Patent ID: RE41290

Claim:
A process for purifying phenol-containing bisphenol A comprising a first step in which crude molten bisphenol A containing phenol is supplied to a flash evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising bisphenol A and residual phenol, and a second step in which the liquid phase obtained in the first step is heated by a thin film evaporator and separated into a gaseous phase comprising phenol and a liquid phase comprising concentrated bisphenol A and residual phenol, wherein part of the liquid phase obtained in the first second step being circulated to the first step and supplied to the flash evaporator along with crude molten bisphenol A , and further comprising a purification step with water vapor in which the concentrated liquid phase of bisphenol A obtained in the second step is supplied to the top of a packed column to let it flow down in the column while water vapor is blown into the column from its bottom to let it rise in the column so that phenol in the concentrated liquid phase of bisphenol A is removed entrained by water vapor .