A solvent regeneration system for a benzene hydrogenation extractive distillation process

Abstract

The utility model discloses a kind of solvent regeneration systems of benzene hydrogenation extraction distillation process, including regenerator and regeneration tower, regenerator is separated into filter cavity, impurity removal cavity and distillation cavity by riser, filter cavity is provided with filter cartridge, filter cartridge is blocked at one end, and the other end is communicated with impurity removal cavity, heating pipe that is communicated with each other is provided in impurity removal cavity and distillation cavity, the upper portion of riser between impurity removal cavity and distillation cavity is provided with communicating pipe, the lower end of regeneration tower is communicated with the top of distillation cavity, packing, spraying mechanism, transverse plate and condenser are sequentially provided in regeneration tower from bottom to top, the gas inlet of condenser is communicated with spraying mechanism by ascending pipe on the sidewall of regeneration tower between spraying mechanism and transverse plate, the condensate outlet of condenser is communicated with spraying mechanism by reflux tube, the top of filter cavity is provided with liquid inlet, the top of impurity removal cavity is provided with exhaust port, the bottom of distillation cavity is provided with residue discharge port. In conclusion, the utility model has the advantages of compact structure, lower energy consumption and high regeneration efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of solvent regeneration systems for extraction and distillation processes, specifically to a solvent regeneration system for a benzene hydrogenation extraction and distillation process. Background Technology

[0002] In the benzene hydrogenation process, the extractive distillation column works by using a selective solvent to alter the relative volatility of the components in the mixture, thereby achieving efficient separation of benzene from cyclohexane and non-aromatic hydrocarbons. The core principle is to change the gas-liquid equilibrium of benzene and cyclohexane by adding a high-boiling-point, polar solvent. The volatility of cyclohexane increases, making it easier to enter the gas phase, while benzene remains more readily in the liquid phase. Ultimately, high-purity cyclohexane and a small amount of light components are obtained at the top of the column, while a mixture of benzene and the solvent is obtained at the bottom. As the unit operates, high-boiling-point substances in the feedstock accumulate in the solvent, and the solvent may undergo thermal decomposition or oxidation under prolonged high-temperature operation. Furthermore, increased moisture content reduces solvent selectivity. Therefore, to maintain solvent activity and purity, extend solvent lifespan, and reduce operating costs, a solvent regeneration system is necessary to regenerate the solvent.

[0003] Existing solvent regeneration systems used in benzene hydroextraction distillation processes require filtration, stripping, distillation, and condensation equipment. Multiple sets of equipment operate simultaneously, sequentially performing filtration, stripping, distillation, and condensation operations on the solvent. This results in a large number of devices, a large footprint, and significant time and energy consumption for solvent transfer between devices, leading to heat loss and waste. Consequently, solvent regeneration is energy-intensive and inefficient. Furthermore, the stripping and distillation processes consume substantial amounts of heat, further increasing energy consumption. Therefore, developing a compact, energy-efficient, and highly efficient solvent regeneration system for benzene hydroextraction distillation processes is essential. Utility Model Content

[0004] The purpose of this invention is to provide a solvent regeneration system for a benzene hydrogenation extraction distillation process that is compact in structure, consumes less energy, and has high regeneration efficiency.

[0005] The purpose of this utility model is achieved as follows: it includes a regeneration tank and a regeneration tower. The regeneration tank is divided into a filtration chamber, a purification chamber, and a distillation chamber by a vertical plate. A filter cartridge is installed in the filtration chamber, with one end of the cartridge sealed and the other end connected to the purification chamber. Heating pipes are installed in the purification chamber and the distillation chamber. A connecting pipe is installed at the upper part of the vertical plate between the purification chamber and the distillation chamber. The lower end of the regeneration tower is connected to the top of the distillation chamber. The regeneration tower is equipped with packing, a spray mechanism, a horizontal plate, and a condenser in sequence from bottom to top. The side wall of the regeneration tower between the spray mechanism and the horizontal plate is connected to the gas inlet of the condenser through a riser pipe. The condensate outlet of the condenser is connected to the spray mechanism through a reflux pipe. A liquid inlet is installed at the top of the filtration chamber, an exhaust port is installed at the top of the purification chamber, and a slag discharge port is installed at the bottom of the distillation chamber.

[0006] Furthermore, a jacket is provided on the outer wall of the regeneration tank in the filter chamber, and the outlet of the heating pipe in the impurity removal chamber is connected to the inlet of the jacket through a conveying pipe.

[0007] Furthermore, a motor is installed on the regeneration tank. The output shaft of the motor extends into the filter chamber and is connected to the sealing end of the filter cartridge. The open end of the filter cartridge is rotatably connected to the vertical plate.

