| 摘要 |
PURPOSE:To obtain methacrylic acid in high yield along with stable use of the catalysts for a long period of time, by introducing compound(s) selected from methacrolein, isobutyraldehyde and isobutyric acid into a specific catalytic bed packed with plural catalyst differing in activity from one another followed by oxidation with O2. CONSTITUTION:At least one compound selected from methacrolein, isobutyraldehyde and isobutyric acid is introduced into a catalytic bed prepared by packing (A) plural reaction zones provided by dividing a reaction tube in its axial direction with (B) plural catalysts differing in activity from one another in such a way as to rise in catalytic activity from the stock gas inlet toward the outlet, followed by oxidation with O2 or an O2-contg. gas, thus obtaining the objective methacrylic acid. With this method, high yield can be attained and the heat storage at the hot spots within the catalytic bed suppressed. Thereby, the catalysts will be prevented from deterioration and used stably for a long period of time. |
