METHOD OF PRODUCING (METH)ACRYLIC ACID Russian patent published in 2014 - IPC C07C51/43 C07C57/07 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing (meth)acrylic acid, where the method includes a crystallisation step by feeding a coolant from a cooler into a crystalliser and returning the coolant from the crystalliser into the cooler to obtain crystalline (meth)acrylic acid from a (meth)acrylic acid-containing solution; and a melting step by feeding heat carrier from the cooler into the crystalliser and returning the heat carrier from the crystalliser into the cooler, thereby melting the crystalline (meth)acrylic acid; where the crystallisation step and the melting step are carried out at least once to obtain purified (meth)acrylic acid from a solution of raw (meth)acrylic acid; temperature of the coolant coming out of the cooler is at a constant value T1; temperature of the coolant returning into the cooler is kept at a constant value T2 at the crystallisation step via a first control operation and/or a second control operation; temperature T2 is controlled depending on the obtained amount of purified (meth)acrylic acid per unit time; the first control operation is carried out by feeding at least a portion of the coolant to be returned to the cooler from the crystalliser into the top part of a first buffer tank and removing the coolant from the lower part of the first buffer tank and returning to the cooler; the second control operation is carried out by feeding at least a portion of the coolant to be fed into the crystalliser from the cooler and/or coolant to be returned to the cooler from the crystalliser into the lower part of the first buffer tank and removing the coolant from the top part of the first buffer container and returning to the cooler.

EFFECT: high efficiency of the method.

6 cl, 9 dwg, 2 ex