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US 2022/0089527 A1Published application
Ammonia removal from urea finishing
AssigneeStamicarbon B.V.
InventorsRahul PATIL, Branislav MANIC, Petrus Anna Maria Robertus SIMONS
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AssigneeStamicarbon B.V.
InventorsRahul PATIL, Branislav MANIC, Petrus Anna Maria Robertus SIMONS
Estimating the term…
Disclosed is a method for the removal of ammonia from the off-gas of a finishing section of a urea production plant. Also disclosed is a corresponding urea plant, and a method of accordingly modifying a pre-existing urea plant. In a scrubbing section, the off-gas is brought into contact with an acidic scrubbing liquid so as to provide a scrubbed off-gas and a utilized scrubbing liquid comprising ammonium salt. The method specifies an evaporation section, which is part of the urea plant that produces urea melt, that is divided into first and second stages. The first stage is part of the urea melt production plant. The second stage decoupled, as regards recirculation of liquids other than the urea product stream, from the urea melt production plant. This is accomplished by sending utilized scrubbing liquid that contains ammonium salts to the second stage evaporation section, and by sending condensed vapours from said second stage evaporation section to said scrubbing section.
A method for the removal of ammonia from the off-gas of a finishing section of a urea production plant, wherein the finishing section operates to convert a urea melt into solid urea products, thereby generating ammonia-containing off-gas;
A method for the production of a solid urea product, comprising producing an aqueous urea solution, evaporating water from said aqueous solution in a first stage evaporation section so as to form a concentrated urea solution, further evaporating water from the concentrated urea solution in a second stage evaporation section into a urea melt, and subjecting the urea melt to finishing so as to convert it into solid urea products, thereby generating ammonia-containing off-gas;
A method of modifying an existing urea plant, the existing plant comprising a production section for urea melt having a liquid urea connection to a finishing section for converting the urea melt into solid urea products, whereby the production section comprises an evaporation section for converting produced aqueous urea solution into 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 having a liquid outlet for 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, 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 evaporation section with a connection to an outlet for utilized scrubbing liquid from a scrubbing system of the finishing section, particularly for utilized scrubbing liquid that comprises ammonium salt, and providing the corresponding second stage condenser with a connection for sending condensed vapours to a scrubbing system in the finishing section.
A plant for the production of solid urea products, the plant comprising a production section for urea melt having a liquid urea connection to a finishing section for converting the urea melt into solid urea products, whereby the production section comprises an evaporation section for converting produced aqueous urea solution into urea melt, and a water purification section downstream of the evaporation section, said evaporation section comprising a first stage evaporation section comprising a first stage evaporator having a liquid outlet for 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 comprising a second stage evaporator and a second stage condenser, wherein the first stage condenser has a liquid outlet for sending condensed vapours to the water purification section, whereby the second stage evaporator has a connection to an outlet for utilized scrubbing liquid from a scrubbing system of the finishing section, and wherein said second stage evaporator has a gas outlet to a second stage condenser, wherein said second stage condenser has a liquid connection for sending condensed vapours to a scrubbing system in the finishing section.
(canceled)
Dependencies are inferred from the claim text.