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:
May. 13, 2008
Filed:
Sep. 29, 2004
Ramachandran Kumar, Bangalore, IN;
Gomatam Raghavan Ravi, Bangalore, IN;
Hyacinth Mary Bastian, Bangalore, IN;
Gururaj Sathyanarayana, Bangalore, IN;
Sheldon Jay Shafer, Clifton Park, NY (US);
Kumar Krishna Ramamurthy, Bangalore, IN;
Dwijaraja Mouli Murukutla, Bangalore, IN;
Venkata Rama Narayanan Ganapathy Bhotla, Puram Bangalore, IN;
Ramachandran Kumar, Bangalore, IN;
Gomatam Raghavan Ravi, Bangalore, IN;
Hyacinth Mary Bastian, Bangalore, IN;
Gururaj Sathyanarayana, Bangalore, IN;
Sheldon Jay Shafer, Clifton Park, NY (US);
Kumar Krishna Ramamurthy, Bangalore, IN;
Dwijaraja Mouli Murukutla, Bangalore, IN;
Venkata Rama Narayanan Ganapathy Bhotla, Puram Bangalore, IN;
General Electric Company, Schenectady, NY (US);
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.