| 摘要 |
PURPOSE:To collect liquid methacrylic acid industrially and advantageously, by recovering heat from a reaction gas containing methacrylic acid formed through the vapor phase oxidation reaction in a heat exchanger, and keeping the reaction gas temperature at the scrubber inlet at a specific value or above. CONSTITUTION:Methacrylic acid is formed in an oxidizing and dehydrogenating reactor 1 by the isobutyric acid, isobutyraldehyde, isobutylene or methacrolein method, and the heat is recovered by a heat exchanger 2 to keep the gas temperature at the inlet of a scrubber 3 at 130 deg.C or above, preferably 140 deg.C or above but not higher than the reaction temperature, more preferably 160-200 deg.C, and further cooled to collect the liquid methacrylic acid. A polymerization inhibitor, e.g. hydroquinone, may be added to the collected methacrylic acid to prevent the polymerization thereof. EFFECT:The method described above is industrial and advantageous from the viewpoint of load on the scrubber, heat loss, prevention of pipe clogging, etc. |
