PHENOL MANUFACTURE IN GERMANY BY THE CHLORINATION, SULFONATION, AND RASCHIG PROCESSES

摘要

A comparative study la presented of the three processes which are in use today, for the manufacture of phenol. In one process, chlorobenzemea la made by the chlorination of benzene, and hydrolyzed to phenol with aqueous sodium hydroxide at high temperatures and pressures. This s the most straightforward process. In another, benzene sulfonic add is made by the treatment of benzene with excess 100 percent sulfuric acid and is fused with sodium hydroxide at high temperatures in open pans to give phenol. This process is the classical one and its economy is largely dependent on the Market for the by-product sodium sulfite. In the third process, chlorobenzene is made by the catalytic reaction of hydrogen chloride, benzene, and air. The chlorobenzene is subsequently hydrolyzed at high temperatures by steam in the presence of a catalyst, thereby producing phenol and regenerating hydrogen chloride. This process involves two reactions, each of which operate at a low conversion, per pass. It is the most efficient in regard to consumption of raw materials but involve serious corrosion problems.