Process for the modernization of existing urea plants and a modernized urea plant
US5176800A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 27, 1990 |
| Grant date | Jan 5, 1993 |
| Priority date | — |
| Expiry date | Dec 27, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/141
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process to modernize existing urea plants which use a stripping with carbon dioxide, and to increase urea yields and flexibility under overload conditions while at the same time reducing energy consumption, corrosion phenomena and possible risks of explosive mixtures. The plant includes: a passivation stage with the introduction of an oxidizing agent and reduction of the air fed to the system; a medium pressure distillation stage of the products leaving the stripping section, and a condensation of the products of the distillation, effected in a pre-evaporation phase to concentrate at low pressure the urea solution. The modernized plant, includes at the start at least a reactor, a scrubber, a condenser, a stripper and the evaporators, includes also a passivation section, a medium pressure distillation section, and a distillation section with double-effect technique.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.