PURPOSE: To prepare isobutyric acid useful as food additives, etc., in high conversion and reaction rate, by oxidizing isobutylaldehyde continuously with O2, etc. in a bubble column reactor, and recycling a part of extracted reaction liquid to the reaction column.
CONSTITUTION: Isobutyric acid is prepared continuously by oxidizing isobutyl aldehyde with O2 or an O2-containing gas, in liquid phase, using a bubble column reactor, in the presence of an alkali metal-containing compound at 50W70°C, pref. 55W65°C and a residence time of 1W10 hours, while extracting a part of the reaction mixture pref. by overflow, and recycling to the bottom of the bubble column reactor. The linear velocity of the recycled reaction mixture in the column is controlled to ≥5 m/hour, pref. ≥10 m/hour. Further oxidation of the reaction product in a reaction vessel with agitator, improves the conversion.
USE: Raw material of methacrylic acid and methyl methacrylate.
FUKAYA SHIGEO
MURAI NOBUYUKI
NOMA JIYUN
