Methacrolein → Methyl Methacrylate

Participants

Reaction Steps

240 g of the above-obtained activated catalyst was charged in the bubble column reactor of the same type as mentioned above, and a reaction for producing methyl methacrylate (MMA) was carried out as follows. A 36.7% by weight solution of methacrolein in methanol and a 2 to 4% by weight solution of NaOH in methanol were continuously fed to the reactor at 0.54 liter/hr and at 0.06 liter/hr, respectively (the methacrolein concentration in the reaction system consisting of the above-mentioned two different solutions was about 33% by weight), while introducing air to the reactor so that the oxygen concentration at the outlet of the reactor became 4.0% by volume (which is equivalent to the oxygen partial pressure of 0.20 kg/cm2), thereby effecting a reaction for producing MMA. The reaction was conducted at a temperature of 80° C. under a pressure of 5 kg/cm2. The concentration of NaOH in the above-mentioned methanol solution of NaOH was controlled so that the reaction system has a pH of 7.1. The reaction mixture obtained by the above reaction was continuously withdrawn by overflowing from the outlet of the reactor. Analysis was made with respect to the reaction mixture which was withdrawn from the outlet of the reactor 10 hours after the start of the reaction. As a result, it was found that the conversion of methacrolein was 57.3%, the selectivity for MMA was 90.7%, and the selectivity for propylene as a by-product was 1.7%, and that methyl formate was by-produced in an amount of 0.085 mol/mol of MMA. It was also found that the productivity of MMA was 0.49 {MMA(g)/g of catalyst.hr}.

Provenance & Evidence