CN104844420B - The continuous treatment technique of neopentyl glycol condensation water cleaning mother liquor and device - Google Patents

Abstract

The invention relates to a continuous treatment device for neopentyl glycol condensation water washing mother liquor, characterized in that the device includes a filter, a primary preheater, a secondary preheater, a rectification tower, a chromatograph and a cyclone liquid separator, the filter is at the front end of the primary preheater, the primary preheater is connected to the secondary preheater through pipelines, and the rectification column is connected to the secondary preheater The rear end of the rectification tower is provided with a reflux tank and a chromatograph at the top of the rectification tower, and a liquid cyclone separator and a reboiler are provided at the bottom of the rectification tower. The invention relates to a continuous treatment process flow for neopentyl glycol condensation washing mother liquor, which can continuously and stably remove organic impurities in neopentyl glycol condensation washing mother liquor and concentrate neopentyl glycol.

Description

Continuous treatment process and equipment for neopentyl glycol condensation water washing mother liquor

technical field

The invention belongs to the separation field of the pharmaceutical industry, and in particular relates to a continuous treatment process and device for neopentyl glycol condensation water washing mother liquor.

Background technique

Neopentyl glycol, referred to as NPG, is a white crystalline solid, easily soluble in water, low-carbon alcohols, low-carbon ketones, ethers and aromatic compounds. At present, the synthesis methods of neopentyl glycol mainly include hydrogenation method and methanol method. Neopentyl glycol molecule has a specific neopentyl structure, which contains two primary carbonyl groups, and there is no α-hydrogen atom on the central carbon atom. These characteristics make neopentyl glycol have high thermal and chemical stability , Therefore, it is often used in the production fields such as medicine, chemical industry, paint, pesticide, plastic and petroleum. Among them, in the pharmaceutical industry, neopentyl glycol can be used as an important raw material for the synthesis of ibuprofen intermediate-ketal, which undergoes condensation reaction with chlorketone dissolved in petroleum ether to form ketal. The unreacted neopentyl glycol and the generated ketal products are washed with water to obtain a ketal solution and a neopentyl glycol solution containing petroleum ether. After concentrating the neopentyl glycol condensation water washing mother liquor containing petroleum ether and other organic impurities to a neopentyl glycol mass fraction of 60%, it can be recycled for the condensation reaction of ketone, reducing the unit consumption of production.

The existing water vapor equilibrium distillation process for the treatment of the neopentyl glycol condensation water washing mother liquor is as follows: first, the neopentyl glycol condensation water washing mother liquor is input into a distillation storage tank of 20 cubic meters, and then fresh steam is introduced for heating, and then As the temperature in the tank rises, the organic impurities and water in the neopentyl glycol condensation water washing mother liquor gradually gather on the top of the tank in the form of gas. The gas phase containing organic impurities and water is drawn from the top of the tank, and then cooled to form waste water containing organic impurities, and the process is repeated after a batch is completed. In the existing technology, every ton of neopentyl glycol condensation washing mother liquor is processed, and 900 liters of waste water is produced, and the chemical oxygen demand (COD) in the waste water is 2000-3000 mg/liter. After the above treatment process lasts for 20-22 hours, the introduction of fresh water vapor is stopped, and the concentrated neopentyl glycol in the tank is recycled for the condensation reaction of ketone.

The existing steam equilibrium distillation process has the following problems: first, the loss of neopentyl glycol is large during the treatment process, and the mass fraction of neopentyl glycol in the wastewater produced from the top of the tank is 2 to 3%, and every ton of neopentyl glycol is processed Alcohol condensation water washing mother liquor, the loss of neopentyl glycol is 20-30 kg; second, the operation period is long, and it takes 20-22 hours to process a batch of 20 tons of neopentyl glycol condensation water washing mother liquor, and the production efficiency is low; third , the color of the treated neopentyl glycol solution is yellowish, and it needs to be decolorized by activated carbon before it can be recycled. The existing process adopts intermittent treatment, and the solution in the tank is kept at high temperature for a long time, resulting in partial carbonization of the organic matter in the solution, and the color is yellowish. 4. Scaling easily occurs in the neopentyl glycol distillation tank, which leads to deviation of heat transfer effect. The neopentyl glycol condensation washing mother liquor contains a small amount of calcium sulfate. After a large amount of water is steamed out by balanced distillation, the calcium sulfate in the tank gradually Accumulation leads to scaling inside the retort walls.

