Recycling process of waste organic solvent containing dimethyl sulfoxide

Abstract

The disclosed dimethyl sulfoxide-containing waste organic solvent recycling process comprises the following steps: S1, feeding a waste organic solvent into a pretreatment tower, controlling the operation pressure of the tower to be 2-3.2 kPaA, extracting water from the tower top at the extraction temperature of 24-26 DEG C, extracting a semi-finished product containing N-methyl pyrrolidone from the tower kettle, and feeding a side line discharged material of the pretreatment tower into a heat pump rectifying tower; s2, the operation pressure of the heat pump rectifying tower is controlled to be 3-3.5 kPaA, a water-containing dimethyl sulfoxide solution is discharged in a gas phase mode at the tower top and then compressed by a compressor to do work, the acting power of the compressor is controlled to be 190-210 kW, the water-containing dimethyl sulfoxide solution enters a heat exchanger to release heat after acting, and finally the water-containing dimethyl sulfoxide solution serves as a semi-finished product to be extracted; s3, materials discharged from the tower kettle of the heat pump rectifying tower enter a heat exchanger to absorb heat and then are pumped into the heat pump rectifying tower again; and a qualified dimethyl sulfoxide product is extracted from the tower kettle and enters a product tank. The recycling process can effectively solve the problem of decomposition of dimethyl sulfoxide due to improper treatment aiming at the waste organic solvent in the field of electronic chips, and meanwhile, the process has the benefits of energy conservation and emission reduction.

Description

Technical Field

[0001] The present invention belongs to the field of waste liquid separation, purification and disposal, and particularly relates to a recycling process for waste organic solvents containing dimethyl sulfoxide in the field of electronic chips. Background Art

[0002] Dimethyl sulfoxide, also known as DMSO, is an organic solvent with a wide range of uses, commonly used in fields such as chemical industry, medicine, pesticides, fertilizers, and electronic chips; in the pharmaceutical and medical fields, dimethyl sulfoxide can be used as a raw material and carrier for certain drugs, in the pesticide field, dimethyl sulfoxide can be used as an additive and synergist for pesticides, and in the fertilizer field, dimethyl sulfoxide can be used as a solvent, penetrant, and synergist in fertilizer aqueous solutions.

[0003] In the field of electronic chips, dimethyl sulfoxide is usually used as a cleaning agent and is widely used in the cleaning of electronic components and integrated circuits. It has the function of removing organic substances, inorganic substances, and polymers at one time. Therefore, a large amount of waste organic solvents containing dimethyl sulfoxide will be generated in the electronic chip industry.

[0004] At present, there is no efficient process in China for recycling waste organic solvents containing dimethyl sulfoxide in the field of electronic chips. The recycling methods of dimethyl sulfoxide mentioned in patents such as "Dimethyl Sulfoxide Recovery Device and Method" (CN116020150A), "Method for Recycling and Purifying Dimethyl Sulfoxide in Carbon Fiber Spinning Solid Waste" (CN117658873A), and "Method for Recycling Dimethyl Sulfoxide from Polyacrylonitrile Waste Slurry" (CN117658874A) all have chemical waste liquid as the source of the waste liquid. Compared with the waste organic solvents generated in the field of electronic chips, their component compositions are different. Therefore, these existing recycling technologies for dimethyl sulfoxide are not suitable for the waste organic solvents generated in the field of electronic chips. This is mainly because the waste organic solvents generated in the field of electronic chips contain N-methylpyrrolidone (NMP), whose boiling point is higher than that of dimethyl sulfoxide. Improper disposal will cause dimethyl sulfoxide to decompose when heated, resulting in serious environmental impacts and safety risks. Summary of the Invention

[0005] In response to the content described in the background art, the present application provides a recycling process for waste organic solvents containing dimethyl sulfoxide, which can be adapted to the waste organic solvents in the field of electronic chips, effectively solve the problem of dimethyl sulfoxide decomposition due to improper disposal, and at the same time, the recycling process has the benefits of energy conservation and emission reduction.

