摘要:
Impurities are removed from phenol by a process, comprising: first treating phenols containing impurities with at least one acid catalyst which converts the impurities into compounds which can be separated from phenol; separating the acid treated phenol from the compounds; and treating the distilled phenol a second time with at least one acid catalyst; thereby effectively removing the impurities from phenol.
摘要:
A process for reducing the salt content of fractions comprising high boilers obtained in the preparation of phenol from cumene, by extraction, is claimed. In the preparation of phenol from cumene, not only phenol and acetone but also by-products such as dimethyl phenyl carbinol or acetophenone are formed in the cleavage of cumene hydroperoxide. In the work-up of the cleavage product phase by distillation, these by-products are obtained as a fraction which boils only at high temperatures. These fractions further comprise alkali metal in the form of salts as a result of the neutralization by means of aqueous sodium hydroxide after the acid catalyzed cleavage. The presence of salt in this phase makes the work-up of this phase considerably more difficult. The salt is usually removed from the fraction by extraction of the fraction with water. However, considerable problems can occur if the aqueous phase cannot be cleanly separated from the organic phase. According to the invention, not only water but also an organic liquid is added to the fractions comprising high boilers for the purposes of extraction. This aids and accelerates the subsequent phase separation. The organic liquid to be added to the fractions comprising high boilers can be removed again from the treated fractions by simple distillation. Furthermore, the process of the invention lowers the phenol content of the fractions comprising high boilers and phenol is recovered. Fractions comprising high boilers which have been treated according to the invention can be used as starting material for the production of carbon black.