| 摘要 |
PURPOSE:To obtain methacrylic acid in high yield while decreasing the formation of high-boiling acid such as maleic acid, by contacting a solid compound of a specific alkaline earth metal with an oxidation product gas produced by the catalytic vapor-phase oxidation of methacrolein, etc., with molecular O2. CONSTITUTION:Methacrolein, isobutylaldehyde or isobutyric acid is subjected to catalytic vapor-phase oxidation with molecular O2 or a gas containing molecular O2 in the presence of an oxidation catalyst containing Mo and P and expressed by formula (X is Na, Li, K, Rb, etc.; Y is Cu, As, W, Al, Sm, etc.; a is 0.5-5; b and d are 0-5; c is 0-3; e is a number determined by the atomic valences of other elements). The obtained oxidation production gas is made to contact with a solid compound of one or more alkaline earth metals selected from Be, Ca, Mg, Sr and Ba, e.g. CaCO3, CaSO4, BeO, MgO, etc., and the resultant product is quenched to obtain methacrylic acid. |
