Processes for producing (meth)acrylic acid

摘要

In the purification and distillation step of acrylic acid (including (meth)acrylic acid), stable continuous operation for a long period is enabled by inhibiting the undesirable polymerization reaction of acrylic acid thereby to prevent the device from a trouble such as clogging. A process for producing acrylic acid which comprises purifying crude acrylic acid prepared by vapor-phase catalytic oxidation by distillation, wherein the concentration of beta-acryloxypropionic acid in the feed stream to a distillation column mainly for the separation of water from acrylic acid is controlled to be at most one-fiftieth of the concentration of acrylic acid; the concentration of beta-acryloxypropionic acid in the feed stream to a distillation column mainly for the separation of acetic acid from acrylic acid is controlled to be at most one-fortieth of the concentration of acrylic acid; and the concentration of beta-acryloxypropionic acid in the feed stream to a distillation column mainly for the separation of acrylic acid from water, acetic acid and a solvent is controlled to be at most one-fiftieth of the concentration of acrylic acid.