Method for removal of nox and n2o
OwnerMeinhard Schwefer, Erich Szonninventors
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Abstract
An apparatus and a process are described for reducing the content of NOx and N2O in process gases and waste gases. The apparatus encompasses at least one catalyst bed comprising a catalyst which is substantially composed of one or more iron-loaded zeolites, and two reaction zones, where the first zone (reaction zone I) serves for decomposing N2O and in the second zone (reaction zone II) NOx is reduced, and, located between the first and second zone, there is an apparatus for the introduction of NH3 gas.
Claims15
An apparatus for reducing the content of NOx and N2O in process gases and waste gases, encompassing at least one catalyst bed divided into two reaction zones and comprising a catalyst which is substantially composed of one or more iron-loaded zeolites, where the first zone (reaction zone I) serves for decomposing N2O and in the second zone (reaction zone II) NOx is reduced, and, located between the first and second zone, there is an apparatus for the introduction of NH3 gas.
The apparatus as claimed in at least one of the preceding claims, characterized in that the iron-loaded zeolite(s) present in the catalyst is/are of the type MFI, BEA, FER, MOR and/or MEL.
The apparatus as claimed in at least one of the preceding claims, characterized in that the iron-loaded zeolite(s) is/are of the type MFI.
The apparatus as claimed in at least one of the preceding claims, characterized in that the zeolite is an Fe-ZSM-5.
A process for reducing the content of NOx and N2O in process gases and waste gases, where the process is carried out the presence of a catalyst which is substantially composed of one or more iron-loaded zeolites, and, to remove N2O, a first step passes the gas comprising N2O and NOx over the catalyst in a reaction zone I at a temperature <500° C., and a second step conducts the resultant gas stream onward over an iron-containing zeolite catalyst in a reaction zone II, a proportion of NH3 adequate for the reduction of the NOx being added to the gas stream prior to its entry into reaction zone II.
Dependencies are inferred from the claim text.