Patent ID: 11958793
Assignee: THYSSENKRUPP AG
Field: Chemical engineering (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 7:
8. A method for the preparation of urea granules, comprising:
one or more synthesis and recovery steps wherein carbon dioxide is reacted with ammonia to form a solution comprising urea and water;
evaporation of water from the solution resulting in a first concentrated urea solution and a first water containing vapor;
subjecting the first water containing vapor to a condensing step resulting in a first condensate;
subjecting the concentrated urea solution to a granulation step resulting in urea granules and a urea dust containing off gas stream;
subjecting the urea dust containing off gas stream to a scrubbing step resulting in an aqueous urea solution;
subjecting the aqueous urea solution to a separate evaporation step resulting in a second concentrated urea solution and a second water containing vapor;
conveying the second concentrated urea solution to the granulation step;
subjecting the second water containing vapor to a separate condensation step resulting in a second condensate; and
subjecting the second condensate and a quenching liquid to the urea dust containing off gas stream after leaving the granulation step and before entering the dust scrubbing step.