Patent ID: 11905234
Assignee: STAMICARBON B.V.
Field: Chemical engineering (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 0:
1. A method of modifying an existing urea plant, the existing plant comprising a production section for producing a urea melt having a liquid urea connection to a finishing section for converting the urea melt into solid urea products and comprising a scrubbing section, whereby the production section comprises an evaporation section comprising at least one evaporator and at least one condenser for converting produced aqueous urea solution into the urea melt, and a water purification section downstream of the evaporation section, said evaporation section comprising a liquid outlet for sending condensed vapours to the water purification section, wherein the method comprises adapting the evaporation section so as to provide a first stage evaporation section comprising a first stage evaporator having a liquid outlet for a concentrated urea solution and a gas outlet to a first stage condenser, and a second stage evaporation section downstream from the first stage evaporation section, said second stage evaporation section comprising a second stage evaporator having a gas outlet to a corresponding second stage condenser, a liquid inlet for receiving all of the concentrated urea solution, and a liquid outlet for the urea melt, the first stage condenser having a liquid outlet for sending condensed vapours to the water purification section, wherein the method further comprises providing the second stage evaporator with a connection to an outlet for utilized scrubbing liquid from a scrubbing system of the finishing section, and providing the corresponding second stage condenser with a condensed vapour outlet fluidly connected to the scrubbing system in the finishing section.