[0006] A disclosed recycling process for waste organic solvents containing dimethyl sulfoxide includes the following steps:

[0007] S1. Feed the waste organic solvent containing water, dimethyl sulfoxide and N-methylpyrrolidone into the pretreatment column (T0101), i.e., line F1 in the figure. Control the feed rate at 1300 - 1600 kg / h, and control the operating pressure of the pretreatment column (T0101) at 2 - 3.2 kPaA (absolute pressure);

[0008] Water is taken out from the top of the pretreatment column (T0101) and sent to the water treatment station, i.e., line D1 in the figure. Control the top product withdrawal temperature at 24 - 26 °C and the top product withdrawal flow rate at 42 - 87 kg / h. Under such a process, the concentration of the wastewater withdrawn from the top can reach 99.96 wt%;

[0009] The semi-finished product containing N-methylpyrrolidone is taken out from the bottom of the pretreatment column (T0101), i.e., line W1 in the figure. Control the bottom product withdrawal amount at 871 - 1205 kg / h. The content of dimethyl sulfoxide and N-methylpyrrolidone in this semi-finished product can be collected and then subjected to post-treatment for separating and extracting dimethyl sulfoxide products and N-methylpyrrolidone products;

[0010] The side stream discharge (containing dimethyl sulfoxide and a small amount of water) of the pretreatment column (T0101) enters the heat pump distillation column (T0201), i.e., line D2 in the figure. Control the side stream discharge flow rate at 325 - 350 kg / h. Most of the side stream discharge is dimethyl sulfoxide and contains a small amount of water, and the rest is trace amounts of N-methylpyrrolidone and other impurities;

[0011] S2. Control the operating pressure of the heat pump distillation column (T0201) at 3 - 3.5 kPaA (absolute pressure). After the dimethyl sulfoxide solution containing water is discharged as a gas from the top of the heat pump distillation column (T0201), it is compressed by the compressor (C0201) to do work, i.e., line D3 in the figure, so that its pressure and boiling point both increase significantly. Control the work power of the compressor (C0201) at 190 - 210 kW. After being compressed by the compressor (C0201), it enters the shell side of the heat exchanger (E0201) to release heat, serving as the heat source for the distillation of the heat pump distillation column (T0201), i.e., line D4 in the figure. Finally, it is taken out as a semi-finished product at 100 - 125 kg / h, i.e., line D5 in the figure. The water and dimethyl sulfoxide contained in this semi-finished product can be re-entered into this system for purification treatment according to the process of this application;

[0012] S3. The bottom discharge of the heat pump distillation column (T0201) enters the tube side of the heat exchanger (E0201) to absorb heat and then is pumped back into the heat pump distillation column (T0201), i.e., line W3 in the figure;

[0013] The qualified dimethyl sulfoxide product is withdrawn from the bottom of the heat pump distillation column (T0201) and enters the product tank, i.e., line W2 in the figure. The flow rate of the bottom product withdrawal is controlled at 200 - 250 kg / h, and the dimethyl sulfoxide purity content can reach over 99.85 wt%.

[0014] Preferably, the pretreatment column (T0101) is a packed distillation column, with a total of 60 trays, an effective packing layer of 16 meters, and the side line outlet is 5 meters below the top packing;

[0015] The heat pump distillation column (T0201) is also a packed distillation column, with a total of 10 trays and an effective packing layer of 6 meters.

[0016] Furthermore, due to certain variations in the concentrations of water, dimethyl sulfoxide, and N - methylpyrrolidone in the waste organic solvent, it is necessary to control the operating reflux ratio of the pretreatment column (T0101). The side line discharge of the pretreatment column (T0101) is refluxed, and the reflux ratio is controlled at 5 - 10 to ensure that the water content in the side line discharge can be reduced to below 3 wt%.

[0017] Furthermore, the side line discharge of the pretreatment column (T0101) also passes through an intermediate buffer tank (V0101), i.e., an intermediate buffer tank (V0101) is set on line D2; due to the above reflux operation, the flow rate of the side line discharge of the pretreatment column (T0101) will also fluctuate. To ensure the stability of its flow rate entering the heat pump distillation column (T0201), this intermediate buffer tank (V0101) is added to collect the dimethyl sulfoxide solvent containing water.

[0018] Through the above technical solutions, the present invention has at least the following beneficial effects:

[0019] The recycling process described in the present application can separate and purify the waste organic solvent containing dimethyl sulfoxide in the field of electronic chips, realizing the reduction and resource utilization of the waste liquid, turning waste into treasure, and achieving the effective utilization of resources.

