Patent ID: 8178717

Claim:
A process for production of (meth)acrylic acid, comprising the steps of: a) synthesizing a crude (meth)acrylic acid phase wherein crude (meth)acrylic acid comprises from about 1 to about 80 wt % of (meth)acrylic acid; wherein said synthesizing a crude (meth)acrylic acid phase is selected from the group consisting of gas phase oxidation, dehydration of an organic molecule having at least one OH-group wherein the organic molecule is selected from the group consisting of glycerine, lactic acid and β-hydroxypropionic acid, optionally followed by an oxidation, and liquid phase oxidation b) distillatively working-up the crude (meth)acrylic acid phase to obtain: a (meth)acrylic acid phase, and a dimer phase comprising (meth)acrylic acid dimers or (meth)acrylic acid oligomers or both; c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain: a (meth)acrylic acid-comprising a low boiling phase, and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; wherein said high boiling phase is discarded; d) separating at least a part of the (meth)acrylic acid from the low boiling phase by forming one or more crystals to obtain: a pure (meth)acrylic acid, and a residue.