| abstract |
(57) [Problem] To provide a method for producing acrylic acid using an azeotropic dehydration tower and an acetic acid separation tower. SOLUTION: It is obtained in a catalytic gas phase oxidation reaction step of propylene and / or acrolein, a step of collecting acrylic acid contained in a reaction product gas of the catalytic gas phase oxidation reaction with a collecting aqueous solution, and a collecting step. Dehydrating an aqueous solution containing acrylic acid, wherein the dehydration step is performed by adding an azeotropic solvent that azeotropes with water and acetic acid, and distilling the acrylic acid. The acid concentration is adjusted to 0.06 to 0.80% by mass, and the azeotropic dehydration tower bottom liquid is substantially free of an azeotropic solvent and water. By the setting of the acrylic acid concentration, no polymer of acrylic acid is generated in each distillation column. In addition, by supplying the distillate from each distillation column to the acrylic acid production line, acrylic acid is effectively used to improve the yield, and the distillate is contained in the azeotropic solvent in the bottom liquid of the azeotropic dehydration column. This eliminates the energy required to separate the azeotropic solvent. |