Solvent regeneration system

Abstract

The utility model relates to a solvent regeneration system which comprises a solvent regenerator, a distillation column, a solvent cooler and a vapor-liquid separation chamber, a solvent inlet is formed in the top of the solvent regenerator, a heating device is arranged in the solvent regenerator, the top of the solvent regenerator is communicated with the bottom of the distillation column, and filler and a nozzle are arranged in the distillation column; a vapor phase outlet of the distillation column is connected with a vapor phase inlet of a solvent cooler, a cooling device is arranged in the solvent cooler, the top of the solvent cooler is communicated with the bottom of a vapor-liquid separation chamber, and a non-condensed vapor outlet is formed in the top of the vapor-liquid separation chamber and connected with a vacuum vapor exhaust system; and a liquid phase outlet at the bottom of the solvent cooler is connected with a spray head in the distillation column and a regenerated solvent return pipeline. According to the utility model, the regeneration of solvents such as N-formylmorpholine and the like can be realized, the regeneration quality of the N-formylmorpholine solvent which is recycled in a production system is improved, and the extraction operation efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, in particular to a solvent regeneration system. Background Art

[0002] N-Formylmorpholine (NFM) has the advantages of good selectivity, good thermal and chemical stability, non-toxicity, and non-corrosiveness. It is an important solvent commonly used in processes such as extraction and distillation in the chemical industry. However, during long-term use, due to the influence of factors such as excessively high operating temperature and entrained moisture in the raw materials, N-Formylmorpholine itself will decompose a small amount. In addition, heavy components in the solute will also accumulate in N-Formylmorpholine. Therefore, after a period of operation, the extraction and distillation system using N-Formylmorpholine as a solvent usually needs to regenerate the solvent to remove the residue in the solvent, improve the purity of the solvent, and ensure the extraction effect.

[0003] The Chinese invention patent with the authorization announcement number CN 103980954 B discloses "a method for removing benzene hydrocarbons from coke oven gas", which uses an absorbent to absorb and purify benzene hydrocarbons in coke oven gas. The absorbent is a mixed solution of N-formylmorpholine and N-acetylmorpholine, and also includes a mixture of one or more of cyclopentane, water and morpholine as the main component; a mixture of one or more of dimethyl silicone oil, silicone oil oleic acid stearic acid, octylphenol polyoxyethylene ether and silicon dioxide as the auxiliary component; the specific process includes three steps of using an aromatic hydrocarbon capture and purification method, solvent recovery and regeneration: the aromatic hydrocarbon capture and purification method includes the following steps: the pretreated raw gas enters from the lower part of the absorption tower, the absorption solvent enters from the top of the tower and contacts with the gas to be purified in the absorption tower in countercurrent, and the pressure is 0.11MPa(A)-0.5M Pa(A), absorb benzene and naphthalene aromatic impurities in the gas under the conditions of temperature of 15℃-50℃, so as to purify the gas; the solvent recovery step is: use a vacuum distillation tower to treat the rich liquid after absorbing benzene hydrocarbons, the top pressure of the distillation tower is 0.01MPa(A)-0.05MPa(A), the bottom temperature is 160℃-210℃, the reflux ratio is 1-4, the top of the tower is produced benzene hydrocarbons and water, the bottom of the tower is produced after regeneration, that is, lean liquid I; the regeneration step is: extract part of the lean liquid I obtained from the recovery tower and send it to the regeneration tower for regeneration, the top pressure of the tower is 0.01MPa(A)-0.03MPa(A), the bottom temperature is 130-190℃, the reflux volume ratio is 0.1-2, the top of the tower is produced, that is, lean liquid II, and the bottom of the tower discharges waste materials. Summary of the invention

[0004] The utility model provides a solvent regeneration system, which can realize the regeneration of N-formylmorpholine, improve the regeneration quality of solvents such as N-formylmorpholine that are circulated in a production system, and improve the efficiency of extraction operations.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A solvent regeneration system comprises a solvent regenerator, a distillation column, a solvent cooler and a vapor-liquid separation chamber; a solvent inlet is arranged at the top of the solvent regenerator; a heating device is arranged inside the solvent regenerator, the top of the solvent regenerator is connected to the bottom of the distillation column, a filler is arranged inside the distillation column, and a nozzle is arranged above the filler; the vapor phase outlet at the top of the distillation column is connected to the vapor phase inlet at the top of the solvent cooler, a cooling device is arranged inside the solvent cooler, the top of the solvent cooler is connected to the bottom of the vapor-liquid separation chamber, a non-condensable steam outlet is arranged at the top of the vapor-liquid separation chamber and is connected to a vacuum exhaust system; the liquid phase outlet at the bottom of the solvent cooler is connected to the nozzle in the distillation column and a regenerated solvent return pipeline.

