Process for preparing acrylic acid

Patent metadata

Field	Value
Publication number	US-9738583-B2
Application number	US-201615348130-A
Country	US
Kind code	B2
Filing date	Nov 10, 2016
Priority date	Nov 11, 2015
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A process for preparing acrylic acid from formaldehyde and acetic acid, is performed by (i) providing a gaseous stream S1 comprising formaldehyde, acetic acid, oxygen and water, where the formaldehyde content of stream S1 is in the range from 8% to 18% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde is in the range from 0.6:1 to 1.1:1, and the molar ratio of oxygen to the total amount of organic carbon is in the range from 0.02:1 to 0.15:1; and (ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 containing acrylic acid.

First claim

The invention claimed is:

1. A process for preparing acrylic acid from formaldehyde and acetic acid, comprising
(i) providing a gaseous stream S1 comprising formaldehyde, acetic acid, oxygen and water, where the formaldehyde content of stream S1 is in the range from 8% to 18% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde is in the range from 0.6:1 to 1.1:1, the molar ratio of oxygen from gaseous stream S1 to the total amount of organic carbon is in the range from 0.02:1 to 0.15:1 and the ratio of the volumes of formaldehyde to water is in the range from 0.8:1 to 1.3:1;
(ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 comprising acrylic acid, wherein the aldol condensation catalyst in (ii) comprises a vanadium phosphorus oxide V x P y O z wherein the x:y weight ratio is in the range from 1:0.5 to 1:5, and the x:z weight ratio is in the range from 1:0.1 to 1:10.

2. The process according to claim 1 , wherein the space velocity GHSV in the reaction zone is in the range from 800 to 6500 h −1 and is defined as the total volume flow rate of stream S1, in m 3 /h, per unit catalyst volume, in m 3 , under standard conditions at 0° C.; absolute pressure 1.013 bar.

3. The process according to claim 1 , wherein the temperature in the reaction zone, defined as the temperature at which stream S1 is contacted with the aldol condensation catalyst, is in the range from 350 to 400° C.

4. The process according to claim 1 , wherein the formaldehyde content of stream S1 is in the range from 8% to 14% by volume, based on the total volume of stream S1.

5. The process according to claim 1 , wherein the ratio of the volumes of acetic acid to formaldehyde in stream S1 is in the range from 0.9:1 to 1.1:1.

6. The process according to claim 1 , wherein the space velocity GHSV in the reaction zone is in the range from 800 to 2600 h −1 .

7. The process according to claim 1 , wherein the temperature in the reaction zone is in the range from 360 to 380° C.

8. The process according to claim 1 , wherein the formaldehyde content of stream S1 is in the range from 8% to 14% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde in stream S1 is in the range from 0.9:1 to 1.1:1, the molar ratio of oxygen to the total amount of organic carbon is in the range from 0.02:1 to 0.15:1, the ratio of the volumes of formaldehyde to water is in the range from 0.8:1 to 1.3:1, the space velocity GHSV in the reaction zone is in the range from 800 to 2600 h −1 and the temperature in the reaction zone is in the range from 360 to 380° C.

9. The process according to claim 1 , wherein the ratio of the volumes of acetic acid to formaldehyde in stream S1 is in the range from 0.75:1 to 1.1:1.

10. The process according to claim 1 , wherein the space velocity GHSV in the reaction zone is in the range from 1600 to 6500 h −1 .

11. The process according to claim 1 , wherein the temperature in the reaction zone is in the range from 380 to 400° C.

12. The process according to claim 1 , wherein the formaldehyde content of stream S1 is in the range from 8% to 18% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde in stream S1 is in the range from 0.75:1 to 1.1:1, the molar ratio of oxygen to the total amount of organic carbon in stream S1 is in the range from 0.02:1 to 0.15:1, the ratio of the volumes of formaldehyde to water in stream S1 is in the range from 0.8:1 to 1.3:1, the space velocity GHSV in the reaction zone is in the range from 1600 to 6500 h −1 and the temperature in the reaction zone is in the range from 380 to 400° C.

Assignees

• Basf Se

Inventors

• Hartmann Marco
• Schulz Lukas
• Woerz Nicolai Tonio
• Liu Yong
• Brueggemann Till Christian
• Lejkowski Michael
• Lieberknecht Johannes

Classifications

• C07C57/04

  Acrylic acid; Methacrylic acid · CPC title

• C07C51/353 Primary

  by isomerisation; by change of size of the carbon skeleton · CPC title

• B01J37/0201

  Impregnation · CPC title

• B01J23/002

  Mixed oxides other than spinels, e.g. perovskite · CPC title

• B01J2523/00

  Constitutive chemical elements of heterogeneous catalysts · CPC title