METHOD OF PRODUCING METHACROLEIN AND ITS AIR-CONDITIONING / DEHYDRATION FOR DIRECT OXIDATIVE ETHERIFICATION Russian patent published in 2018 - IPC C07C67/39 C07C69/54 C07C45/75 C07C45/82 C07C47/22 

FIELD: chemistry.

SUBSTANCE: invention relates to the method of continuous producing methyl methacrylate, includes the stages of A) producing methacrolein from propanal and formaldehyde in the presence of amine salts, B) isolating liquid crude methacrolein by distillation in the first distillation column and the subsequent separation from the aqueous phase, C) distilling crude methacrolein obtained in stage B) in the second distillation column in the presence of methanol, D) subsequent oxidative esterificating methacrolein obtained in stage C) with methanol and oxygen in the presence of noble metal containing a heterogeneous oxidation catalyst containing metals and/or metal oxides in the reactor, and E) distilling the product obtained in stage D) in a distillation column and recycling the distillate containing methacrolein and methanol to the reactor of stage D), where the distillation columns of stages C) and E) represent one of the single distillation column, and methanol at stage C) is recovered from the reactor of stage D) and submitted together with the product obtained in stage D) to the second distillation column, and additional methanol optionally is added to the second distillation column in stage E).

EFFECT: increasing the efficiency and yield of the method as compared to the prior art through a sequence of different distillation stages.

14 cl, 2 dwg