Patent ID: 7981255

Claim:
A method for rectifying a vinyl compound liquor, comprising: a) providing a rectification column operated at a temperature of from 40 to 130° C. and a pressure of from 1 to 80 kPa; b) feeding the vinyl compound liquor into the rectification column, which is heated by the operating temperature of the rectification column in a), when an overhead output in the rectification column is more than a bottom discharge, said vinyl compound liquor comprises a vinyl compound, said vinyl compound is one selected from the group consisting of (meth)acrylic acid, (meth)acrylate salt and (meth)acrylic esters; wherein the temperature of said fed vinyl compound liquor is controlled to be in a range of from its bubble point at the pressure of said rectification column to 10° C. lower than said bubble point, so that the rectification column is not clogged caused by spontaneous polymerization of the vinyl compound.