Process for preparing acrylic acid

Patent metadata

Field	Value
Publication number	US-12441676-B2
Application number	US-202117923885-A
Country	US
Kind code	B2
Filing date	Oct 27, 2021
Priority date	Dec 3, 2020
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

The present application relates to a process for producing acrylic acid.

First claim

The invention claimed is:

1. A process for producing acrylic acid, the process comprising:
(1) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by cooling a reaction product of a bio-raw material;
(2) separating a condensed second low-boiling-point material including acetaldehyde (ACHO) and a second high-boiling-point material including acrylic acid (AA) by compressing the first low-boiling-point material including acetaldehyde (ACHO);
(3) separating a first incompressible material and a third low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the condensed second low-boiling-point material including acetaldehyde (ACHO) and cooling thereof; and
(4) purifying the first high-boiling-point material including acrylic acid (AA) to obtain acrylic acid.

2. The process for producing acrylic acid of claim 1 , further comprising a process of adding a first absorbent during cooling the reaction product of the bio-raw material of the step (1).

3. The process for producing acrylic acid of claim 2 , wherein the first absorbent comprises 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).

4. The process for producing acrylic acid of claim 1 , wherein the second absorbent comprises a material having a boiling point which is 20° C. or higher than a normal boiling point (NBP) of the acetaldehyde (ACHO).

5. The process for producing acrylic acid of claim 1 , wherein the step (1) is performed by using a cooling tower; and
wherein 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.

6. The process for producing acrylic acid of claim 2 , wherein the first absorbent is included in an amount to make the acrylic acid (AA) included in the first low-boiling-point material of the step (1) to be 1 parts by weight or less with respect to 100 parts by weight of acrylic acid included in the reaction product of the bio-raw material.

7. The process for producing acrylic acid of claim 1 , wherein the step (3) is performed by using an absorption tower; and
wherein the absorption tower has a temperature of higher than or equal to 0° 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 10.0 bar.

8. The process for producing acrylic acid of claim 1 , wherein the second absorbent is included in an amount to make the acetaldehyde (ACHO) included in the first incompressible material of the step (3) to be 1 parts by weight or less with respect to 100 parts by weight of acetaldehyde included in the reaction product of the bio-raw material.

9. The process for producing acrylic acid of claim 1 , further comprising a step of circulating the second high-boiling-point material including acrylic acid (AA) of the step (2) to the step (1).

10. The process for producing acrylic acid of claim 1 , wherein the step (2) is performed by using a compressor; and
wherein the compressor has a discharge pressure of greater than or equal to 1.2 bar and less than or equal to 10.0 bar.

11. The process for producing acrylic acid of claim 1 , further comprising a step of separating the third low-boiling-point material including acetaldehyde (ACHO) into acetaldehyde and the second absorbent.

12. The process for producing acrylic acid of claim 11 , wherein the step of separating the third low-boiling-point material is performed by using a separation tower; and
wherein 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.

13. The process for producing acrylic acid 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.

14. The process for producing acrylic acid of claim 11 , wherein 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

• C07C57/04 Primary

  Acrylic acid; Methacrylic acid · CPC title

• C07C45/783

  by gas-liquid treatment, e.g. by gas-liquid absorption · CPC title

• C07C51/44 Primary

  by distillation · CPC title