Patent ID: 9738583
Date: 2017-08-22
CPC Classifications: B01J,C07C

Claim:
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