[0007] Furthermore, the main body of the solvent regenerator is a horizontal closed tank body, the solvent inlet is arranged at one end of the top of the solvent regenerator, and the residue outlet is arranged at the bottom of the other end of the solvent regenerator away from the solvent inlet.

[0008] Furthermore, the distillation column is of a tower structure, a support grid is provided in the distillation column, and the filler is supported by the support grid.

[0009] Furthermore, the heating device is a coil-type heat exchanger, one end of the coil-type heat exchanger is a heat medium inlet, and the other end is a heat medium outlet.

[0010] Furthermore, the cooling device is a shell-and-tube heat exchanger, one end of the shell-and-tube heat exchanger is a refrigerant inlet, and the other end is a refrigerant outlet.

[0011] Furthermore, the body of the solvent cooler is a horizontal closed tank.

[0012] Furthermore, the vapor-liquid separation chamber is of a tower structure, and a mist catching layer is provided on the top of the vapor-liquid separator below the non-condensable steam outlet.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] 1) The process flow of the solvent regeneration system of the utility model is simple, the number of equipment of the solvent regeneration system is small, and the investment cost is low;

[0015] 2) The process of the solvent regeneration system of the utility model does not involve water throughout the process, which effectively avoids the decomposition of N-formylmorpholine;

[0016] 3) A solvent cooler is provided downstream of the solvent regeneration system of the utility model, and the temperature of the regenerated N-formylmorpholine is low, so it can be directly returned to the extraction system for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a structural schematic diagram of a solvent regeneration system described in the utility model.

[0018] Figure 2 It is a structural schematic diagram of the distillation column of the utility model.

[0019] Figure 3 It is a structural schematic diagram of the vapor-liquid separation chamber at the top of the solvent cooler described in the utility model.

[0020] In the figure: 1. Solvent regenerator 2. Distillation column 21. Nozzle 22. Packing 23. Support grid 3. Solvent cooler 4. Vapor-liquid separation chamber 41. Mist capture layer 5. Heating device 6. Cooling device DETAILED DESCRIPTION

[0021] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings:

[0022] like Figure 1-Figure 3 As shown, a solvent regeneration system described in the utility model comprises a solvent regenerator 1, a distillation column 2, a solvent cooler 3 and a vapor-liquid separation chamber 4; a solvent inlet is arranged at the top of the solvent regenerator 1; a heating device 5 is arranged inside the solvent regenerator 1, the top of the solvent regenerator 1 is connected with the bottom of the distillation column 2, a packing 22 is arranged in the distillation column 2, and a nozzle 21 is arranged above the packing 22; the vapor phase outlet at the top of the distillation column 2 is connected to the vapor phase inlet at the top of the solvent cooler 3, a cooling device 6 is arranged in the solvent cooler 3, the top of the solvent cooler 3 is connected with the bottom of the vapor-liquid separation chamber 4, a non-condensable steam outlet is arranged at the top of the vapor-liquid separation chamber 4 and is connected to the vacuum exhaust system; the liquid phase outlet at the bottom of the solvent cooler 3 is connected to the nozzle 21 in the distillation column 2 and the regenerated solvent return pipeline.

[0023] Furthermore, the main body of the solvent regenerator 1 is a horizontal closed tank body, the solvent inlet is arranged at one end of the top of the solvent regenerator 1, and the solvent regenerator 1 is provided with a residue outlet at the bottom of the other end away from the solvent inlet.

[0024] Furthermore, the distillation column 2 is a tower structure, a support grid 23 is provided in the distillation column 2 , and the filler 22 is supported by the support grid 23 .

[0025] Furthermore, the heating device 5 is a coil-type heat exchanger, one end of the coil-type heat exchanger is a heat medium inlet, and the other end is a heat medium outlet.

[0026] Furthermore, the cooling device 6 is a shell-and-tube heat exchanger, one end of the shell-and-tube heat exchanger is a refrigerant inlet, and the other end is a refrigerant outlet.

[0027] Furthermore, the body of the solvent cooler 3 is a horizontal closed tank.

[0028] Furthermore, the vapor-liquid separation chamber 4 is a tower structure, and a mist catching layer 41 is provided on the top of the vapor-liquid separator 4 below the non-condensable steam outlet.

