Process for continuous recovering (meth) acrylic acid and apparatus for the process

Patent metadata

Field	Value
Publication number	US-2016200657-A1
Application number	US-201414914233-A
Country	US
Kind code	A1
Filing date	Aug 26, 2014
Priority date	Aug 30, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

This disclosure relates to a method for continuous recovery of (meth)acrylic acid and an apparatus used for the recovery method. The method of continuous recovery of (meth)acrylic acid according to the present invention may minimize loss of (meth)acrylic acid particularly in the distillation process, and yet enables stable operation of the distillation process and energy reduction.

First claim

1 . A method for continuous recovery of (meth)acrylic acid, comprising:
an absorption process wherein a mixed gas comprising (meth)acrylic acid, organic by-products, and vapor, which is produced by a synthesis reaction of (meth)acrylic acid, is contacted with an absorption solvent including water to obtain a (meth)acrylic acid aqueous solution; an extraction process wherein a part of the (meth)acrylic acid aqueous solution obtained through the absorption process is contacted with an extraction solvent in an extraction column to obtain a (meth)acrylic acid extract solution through the upper outlet of the extraction column and obtain a raffinate solution passing through the lower stationary section of the extraction column through the lower outlet; and a distillation process wherein a feed containing the remainder of the (meth)acrylic acid aqueous solution obtained through the absorption process and the (meth)acrylic acid extract obtained through the extraction process is distilled to obtain (meth)acrylic acid, wherein the distillation process is conducted in a distillation column having a plurality of stages partitioned by perforated trays, and wherein, based on a feed point to which the feed is supplied, perforated trays located at a rectifying section have a lower tray open area ratio than perforated trays located at a stripping section.

2 . The method according to claim 1 , wherein the distillation process is conducted in a distillation column with an tray open area ratio of the perforated trays located at the rectifying section based on the tray open area ratio of the perforated trays located at the stripping section being 1:0.6 to 1:0.9.

3 . The method according to claim 1 , wherein the distillation process is conducted in a distillation column of which perforated trays are dual-flow-type countercurrent trays.

4 . The method according to claim 1 , wherein the feed point is any one point corresponding to 40 to 60% of total stages from the uppermost stage of the distillation column.

5 . An apparatus for continuous recovery of (meth)acrylic acid, comprising:
a (meth)acrylic acid absorption tower equipped with a mixed gas inlet to which mixed gas including (meth)acrylic acid, organic by-products, and vapor, which is produced by a synthesis reaction of (meth)acrylic acid, is fed, and a (meth)acrylic acid aqueous solution outlet from which a (meth)acrylic acid aqueous solution obtained by contact of the mixed gas with an absorption solvent including water is discharged; a (meth)acrylic acid extraction column equipped with a (meth)acrylic acid aqueous solution inlet connected with the aqueous solution outlet of the absorption tower through an aqueous solution transfer line, to which a part of the (meth)acrylic acid aqueous solution is fed, an extract outlet from which the (meth)acrylic acid extract obtained by contact of the introduced (meth)acrylic acid aqueous solution with an extraction solvent is discharged, and a raffinate outlet from which the raffinate solution obtained by contact of the (meth)acrylic acid aqueous solution with an extraction solvent is discharged; and a distillation column equipped with a feed point that is connected with the (meth)acrylic acid aqueous solution outlet of the absorption tower through an aqueous solution transfer line, and is connected with the extract outlet of the extraction column through an extract transfer line, to which a feed containing the remainder of the (meth)acrylic acid aqueous solution and the extract solution is supplied, and a (meth)acrylic acid outlet from which (meth)acrylic acid obtained by distillation of the introduced feed is discharged, wherein the distillation column has a plurality of stages partitioned by perforated trays, and wherein, based on the feed point, perforated trays located at a rectifying section have a lower tray open area ratio than perforated trays located at a stripping section.

6 . The apparatus according to claim 5 , wherein the ratio of the tray open area ratio of the perforated trays located at the rectifying section based on the tray open area ratio of the perforated trays located at the stripping section of the distillation column is 1:0.6 to 1:0.9.

7 . The apparatus according to claim 5 , wherein the perforated trays of the distillation column are dual-flow-type countercurrent trays.

8 . The apparatus according to claim 5 , wherein the feed point of the distillation column is any one point corresponding to 40 to 60% of total stages from the uppermost stage of the distillation column.

Assignees

• Lg Chemical Ltd

Inventors

• Song Jong Hun
• Baek Se Won
• Yoo Sul Hee
• Min Yoon Jae

Classifications

• C07C51/48

  by liquid-liquid treatment · CPC title

• B01D3/00

  Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping ({evaporation in general, e.g. of liquids for gas phase reactions B01B1/005;} gas chromatography B01D15/08; destructive distillation C10B; preparation of alcoholic beverages by distillation C12H6/02) · CPC title

• B01D11/04

  of solutions which are liquid · CPC title

• C07C51/44 Primary

  by distillation · CPC title

• C07C51/47

  by solid-liquid treatment; by chemisorption · CPC title