GB649286A - Manufacture of phenol - Google Patents

Abstract

Phenol substantially free from acetophenone is obtained from the mixture containing phenol, acetone, acetophenone and methyl styrene made by oxidising isopropyl benzene to isopropyl benzene hydroperoxide and decomposing the latter in solution in unchanged isopropyl benzene by extracting with water at 50-100 DEG C., preferably 70-80 DEG C., and recovering the phenol from the aqueous extract. The process is preferably effected after acetone has been removed, e.g. by distillation. Phenol may be recovered from the aqueous solution by any suitable method, e.g. extraction with a selective solvent such as butyl acetate or diisopropyl ether. Treatment in countercurrent is preferred. The isopropyl benzene phase may be purified and recycled to the oxidation stage. Thus acetophenone may be separated by distillation, methyl styrene hydrogenated to isopropyl benzene and if necessary small quantities of phenol removed by extraction with aqueous alkali metal hydroxide solution. De-composition is effected by acids, e.g. sulphuric acid. In an example a mixture resulting from the oxidation of isopropyl benzene and decomposition with aqueous sulphuric acid is fed to a distillation column to remove acetone, treated in countercurrent with water in a tower at 70-80 DEG C., the extracted isopropyl benzene after distillation to remove acetophenone and treatment to remove methyl styrene is recycled to the oxidation stage, the aqueous extract is cooled to 20 DEG C. and treated in countercurrent with butyl acetate the aqueous residue being treated for solvent recovery and then passed to the first tower, phenol being recovered from the butyl acetate by distillation and finally separated from a small quantity of acetophenone by distillation. Specifications 626,095, 629,429 and 630,286 are referred to.