Contents of the invention

The present invention overcomes the deficiencies in the prior art, and develops a continuous treatment process and device for neopentyl glycol condensation water washing mother liquor, which can effectively remove organic impurities in neopentyl glycol solution to concentrate neopentyl glycol, and provide A device for realizing the above process.

A continuous treatment device for neopentyl glycol condensation water washing mother liquor, characterized in that it includes a filter, a primary preheater, a secondary preheater, a rectifying tower, a chromatograph and a hydrocyclone, the The filter is provided with a material inlet and a material outlet, the material outlet is connected to the primary preheater through a pipeline, the material outlet of the primary preheater is connected to the secondary preheater through a pipeline, and the material of the secondary preheater The outlet is connected to the rectification tower through a pipeline, and the rectification tower is provided with a material inlet, a gas phase outlet at the top of the tower, a reflux inlet and a material outlet at the bottom of the tower, and the gas phase outlet at the top of the tower is connected with a primary preheater through a pipeline. The top of the rectification tower is provided with a reflux tank, the primary preheater is connected to the inlet of the reflux tank through a pipeline, the reflux tank is provided with an outlet for water phase material and an outlet for organic phase material, and the outlet for water phase material is The road is connected with the reflux inlet of the rectification tower, and the bottom of the rectification tower is provided with a liquid cyclone separator and a secondary preheater, and the liquid cyclone separator is connected with the rectification tower and a reboiler through a pipeline. The secondary preheater is connected with the rectification column and the primary preheater through pipelines.

The first-stage preheater is a tube-and-tube heat exchanger made of graphite; the second-stage preheater is a plate heat exchanger.

A continuous treatment process flow for neopentyl glycol condensation water washing mother liquor, characterized in that: said flow process uses water and neopentyl glycol as main raw materials, comprising the following steps:

The first step: filter the solid particles in the neopentyl glycol condensation washing mother liquor

The neopentyl glycol condensation water washing mother liquor contains petroleum ether, dichloromethane organic impurities and insoluble solid particles, and the neopentyl glycol condensation water washing mother liquor is transported from the storage tank to the rectification tower through a filter by a pump, and intercepted Insoluble solid particles, regularly clean the filter residue in the filter, and the neopentyl glycol condensation washing mother liquor obtained after filtration contains petroleum ether and methylene chloride;

The second step: preheating neopentyl glycol condensation water washing mother liquor

Using the vapor phase at the top of the rectification tower and the concentrated neopentyl glycol solution at the bottom of the tower as the heat source, the neopentyl glycol condensation water washing mother liquor is heated from normal temperature to 85-95°C in the primary and secondary preheaters. ℃;

The third step: removal of organic impurities in the neopentyl glycol condensation water washing mother liquor

The preheated neopentyl glycol condensation water washing mother liquor is pumped into the rectification tower, and the bottom reboiler is fed with 0.1-0.5 MPa (gauge pressure) heating steam to maintain the tower bottom pressure at 0.01-0.05 MPa (gauge pressure), part of the liquid at the bottom of the tower is vaporized by a reboiler, and the rising gas carries out multi-stage gas-liquid mass transfer with the falling liquid in the rectifying tower, and petroleum ether and methylene chloride organic impurities are constantly enriched in the gas phase. Set, finally discharged from the gas phase outlet of the rectifying tower in the form of gas;

In the rectification tower, the pressure at the top of the tower is maintained at 0-0.01MPa (gauge pressure). After condensation, the gas containing petroleum ether, dichloromethane and water will form upper, middle and lower layers in the reflux tank. The lower layer of dichloromethane is organic The phase is extracted and used as a solvent for the original production process; the water phase containing a small amount of organic matter in the middle layer is returned to the rectification tower through the pipeline, and exchanges heat and mass with the rising gas phase; the petroleum ether in the upper layer enters the chromatography with water The device is divided into two phases in the chromatograph, and the organic phase petroleum ether is used as a solvent for the original production process;

