| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method enabling continuous preparation of methacrylic acid over a long period of time through vapor-phase catalytic oxidation of methacrolein under a condition wherein reduction of a catalytic activity is suppressed. <P>SOLUTION: When preparing methacrylic acid through vapor-phase catalytic oxidation reaction of methacrolein by feeding raw material gas containing methacrolein, molecular oxygen and water vapor to a fixed bed reactor filled with a heteropolyacid catalyst containing phosphorus, molybdenum and vanadium. Initial operation is performed at a reaction temperature of 290-310°C, and steady operation is subsequently performed at a reaction temperature of 270-lower than 290°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
