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CN-121971877-A - Mixture purification and separation process based on melt crystallization and equipment thereof

CN121971877ACN 121971877 ACN121971877 ACN 121971877ACN-121971877-A

Abstract

The invention discloses a mixture purification and separation process and equipment based on melt crystallization, which are characterized in that crude product materials are sent into a crystallization and purification device through a crude product storage tank to obtain high-purity target crystals and low-purity mother liquor, the low-purity mother liquor is sent into a mother liquor storage tank to be used as materials for further purification, the high-purity crystals are subjected to countercurrent washing in the crystallization and purification device, surface impurities are melted and taken away to obtain high-purity target crystal products, and the high-purity crystals are melted to obtain liquid products or granulated to obtain solid products. The crude product is conveyed to a second crystallization area through a raw material pump, is contacted with cold materials for crystallization and precipitation after entering, and solid falls to a third crystallization area, and the crystal enters a melting area for melting through a washing area, and liquid part is extracted after melting, so that a high-purity product can be obtained.

Inventors

  • JIANG WEI
  • QI YUNBIAO

Assignees

  • 南京大学

Dates

Publication Date
20260505
Application Date
20260123

Claims (10)

  1. 1. A process for purifying and separating a mixture based on melt crystallization, comprising the steps of: S1, feeding the mixture crude product material into a crystallization purification device (T101) through a crude product storage tank (V101) to obtain a high-purity target crystal and a low-purity mother solution, and feeding the low-purity mother solution into a mother solution storage tank (V102) to be used as a material for further purification; s2, carrying out countercurrent washing on the crystals with higher purity in a crystallization purification device (T101), and taking away surface impurities after melting to obtain a high-purity target crystal product; s3, melting the high-purity crystal to obtain a liquid product or granulating to obtain a solid product; The crystallization purification device (T101) comprises a crystallization area (100), a washing area (200) and a melting area (300) which are sequentially arranged from top to bottom, wherein the crystallization area (100) is composed of a first crystallization area, a second crystallization area and a third crystallization area which are arranged from top to bottom; The crude product material enters a second crystallization area of a crystallization purification device (T101) for medium-temperature crystallization, the solid enters a third crystallization area for surface micro-melting purification, the liquid enters an upper first crystallization area for recovery, the crystallized solid in the first crystallization area enters the second crystallization area, and the liquid is discharged through an overflow port; the operation temperature of the first crystallization area is Tm- (15-45) DEG C; the second crystallization region has an operating temperature Tm- (10-30) DEG C; The operating temperature of the third crystallization area is Tm- (5-20) DEG C; The temperature of the washing area is controlled at Tm+ (5-15 ℃) to prevent crystals from being solidified; Tm is the melting point temperature of the target crystal.
  2. 2. The process for purifying and separating a mixture based on melt crystallization according to claim 1, the method is characterized in that the target crystal is any one of isomers.
  3. 3. The equipment for purifying and separating the mixture based on the melt crystallization is characterized by comprising a crude product storage tank (V101), a crystallization purification device (T101) and a mother liquor collection tank (V102) which are connected in sequence; The crystallization and purification device (T101) comprises a crystallization zone (100), a washing zone (200) and a melting zone (300) which are sequentially arranged from top to bottom; The crystallization zone (100) consists of a first crystallization zone, a second crystallization zone and a third crystallization zone which are arranged from top to bottom, wherein independent jackets are respectively arranged at the outer part of each crystallization zone for controlling temperature, a scraper agitator (107) which rotates synchronously is arranged at the inner part of each crystallization zone, a feed inlet of the second crystallization zone is connected with a crude product storage tank (V101), the side surface of the top of the first crystallization zone is connected with a mother liquor collection tank (V102) through a mother liquor discharge pipe (104), and a spiral propeller (106) for feeding materials downwards into a washing zone is arranged at the bottom of the third crystallization zone; a temperature-controlled jacket and an imaging module for monitoring the internal crystal properties are arranged outside the washing area (200); The outside of the melting zone (300) is provided with a temperature-controlled jacket, a heating pipe (302) is arranged in the inner cavity, and a discharge pump (P102) is arranged at the bottom.
  4. 4. The equipment for purifying and separating mixture based on melt crystallization according to claim 3, wherein a bottom discharge hole of the crude product storage tank (V101) is connected to a second crystallization area feed hole of the crystallization and purification device (T101) through a material pipeline, the bottom discharge hole of the crystallization and purification device (T101) is returned to the middle part of the crystallization and purification device (T101) through a material circulating pipeline, a top discharge hole of the crystallization and purification device (T101) is connected to a mother liquor collecting tank (V102) through a material pipeline, a product discharge pipeline is further connected to a bottom material circulating pipeline of the crystallization and purification device (T101), and the bottom of the mother liquor collecting tank (V102) is connected to the crystallization and purification device (T101) through a material pipeline.
  5. 5. The equipment for purifying and separating a mixture based on melt crystallization according to claim 3, wherein a mother liquor filter plate (105) is arranged below the mother liquor discharge at the top of the first crystallization area, a sealing bearing (1052) for allowing a longitudinal stirring rod to pass through is reserved in the middle of the mother liquor filter plate (105), and a filter hole (1051) is formed in the plate surface.
  6. 6. The apparatus for purifying and separating a mixture based on melt crystallization according to claim 3, wherein the scraper agitator (107) and the screw (106) in each crystallization area are sequentially installed on a longitudinal agitating shaft from top to bottom, the agitating shaft is connected with an external motor (M101), and the scraper agitator (107) and the screw (106) are synchronously driven to rotate by the motor (M101).
  7. 7. The apparatus for purifying and separating a mixture based on melt crystallization according to claim 3, wherein the washing zone is a longitudinal long and narrow passage having an inner diameter smaller than that of the crystallization zone and the melting zone, the bottom of the crystallization zone is reduced in diameter from top to bottom, the melting zone is expanded in diameter from top to bottom, and the ratio of the height to the diameter of the washing zone is 3:1 to 10:1.
  8. 8. The equipment for purifying and separating the mixture based on the melt crystallization according to claim 3, wherein the melting zone is positioned above the heating pipe (302) and is provided with a crystal cavity (301) so that the crystal is uniformly contacted with the heating pipe (302) below, and the heating pipe (302) is one or two of a column heat exchanger, a U-shaped pipe heat exchanger and a plate heat exchanger which are matched for use and are uniformly distributed in the melting zone; a discharge filter plate (303) is arranged below the heating pipe (302).
  9. 9. The apparatus for purifying and separating a mixture based on melt crystallization according to claim 3, wherein the scraper agitator (107) is a hard plastic wall-mounted scraper agitator, and the heat transfer efficiency is reduced by preventing the occurrence of solid precipitation on the wall, and the rotation speed is controlled to be 1-10 rpm.
  10. 10. The apparatus for purifying and separating a mixture based on melt crystallization as claimed in claim 3, wherein said mother liquor discharge pipe (104) is provided as an overflow melting pipe, and a winding pipe heater is provided inside the overflow melting pipe to prevent clogging.

