US 2006/0069292 A1 · Methods for purifying p,p-bisphenol-A

Abstract

Methods for purifying a p,p-bisphenol A generally include distilling a feed stream comprising p,p-BPA in a distillation column at a pressure less than or equal to 20 millibars. The distillation column separates the bisphenol feed stream to produce a light fraction, an intermediate fraction and a heavy fraction. The intermediate fraction comprising the purified bisphenol contains lesser impurities that the p,p-BPA in the feed stream. In one embodiment, the intermediate stream is recovered using a side-draw. The side-draw is located between a first zone and a third zone in the distillation column.

Claims25

Dependent claims

A method for purifying p,p-bisphenol A, said method comprising:

distilling a feedstream comprising p,p-bisphenol A in a distillation column at a pressure less than or equal to 20 millibars;
producing a light fraction, an intermediate fraction, and a heavy fraction from the distillation column;
and
recovering the intermediate fraction, wherein the p,p-bisphenol A in the intermediate fraction contains less impurities than the p,p-bisphenol A in the feedstream.

1 more element

Dependencies are inferred from the claim text.

Methods for purifying p,p-bisphenol-A

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Methods for purifying p,p-bisphenol-A

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Abstract

Claims25