Process for the recovery of valuable components from the waste streams obtained in the preparation of urea

Patent 4652678 Issued on March 24, 1987. Estimated Expiration Date:

October 10, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

2854482

3025571

Method of separating liquid drops from a gas stream
Patent #: 3979392
Issued on: 09/07/1976
Inventor: Eguchi , et al.

Method of hydrolyzing urea contained in waste water streams
Patent #: 4087513
Issued on: 05/02/1978
Inventor: Schell

Integrated ammonia-urea producing process, for the production of urea
Patent #: 4138434
Issued on: 02/06/1979
Inventor: Lagana , et al.

Urea hydrolysis Patent #: 4341640
Issued on: 07/27/1982
Inventor: Landis

Inventor

Douwes, Adolphe M.

Assignee

Stamicarbon B.V.

Application

No. 06/659307 filed on 10/10/1984

US Classes:

564/73, Purification or recovery210/750, Including degassing423/237, Ammonia423/238, Utilizing liquid as reactant423/358, From organic material containing nitrogen423/437.1, Carbon dioxide or carbonic acid564/67, Preparing directly from ammonia and carbon dioxide564/69With ammonia synthesis

Examiners

Primary: Hines, Robert V.

Attorney, Agent or Firm

Cushman, Darby & Cushman

International Classes

C07C 273/04 (20060101)
C07C 273/00 (20060101)

Foreign Application Priority Data

1981-05-15 NL

Abstract

An improved process for recovering usable components from waste streams containing urea, including a dilute aqueous urea solution, which result from the preparation of particulate urea products. The dilute aqueous urea solution is used to wash a urea containing waste gas stream whereby urea contained in the gas stream is dissolved in the aqueous urea solution. The aqueous urea solution thus obtained is then subjected to a hydrolysis treatment whereby the urea contained therein is hydrolyzed, and the ammonia and carbon dioxide thus formed are separated from the residual liquid stream.