[0008] Furthermore, a scraper is provided inside the filter chamber, with one end of the scraper fixed to the inner wall of the filter chamber and the side of the scraper in contact with the filter cartridge.

[0009] Furthermore, a stirrer is installed in the impurity removal chamber and the distillation chamber.

[0010] Furthermore, the condensate outlet is connected to a purification device, which contains activated carbon and molecular sieves arranged sequentially from bottom to top. The condensate outlet is connected to the bottom of the purification device, and the top of the purification device is equipped with a discharge outlet.

[0011] Furthermore, the end of the connecting tube extends into the distillation chamber and then bends downwards.

[0012] This invention relates to the regeneration of solvent in the benzene hydrogenation extraction distillation process. During operation, the solvent discharged from the benzene hydrogenation extraction distillation process is fed into the filtration chamber through the inlet. After passing through the filter cylinder, impurities such as particles and colloids in the solvent are filtered out. Then, the solvent flows into the impurity removal chamber from the filter cylinder. The heating tube heats the solvent in the impurity removal chamber, and unreacted light components such as benzene, cyclohexane, and water in the solvent vaporize and separate from the solvent. The remaining solvent flows into the distillation chamber through the connecting pipe. The heating tube heats the solvent in the distillation chamber, and the solvent evaporates and enters the regeneration tower. Heavy components such as polymers and heavy aromatics are deposited in the distillation chamber. The solvent continues to rise into the packing material, where it undergoes mass and heat transfer with the regenerated solvent flowing downward from the spray mechanism, further improving the purity of the regenerated solvent. Finally, it enters the condenser through the riser pipe, where it exchanges heat with the cooling medium introduced into the condenser. After condensation, the solvent is discharged from the condensate outlet. Part of the regenerated solvent enters the spray mechanism through the return pipe, and the remaining regenerated solvent is sent to the storage device or returned to the benzene hydrogenation extraction distillation process for recycling as needed. In this invention, filtration, stripping, distillation, and condensation equipment are integrated into a single, compact structure, significantly reducing the footprint and construction costs. Secondly, the solvent regeneration process is simple, with a short transport path, eliminating the need for extensive pipelines and minimizing transfer time. No additional pumps or other power equipment are required; the solvent can flow freely between the filtration, purification, and distillation chambers, resulting in short processing time, low energy consumption, and minimal heat loss, thus reducing energy consumption and improving regeneration efficiency. Furthermore, the heating tubes in the purification and distillation chambers are interconnected. The purification chamber vaporizes light components in the solvent, while the distillation chamber separates heavy components. Utilizing the higher heating temperature in the distillation chamber compared to the purification chamber, the heating medium is first introduced into the distillation chamber, and after a slight temperature drop, it is introduced into the purification chamber. This satisfies the heating requirements of both chambers while fully utilizing the heat in the heating medium, improving heat utilization and reducing heat consumption. In summary, this utility model has the advantages of compact structure, low energy consumption, and high regeneration efficiency. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram: 1-Regeneration tank, 2-Regeneration tower, 3-Filter chamber, 4-Impurity removal chamber, 5-Distillation chamber, 6-Filter cartridge, 7-Heating pipe, 8-Connecting pipe, 9-Packaging material, 10-Spraying mechanism, 11-Condenser, 12-Rising pipe, 13-Reflux pipe, 14-Jacket, 15-Conveying pipe, 16-Scraper, 17-Agitator, 18-Purification device, 19-Activated carbon, 20-Molecular sieve. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.

[0015] like Figure 1 As shown, this utility model includes a regeneration tank 1 and a regeneration tower 2. The regeneration tank 1 is divided into a filtration chamber 3, a purification chamber 4, and a distillation chamber 5 by a vertical plate. A filter cartridge 6 is installed in the filtration chamber 3. Particles and other impurities are trapped outside by the filter holes on the filter cartridge 6. The filtered solvent passes through the filter holes and enters the filter cartridge 6. One end of the filter cartridge 6 is sealed, and the other end is connected to the purification chamber 4. Heating tubes 7 are installed in the purification chamber 4 and the distillation chamber 5. The specific structure and form of the heating tubes 7 can be determined according to the actual situation, and can be serpentine, spiral, etc. A heating tube is installed on the upper part of the vertical plate between the purification chamber 4 and the distillation chamber 5. The lower end of the regeneration tower 2 is connected to the top of the distillation chamber 5 via the connecting pipe 8. The regeneration tower 2 is equipped with packing 9, spray mechanism 10, horizontal plate and condenser 11 from bottom to top. The condenser 11 is an existing condensation structure used to condense the solvent. The side wall of the regeneration tower 2 between the spray mechanism 10 and the horizontal plate is connected to the gas inlet of the condenser 11 via the riser pipe 12. The condensate outlet of the condenser 11 is connected to the spray mechanism 10 via the return pipe 13. The top of the filter chamber 3 is provided with a liquid inlet. The top of the impurity removal chamber 4 is provided with an exhaust port. The bottom of the distillation chamber 5 is provided with a slag discharge port.

