flow rate of 1.8 cubic meters per hour via alcohol storage tank pump outlet pipeline 14. Distillation kettle 3 is heated by 0.6 MPa saturated steam to maintain the kettle temperature at 98°C, thereby enhancing azeotropic formation efficiency.
[0041] Distillation and Condensation: The alcohol-water azeotropic vapor generated at the top of the distillation kettle 3 enters the distillation tower 4 through the steam pipeline 15 at the top of the distillation kettle. The distillation tower 4 is equipped with 15 sieve plates. During operation, the liquid at the bottom of the distillation tower is returned to the distillation kettle 3 through the bottom liquid return pipeline 17. The alcohol vapor at the top of the distillation tower 4 enters the condenser 5 through the steam pipeline 16 at the top of the distillation tower, with the circulating water temperature controlled at 22℃. The condensed liquid enters the cooler A6 through the liquid inlet cooler pipeline 18, where the cooling water further reduces the liquid temperature to 30℃. A small amount of uncondensed non-condensable gas in the condenser 5 enters the alcohol-water separator 7 through the non-condensable gas inlet alcohol-water separator pipeline 19.
[0042] Alcohol-water separation and impurity separation: The liquid cooled by cooler A6 enters alcohol-water separator 7 through liquid inlet line 20. Initially, the alcohol-to-distillation tower reflux line 21 of the alcohol-water separator is turned on for a full reflux operation for 60 minutes to ensure the system reaches optimal separation. After the full reflux is completed, a sample of the upper alcohol phase from alcohol-water separator 7 is taken for analysis. The color number is 25APHA, and the butanol purity is 96.5%, meeting the qualification standard. Subsequently, the reflux ratio is adjusted to 5:1 (reflux flow rate: outflow rate), and qualified alcohol is collected through qualified alcohol line 25, with a collection volume of approximately 4.9 cubic meters. The aqueous phase at the bottom of alcohol-water separator 7 (approximately 1.0 cubic meter) is discharged to distillation vessel 3 for reprocessing through bottom water to distillation vessel line 22. The tail gas at the top of alcohol-water separator 7 is discharged to the tail gas treatment system for incineration through alcohol-water separator tail gas line 24.
[0043] Waste alcohol treatment: The by-product ethers and heavy components (approximately 1.1 cubic meters) accumulated at the bottom of the distillation kettle 3 are extracted by the waste alcohol pump 8 through the waste alcohol pump inlet pipeline 26, and then transported to the cooler B9 through the cooler pipeline 27 via the waste alcohol pump outlet pipeline, where they are cooled to 40°C. The cooled impurities then enter the alcohol transfer tank 10 through the cooler to the alcohol transfer tank pipeline 28, and are finally transported to the hazardous waste treatment unit through the alcohol transfer tank material outlet pipeline 29.
[0044] After processing, the color of the recovered alcohol significantly decreased from 220 APHA to 25 APHA, and the purity increased from 70% to 96.5%, exceeding the production reuse standard. The butanol recovery rate was further improved to approximately 93%. Even with recovered alcohol of poor initial quality, this unit can still stably and efficiently provide high-quality recovered alcohol, demonstrating good adaptability and processing capacity.
Claims
1. A dibutyl phthalate recovery alcohol treatment apparatus characterized by comprising: It includes an alcohol storage tank (1), which is connected to a water distillation kettle (3) via an alcohol storage tank pump (2). The top of the water distillation kettle (3) is connected to a condenser (5) via a water distillation tower (4). The condenser (5) is connected to an alcohol-water separation tank (7) via a cooler A (6). The bottom of the water distillation kettle (3) is connected to a cooler B (9) via a water distillation kettle waste alcohol pump (8). The cooler B (9) is connected to the alcohol-spinning tank (10) via a cooler-to-alcohol-spinning-tank pipeline (28).
2. The dibutyl phthalate recovery alcohol treatment device according to claim 1, characterized in that, The alcohol storage tank (1) is connected to a recovery alcohol pipeline (12) from the self-distilled water alcohol-water separator, and the recovery alcohol pipeline (12) from the self-distilled water alcohol-water separator is connected to a recovery alcohol pipeline (11) from the esterification alcohol-water separator. An alcohol storage tank pump inlet pipeline (13) is provided between the alcohol storage tank (1) and the alcohol storage tank pump (2).
3. The dibutyl phthalate recovery alcohol treatment device according to claim 1, characterized in that, The alcohol storage tank pump (2) is connected to the water distillation kettle (3) by an outlet pipeline (14), the top of the water distillation kettle (3) is connected to the water distillation tower (4) by a steam pipeline (15), and the water distillation tower (4) is connected to the steam tower top (16).
4. The dibutyl phthalate recovery alcohol treatment device according to claim 1, characterized in that, The condenser (5) and cooler A (6) are connected by a liquid inlet cooler pipeline (18). The bottom of the water distillation tower (4) is connected to the water distillation kettle (3) via the water distillation tower bottom liquid return pipeline (17). The cooler A (6) and alcohol-water separator (7) are connected by a liquid inlet alcohol-water separator pipeline (20).
5. The dibutyl phthalate recovery alcohol treatment device according to claim 1, characterized in that, The condenser (5) and the alcohol-water separator (7) are connected by a non-condensable gas inlet pipeline (19), the top of the alcohol-water separator (7) is connected by an alcohol-water separator tail gas pipeline (24), the alcohol-water separator (7) is connected by a qualified alcohol pipeline (25), and the alcohol-water separator (7) is connected to the steam tower (4) through the alcohol-water separator alcohol to steam tower return pipeline (21).
6. The dibutyl phthalate recovery alcohol treatment device according to claim 4, characterized in that, The alcohol-discharging tank (10) is connected to a non-conforming material discharge pipeline (23). The liquid at the bottom of the distillation tower flows back to the distillation tower pipeline (17) and is connected to the non-conforming material discharge pipeline (23) through the water at the bottom of the alcohol-water separator to the distillation kettle pipeline (22). The alcohol-water separator (7) is connected to the water at the bottom of the alcohol-water separator to the distillation kettle pipeline (22) through a pipeline.
7. The dibutyl phthalate recovery alcohol treatment device according to claim 1, characterized in that, The steaming kettle (3) is connected to the steaming kettle waste alcohol pump (8) by an inlet pipeline (26), the steaming kettle waste alcohol pump (8) is connected to the cooler B (9) by an outlet pipeline (27), and the alcohol-spinning tank (10) is connected to the alcohol-spinning tank material outlet pipeline (29).