The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 2007
Filed:
Jun. 28, 2005
Michael Prein, Krefeld, DE;
Rob Eek, Leverkusen, DE;
Raymond Audenaert, Hamme, BE;
Bayer MaterialScience AG, Leverkusen, DE;
Abstract
A continuous process for the separation of phenol is disclosed. The process includes (a) feeding a stream of material, produced while preparing bisphenol A by reacting phenol with acetone, into a distillation column containing at least 5 theoretical separation stages, b) distilling-off the phenol as a top product and discharging from the column a bottom product containing secondary components, c) continuously introducing a portion of the bottom product into a dwell-time container operating at process parameters sufficient to cause, in the presence of an acidic catalyst, at least partial isomerization of the secondary components to form an isomerized product and d) introducing the isomerized product to the distillation column. The introducing of the bottom product is at a rate that is more than 30% of the rate of feeding of the stream at temperatures greater than 190° C. and hydrodynamic dwell time of at least 120 minutes.