Patent · US Expired

Process for urea production

US4613696A · kind A · utility

9Cited by
3References
12Claims
0Family size

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Inventor

Key dates

Filing dateMay 2, 1985
Grant dateSep 23, 1986
Priority date
Expiry dateMay 2, 2005

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C273/04
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

A process for the production of urea from ammonia and carbon dioxide via synthesis where the urea formation takes place in a synthesis zone (or zones) in which an excess of free ammonia is kept to favor high conversions, said synthesis zone (or zones) being followed by an ammonia separation and direct recycle to the reaction step, where the urea solution from said reaction zone (or zones) is intimately contacted for a short duration time with a minor portion of the fresh CO.sub.2. The separation step is followed by a CO.sub.2 stripping step where the residual carbamate is removed using a countercurrent fresh CO.sub.2 stream.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.