METHOD OF SEPARATING ACRYLIC ACID, CONTAINED AS MAIN COMPONENT, AND GLYOXAL, CONTAINED AS BY-PRODUCER IN GASEOUS MIXTURE OF PRODUCTS OF PARTIAL HETEROGENIOUSLY CATALYSED VAPOUR-PHASE OXIDATION OF COMPOUND, ACRYLIC ACID PRECURSOR, CONTAINING 3 CARBON ATOMS Russian patent published in 2014 - IPC C07C51/25 C07C51/43 C07C51/16 C07C51/44 C07C57/04 C07C57/05 C07C57/07 

FIELD: chemistry.

SUBSTANCE: invention relates to method of separating acrylic acid contained as main product, and glyoxal contained as by-product, in mixture of products of partial heterogeneously catalysed vapour-phase oxidation of acrylic acid precursor compound, which contains 3 carbon atoms, in which liquid phase P is obtained, which comprises acrylic acid to an extent of at least 70% of its weight, and, calculated for molar quantity of acrylic acid, contained therein, comprises at least 200 molar ppm of glyoxal, in which separation of glyoxal from acrylic acid is realised by crystallisation from liquid phase P.

EFFECT: method makes it possible to prevent undesirable polymerisation of acrylic acid.

25 cl