Patent ID: 11925900
Assignee: CASALE SA
Field: Chemical engineering (Chemistry)
Classification: CPC B  C  Y | IPC B  C

Claim 0:
1. A process for reducing the content of NOx and N2O from an input tail gas produced in a nitric acid process, said input tail gas having a temperature lower than 400° C., the process comprising:
an abatement stage including at least a stage of catalytic N2O decomposition (deN2O) over an iron-loaded zeolite catalyst and a stage of catalytic NOx reduction (deNOx), said abatement stage providing a conditioned tail gas having a temperature greater than the input tail gas, wherein:
prior to submission to said abatement stage, said input tail gas is pre-heated to a temperature of at least 400° C. by indirect heat exchange with at least a portion of said conditioned tail gas;
said deN2O and deNOx stages being carried out:
in separated catalytic beds and said deNOx stage being carried out over at least one of: a vanadium catalyst, a copper-loaded zeolite catalyst, or an iron-loaded zeolite catalyst, or
concurrently in the same catalytic bed over at least an iron-loaded zeolite catalyst.