[0020] In the pretreatment column, N - methylpyrrolidone is separated from the waste organic solvent by means of negative pressure and low temperature, which can avoid the decomposition of dimethyl sulfoxide at the top of the column due to excessive temperature; in the heat pump distillation system composed of the heat pump distillation column, compressor, and heat exchanger, heat exchange is carried out between the overhead material and the bottom material, and heat is supplemented by the work of the compressor. Compared with the reboiler heating of the traditional distillation column system, it can effectively avoid the local instantaneous overheating of dimethyl sulfoxide in the material in the reboiler and decomposition.

[0021] Moreover, the heat pump distillation system in the process of this application can take into account the effective utilization of the energy at the top of the column, omits the condenser and reboiler of the traditional distillation column system, reduces the equipment cost and operation energy consumption of the overall process, and creates better economic benefits while saving energy and reducing emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic flow chart of a process for recycling waste organic solvents containing dimethyl sulfoxide described in the embodiments of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Next, the process of the present invention will be clearly and completely described with reference to the accompanying drawings through specific actual cases, and the application of the present invention is not limited to the examples given.

[0024] Example 1

[0025] A process for recycling waste organic solvents containing dimethyl sulfoxide includes the following steps:

[0026] S1. Feed the waste organic solvent containing 5 wt% water, 50 wt% dimethyl sulfoxide and 45 wt% N-methylpyrrolidone into the pretreatment column (T0101), i.e., line F1 in the figure, with the feed rate controlled at 1500 kg / h. The pretreatment column (T0101) is a packed distillation column with a total of 60 trays and an effective packing layer of 16 meters. Control the operating pressure of the pretreatment column (T0101) at 2.6 kPaA (absolute pressure);

[0027] Water is taken out from the top of the pretreatment column (T0101) to the water treatment station, i.e., line D1 in the figure. Control the top product withdrawal temperature at 25 °C and the top product withdrawal flow rate at 62 kg / h. Under such a process, the concentration of the wastewater withdrawn from the top can reach 99.96 wt%;

[0028] The semi-finished product containing N-methylpyrrolidone is taken out from the bottom of the pretreatment column (T0101), i.e., line W1 in the figure. The bottom product withdrawal amount is controlled at 1113 kg / h. This semi-finished product contains 40 wt% dimethyl sulfoxide and 60 wt% N-methylpyrrolidone. After collection, it can be further processed and disposed of to separate and extract dimethyl sulfoxide products and N-methylpyrrolidone products;

[0029] The side stream discharge (containing dimethyl sulfoxide and trace amounts of water) from the pretreatment column (T0101) enters the heat pump distillation column (T0201), i.e., line D2 in the figure. The side stream outlet is located 5 meters below the top packing of the pretreatment column (T0101). The flow rate of the side stream discharge is controlled at 325 kg / h. Since the concentrations of water, dimethyl sulfoxide, and N-methylpyrrolidone in the waste organic solvent vary to some extent, it is necessary to control the operating reflux ratio of the pretreatment column (T0101). The side stream discharge from the pretreatment column (T0101) is refluxed, and the reflux ratio is controlled at 8 to ensure that the water content in the side stream discharge can be reduced to less than 3 wt%. In this embodiment, the side stream discharge contains 2.7 wt% water and 96.8 wt% dimethyl sulfoxide, and the rest is N-methylpyrrolidone and other impurities;

[0030] In this specific embodiment, the side stream discharge from the pretreatment column (T0101) also passes through an intermediate buffer tank (V0101), i.e., an intermediate buffer tank (V0101) is provided on line D2. Due to the above reflux operation, the flow rate of the side stream discharge from the pretreatment column (T0101) will also fluctuate. To ensure the stability of its flow rate into the heat pump distillation column (T0201), this intermediate buffer tank (V0101) is added to collect the dimethyl sulfoxide solvent containing water.

