Phenol

Brief Overview

Phenol solution comprises of a white crystalline mass dissolved in an aqueous solution. The solution may be colorless to slightly pink in color with a distinctive phenol odor and a sharp burning taste. Aqueous solutions of phenol are weakly acidic and turn blue litmus slightly to red.

Manufacturing Process

The vast majority of phenol is made by the cumene process, which comprises of three stages:

1) Production of Cumene

Cumene is produced via the Friedel-Crafts reaction by reacting benzene and propene with an acid catalyst such as ZSM-5, under pressure (ca 10 atm) in a fixed bed reactor.

2) Conversion of Cumene to Cumene hydroperoxide

Cumene is then oxidized with air to give the hydroperoxide and the reaction is autocatalyzed by cumene hydroperoxide. The reaction takes place at temperatures between 350-390 K and 1-7 atm pressure, the latter to retain the system in the liquid phase. At higher temperatures, the hydroperoxide is unstable and could decompose violently.

3) Decomposition of Cumene hydroperoxide

Finally, the hydroperoxide is mixed with sulfuric acid at 313-373 K to give phenol and propanone. The products are separated by distillation and a product yield of 85-87% is obtained, based on benzene.

Phenol is used to make chemical intermediates for a wide range of other applications.

Dyes
Phenol is used to produce phenylamine (aniline) which is used in the manufacturing of dyes.

Pharmaceutical Industry
Phenol is used in the production of antiseptics such as 2,4-and 2,6-dichlorophenols.
Plastics
Phenol is used to manufacture bisphenol A, which is used to make polycarbonates for plastics.

Synthetic Polymers
Phenol is used to produce epoxy resins for paints, coatings and mouldings.