Process for the production of phenols

In a process for the production of phenols and by-product ketone by the acid catalysed decomposition or alkaryl hydroperoxides superheating of the surface layer of the reaction mixture and the gas phase above is minimised by condensing vaporized ketone and intimately premixing and diluting the alkaryl hydroperoxide within the reaction vessel with the recycled stream of condensed ketone before contact with the acid reaction mixture. The premixing of the hydroperoxide and ketone may be effected by causing jets of the liquid reactants to impinge in the gas phase above the reaction mixture, or to impinge on an open surface, e.g. a plate positioned above the reaction mixture, or on the sides or roof of the vessel itself. In a preferred embodiment shown in Figs. 1 and 2, premixing is effected by introducing the hydroperoxide and ketone into the reaction vessel through two separate coaxial sparging rings of different radii. The ketone is preferably fed into the larger sparging ring 2 from line 1 and the hydroperoxide into the smaller sparging ring 3 from line 4. A stream of ketone and a stream of hydroperoxide are fed through holes 5 and 6 provided in rings 2 and 3 respectively into radially sloping troughs 7. The streams become suitably admixed as they flow down the trough and the mixture is discharged into the reaction mixture below. The reaction may be carried out at 50 DEG to 90 DEG C.; at atmospheric or under reduced pressure and employing between 0.05 and 10% by weight based on the total weight of reaction mixture of acid catalyst. The hydroperoxide may be utilised in the form of pure hydroperoxide or in the form of a crude oxidation mixture containing the hydroperoxide. The invention is described by reference to the sulphuric acid-catalysed decomposition of cumene hydroperoxide to give acetone and phenol. Specification 684,039 is referred to.