The fourth step: extract the concentrated neopentyl glycol solution

In the rectification tower, due to the high boiling point of neopentyl glycol, it is continuously enriched in the liquid phase and falls to the bottom of the tower. Part of the liquid at the bottom of the tower is vaporized through the reboiler, and the other part is concentrated neopentyl glycol. The pipeline is extracted after passing through the secondary preheater.

The principle that the present invention realizes is:

Impurities in the neopentyl glycol condensation washing mother liquor include insoluble solid particles, trace amounts of calcium sulfate, petroleum ether, dichloromethane, and the like. In the present invention, the neopentyl glycol condensation water-washing mother liquor is passed through a filter, the solid particles in the solution are firstly filtered out, and then the mother liquor is preheated to 85-95°C through the first-stage and second-stage preheaters. into the tower. The neopentyl glycol condensation water washing mother liquor entering the tower conducts heat and mass transfer with the rising gas phase in the tower. The light component organic impurities and part of water are continuously enriched in the gas phase, rise to the top of the tower and pass through the condenser and chromatography to extract the organic phase and part of the water phase; the heavy component neopentyl glycol is continuously enriched in the liquid phase, It is extracted after falling to the bottom of the tower. The content of neopentyl glycol in the water phase extracted from the top of the tower is below 10ppm, and the content of organic matter in the concentrated product of neopentyl glycol extracted from the bottom of the tower is below 2ppm. Since the trace amount of calcium sulfate in the neopentyl glycol condensation water washing mother liquor is not volatile, it will gradually accumulate at the bottom of the tower during the treatment process, and be separated and extracted by the hydrocyclone. The liquid coming out of the hydrocyclone is heated and vaporized, and enters the tower The heat and mass transfer between the inside and the descending liquid in the tower.

The present invention has following beneficial effect:

(1) The present invention reduces the loss of neopentyl glycol during the treatment process of neopentyl glycol condensation water washing mother liquor. When the existing water steam distillation process concentrates neopentyl glycol condensation water washing mother liquor, along with the organic matter impurities are distilled off, the mass fraction of neopentyl glycol in the liquid condensed on the top of the equilibrium distillation tank is 2 to 3%, resulting in the loss of raw materials. waste. The technology and device adopted in the present invention process neopentyl glycol condensation washing mother liquor, the neopentyl glycol content in the water evaporated from the tower top is below 10ppm, and 35-55 kg more neopentyl glycol is recovered for each batch of mother liquor.

(2) The present invention increases the treatment efficiency of the neopentyl glycol condensation water washing mother liquor. When the existing steam distillation process concentrates the neopentyl glycol solution, each batch of material is about 20 tons and needs to be processed for 20 hours. The invention adopts a continuous treatment process, and it only takes 6 hours to process 20 tons of neopentyl glycol solution.

(3) The present invention reduces the consumption of steam and circulating water, and reduces the production cost. The invention adopts the heat integration method, and the neopentyl glycol condensation washing mother liquor is preheated in two stages of the gas phase at the top of the rectification tower and the liquid phase at the bottom of the tower. , On the other hand, it reduces the circulating water consumption of the overhead condenser. Treating each ton of neopentyl glycol condensation washing mother liquor saves 110-130 kg of fresh water vapor and 6,000-7,000 kg of circulating water.

(4) The present invention improves the appearance characteristics of the concentrated neopentyl glycol. The existing steam distillation process adopts intermittent operation, and it takes 20 to 22 hours to process a batch of neopentyl glycol condensation washing mother liquor. Because the solution in the tank is kept at high temperature for a long time, part of the solution is carbonized and the color is yellowish. The invention adopts a continuous treatment process, and the qualified neopentyl glycol solution is extracted from the bottom of the tower in time to ensure the purity and chroma of the neopentyl glycol product.

