METHOD OF PREPARING PHENOL, ACETONE AND ALFA- METHYLSTYRENE, AND METHOD OF PREPARING PHENOL Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: phenol, acetone and alfa- methylstyrene are prepared by decomposition of cumene oxidation product comprising cumene hydroperoxide, cumene and dimethylphenyl carbinol in the presence of sulfuric acid. The claimed method comprises detaching cumene hydroperoxide in reversed mixing reactor at 55-80 C to obtain alfa-methylstyrene from dimethylphenyl carbinol and subsequently treating reaction mixture thus formed in piston flow reactor in which higher temperature is maintained. In reversed mixing reactor the process is carried out till conversion of dimethylphenyl carbinol of not higher than 35% is attained, acetone is added to the resulting reaction mixture and the latter is thereafter directed into piston-type reactor. Water concentration is maintained within 0.5-3.0 wt %. In order to obtain phenol, use is made of reaction mixture which comprises phenol, acetone, cumene, dimethylphenyl carbinol and dicumylperoxide. Phenol and acetone are present in equimolar amounts. To said reaction mixture is added acetone in amount that exceeds by 1.15-1.8 times acetone original concentration. Said mixture is heated to 80-100 C, and mixture is admitted into piston flow reactor for dehydration of dimethylphenyl carbinol and detachment of dicumyl peroxide, stream flowing out of piston flow reactor is immediately cooled and neutralized to stop reaction. EFFECT: increased yield of the desired products. 17 cl, 5 ex, 5 tbl