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. 31, 2012
Filed:
May. 19, 2008
Lino Carlessi, Dalmine, IT;
Alessandro Gianazza, Legnano, IT;
Lino Carlessi, Dalmine, IT;
Alessandro Gianazza, Legnano, IT;
Saipem S.p.A., San Donato Milanese, IT;
Abstract
An enhanced process is described for the synthesis of urea from ammonia and carbon dioxide, at a high pressure and temperature, with the formation of ammonium carbamate as intermediate, which includes a high pressure synthesis section, comprising at least one separation step by decomposition-stripping with ammonia of the non-converted ammonium carbamate, carried out in a vertical apparatus, commonly called stripper, characterized in that said step also comprises a feeding, in the lower part of said stripper, of a stream of CO, heated to a temperature ranging from 130 to 230° C., in a quantity of 1 to 15% by weight with respect to the total weight of the fresh COfed to the process, containing a passivating agent in such a quantity that its equivalent content of Oin moles varies from 0.05% to 0.80% with respect to the moles of COof said stream.