FIELD: chemistry.
SUBSTANCE: method of (meth)acrylic acid purification includes the stages as follows: distillations of the liquid containing raw (meth)acrylic acid being acrylic acid or methacrylic acid with one or more polymerisation inhibitors added as chosen from group consisting of phenol derivative, phenothiazine derivative, copper (meth)acrylate and copper dithiourethane, for the purpose to produce condensate of (meth)acrylic acid, containing (meth)acrylic acid of purity at least 90%; adding polymerisation inhibitor containing phenol derivative to condensate; and delivery of oxygen-containing gas that contains oxygen to condensate of (meth)acrylic acid in reflux tank wherein condensate of (meth)acrylic acid is collected, wherein oxygen-containing gas is delivered to condensate in reflux tank with using small-size bubble liquid injector, and pressure connection for oxygen-containing gas delivery to liquid injector whereat ratio (nm/tn) of oxygen delivery in oxygen-containing gas and condensate flow supplied to reflux tank at 0°C, 1 atm complies with ratio shown in equation 0.004≤A/B≤1.0, where A stands for O2 delivery (nm3/hour), B stands for condensate flow (tn/hour) of the condensate supplied to reflux tank, and symbol n in nm3/hour specifies the value under normal conditions (0°C, 1 atm: normal conditions).
EFFECT: effective method of high purity acid production wherein acid polymer formation in made condensate is prevented.
12 cl, 6 dwg, 7 ex
