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US 11,104,576 B2Granted
Process for argon and nitrogen production
AssigneeCasale SA
InventorGiacomo Colmegna
Life of this patent
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Abstract
A process comprising: subjecting a process gas containing NOx to a stage for absorption of NOx in a suitable absorption means, obtaining nitric acid and a tail gas containing nitrogen, argon and residual NOx; subjecting said tail gas to a treatment which comprises at least one NOx removal stage, obtaining a conditioned tail gas; subjecting at least a portion of said conditioned tail gas to a separation treatment, obtaining a product stream containing argon and a product stream containing nitrogen.
Claims28
A process, comprising:
- subjecting a process gas containing NOx to a NOx absorption stage in an absorption means, thereby obtaining nitric acid and a tail gas containing nitrogen, argon and residual NOx;
- subjecting said tail gas to a treatment comprising at least one NOx removal stage, thereby obtaining a conditioned tail gas;
- and
- subjecting at least a portion of said conditioned tail gas to a separation treatment, thereby obtaining a first product stream containing argon and a second product stream containing nitrogen.
1 more element
The process of 38, wherein said separation treatment comprises:
- cooling and subsequently expanding the conditioned tail gas, thereby obtaining a partial liquefaction, and subjecting the liquefied fraction to fractional distillation.
A plant, comprising:
- an absorption tower, fed with a process gas containing NO and configured to absorb NOx in an absorption means, for providing nitric acid and a tail gas containing nitrogen, argon and residual Nox;
- a treatment unit for said tail gas, configured to remove NO and give a conditioned tail gas;
- and
- a separation section, configured to separate a first product stream containing argon and a second product stream containing nitrogen, said separation section being fed with at least a portion of said conditioned tail gas.
1 more element
Dependencies are inferred from the claim text.