Process for producing acrylic acid

Patent metadata

Field	Value
Publication number	US-12570595-B2
Application number	US-202117921693-A
Country	US
Kind code	B2
Filing date	Oct 27, 2021
Priority date	Dec 3, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

Provided is a process for producing acrylic acid, wherein the process comprises a first step and a second step in which a first absorbent is added to a reaction product of a bio-material and cooled to separate a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA). The process is capable of producing high-purity acrylic acid at high yield, and acetaldehyde is produced as by-product along with the reaction product of the bio-material. The process includes separating the acetaldehyde produced as by-product into a high-purity product at high yield.

First claim

The invention claimed is:

1 . A process for producing acrylic acid, the process comprising:
(step 1 ) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by adding a first absorbent to a reaction product of a bio-raw material and cooling the result; (step 2 ) separating a second low-boiling-point material including acetaldehyde (ACHO) and a second high-boiling-point material including acrylic acid (AA) by distilling the first high-boiling-point material including acrylic acid (AA); (step 3 ) separating a first incompressible material and a third low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the first low-boiling-point material including acetaldehyde (ACHO) and cooling the result; and (step 4 ) producing acrylic acid by purifying the second high-boiling-point material including acrylic acid (AA), wherein the step 3 includes a step of separating through an absorption tower; and the absorption tower has a temperature of higher than or equal to 0° C. and lower than or equal to 100° C. and an inner pressure of greater than or equal to 0.1 bar and less than or equal to 10.0 bar.

2 . The process of claim 1 , wherein the first absorbent includes a material having a boiling point difference of 20° C. or higher compared to a normal boiling point (NBP) of the acrylic acid (AA) and a boiling point difference of 50° C. or higher compared to a normal boiling point (NBP) of the acetaldehyde (ACHO).

3 . The process of claim 1 , wherein the second absorbent includes, as a material having a higher boiling point compared to a normal boiling point (NBP) of the acetaldehyde (ACHO), a material having a boiling point difference of 20° C. or higher.

4 . The process of claim 1 , wherein the step 1 includes a step of separating through a cooling tower; and
the cooling tower has a cooling temperature of higher than or equal to 10° C. and lower than or equal to 150° C. and an inner pressure of greater than or equal to 0.5 bar and less than or equal to 5.0 bar.

5 . The process of claim 1 , wherein the first absorbent is included so that acrylic acid (AA) included in the first low-boiling-point material of the step 1 is included in 1 parts by weight or less with respect to 100 parts by weight of acrylic acid in the reaction product of the bio-raw material.

6 . The process of claim 1 , wherein the second absorbent is included so that acetaldehyde (ACHO) included in the first incompressible material of the step 3 is included in 1 parts by weight or less with respect to 100 parts by weight of acetaldehyde in the reaction product of the bio-raw material.

7 . The process of claim 1 , wherein separating of the second low-boiling-point material including acetaldehyde (ACHO) is carried out in step 2 and the separating of the third low-boiling-point material including acetaldehyde (ACHO) is carried out in step 3 to separate acetaldehyde and the second absorbent.

8 . The process of claim 7 , wherein the separating the second low-boiling-point material includes separating through a separation tower; and
the separation tower has a temperature of higher than or equal to 10° C. and lower than or equal to 200° C. and an inner pressure of greater than or equal to 0.3 bar and less than or equal to 10.0 bar.

9 . The process of claim 1 , wherein the second absorbent has a temperature of higher than or equal to −5° C. and lower than or equal to 20° C.

10 . The process of claim 7 , wherein a purity of the acetaldehyde is 95% or greater, and a recovery rate thereof based on the reaction product of the bio-raw material is 95% or greater.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Hyebin
• Kim Mi Kyung
• Kim Eunkyo
• Shin Joon Ho

Classifications

• C07C51/44 Primary

  by distillation · CPC title

• C07C57/04

  Acrylic acid; Methacrylic acid · CPC title

• C07C51/47 Primary

  by solid-liquid treatment; by chemisorption · CPC title