Methods and Systems Including CO Oxidation Catalyst With Low NO to NO2 Conversion
AssigneeBASF SE
InventorsXinsheng Liu, Xinyi Wei, Pascaline Tran, Gerard Lapadula
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Abstract
Catalysts, catalyst systems, and methods for removing ammonia and/or carbon monoxide in flue gases are provided where ammonia is used with a selective catalytic reduction catalyst for reducing oxides of nitrogen. An oxidation catalyst is utilized, which comprises particulate platinum or platinum/palladium dispersed on zirconia particles, the particulate platinum or platinum/palladium having an average particle size less than about 10 nm. The catalyst is effective to convert less than 20% of NO to NO2 passing through the oxidation catalyst.
Claims17
A stationary source catalyst system for the treatment of an exhaust gas stream from a stationary power plant comprising an oxidation catalyst comprising particulate platinum dispersed on zirconia support particles, the oxidation catalyst being effective to convert no more than 20% NO to NO2 in the exhaust gas stream from the power plant when the catalyst is fresh and after the catalyst has been exposed to a stationary power plant exhaust gas stream for up to at least one year and the particulate platinum having an average particle size less than about 10 nm when the catalyst is fresh and after the catalyst has been exposed to a stationary power plant exhaust gas stream for up to at least one year, the platinum having an SCR catalyst disposed downstream from the oxidation catalyst and an ammonia injection system located upstream from the SCR catalyst.
A catalyst system comprising:
- an oxidation catalyst consisting essentially of particulate platinum dispersed on zirconia particles, the particulate platinum having an average particle size less than about 10 nm when the catalyst is fresh and after the catalyst has been exposed to a stationary power plant exhaust gas stream for up to at least one year;
- a SCR catalyst located downstream from the oxidation catalyst;
- and
- an ammonia source upstream of the SCR catalyst.
A method of treating an exhaust gaseous stream of a stationary source containing at least ammonia (NH3), NO, and carbon monoxide (CO), the method comprising contacting the gaseous stream an oxidation catalyst comprising particulate platinum dispersed on a zirconia support particles, the oxidation catalyst effective for converting less than about 20% of the NO to NO2 in the exhaust gas stream when the catalyst is fresh and after the catalyst has been exposed to a stationary power plant exhaust gas stream for up to one year, the particulate platinum having an average particle size less than about 5 nm when the catalyst is fresh and after the catalyst has been exposed to a stationary power plant exhaust gas stream for up to one year;
- and passing the exhaust gas exiting the oxidation catalyst through an SCR catalyst.
Dependencies are inferred from the claim text.