(5) The present invention has the ability to handle trace amounts of calcium sulfate in the neopentyl glycol condensation washing mother liquor. The existing steam distillation process uses a distillation tank to intermittently process the neopentyl glycol condensation water washing mother liquor. As the water in the mother liquor is continuously evaporated, calcium sulfate in the solution in the tank gradually accumulates, resulting in scaling in the distillation tank wall. The present invention utilizes the hydrocyclone to remove the calcium sulfate accumulated at the bottom of the tower in time, increases the calcium sulfate treatment capacity of the neopentyl glycol condensation water washing mother liquor continuous treatment device, and prevents the calcium sulfate from scaling in the rectifying tower wall.

Description of drawings

Accompanying drawing is the structural representation of the present invention.

In the figure, 1. filter; 2. primary preheater; 3. secondary preheater; 4. rectification column; 5. reflux tank; 6. reboiler; liquid separator.

detailed description

The following will be further described in conjunction with the accompanying drawings, not to limit the scope of the present invention.

As shown in the drawings, the present invention first passes the neopentyl glycol condensation washing mother liquor through the filter 1 to filter out insoluble solid particles therein. The filtered solution is preheated to a certain temperature by the primary preheater 2 and the secondary preheater 3 and then enters the rectification column 4 . The rectification column is heated by a reboiler 6, and the rising gas in the column enters the reflux tank 5 after being cooled. Dichloromethane is extracted from the bottom of the reflux tank 5, petroleum ether and water are extracted from the upper part of the reflux tank and enter the chromatography 7, water is extracted from the bottom of the chromatography 7, and petroleum ether is extracted from the upper part of the chromatography 7. The neopentyl glycol condensation water washing mother liquor contains a small amount of calcium sulfate, which will be gradually concentrated during the heating process, and will be discharged from the bottom after passing through the hydrocyclone 8, and the liquid will enter the reboiler for heating and vaporization.

The following are specific implementation examples of the present invention:

Implementation example 1: The feed rate of neopentyl glycol condensation water washing mother liquor is 4000 kg/h, the temperature rises from 20°C to 70°C after passing through the primary preheater, and the temperature rises to 90°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 109°C to 75°C, and the steam consumption was 450 kg/hour. The treatment time of 20 tons of neopentyl glycol solution is about 5 hours, the volume of dichloromethane produced at the top of the tower is 800 liters, and the volume of petroleum ether is 500 liters. After the water produced at the top of the tower passes through the water separator, the neopentyl glycol content is 8ppm and the COD is 236 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 70%, wherein dichloromethane and petroleum ether Not detected.

Implementation example 2: The feed rate of neopentyl glycol condensation water washing mother liquor is 4000 kg/h, the temperature rises from 20°C to 75°C after passing through the first-stage preheater, and the temperature rises to 95°C after passing through the second-stage preheater , The temperature of the bottom material of the rectification tower dropped from 108°C to 70°C, and the steam consumption was 400 kg/hour. The treatment time of 20 tons of neopentyl glycol solution is about 5 hours, the volume of dichloromethane extracted from the tower top is 830 liters, and the volume of petroleum ether is 550 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 9ppm and the COD is 156 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 68%, of which dichloromethane and petroleum ether The concentration is 1ppm.

Implementation example 3: The feed rate of neopentyl glycol condensation water washing mother liquor is 5000 kg/hour, the temperature rises from 20°C to 65°C after passing through the primary preheater, and the temperature rises to 92°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 108°C to 72°C, and the steam consumption was 550 kg/hour. The treatment time of 20 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane extracted from the tower top is 850 liters, and the volume of petroleum ether is 520 liters. After the water produced at the top of the tower passes through the water separator, the neopentyl glycol content is 5ppm and the COD is 221 mg/liter, and the concentrated mass fraction of neopentyl glycol produced at the bottom of the tower is 67%, of which dichloromethane and petroleum The ether concentration was 1 ppm.

