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. 18, 1977
Filed:
Jun. 24, 1974
Antonius M Heunks, Geleen, NL;
Stamicarbon N.V., Geleen, NL;
Abstract
A process is described for the preparation of urea at a high temperature and pressure whereby the quantity of water recycled to the urea-synthesis reactor along with the recycle ammonium carbamate may be reduced. The high pressure aqueous urea solution from the reactor is expanded into two or more ammonium carbamate decomposition stages operating at successively lower pressures. In at least one of the ammonium carbamate decomposition stages the expanded aqueous urea solution is heated in a controlled manner and a first off-gas is separated. The residual aqueous urea solution is again heated and a second off-gas is removed, which off-gas is combined with the first off-gas, condensed and recycled to the urea-synthesis reactor.