[0016] This invention is used for solvent regeneration in the benzene hydrogenation extraction distillation process. During operation, the solvent discharged from the benzene hydrogenation extraction distillation process is fed into the filter chamber 3 through the inlet. After passing through the filter cylinder 6, impurities such as particles and colloids in the solvent are filtered out. Then, the solvent flows into the impurity removal chamber 4 from the filter cylinder 6. The heating tube 7 heats the solvent in the impurity removal chamber 4, and unreacted light components such as benzene, cyclohexane, and water in the solvent vaporize and separate from the solvent. The remaining solvent flows into the distillation chamber 5 through the connecting tube 8. The heating tube 7 heats the solvent in the distillation chamber 5, and the solvent evaporates and enters the regeneration chamber. In the distillation tower 2, heavy components such as polymers and heavy aromatics are deposited in the distillation chamber 5. The solvent continues to rise into the packing 9, where it exchanges mass and heat with the regenerated solvent flowing downward from the spray mechanism 10, further improving the purity of the regenerated solvent. Finally, it enters the condenser 11 from the riser pipe 12, where it exchanges heat with the cooling medium introduced into the condenser 11. After the solvent condenses, it is discharged from the condensate outlet. Part of the regenerated solvent enters the spray mechanism 10 through the return pipe 13, and the remaining regenerated solvent is sent to the storage device or returned to the benzene hydrogenation extraction distillation process for recycling as needed.

[0017] In this invention, filtration equipment, stripping equipment, distillation equipment, and condensation equipment are integrated into a single, compact structure, significantly reducing the floor space and construction costs. Secondly, the solvent regeneration process in this invention is simple, with a short solvent transport path, eliminating the need for extensive pipeline construction. Solvent transfer is time-efficient and eliminates the need for pumps or other power equipment. The solvent can flow freely between the filtration chamber 3, the impurity removal chamber 4, and the distillation chamber 5, resulting in short processing time, low energy consumption, and minimal heat loss, thereby reducing energy consumption for solvent regeneration and improving solvent efficiency. The regeneration efficiency of the solvent is improved. In addition, in this invention, the heating tubes 7 in the impurity removal chamber 4 and the distillation chamber 5 are interconnected. The impurity removal chamber 4 is used to vaporize the light components in the solvent, and the distillation chamber 5 is used to separate the heavy components in the solvent. Taking advantage of the fact that the heating temperature in the distillation chamber 5 is higher than that in the impurity removal chamber 4, the heating medium is first introduced into the heating tube 7 in the distillation chamber 5. After the temperature drops, it is introduced into the heating tube 7 in the impurity removal chamber 4. This satisfies the heating requirements of the impurity removal chamber 4 and the distillation chamber 5, and makes full use of the heat in the heating medium, thereby improving the heat utilization rate and reducing the heat consumption.

[0018] A jacket 14 is provided on the outer wall of the regeneration tank 1 in the filter chamber 3. The outlet of the heating pipe 7 in the impurity removal chamber 4 is connected to the inlet of the jacket 14 through the conveying pipe 15. The heating medium first enters the heating pipe 7 in the distillation chamber 5 and then enters the heating pipe 7 in the impurity removal chamber 4. When discharged, the heating medium still contains a certain amount of heat. Passing it into the jacket 14 can heat the solvent in the filter chamber 3, thereby achieving the purpose of solvent preheating and improving the efficiency of subsequent solvent heating and impurity removal.

[0019] The regeneration tank 1 is equipped with a motor. The output shaft of the motor extends into the filter chamber 3 and is connected to the sealing end of the filter cartridge 6. The open end of the filter cartridge 6 is rotatably connected to the vertical plate. During operation, the motor drives the filter cartridge 6 to rotate, thereby throwing out the impurities adhering to the filter cartridge 6, thus improving the solvent filtration efficiency.

[0020] A scraper 16 is provided inside the filter chamber 3. One end of the scraper 16 is fixed to the inner wall of the filter chamber 3, and the side of the scraper 16 is in contact with the filter cartridge 6. In actual use, a large number of particulate impurities will adhere to the filter cartridge 6, thereby reducing the filtration efficiency of the solvent. The scraper 16 is provided for this purpose. When the filter cartridge 6 rotates, the scraper 16 will scrape off the impurities adhering to the filter cartridge 6, thereby ensuring the filtration efficiency of the filter cartridge 6.