Implementation example 4: The feed rate of neopentyl glycol condensation water washing mother liquor is 5000 kg/h, the temperature rises from 20°C to 63°C after passing through the primary preheater, and the temperature rises to 95°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 110°C to 68°C, and the steam consumption was 580 kg/hour. The treatment time of 20 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane extracted from the tower top is 900 liters, and the volume of petroleum ether is 550 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 2ppm and the COD is 250 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 72%, of which dichloromethane and petroleum ether Not detected.

Implementation example 5: The feed rate of neopentyl glycol condensation water washing mother liquor is 3000 kg/h, the temperature rises from 20°C to 78°C after passing through the primary preheater, and the temperature rises to 95°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 112°C to 73°C, and the steam consumption was 350 kg/hour. The treatment time of 18 tons of neopentyl glycol solution is about 6 hours, the volume of dichloromethane extracted from the tower top is 700 liters, and the volume of petroleum ether is 450 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 8ppm and the COD is 153 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 73%, wherein dichloromethane and petroleum ether Not detected.

Implementation Example 6: The feed rate of neopentyl glycol condensation water washing mother liquor is 3000 kg/h, the temperature rises from 20°C to 74°C after passing through the primary preheater, and the temperature rises to 93°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 109°C to 67°C, and the steam consumption was 380 kg/hour. The treatment time of 18 tons of neopentyl glycol solution is about 6 hours, the volume of dichloromethane extracted from the tower top is 720 liters, and the volume of petroleum ether is 440 liters. After the water produced at the top of the tower passes through the water separator, the neopentyl glycol content is 5ppm and the COD is 142 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 70%, wherein dichloromethane and petroleum ether The concentration is 1ppm.

Implementation Example 7: The feed rate of neopentyl glycol condensation water washing mother liquor is 4500 kg/h, the temperature rises from 20°C to 69°C after passing through the primary preheater, and rises to 91°C after passing through the secondary preheater , The temperature of the material at the bottom of the rectification tower dropped from 110°C to 70°C, and the steam consumption was 500 kg/hour. The treatment time of 18 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane extracted from the tower top is 710 liters, and the volume of petroleum ether is 450 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 5ppm and the COD is 285 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 71%, wherein dichloromethane and petroleum ether Not detected.

Implementation Example 8: The feed rate of neopentyl glycol condensation water washing mother liquor is 4500 kg/h, the temperature rises from 20°C to 70°C after passing through the primary preheater, and the temperature rises to 88°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 107°C to 69°C, and the steam consumption was 520 kg/hour. The treatment time of 18 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane extracted from the tower top is 730 liters, and the volume of petroleum ether is 400 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 3ppm and the COD is 213 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 66%, of which dichloromethane and petroleum ether The concentration is 2ppm.

Implementation example 9: The feed rate of neopentyl glycol condensation water washing mother liquor is 6000 kg/h, the temperature rises from 20°C to 72°C after passing through the primary preheater, and the temperature rises to 95°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 111°C to 72°C, and the steam consumption was 850 kg/hour. The treatment time of 22 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane extracted from the tower top is 880 liters, and the volume of petroleum ether is 530 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 4ppm and the COD is 157 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 72%, wherein dichloromethane and petroleum ether Not detected.

Implementation example 10: The feed rate of neopentyl glycol condensation water washing mother liquor is 6000 kg/hour, the temperature rises from 20°C to 70°C after passing through the primary preheater, and the temperature rises to 86°C after passing through the secondary preheater , The temperature of the bottom material of the rectification tower dropped from 115°C to 76°C, and the steam consumption was 800 kg/hour. The treatment time of 22 tons of neopentyl glycol solution is about 4 hours, the volume of dichloromethane produced at the top of the tower is 800 liters, and the volume of petroleum ether is 580 liters. After the water produced at the top of the tower passes through the water separator, the content of neopentyl glycol is 6ppm and the COD is 108 mg/liter, and the mass fraction of neopentyl glycol produced at the bottom of the tower is 76%, of which dichloromethane and petroleum ether Not detected.

