Catalyst and process for nitric oxide reduction in a waste gas
First Claim
1. A process for treating waste gas from a combustion plant,the method comprising contacting the waste gas with a reducing agent in the presence of a catalyst for nitric oxide reduction in a waste gas from a combustion plant, wherein the waste gas comprises nitric oxides, alkali metals, phosphorus, chromium, or mercury,the catalyst comprising:
- a first layer comprising a sacrificial component comprising halloysite, wherein the sacrificial component absorbs catalyst poison in the waste gas, anda second layer comprising a catalytically active component which comprises (1) a vanadium oxide and (2) tungsten oxide and/or molybdenum oxide,thereby reducing at least some of the nitric oxides to nitrogen and water;
wherein the first and second layer are configured such that the first layer is positioned as an outer component; and
optionally, the second layer is located on or in a support substrate and the first layer is located at least partially over the second layer.
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Abstract
In order to improve the lifetime of an SCR catalyst in the waste gas purification by means of the SCR process of waste gas of a biomass combustion plant, the catalyst comprises a sacrificial component selected from a zeolite and/or a clay mineral, in particular halloysite. During operation, catalyst poisons contained in the waste gas, in particular alkali metals, are absorbed by the sacrificial component so that catalytically active centers of the catalyst are not blocked by the catalyst poisons.
21 Citations
10 Claims
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1. A process for treating waste gas from a combustion plant,
the method comprising contacting the waste gas with a reducing agent in the presence of a catalyst for nitric oxide reduction in a waste gas from a combustion plant, wherein the waste gas comprises nitric oxides, alkali metals, phosphorus, chromium, or mercury, the catalyst comprising: -
a first layer comprising a sacrificial component comprising halloysite, wherein the sacrificial component absorbs catalyst poison in the waste gas, and a second layer comprising a catalytically active component which comprises (1) a vanadium oxide and (2) tungsten oxide and/or molybdenum oxide, thereby reducing at least some of the nitric oxides to nitrogen and water; wherein the first and second layer are configured such that the first layer is positioned as an outer component; and
optionally, the second layer is located on or in a support substrate and the first layer is located at least partially over the second layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification