| abstract |
PURPOSE:To prevent after-oxidation of the aimed compound, by feeding and blending an inert gas, etc., to reaction production gas directly after outlet of reacting tube in producing methacrolein by subjecting isobutylene, etc., to catalytic vapor phase oxidation with a molecular oxygen-containing gas in the presence of a catalyst. CONSTITUTION:When isobutylene, tert. butanol or methacryl alcohol is subjected to catalytic vapor phase oxidation with a molecular oxygen-containing gas to provide methacrolein, an inert gas such as nitrogen, carbon dioxide or steam and/or reaction circulating gas (feed gas) is fed and blended to a reaction production gas directly after outlet of a reaction tube preferably at a linear velocity of 2 times or more of that of reaction production gas and flow rate of feed gas/reaction production gas of preferably 0.1-3.0, especially 0.3-1.5 so that temperature in being blended with the reaction production gas is 200-300 deg.C to prevent after-oxidation of the aimed compound without complicating and enlarging the apparatus and prevent lowering of the yield. |