Urea finishing process with acid scrubbing
US10486125B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 2015 |
| Grant date | Nov 26, 2019 |
| Priority date | — |
| Expiry date | Sep 5, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C273/16
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the finishing of urea comprising: (a) removing water from an aqueous urea solution in a first evaporation and condensation section, obtaining a urea melt; (b) subjecting said urea melt to a finishing treatment comprising granulation and resulting in solid urea and air contaminated with urea dust and ammonia; (c) subjecting said contaminated air to acid scrubbing, producing an aqueous solution comprising urea and ammonium salts; (d) subjecting at least part of said aqueous solution to evaporation in a second evaporation section, obtaining a liquid stream comprising urea and ammonium salts and a gaseous stream; (e) condensing said gaseous stream in a second condensation section, obtaining a recycle aqueous stream; (f) using at least a part of said recycle aqueous stream for the scrubbing of contaminated air; (g) converting at least a portion of said liquid stream comprising urea and ammonium salts into solid particles, and (h) using said solid particles as seeds for the granulation; a corresponding urea plant and method of revamping a urea plant are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.