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:
Sep. 18, 2007
Filed:
Jul. 28, 2006
Michael Jödecke, Bobenheim-Roxheim, DE;
Ortmund Lang, Quirnbach, DE;
Gunther Van Cauwenberge, Wachenheim, DE;
Matthias Frauenkron, Kalmhout, NL;
Michael Jödecke, Bobenheim-Roxheim, DE;
Ortmund Lang, Quirnbach, DE;
Gunther van Cauwenberge, Wachenheim, DE;
Matthias Frauenkron, Kalmhout, NL;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
The invention relates to a process for continuously, distillatively removing piperazine from an ethylenediamine-piperazine mixture under pressure at elevated temperature, by discharging the ethylenediamine at the top and the piperazine at the bottom of a distillation column. For the purpose of improving the quality of the piperazine, especially its color and color stability, the piperazine is subjected directly to circulation conveying it through an evaporator unit operated at a temperature of from about 160° C. to about 170° C. and returning it into the distillation column. After a residence time of from about 30 min to about 60 min in the circulation system, the piperazine is discharged in vapor form from a side draw in the lower section of the distillation column.