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:
Aug. 26, 2008
Filed:
Apr. 05, 2007
Pin-to Yao, Taipei, TW;
Cheng-fa Hsieh, Taipei, TW;
Yuh-ing Hwang, Taipei, TW;
China Petrochemical Development Corporation, Taipei, TW;
Abstract
A method for preparing hydroxylamine is provided that includes the steps of (i) pretreating an acidic buffer solution; and (ii) reducing nitrate ions in the acidic buffer solution with hydrogen to give hydroxylamine in the presence of catalysts, wherein the pretreatment is performed by adding a precipitant represented by formula (I) to the acidic buffer solution,[(A)aM(CN).xHO]  (I)allowing the metal impurities in the acidic buffer solution to react with the precipitant to form metal complex, and then to remove the metal complex. The metal complex is formed and separated by pretreating the acidic buffer solution with a specific precipitant without adjusting pH and changing the composition of the acidic buffer solution prior to hydroxylamine synthesis, thus enhancing the selectivity of the hydroxylamine production.