PROCESS FOR PREPARING ACRYLIC ACID WITH HIGH EFFICIENCY VIA TWO-STEP OF SEPARATION

摘要

PURPOSE: Provided is a process for preparing acrylic acid with high efficiency by virtue of minimizing the loss of acrylic acid and optimizing the collection of acrylic acid. CONSTITUTION: The process comprises the steps of (a) cooling and absorbing a reaction product obtained by vapor-phase catalytic oxidation of propylene, acrolein, or propylene and acrolein, using water to obtain an aqueous solution of acrylic acid, (b) supplying the aqueous solution of acrylic acid to a distillation tower and subjecting it to distillation under the presence of an azeotropic solvent to separate a distillate containing water and the azeotropic solvent, (c) phase-separating the distillate into an azeotropic solvent layer and a water layer, and refluxing the azeotropic solvent layer and a part of the water layer to the distillation tower, (d) collecting a mixture containing acetic acid and acrylic acid which is obtained in the step (b), and (e) separating out acetic acid and high boiling point impurities from the mixture to obtain acrylic acid.