Published: January 1981
The fast growth in the use of urea as a fertilizer, and to a lesser extent as an animal feed supplement and as a chemical intermediate in plastics and resins, continues worldwide. It's rapid growth is due to its being used increasingly to replace ammonium nitrate as the principal source of solid nitrogen in fertilizer.
In this first supplement to PEP Report 56, we review urea markets and urea production capacities worldwide. The general technical field and recent process developments for manufacturing urea are reviewed but detailed designs and evaluations are limited to processes to produce prilled urea containing an intermediate amount of biuret (0.7-0.9X).
We have revised and brought up-to-date three previous evaluations of total-recycle processes on the basis of the most recent information. These evaluations cover the following total-recycle processes:
- Stamicarbon--CO2 Stripping Process
- Snamprogetti--NH3 Self-Stripping Process
- Mitsui Toatsu--Base (Conventional) Process (Simplified C-Improved Process)
We have brought all the evaluations to the same base production level of 1,500 short tons/day (986 million lb/yr or 447,000 metric tons/yr) of prilled urea. Methods for pollution abatement have been described in detail. Several alternative procedures are given for treating liquid and gaseous wastes.
Our designs and evaluations were reviewed with the respective licenser companies. However, such review does not imply agreement with SRI's conception of the process in all respects. SRI is solely responsible for the designs, evaluations, and any conclusions therefrom presented in this report.