OPTIMIZED METHOD OF PRODUCING METHACROLEIN Russian patent published in 2019 - IPC C07C45/75 C07C47/22 

FIELD: physics.

SUBSTANCE: present invention relates to a method for continuous Mannich reaction, in which methacrolein is obtained from formaldehyde and propionaldehyde using at least one acid and at least one amine as catalysts. Reaction is carried out in a continuous tubular reactor using temperature gradients, wherein temperature of fed reagents and catalysts at reactor inlet is from 100 to less than 150 °C, and temperature of reaction mixture at reactor outlet is not more than 180 °C, water content in the stream fed into the reactor is greater than 45 wt. % and not more than 85 wt. %, amount of the amine (organic base) in the stream fed into the reactor, containing a pure base, as well as part of corresponding base in salts with acid and in base containing intermediate compounds of Mannich reaction, is more than 5 mol. % in terms of propionaldehyde, internal pressure in the reactor is controlled so that it is greater than the boiling point of the reaction mixture and the residence time of the reaction mixture in the reactor ranges from 5 to 15 s.

EFFECT: disclosed method enables to obtain an end product with good output and low content of dimeric methacrolein.

12 cl, 2 tbl, 21 ex