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:
Jan. 13, 2004
Filed:
Oct. 26, 2001
Matthias Creutz, Frankfurt, DE;
Stefan Nordhoff, Aschaffenburg, DE;
Rudolf Wagner, Grosskrotzenburg, DE;
Jürgen Glenneberg, Offenbach, DE;
Dieter Möller, Babenhausen, DE;
Degussa AG, Düsseldorf, DE;
Abstract
A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H O starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H O concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H O concentration in the crystal layer is increased further.