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:
Jun. 21, 1977
Filed:
Dec. 17, 1975
Diego Barba, Rome, IT;
Fabrizio Battistoni, Rome, IT;
Candido D'Agostini, Rome, IT;
Giorgio Macchi, Rome, IT;
Societa' Italiana Resine S.I.R. S.p.A., Milan, IT;
Abstract
Nitric acid having a concentration of at least 98% by weight is obtained from a gaseous stream resulting from catalytic oxidation of ammonia and containing nitrogen oxide and steam, by flowing said stream in an oxidation and condensation column in countercurrent with a stream of nitric acid at 40-60 wt.%, recovering nitrogen peroxide at the top of the column, liquefying said peroxide, bringing it into contact with aqueous nitric acid, oxygen and air in a chemical absorption stage, and distilling the resulting superazeotropic nitric acid. A part of the nitric acid discharged from the oxidation column is directly recycled and the remainder is recycled after distillation to give azeotropic acid and remove water, a part of the latter being used for the chemical absorption.