[0021] A stirrer 17 is installed in the impurity removal chamber 4 and the distillation chamber 5. The stirrer 17 is an existing device used to agitate the solvent, so that the solvent is in a continuous flow state, thereby improving the uniformity of heating the solvent by the heating tube 7.

[0022] The condensate outlet is connected to a purification device 18. Activated carbon 19 and molecular sieve 20 are arranged sequentially from bottom to top inside the purification device 18. The condensate outlet is connected to the bottom of the purification device 18, and a discharge outlet is provided at the top of the purification device 18. Activated carbon 19 can remove impurities such as pigments, heavy metals, odors, particulate matter, colloids, and suspended solids from the solvent. Molecular sieve 20 has a strong affinity for water, and water in the solvent can be removed by passing through molecular sieve 20. Various impurities in the solvent can be removed by passing through activated carbon 19 and molecular sieve 20, thereby improving the purity of the solvent.

[0023] The end of the connecting pipe 8 extends into the distillation chamber 5 and then bends downward. When this invention is in operation, the solvent is heated in the impurity removal chamber 4, and the light components therein vaporize and separate out. In actual operation, the light components in the impurity removal chamber 4 will enter the distillation chamber 5 through the connecting pipe 8 and mix into the solvent vapor, thereby reducing the purity of the solvent. In order to prevent this problem, the connecting pipe 8 with its end bent downward is provided. In actual use, the lower end of the connecting pipe 8 extends into the solvent, thereby preventing the gaseous light components from entering the distillation chamber 5 from the connecting pipe 8 and ensuring the purity of the solvent.

[0024] In order to completely drain the solvent in the filtration chamber 3 and the impurity removal chamber 4, a drain pipe can be installed at the bottom of the vertical plate, and a slag discharge pipe can be installed at the bottom of the distillation chamber 5 to discharge the precipitated impurities.

Claims

1. A solvent regeneration system for a benzene hydrogenation extraction distillation process, comprising a regeneration tank (1) and a regeneration tower (2), characterized in that: The regeneration tank (1) is divided into a filtration chamber (3), a purification chamber (4), and a distillation chamber (5) by a vertical plate. A filter cartridge (6) is installed in the filtration chamber (3), with one end of the filter cartridge (6) sealed and the other end connected to the purification chamber (4). Heating pipes (7) are installed in the purification chamber (4) and the distillation chamber (5) and are connected to each other. A connecting pipe (8) is installed on the upper part of the vertical plate between the purification chamber (4) and the distillation chamber (5). The lower end of the regeneration tower (2) is connected to the top of the distillation chamber (5). The following components are arranged sequentially from bottom to top: packing (9), spray mechanism (10), horizontal plate and condenser (11). The side wall of the regeneration tower (2) between the spray mechanism (10) and the horizontal plate is connected to the gas inlet of the condenser (11) through the riser pipe (12). The condensate outlet of the condenser (11) is connected to the spray mechanism (10) through the return pipe (13). The top of the filter chamber (3) is provided with a liquid inlet, the top of the impurity removal chamber (4) is provided with an exhaust port, and the bottom of the distillation chamber (5) is provided with a slag discharge port.

2. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 1, characterized in that: A jacket (14) is provided on the outer wall of the regeneration tank (1) in the filter chamber (3). The outlet of the heating pipe (7) in the impurity removal chamber (4) is connected to the inlet of the jacket (14) through the conveying pipe (15).

3. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 1, characterized in that: The regeneration tank (1) is equipped with a motor. The output shaft of the motor extends into the filter chamber (3) and is connected to the sealing end of the filter cylinder (6). The open end of the filter cylinder (6) is rotatably connected to the vertical plate.

4. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 3, characterized in that: A scraper (16) is provided inside the filter chamber (3). One end of the scraper (16) is fixed on the inner wall of the filter chamber (3), and the side of the scraper (16) is in contact with the filter cylinder (6).

5. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 1, characterized in that: A stirrer (17) is provided in the impurity removal chamber (4) and the distillation chamber (5).

6. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 1, characterized in that: The condensate outlet is connected to a purification device (18). Activated carbon (19) and molecular sieve (20) are arranged sequentially from bottom to top inside the purification device (18). The condensate outlet is connected to the bottom of the purification device (18), and the top of the purification device (18) is provided with a discharge port.

7. The solvent regeneration system for a benzene hydrogenation extraction distillation process according to claim 1, characterized in that: The end of the connecting tube (8) extends into the distillation chamber (5) and then bends downward.

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