METHOD FOR STEAM STRIPPING

摘要

PURPOSE:To feed a distilled gas to a distillation column for separating water without condensing the gas in removing a small amount of phenol in bisphenol A by steam stripping to obtain high-purity bisphenol A. CONSTITUTION:A reaction mixture 1 of phenol with acetone is fed to a dehydrochlorinating column 2 to provide a mixture 4 of the phenol with bisphenol A and reaction by-product from the column bottom. The obtained mixture is then cooled in a crystallization vessel 5 to afford a slurry 6 of an adduct of the bisphenol A with phenol. The resultant slurry is subsequently passed through a separator 7 and then phenol removing column 10 to give bisphenol A 12 containing a small amount of phenol from the column bottom. The above-mentioned bisphenol A 12 is fed to a steam stripping column 13 and brought into countercurrent contact with steam 14 to provide bisphenol A 15 and the distilled gas 16 is simultaneously fed to the column 2. Clogging by solidification of the distilled bisphenol A can be prevented according to this method.