METHOD OF OBTAINING AQUAOUS (MET)ACRYLIC ACID Russian patent published in 2014 - IPC C07C51/44 C07C57/07 C07C51/215 C07C51/25 C07C51/43 C07C57/04 C07C51/42 

FIELD: chemistry.

SUBSTANCE: invention relates to method of obtaining aqueous acrylic acid from flow of gaseous material, which includes the following stages: a) supply of gaseous flow into condenser, where flow of gaseous material includes at least acrylic acid, water and formaldehyde; and b) operation of condenser and obtaining gaseous output flow, which includes non-condensed components released from the upper part of condenser, and condensed flow of aqueous acrylic acid, including acrylic acid, which is discharged from condenser mud-box, where flow of aqueous acrylic acid includes not more than 0.1 wt % of formaldehyde in terms of total weight of flow of aqueous acrylic acid. Flow, which contains (met)acrylic acid can represent flow of raw product of catalytic oxidation of at least one C₂-C₄-alkane or -alkene.

EFFECT: method is characterised by high concentration of (met)acrylic acid and lower concentration of formaldehyde, ie not higher than 0,1 wt %, than in aqueous (met)acrylic acid, obtained by application of separation methods known before.

8 cl, 1 dwg, 2 ex