| 摘要 |
Phenols, i.e. phenol itself and other compounds having one or more hydroxyl groups attached to a single aromatic nucleus and homologues thereof having alkyl groups attached to the aromatic nucleus, are separated from hydrocarbons, e.g. aromatic, paraffin or naphthene hydrocarbons, with which they are mixed by using glycerol, ethylene glycol, diethylene glycol or tri-ethylene glycol as a preferential solvent for the phenols. The process may be applied to mixtures of phenols and hydrocarbons, substantially free from bases or to mixtures, such as the neutral oil from a coaltar fraction, which contain both phenols and bases. Mixtures in which a substantial part of the phenolic content is phenol such as for example a mixture of 70 per cent hydrocarbon and 30 per cent of phenols composed of 45 per cent phenol, 15 per cent o-cresol, 21 per cent m-cresol and 14 per cent p-cresol may suitably be extracted with glycerol, or in the case where a substantial part of the phenolic content comprises cresols, the solvent may suitably be an aqueous, e.g. 63 per cent solution of tri-ethylene glycol. A preferred process comprises treating the mixture with the solvent, e.g. by countercurrent extraction, to give an extract rich in phenols, distilling off the solvent from the extract preferably under reduced pressure and steam-distilling the extract to give a mixture of phenols and water from which the water is removed by steam distillation. Alternatively, the mixture of phenols and water from the steam distillation may be separated into an aqueous fraction containing phenols, and a phenol fraction which may contain over 20 per cent of hydrocarbon oils. The aqueous phase may be extracted with hydrocarbon oils to recover the phenols, the resulting mixture of phenols and hydrocarbons being returned to the solvent extraction stage. Similarly the phenolic phase containing hydrocarbon oils may also be returned to the extraction stage. A continuous process for separating phenols and hydrocarbon oils is described.
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