Patent ID: 8426640

Claim:
Production method for acrylic acid comprising: A) a step of obtaining an acrylic acid-containing gas by catalytic gas-phase oxidation reaction of a gas containing an acrylic acid raw material; B) a step of obtaining an acrylic acid-containing solution by introducing the acrylic acid-containing gas to a collection column or a condensation column and performing collection or condensation; and C) a step of obtaining a crude acrylic acid by introducing the acrylic acid-containing solution to a distillation column or a crystallizer and performing distillation or crystallization, C′) a step of obtaining acrylic acid product by introducing the crude acrylic acid from the distillation column into a high boiling point distillation column for further distilling, or by introducing the crude acrylic acid from the crystallizer to a crystallizer for further crystallizing; wherein a step of heat treating the acrylic acid-containing solution or the crude acrylic acid, containing 100 ppm by mass or more of protoanemonin, under the condition of 100° C. or more of temperature, 1 hour or more of time; and a step of introducing the acrylic acid-containing solution or the crude acrylic acid, having been heat treated, to the collection column, the condensation column, the distillation column or the crystallizer, are included in the production method wherein the step of heat treating decreases the amount of protoanemonin to 60% or less of that before the heat treatment.