Abstract:
PROBLEM TO BE SOLVED: To easily separate impurities in a process for producing (meth)acrylic acid, without making difficult the crystallization of (meth)acrylic acid to be carried out successively.SOLUTION: The process includes first forming crude (meth)acrylic acid, and then continuously refining the crude (meth)acrylic acid, wherein the continuous refinement process includes: a step (a) of depositing impurities as crystals from a composition containing (meth)acrylic acid and the impurities; and a step (b) of separating the deposited crystal impurities from the composition. There are also provided (meth)acrylic acid obtained by the process, a production apparatus of (meth)acrylic acid, use of a refining apparatus of the apparatus or to produce (meth)acrylic acid, (meth)acrylic acid, a water-absorbing polymer, use of a water-absorbing polymer, a fiber, a sheet, a foam and a composite.
Abstract:
PROBLEM TO BE SOLVED: To provide an apparatus for producing high purity (meth)acrylic acid.SOLUTION: The apparatus for producing (meth)acrylic acid includes a synthesis section for synthesizing a crude (meth)acrylic acid phase, a section for the distillation treatment of the crude (meth)acrylic acid, a pressure container for decomposing at least part of the (meth)acrylic acid dimer and the (meth)acrylic acid oligomer or both from the dimer phase to obtain a low-boiling point solvent phase containing (meth)acrylic acid and the like, and a crystallization section for separating at least part of the (meth)acrylic acid from the low-boiling point solvent phase by crystallization.