The invention relates to a method for purification of phenol and specifically to a method for purification of phenol produced within the process of joint phenol and acetone production by cumene method The aim of the invention is to develop a catalyst which has high activity for phenol purification from organic mico-impurities with regeneration of the catalyst and which has high mechanical strength and stability with long catalyst life This result is obtained by phenol purification using a heterogeneous zeolite catalyst The acidity of the catalyst measured by butane cracking (K A ) is more than 10 It is preferable to use zeolites which are designated according to the classification of the International Zeolite Association by indices FAU (zeolites X, Y), MFI (for example, ZSM-5), MOR (mordenite), MAZ (omega), BEA (beta), FER (ferrierite) and others These zeolites can be used with binders (aluminum oxide, silica gel, aluminosilicates or aluminophosphates) and without them It is preferable to use zeolite of the Y type with an aluminosilicate binder and a the value of K A =50-80 cm 3 /min*g and Si/Al ratio more than 3 The concentration of sodium, potassium and other alkali agents on the basis of their oxides does not exceed 2 wt %, preferably not more than 03 wt % It is preferable to use zeolites with medium and large pores Size of zeolites pores should be within the range 4 Å in diameter and more The most preferable zeolites are with large pores (>6 Å in diameter) such as Y and mordenite

Method for purification of phenol

1,148,907. Purification of phenol. IMPERIAL CHEMICAL INDUSTRIES Ltd. 14 Nov., 1966 [26 Nov., 1965], No. 50342/65. Heading C2C. Phenol, derived from cumene via the hydroperoxide, is purified by bringing it into contact at elevated temperatures with a synthetic silicaalumina hydrocarbon cracking catalyst under substantially anhydrous conditions (i.e. not more than 1% by volume of H 2 O is present in the phenol) and recovering the purified phenol. The catalyst is suitably of synthetic silicaalumina catalyst which is highly active as a hydrocarbon cracking catalyst and which contains 5 to 30% by weight alumina and 95 to 70% by weight silica and which may also contain from 0A01 to 5% of chromium, molybdenum or tungsten as such or in the form of a compound such as chromium sesquioxide. The phenol starting material is that obtained from cumene which may have been partially refined by removal of hydrocarbons and high boiling materials by distillation. Examples are furnished.

Purification of phenols

A process for the reduction of methylbenzofuran (MBF) impurities in phenol obtained from the decomposition product of cumene hydroperoxide requires treating the phenol to reduce the level of acetol, contacting the phenol containing a low level of acetol with an acid resin at sufficient temperature and residence time to reduce the level of MBF by conversion to higher boiling compounds, then distilling the phenol to separate phenol from higher boiling compounds. The phenol may be treated in known ways, such as by treatment with an amine, to reduce the level of acetol. The phenol containing a low level of acetol is contacted with a strong acid resin to reduce the level of MBF.

Phenol with low levels of methylbenzofuran

Phenol feed to a steam distilling column, containing alpha-methylstyrene and mesityl oxide, is treated with a base, without acidification, and the heavy phenol product is acidified and distilled in a high purity column to recover high purity phenol as a sidestream and lighter components as overhead. Acidification after steam distilling, rather than prior to steam distilling, increases phenol recovery by reducing the overhead pasteurizing cut from the high purity column.

Production of high purity phenol

1,193,300. Purification of phenol. HALCON INTERNATIONAL Inc. 16 June, 1967 [23 June, 1966], No. 27925/67. Heading C2C. Pure phenol is prepared by treating crude phenol, obtained by the dehydrogenation of a cyclohexanol or cyclohexanone product of a cyclohexane oxidation process with a silicaalumina containing material and fractionating the treated phenol. Preferably the crude phenol is passed through a column containing the silica-alumina, preferably 50-95% SiO 2 and 5-30% Al 2 O 3 , in the form of beads or pellets, at 60-200‹ C.

Purification of phenol

A process for the purification of phenol derived from cumene and containing colour forming impurities including aliphatic a -hydroxy carbonyl compounds comprises subjecting the impure phenol at an elevated temperature to conditions which will cause the substantially complete condensation of the aliphatic a -hydroxy carbonyl compounds with phenol to form benzofurans and separating the phenol substantially completely from the benzofurans. The condensation of the a -hydroxy carbonyl condensation of the a -hydroxy carbonyl compounds with phenol may be carried out by heating the phenol in liquid or vapour phase at atmospheric, reduced or elevated pressures and optionally in the presence condensation catalysts such as activated alumina, aluminium silicate e.g. acid-or alkali-treated pumice or porcelain, acidic or basic ion exchange resins, mineral acids e.g. sulphuric and phosphoric acid, especially in the presence of iron, strong organic acids, e.g. p-toluene sulphonic acid and surface active earths e.g. montmorillonites such as fuller's earth, bentonite and attapulgite which may be acid-activated or alkali or heattreated. In the liquid phase treatment activated charcoal or metal halides of the Friedel-Crafts type and sulphates of the same metals e.g. aluminium ferric, nickel and zinc chlorides, aluminium, ferric and nickel sulphates or boron trifluoride maye be employed as catalyst. The vapour phase treatment may be carried out by passing the vaporised phenol through a tube which may be packed with catalyst. The liquid phase treatment may be carried out batchwise or continuously. The separation of the phenol from the benzofurans and other impurities is carried out by neutralisation of the phenol with an alkali followed by extraction of the benzofurans with a solvent or by steam distillation or by extractive distillation in the presence of a suitable solvent and preferably by extractive distillation in the presence of water, benzofurans being removed overhead. The aqueous phenol may be subjected to dehydration and fractional distillation. The tendency for the phenol to form coloured products on sulphonation and chlorination is shown to be substantially reduced after purification. Examples are furnished in which crude phenol obtained from cumene by oxidatation and an acid-cleavage of the hydroperoxides formed, is purified.

Jr Harrison M Lavender

Papers

Purification of phenol