Search

EP-4212505-B1 - METHOD AND APPARATUS FOR PRODUCING COMPOUND

EP4212505B1EP 4212505 B1EP4212505 B1EP 4212505B1EP-4212505-B1

Inventors

  • KIMURA, HAYATO
  • MUKAE, Masashi
  • MATSUDA, TAKAYUKI

Dates

Publication Date
20260506
Application Date
20210908

Claims (13)

  1. A method for producing a compound, the method comprising: a step of feeding a slurry containing crystals of the compound to a hydraulic wash column (1); a step of melting crystals in a crystal-containing circulation slurry discharged from the hydraulic wash column (1); a step of discharging a mother liquor using a filter (2) from the crystal-containing slurry in the hydraulic wash column (1); and a step of introducing a liquid having a temperature equal to or higher than the temperature of the mother liquor immediately after being discharged in the mother liquor discharging step into a nozzle (13a, 13b) attached to the hydraulic wash column (1) from outside the hydraulic wash column (1), the nozzle (13a, 13b) being other than a nozzle at a return port (25) for a circulation liquid containing a melt obtained in the melting step and a pipe (4) that feeds the crystal-containing slurry to the hydraulic wash column, wherein the nozzle (13a, 13b) attached to the hydraulic wash column (1) is at least one selected from the group consisting of an instrumentation nozzle, a sampling nozzle, a pressure control valve nozzle, a pipe insert nozzle, and an emergency injection nozzle.
  2. The method for producing a compound according to claim 1, wherein the liquid having a temperature equal to or higher than the temperature of the mother liquor contains at least one of the compound or water.
  3. The method for producing a compound according to claim 1 or 2, wherein the liquid having a temperature equal to or higher than the temperature of the mother liquor contains at least a portion of the mother liquor discharged in the mother liquor discharging step.
  4. The method for producing a compound according to any one of claims 1 to 3, wherein the liquid having a temperature equal to or higher than the temperature of the mother liquor contains at least a portion of the mother liquor discharged in the mother liquor discharging step, the portion of the mother liquor having been heated.
  5. The method for producing a compound according to any one of claims 1 to 4, wherein the nozzle (13a, 13b) attached to the hydraulic wash column (1) penetrates a mother liquor collection chamber (14) in which the mother liquor discharged in the mother liquor discharging step is collected, and is connected to a crystallization chamber (15) to which the crystal-containing slurry in the hydraulic wash column is fed.
  6. The method for producing a compound according to any one of claims 1 to 5, further comprising: a step of preparing the slurry containing crystals of the compound from a compound-containing solution.
  7. The method for producing a compound according to claim 6, wherein the compound-containing solution is a (meth)acrylic acid aqueous solution or a crude (meth)acrylic acid solution.
  8. The method for producing a compound according to any one of claims 1 to 7, further comprising: a step of preparing the compound-containing solution from a raw material.
  9. The method for producing a compound according to claim 8, wherein the raw material is at least one selected from the group consisting of propane, propylene, acrolein, isobutene, methacrolein, acetic acid, lactic acid, isopropanol, 1,3-propanediol, glycerol, and 3-hydroxypropionic acid.
  10. A purification apparatus that purifies crystals, the purification apparatus comprising: a hydraulic wash column (1) that includes a discharging port (20) for a crystal-containing circulation slurry and a return port (25) for a circulation liquid containing a melt of discharged crystals; a pipe (4) that feeds a crystal-containing slurry to the hydraulic wash column; a filter (2) that discharges a mother liquor from the crystal-containing slurry in the hydraulic wash column (1); a pipe (3) that is connected to the filter (2) and transports the mother liquor; a nozzle (13a, 13b) at an introduction port that introduces a liquid to the hydraulic wash column, the nozzle being other than a nozzle at the return port (25) and a pipe (4) that feeds the crystal-containing slurry to the hydraulic wash column (1); and a unit (22) that melts crystals in a circulation slurry discharged through the discharging port (20), wherein the nozzle (13a, 13b) at the introduction port is at least one selected from the group consisting of an instrumentation nozzle, a sampling nozzle, a pressure control valve nozzle, a pipe insert nozzle, and an emergency injection nozzle.
  11. The purification apparatus according to claim 10, further comprising a mother liquor collection chamber (14) in which the discharged mother liquor is collected, wherein the nozzle (13a, 13b) at the introduction port penetrates the mother liquor collection chamber (14), and is connected to a crystallization chamber (15) to which the crystal-containing slurry in the hydraulic wash (1) column is fed.
  12. The purification apparatus according to claim 10 or 11, further comprising: a line (16a, 16b) that transports the discharged mother liquor, and is connected to the nozzle (13a, 13b) at the introduction port.
  13. The purification apparatus according to claim 12, wherein the line (16a, 16b) that transports the mother liquor comprises a heating mechanism (17a, 17b).

