Method of reducing the n2o content of gases and selected catalysts
AssigneeUhde GmbH
InventorsMeinhard Schwefer, Joachim Motz, Carsten Gehlen
Life of this patent
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Abstract
Method of reducing the N2O content of gases and selected catalysts A method of reducing the N2O content in gases is described. A selected zeolite catalyst is used in the method. This catalyst is present in the H form and/or contains exchanged iron and is characterized by the presence of nonlattice aluminum in addition to the lattice aluminum in a molar ratio of from 1:2 to 20:1. The method can be used in nitric acid production for reducing the N2O content of process gases or offgases.
Claims23
A method of reducing the content of N2O in gases by passing the N2O-containing gas over a zeolite catalyst which comprises lattice aluminum (which may be partly replaced by one or more elements selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi) together with nonlattice aluminum and, if desired, further nonlattice atoms selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi, has a molar ratio of nonlattice aluminum to lattice aluminum in the range from 1:2 to 20:1 and is present in the H form and/or contains exchanged iron.
A zeolite catalyst which contains both lattice aluminum (which may, if desired, have been partly replaced by one or more elements selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi) and nonlattice aluminum and, if desired, further nonlattice atoms selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi, has a molar ratio of nonlattice aluminum to lattice aluminum in the range from 1:2 to 20:1 and has been laden with iron by solid-state ion exchange.
A zeolite catalyst which contains both lattice aluminum (which may have been partly replaced by one or more elements selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi) and nonlattice aluminum and, if desired, further nonlattice atoms selected from the group consisting of B, Be, Ga, Fe, Cr, V, As, Sb and Bi, has a molar ratio of nonlattice aluminum to lattice aluminum in the range from 1:2 to 20:1 and contains at least 1% by weight of iron (calculated as Fe2O3 and based on the mass of the zeolite).
Dependencies are inferred from the claim text.