Description

Mixture purification and separation process based on melt crystallization and equipment thereof Technical Field The invention belongs to the technical field of material purification, and particularly relates to a chiral or isomer purification method, in particular to a mixture purification and separation process based on melt crystallization and equipment thereof. Background Crystallization refers to the process of precipitation of substances from a mixture to a supersaturation degree, and the method plays an important role in the separation and purification process of products. According to the system, crystallization is classified into solvent crystallization and melt crystallization. The melting crystallization is based on the difference of melting points of isomers, and separation is realized by controlling phase balance, so that compared with the traditional rectification purification, the method has the advantages of low operation temperature, less side reaction, high product purity and low energy consumption. The production is mainly carried out by a laminate crystallizer and a falling film crystallizer at home and the suspension crystallization and washing are adopted at abroad. The suspension crystallizer is continuous production equipment, has high efficiency, but adopts hydraulic washing, has complex equipment and high operation difficulty, and is not seen in China. Disclosure of Invention The invention aims to solve the technical problems of low production efficiency, high operation difficulty and low product purity in the process of purifying and separating isomers. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A process for purifying and separating a mixture based on melt crystallization, comprising the steps of: s1, feeding the mixture crude product material into a crystallization purification device through a crude product storage tank to obtain a high-purity target crystal and a low-purity mother solution, and feeding the low-purity mother solution into a mother solution storage tank to be used as a material for further purification; S2, carrying out countercurrent washing on the crystals with higher purity in a crystallization purification device, and taking away surface impurities after melting to obtain a high-purity target crystal product; s3, melting the high-purity crystal to obtain a liquid product or granulating to obtain a solid product; specifically, the crystallization purification device (T101) comprises a crystallization zone (100), a washing zone (200) and a melting zone (300) which are sequentially arranged from top to bottom. The crystallization region (100) is composed of a first crystallization region, a second crystallization region, and a third crystallization region disposed from top to bottom. The crude product material enters a second crystallization area of a crystallization purification device for medium-temperature crystallization, the solid enters a third crystallization area for surface micro-melting purification, the liquid enters a first crystallization area at the upper part for recovery, the crystallized solid in the first crystallization area enters the second crystallization area, and the liquid is discharged through an overflow port. Preferably, the operation temperature of the first crystallization area is Tm - (15-45) DEG C, namely the melting point temperature of target crystals is subtracted by 15-45℃, the target crystals enter the second crystallization area for high-temperature washing, the uncrystallized mother solution is overflowed and discharged to a mother solution collecting tank after being filtered, and the uncrystallized mother solution is pumped to a front stage for recycling. The operation temperature of the second crystallization area is Tm - (10-30) DEG C, namely the melting point temperature of the target crystal is subtracted by 10-30℃; The operation temperature of the third crystallization area is Tm - (5-20) DEG C, namely the melting point temperature of the target crystal is subtracted by 5-20℃; The crystals in the third crystallization area are conveyed to a washing area through free falling bodies and spiral, and are washed in countercurrent with the solution in the melting area to improve the purity again; Part of the unmelted crystal enters the melting zone to be melted and then is discharged as a product, and part of the unmelted crystal is washed upwards in countercurrent; tm is the melting point temperature of the target crystal. Preferably, the target crystal according to the present invention is any one of isomers. Further, the invention also claims equipment for realizing the purification and separation of the mixture based on the melt crystallization, which comprises a crude product storage tank (V101), a crystallization purification device (T101) and a mother liquor collection tank (V102) which are connected in sequence; The crystallization and purification device