Process and plant for the production of an aqueous solution comprising urea
US9988345B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 2008 |
| Grant date | Jun 5, 2018 |
| Priority date | — |
| Expiry date | May 22, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49826
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention regards a process for the production of an aqueous solution comprising urea for use in the removal of nitrogen oxides from combustion gas or fumes, the process being characterized in that it comprises the steps of: —subjecting at least a part of a urea-concentrated aqueous solution comprising residual free ammonia, obtained directly from or downstream of a recovery section of a plant for the production of urea, to washing with carbon dioxide, so obtaining a first vapor phase comprising carbon dioxide and optionally ammonia and a urea-concentrated aqueous solution comprising carbamate and essentially lacking in free ammonia, and —diluting said urea-concentrated aqueous solution comprising carbamate and essentially lacking in free ammonia with water until the desired concentration of urea in aqueous solution is reached.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.