Ammonia-urea integrated process and plant
AssigneeCasale SA
InventorsFrancesco Nettuno, Luca Rugnone, Raffaele Ostuni
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Abstract
A process for the production of ammonia and urea in an ammonia-urea integrated plant comprising an ammonia section and a tied-in urea section, wherein a hydrocarbon is reformed to produce ammonia make-up synthesis gas; said make-up gas is purified by shift conversion and removal of carbon dioxide; carbon dioxide is removed from the make-up gas by a first and a second CO2 removal sections; the first section removes CO2 by absorption with a suitable medium, and the second section removes CO2 by washing with a carbamate solution taken from the urea section; the make-up gas is reacted to produce ammonia; the CO2 removed from the make-up gas and at least part of the ammonia are used to produce urea.
Claims9
A process for the production of ammonia and urea in an ammonia-urea integrated plant comprising:
- reforming a hydrocarbon source to obtain a make-up gas containing hydrogen, CO2, and nitrogen, wherein said make-up gas, after purification, is converted into ammonia in an ammonia synthesis section,
- at least part of the synthesized ammonia provides an ammonia feed of a urea synthesis process, said urea synthesis process also receiving a carbon dioxide feed,
- the urea synthesis process comprising the reaction of ammonia and carbon dioxide in a urea synthesis section to form a urea aqueous solution, and subsequent treatment of said solution in a urea recovery section that produces a carbamate solution,
- wherein the purification of the make-up gas comprises a first step of CO2 removal in a first CO2 removal unit and a second step of CO2 removal in a second CO2 removal unit, said first and second CO2 removal units not being part of said urea synthesis section,
- one of said first and second CO2 removal steps comprises washing the CO2-containing make-up gas with the carbamate solution taken from said urea recovery section,
- said carbon dioxide feed of the urea synthesis process comprises at least part of the carbon dioxide separated from said make-up gas in the CO2 removal steps, and
- wherein said CO2 removal steps are carried out in series.
Dependencies are inferred from the claim text.