[0029] The process of a solvent regeneration system described in the utility model comprises: when the extraction and rectification system is in normal production, a small amount of recycled solvent is sent to the solvent regenerator 1, and the solvent includes N-formylmorpholine; after the solvent enters the solvent regenerator 1, the heating device 5 is continuously heated to vaporize the light components in the solvent and enter the distillation column 2 above; the vaporized light components are subjected to mass and heat transfer on the surface of the filler 22 with the regenerated solvent sprayed by the nozzle 21 after reflux, so as to further improve the purity of the light components; the heavy components in the solvent are deposited at the bottom of the solvent regenerator 1 and are intermittently discharged through the residue outlet; the vapor phase components at the top of the distillation column 2 enter the solvent cooler 3 through the pipeline, and indirectly exchange heat with the refrigerant in the cooling device 6, and the condensed liquid phase is mostly returned to the extraction and rectification system as the regenerated solvent for recycling, and a small part is refluxed into the nozzle 21 at the top of the distillation column 2 for spraying; the uncondensed vapor phase in the solvent cooler 3 enters the vapor-liquid separation chamber 4 above, and is further separated into vapor and liquid through the mist capture layer 41, and the non-condensed vapor is sent to the vacuum exhaust system.

[0030] Furthermore, the main process parameters include: the regenerator operating temperature is 190 to 220°C; the regenerator operating pressure is -0.1 to -0.086MPa; the vapor-liquid separation chamber top operating temperature is 120 to 150°C; the vapor-liquid separation chamber top operating pressure is -0.055 to -0.045MPa.

[0031] The following embodiments are implemented on the premise of the technical solution of the utility model, but the protection scope of the utility model is not limited to the following embodiments.

[0032] [Example]

[0033] In this embodiment, in a system using N-formylmorpholine as a solvent for extractive distillation separation, the solvent regeneration system of the utility model is applied, and the system uses steam as a heat medium to heat the regenerator. The main process parameters are as follows:

[0034] Regenerator operating temperature: 205℃

[0035] Regenerator operating pressure: -0.095MPa

[0036] Operating temperature at the top of the vapor-liquid separation chamber: 135°C

[0037] Operating pressure at the top of the vapor-liquid separation chamber: -0.05MPa

[0038] After the implementation, compared with before the implementation, the quality of N-formylmorpholine is improved, thereby ensuring the extraction and separation effect.

[0039] The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed by the present invention according to the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A solvent regeneration system, characterized in that: It comprises a solvent regenerator, a distillation column, a solvent cooler and a vapor-liquid separation chamber; a solvent inlet is arranged at the top of the solvent regenerator; a heating device is arranged inside the solvent regenerator, the top of the solvent regenerator is connected with the bottom of the distillation column, a filler is arranged inside the distillation column, and a nozzle is arranged above the filler; the vapor phase outlet at the top of the distillation column is connected with the vapor phase inlet at the top of the solvent cooler, a cooling device is arranged inside the solvent cooler, the top of the solvent cooler is connected with the bottom of the vapor-liquid separation chamber, a non-condensable steam outlet is arranged at the top of the vapor-liquid separation chamber and is connected with a vacuum exhaust system; the liquid phase outlet at the bottom of the solvent cooler is connected with the nozzle in the distillation column and a regenerated solvent return pipeline.

2. A solvent regeneration system according to claim 1, characterized in that: The main body of the solvent regenerator is a horizontal closed tank body, the solvent inlet is arranged at one end of the top of the solvent regenerator, and the bottom of the solvent regenerator is provided with a residue outlet at the other end away from the solvent inlet.

3. A solvent regeneration system according to claim 1, characterized in that: The distillation column is of a tower structure, a support grid is arranged inside the distillation column, and the filler is supported by the support grid.

4. A solvent regeneration system according to claim 1, characterized in that: The heating device is a coil heat exchanger, one end of the coil heat exchanger is a heat medium inlet, and the other end is a heat medium outlet.

5. A solvent regeneration system according to claim 1, characterized in that: The cooling device is a shell-and-tube heat exchanger, one end of which is a refrigerant inlet and the other end is a refrigerant outlet.

6. A solvent regeneration system according to claim 1, characterized in that: The main body of the solvent cooler is a horizontal closed tank.

7. A solvent regeneration system according to claim 1, characterized in that: The vapor-liquid separation chamber is a tower structure, and a mist catching layer is arranged on the top of the vapor-liquid separator below the non-condensable steam outlet.

Images