[0031] S2. The heat pump distillation column (T0201) is also a packed distillation column, with a total of 10 trays and an effective packing height of 6 meters. The operating pressure of the heat pump distillation column (T0201) is controlled at 3.3 kPaA (absolute pressure). After the dimethyl sulfoxide solution containing water exits as a gas from the top of the heat pump distillation column (T0201), it is compressed by a compressor (C0201) to do work, i.e., line D3 in the figure, which significantly increases its pressure and boiling point. The work power of the compressor (C0201) is controlled at 200 kW. After being compressed by the compressor (C0201), it enters the shell side of the heat exchanger (E0201) to release heat, serving as the heat source for the distillation of the heat pump distillation column (T0201), i.e., line D4 in the figure. Finally, it is withdrawn as a semi-finished product at a flow rate of 125 kg / h, i.e., line D5 in the figure. This semi-finished product contains 12.9 wt% water and 87.1 wt% dimethyl sulfoxide and can be re-entered into this system for purification treatment according to the process of this application;

[0032] S3. The bottom discharge of the heat pump distillation column (T0201) enters the tube side of the heat exchanger (E0201) to absorb heat and then is pumped back into the heat pump distillation column (T0201), i.e., line W3 in the figure;

[0033] Qualified dimethyl sulfoxide products are withdrawn from the bottom of the heat pump distillation column (T0201) and enter the product tank, i.e., line W2 in the figure. The bottom product withdrawal flow rate is controlled at 200 kg / h, and its dimethyl sulfoxide purity can reach 99.85 wt%.

[0034] Example 2

[0035] A process for recycling waste organic solvents containing dimethyl sulfoxide includes the following steps:

[0036] S1. Feed the waste organic solvent containing 8 wt% water, 58 wt% dimethyl sulfoxide and 34 wt% N-methylpyrrolidone into the pretreatment column (T0101), i.e., line F1 in the figure, with the feed rate controlled at 1300 kg / h. The pretreatment column (T0101) is a packed distillation column with a total of 60 trays and an effective packing height of 16 meters. Control the operating pressure of the pretreatment column (T0101) at 3.2 kPaA (absolute pressure);

[0037] Water is taken out from the top of the pretreatment column (T0101) to the water treatment station, i.e., line D1 in the figure. Control the top product withdrawal temperature at 26 °C and the top product withdrawal flow rate at 87 kg / h. Under such a process, the concentration of the wastewater withdrawn from the top can reach 99.96 wt%;

[0038] The semi-finished product containing N-methylpyrrolidone is taken out from the bottom of the pretreatment column (T0101), i.e., line W1 in the figure. The bottom product withdrawal amount is controlled at 871 kg / h. The semi-finished product contains 49.7 wt% dimethyl sulfoxide and 50.3 wt% N-methylpyrrolidone. After collection, it can be further processed and disposed of to separate and extract dimethyl sulfoxide products and N-methylpyrrolidone products;

[0039] The side stream (containing dimethyl sulfoxide and a small amount of water) of the pretreatment column (T0101) enters the heat pump distillation column (T0201), i.e., line D2 in the figure. The side stream outlet is 5 meters below the top packing of the pretreatment column (T0101). Control the side stream flow rate at 340 kg / h. Due to certain changes in the concentrations of water, dimethyl sulfoxide and N-methylpyrrolidone in the waste organic solvent, it is necessary to control the operating reflux ratio of the pretreatment column (T0101). The side stream of the pretreatment column (T0101) is refluxed, and the reflux ratio is controlled at 10 to ensure that the water content in the side stream can be reduced to less than 3 wt%. In this example, the side stream contains 3 wt% water and 96.5 wt% dimethyl sulfoxide, and the rest is N-methylpyrrolidone and other impurities;

[0040] In this specific example, the side stream of the pretreatment column (T0101) also passes through an intermediate buffer tank (V0101), i.e., an intermediate buffer tank (V0101) is set on line D2; due to the above reflux operation, the flow rate of the side stream of the pretreatment column (T0101) will also fluctuate. To ensure the stability of its flow rate into the heat pump distillation column (T0201), this intermediate buffer tank (V0101) is added to collect the dimethyl sulfoxide solvent containing water.

[0041] S2. The heat pump distillation column (T0201) is also a packed distillation column, with a total of 10 trays. The effective packing height is 6 meters. The operating pressure of the heat pump distillation column (T0201) is controlled at 3 kPaA (absolute pressure). After the dimethyl sulfoxide solution containing water is discharged in the gas phase from the top of the heat pump distillation column (T0201), it is compressed by the compressor (C0201) to do work, i.e., line D3 in the figure, so that its pressure and boiling point both increase significantly. The work power of the compressor (C0201) is controlled at 210 kW. After being compressed by the compressor (C0201), it enters the shell side of the heat exchanger (E0201) to release heat, serving as the heat source for the rectification of the heat pump distillation column (T0201), i.e., line D4 in the figure. Finally, it is withdrawn as a semi-finished product at 118 kg / h, i.e., line D5 in the figure. This semi-finished product contains 16.9 wt% water and 83.1 wt% dimethyl sulfoxide, and can enter this system again for purification treatment according to the process of this application;

