PROCESS FOR PREPARATION OF HIGH PURITY METHACRYLIC ACID

摘要

The present invention relates to a process for preparation of pure methacrylic acid, at least comprising the process steps: a) gas phase oxidation of a C4 compound to obtain a methacrylic acid-comprising gas phase, b) condensation of the methacrylic acid- comprising gas phase to obtain an aqueous methacrylic acid solution, c) separation of at least a part of the methacrylic acid from the aqueous methacrylic acid solution to obtain at least one crude methacrylic acid- comprising product; d) separation of at least a part of the methacrylic acid from the at least one crude methacrylic acid -comprising product by means of a thermal separa tion process to obtain a pure methacrylic acid.