| 摘要 |
PURPOSE:To efficiently recover methacrolein, by extracting the methacrolein contained in an aqueous solution of methacrylic acid together with the methacrylic acid using an organic solvent and distilling and recovering the methacrolein with the solvent. CONSTITUTION:An aqueous solution, containing methacrylic acid and obtained by catalytically oxidizing isobutylene, tert-butanol, isobutyl aldehyde or methacrolein in the vapor phase with O2 in the presence of steam and cooling and condensing the reaction product gas is extracted with an organic solvent, preferably isopropyl acetate to extract the methacrolein contained in the above- mentioned aqueous solution together with the methacrylic acid into the organic solvent. The methacrolein is then distilled and recovered with the organic solvent from the extracted phase and further distillation is carried out to separate and recover the methacrolein. EFFECT:Since methacrylic acid is not present in a methacrolein recovery column, there is not fear of polymerization and distillation under ordinary pressure can be carried out without requiring a low-temperature refrigerant.
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