Methyl methacrylate is made from isobutylene in two steps. Does methacrolein need to be purified before entering the next reaction, and if so, how to purify it?

Japan's Catalyst Chemical Company and Mitsubishi Rayon Company have successively realized the catalytic oxidative esterification of IB to synthesize MMA in industrial production. This process can be divided into three steps and two steps. The three-step method is that IB is oxidized to methacrolein (MAL) under the action of catalyst, and then MAL is oxidized to methacrylic acid (MAA) under the action of catalyst. Finally, MAA was esterified in the presence of strong acid catalyst to produce MMA；; Two-step method, also known as direct methylation method, combines the oxidative esterification process of MAL under the action of catalyst to produce MMA in one step. On the basis of further simplifying the process, the formation of intermediate acid is avoided, and the degree of greening is further improved.