[0042] S3. The bottom discharge of the heat pump distillation column (T0201) enters the tube side of the heat exchanger (E0201) to absorb heat and then is pumped back into the heat pump distillation column (T0201), i.e., line W3 in the figure;

[0043] Qualified dimethyl sulfoxide products are withdrawn from the bottom of the heat pump distillation column (T0201) and enter the product tank, i.e., line W2 in the figure. The bottom product withdrawal flow rate is controlled at 220 kg / h, and the dimethyl sulfoxide purity content can reach 99.87 wt%.

[0044] Example 3

[0045] A process for recycling waste organic solvents containing dimethyl sulfoxide includes the following steps:

[0046] S1. The waste organic solvent containing 3 wt% water, 63 wt% dimethyl sulfoxide and 34 wt% N-methylpyrrolidone is fed into the pretreatment column (T0101), i.e., line F1 in the figure. The feed rate is controlled at 1600 kg / h. The pretreatment column (T0101) is a packed distillation column, with a total of 60 trays. The effective packing height is 16 meters. The operating pressure of the pretreatment column (T0101) is controlled at 2 kPaA (absolute pressure);

[0047] Water is withdrawn from the top of the pretreatment column (T0101) to the water treatment station, i.e., line D1 in the figure. The top withdrawal temperature is controlled at 24 °C, and the top withdrawal flow rate is 42 kg / h. Under such a process, the concentration of the wastewater withdrawn from the top can reach 99.96 wt%;

[0048] The semi-finished product containing N-methylpyrrolidone is withdrawn from the bottom of the pretreatment column (T0101), i.e., line W1 in the figure. The bottom withdrawal rate is controlled at 1205 kg / h. This semi-finished product contains 55.3 wt% of dimethyl sulfoxide and 44.7 wt% of N-methylpyrrolidone. After collection, it can be further post-treated to separate and extract dimethyl sulfoxide product and N-methylpyrrolidone product;

[0049] The side stream (containing dimethyl sulfoxide and trace amounts of water) of the pretreatment column (T0101) enters the heat pump distillation column (T0201), i.e., line D2 in the figure. The side stream outlet is 5 meters below the top packing of the pretreatment column (T0101). The side stream flow rate is controlled at 350 kg / h. Since the concentrations of water, dimethyl sulfoxide, and N-methylpyrrolidone in the waste organic solvent vary to some extent, it is necessary to control the operating reflux ratio of the pretreatment column (T0101). The side stream of the pretreatment column (T0101) is refluxed, and the reflux ratio is controlled at 5 to ensure that the water content in the side stream can be reduced to less than 3 wt%. In this embodiment, the side stream contains 2.1 wt% of water, 97.6 wt% of dimethyl sulfoxide, and the rest is N-methylpyrrolidone and other impurities;

[0050] In this specific embodiment, the side stream of the pretreatment column (T0101) also passes through an intermediate buffer tank (V0101), i.e., an intermediate buffer tank (V0101) is set on line D2; due to the above reflux operation, the flow rate of the side stream of the pretreatment column (T0101) will also fluctuate. To ensure the stability of its flow rate into the heat pump distillation column (T0201), this intermediate buffer tank (V0101) is added to collect the dimethyl sulfoxide solvent containing water.

[0051] S2. The heat pump distillation column (T0201) is also a packed distillation column, with a total of 10 trays and an effective packing height of 6 meters. The operating pressure of the heat pump distillation column (T0201) is controlled at 3.5 kPaA (absolute pressure). After the water-containing dimethyl sulfoxide solution exits as a gas from the top of the heat pump distillation column (T0201), it is compressed by a compressor (C0201) to do work, i.e., line D3 in the figure, so that its pressure and boiling point both increase significantly. The work power of the compressor (C0201) is controlled at 190 kW. After being compressed by the compressor (C0201), it enters the shell side of a heat exchanger (E0201) to release heat, serving as the heat source for the distillation of the heat pump distillation column (T0201), i.e., line D4 in the figure. Finally, 100 kg / h is withdrawn as a semi-finished product, i.e., line D5 in the figure. This semi-finished product contains 9.15 wt% of water and 90.85 wt% of dimethyl sulfoxide, and can enter this system again for purification treatment according to the process of this application;

[0052] S3. The bottom product of the heat pump distillation column (T0201) enters the tube side of the heat exchanger (E0201), absorbs heat, and then is pumped back into the heat pump distillation column (T0201), i.e., line W3 in the figure.