Claims (7)

1. a continuous treatment process flow for neopentyl glycol condensation washing mother liquor, is characterized in that: described flow process is main raw material with water and neopentyl glycol, comprises the following steps: The first step: filter the solid particles in the neopentyl glycol condensation washing mother liquor The neopentyl glycol condensation water washing mother liquor contains petroleum ether, dichloromethane organic impurities and insoluble solid particles, and the neopentyl glycol condensation water washing mother liquor is transported from the storage tank to the rectification tower through a filter by a pump, and intercepted Insoluble solid particles, regularly clean the filter residue in the filter, and the neopentyl glycol condensation washing mother liquor obtained after filtration contains petroleum ether and methylene chloride; The second step: preheating neopentyl glycol condensation water washing mother liquor Using the vapor phase at the top of the rectification tower and the concentrated neopentyl glycol solution at the bottom of the tower as the heat source, the neopentyl glycol condensation water washing mother liquor is heated from normal temperature to 85-95°C in the primary and secondary preheaters. ℃; The third step: removal of organic impurities in the neopentyl glycol condensation water washing mother liquor The preheated neopentyl glycol condensation water washing mother liquor is pumped to the rectification tower, and the bottom reboiler is fed with heating steam with a gauge pressure of 0.1-0.5MPa to maintain the pressure at the bottom of the tower at 0.01-0.05MPa gauge. pressure, part of the liquid at the bottom of the tower is vaporized through the reboiler, and the rising gas and the descending liquid carry out multi-stage gas-liquid mass transfer in the rectifying tower, and petroleum ether and dichloromethane organic impurities are continuously enriched in the gas phase, and finally The gas form is discharged from the gas phase outlet of the rectification tower; In the rectification tower, the pressure at the top of the tower is maintained at 0-0.01MPa gauge pressure, the gas containing petroleum ether, dichloromethane and water is condensed to form upper, middle and lower layers in the reflux tank, and the organic phase of the lower layer of dichloromethane is recovered. It is used as a solvent and reused in the original production process; the water phase containing a small amount of organic matter in the middle layer flows back into the rectification tower through the pipeline, and exchanges heat and mass with the rising gas phase; the petroleum ether in the upper layer enters the chromatograph with water, It is divided into two phases in the chromatograph, and the organic phase petroleum ether is used as a solvent for the original production process; The fourth step: extract the concentrated neopentyl glycol solution In the rectification tower, due to the high boiling point of neopentyl glycol, it is continuously enriched in the liquid phase and falls to the bottom of the tower. Part of the liquid at the bottom of the tower is vaporized through the reboiler, and the other part is concentrated neopentyl glycol. The pipeline is extracted after passing through the secondary preheater. 2. the continuous treatment technological process of neopentyl glycol condensation washing mother liquor according to claim 1, is characterized in that: in the neopentyl glycol condensation washing mother liquor handled, the massfraction of sherwood oil is 0.02～8%, The mass fraction of dichloromethane is 0.02-2%, and the mass fraction of neopentyl glycol is 10-50%. 3. The continuous processing technological process of neopentyl glycol condensation washing mother liquor according to claim 1, characterized in that: the neopentyl glycol condensation washing mother liquor can be processed continuously. 4. the continuous treatment process flow of neopentyl glycol condensation water washing mother liquor according to claim 3, is characterized in that: adopt continuous treatment process flow, the time required for processing every ton of neopentyl glycol solution is 2～3 hours . 5. the continuous treatment technological process of neopentyl glycol condensation washing mother liquor according to claim 1, is characterized in that: the mass fraction of neopentyl glycol in the water that steams out is below 10ppm, and the rate of recovery of neopentyl glycol is 99.9% %above. 6. the continuous treatment technological process of neopentyl glycol condensation washing mother liquor according to claim 1, is characterized in that: adopt heat integration process, process every ton of neopentyl glycol condensation washing mother liquor, the steam needed by rectification tower 100-500kg. 7. the continuous treatment technological process of neopentyl glycol condensation washing mother liquor according to claim 1, is characterized in that: can handle the solid of calcium sulfate in neopentyl glycol condensation washing mother liquor.