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. 28, 2002
Filed:
Oct. 14, 1999
Heather K. Miles, Newark, CA (US);
Donald H. Westermann, Greenfield, WI (US);
Glenn F. Cunningham, Houston, TX (US);
ChemCycles, Inc., Houston, TX (US);
Abstract
A method and apparatus for purifying acetonitrile from low grade acetonitriles. Low grade acetonitrile from DNA synthesis, HPLC and pharmaceutical drug manufacturing process wastes which comprise acetonitrile, a first set of impurities having a lower boiling temperature than acetonitrile and a second set of impurities having a boiling temperature greater than acetonitrile are processed to produce a purified acetonitrile by first introducing the low grade acetonitrile into a first distillation column and separating the acetonitrile and first set of impurities from the second set of impurities, the acetonitrile and first set of impurities being drawn as a vapor from the first distillation column, the second set of impurities being produced as the first distillation column bottoms. The vapor is then condensed to produce a feed stream that is introduced into a second distillation column where the first set of impurities are separated from the acetonitrile, the purified acetonitrile being collected as the second distillation column bottoms.