| 摘要 |
<p>Methacrylic acid is produced by subjecting isobutyric acid to oxidative dehydrogenation in a gaseous phase in the presence of a catalyst contg. heteropoly-acid of formula: H3+xMo12-x-yWyVxPO40, (where x is 0,1,2 or 3; and y is 0,1,2 or 3; anx x + y 5) and/or its reduced type, and a carrier contg. a relatively large amt. of silicic acid so that the water absorption is >=60% is employed. Examples of carriers contg. relatively large amt. of silicic acid are silica-gel, diatomaceous earth. The ratio of isobutyric acid to oxygen = 0.1-10, concentration of isobutyric acid = 0.1-10 vol. %, temp. is 200-450 degrees C and LHSV - 100-8000 hr-1. The isobutyric acid conversion rate is 56.0-60.2%, methacrylic acid selectivity rate is 70.0-65.0%.</p> |