[0053] The qualified dimethyl sulfoxide product is taken out from the bottom of the heat pump distillation column (T0201) and enters the product tank, i.e., line W2 in the figure. The flow rate of the bottom product is controlled at 250 kg / h, and the dimethyl sulfoxide purity can reach 99.85 wt%.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Based on the inspiration of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0055] The recycling process described in the above embodiments can separate and purify the waste organic solvent containing dimethyl sulfoxide in the field of electronic chips, realizing the reduction and resource utilization of the waste liquid, turning waste into treasure, and realizing the effective utilization of resources.

[0056] In the pretreatment column, N-methylpyrrolidone is separated from the waste organic solvent by means of negative pressure and low temperature, which can avoid the decomposition of dimethyl sulfoxide at the top of the column due to excessive temperature. In the heat pump distillation system composed of a heat pump distillation column, a compressor, and a heat exchanger, heat exchange is carried out between the top and bottom materials of the column, and heat is supplemented by the work of the compressor. Compared with the reboiler heating of the traditional distillation column system, it can effectively avoid the decomposition of dimethyl sulfoxide in the material due to the excessive local instantaneous heating temperature in the reboiler.

[0057] Moreover, the heat pump distillation system in this recycling process can take into account the effective utilization of the top energy, omitting the condenser and reboiler of the traditional distillation column system. The overall process reduces the equipment cost and operation energy consumption, creating better economic benefits while saving energy and reducing emissions.

Claims

1. A process for recycling waste organic solvents containing dimethyl sulfoxide, characterized in that, It includes the following steps: S1. Feed the waste organic solvent containing water, dimethyl sulfoxide and N-methylpyrrolidone into the pretreatment column (T0101), control the feed rate at 1300 - 1600 kg / h, and control the operating pressure of the pretreatment column (T0101) at 2 - 3.2 kPaA; Water is taken out from the top of the pretreatment column (T0101), control the top take-off temperature at 24 - 26 °C, and the top take-off flow rate at 42 - 87 kg / h; The semi-finished product containing N-methylpyrrolidone is taken out from the bottom of the pretreatment column (T0101), and the bottom take-off amount is controlled at 871 - 1205 kg / h; The side stream of the pretreatment column (T0101) enters the heat pump distillation column (T0201), and control the side stream flow rate at 325 - 350 kg / h; S2. Control the operating pressure of the heat pump distillation column (T0201) at 3 - 3.5 kPaA. After the dimethyl sulfoxide solution containing water is discharged as a gas from the top of the heat pump distillation column (T0201), it is compressed by the compressor (C0201) to do work. Control the work power of the compressor (C0201) at 190 - 210 kW. After being compressed by the compressor (C0201), it enters the heat exchanger (E0201) to release heat, and finally is taken out as a semi-finished product at 100 - 125 kg / h; The bottom discharge of the heat pump distillation column (T0201) enters the heat exchanger (E0201) to absorb heat and then is pumped back into the heat pump distillation column (T0201); Qualified dimethyl sulfoxide product is taken out from the bottom of the heat pump distillation column (T0201) and enters the product tank, and the bottom product take-off flow rate is controlled at 200 - 250 kg / h.

2. The process for recycling waste organic solvents containing dimethyl sulfoxide according to claim 1, characterized in that: The pretreatment column (T0101) is a packed distillation column, with a total of 60 trays, the effective packing layer is 16 meters, and the side stream outlet is 5 meters below the top packing; The heat pump distillation column (T0201) is also a packed distillation column, with a total of 10 trays, and the effective packing layer is 6 meters.

3. A process for recycling waste organic solvents containing dimethyl sulfoxide according to claim 1 or 2, characterized in that: The side stream of the pretreatment column (T0101) is refluxed, and the reflux ratio is controlled at 5 - 10.

4. A process for recycling waste organic solvents containing dimethyl sulfoxide according to claim 3, characterized in that: The side stream of the pretreatment column (T0101) also passes through the intermediate buffer tank (V0101).

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