Description

TECHNICAL FIELD The present invention relates to methods for producing compounds. Specifically, the present invention relates to a method for producing a compound, a method for purifying a compound, and a purification apparatus. BACKGROUND ART Compounds, including easily polymerizable compounds such as (meth)acrylic acid, are widely used industrially as raw materials for resins, for example. Various studies have been made on better purification techniques for safe and stable production of high-quality compounds. Industrially, many of crude compounds, which are compounds before purification, are purified through continuous purification processes. Disclosed is a method for producing acrylic acid including: collecting and crystallization purifying a gas containing acrylic acid obtained by catalytic oxidation of a raw material gas in gas phase; and returning acrylic acid obtained by decomposing a substance obtained by Michael addition of acrylic acid in a residual mother liquor to the collecting step, for example (see, for example, Patent Literature 1). In such a purification process, safe and stable operation of the apparatus is required. In the purification process, a wash column such as a hydraulic wash column (HWC) may be used. An example of wash column processes is described in US 2005/006299. Patent Literatures 2 and 3 disclose purification methods using conventional wash columns. CITATION LIST - Patent Literature Patent Literature 1: JP 2007-182437 APatent Literature 2: JP 2013-507427 TPatent Literature 3: JP 2005-509010 T SUMMARY OF INVENTION - Technical Problem As described above, better purification techniques for producing compounds have been desired to obtain high-quality products (compounds) with apparatuses under safe and stable operation. The present invention has been made in view of the above-mentioned current state of the art, and aims to provide a method for obtaining high-quality products safely and stably. - Solution to Problem The present inventors have studied methods for producing compounds, and focused on using a hydraulic wash column with high washing efficiency in the purification of compounds. They found that a mother liquor is discharged using a filter from a crystal-containing slurry in the hydraulic wash column, and is collected, and a liquid having a temperature higher than the temperature of the mother liquor immediately after being discharged is passed through a nozzle attached to the hydraulic wash column, so that freezing can be prevented and the apparatus can be operated more safely and stably. Thereby, the present invention has been achieved. That is, the present invention relates to a method for producing a compound, the method including: a step of feeding a slurry containing crystals of the compound to a hydraulic wash column; a step of melting crystals in a crystal-containing circulation slurry discharged from the hydraulic wash column; a step of discharging a mother liquor using a filter from the crystal-containing slurry in the hydraulic wash column; and a step of introducing a liquid having a temperature equal to or higher than the temperature of the mother liquor immediately after being discharged in the mother liquor discharging step into a nozzle attached to the hydraulic wash column from outside the hydraulic wash column, the nozzle being other than a nozzle at a return port for a circulation liquid containing a melt obtained in the melting step and a pipe that feeds the crystal-containing slurry to the hydraulic wash column. Patent Literatures 2 and 3 neither describe nor suggest the invention relating to prevention of freezing of the liquid in and around a nozzle attached to the hydraulic wash column. Simply thermally insulating an area where instrumentation equipment is attached (the connection between an inner portion and an outer portion of the instrumentation equipment attached to the hydraulic wash column, with a nozzle being usually attached to the connection) with a jacket or an indirect trace system fails to prevent or reduce stagnation of the liquid in and around the nozzle at the area where the instrumentation equipment is attached and fails to sufficiently prevent freezing of the liquid. - Advantageous Effects of Invention The purification apparatus of the present invention can provide a high-quality product safely and stably. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an exemplary schematic diagram of the state of use of the purification apparatus of the present invention. DESCRIPTION OF EMBODIMENTS The present invention will be described in detail below. It should be noted that combinations of two or more of the preferred features of the present invention described below are also preferred embodiments of the present invention. The following first describes a method for producing a compound of the present invention, followed by descriptions of a method for purifying a compound of the present invention and a purification apparatus of the present inventio