Methods for removing iron material from a substrate
AssigneeSteag Energy Services GmbH
InventorsBirgit Marrino, Thies Hoffmann
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Abstract
Methods of removing iron from a catalytic converter having an accumulation of one or more iron compounds and regenerating a catalytic converter are provided. A catalytic converter having an accumulation of one or more iron compounds embedded or deposited thereon can be treated with a substantially aqueous alkaline solution in which the substantially aqueous alkaline solution includes an antioxidant.
Claims34
A method of removing iron from a catalytic converter having an accumulation of one or more iron compounds, comprising:
- (i) treating the catalytic converter with a substantially aqueous alkaline solution, said aqueous alkaline solution comprises an antioxidant, wherein the antioxidant is selected from the group consisting of substituted phenols, hydroquinones, catechols, aliphatic mercapto compounds, araliphatic mercapto compounds, aromatic mercapto compounds, dithiocarbonates, enediols, phosphites, phosphonates, and combinations thereof;
- and
- (ii) removing at least a portion of the one or more iron compounds accumulated on the catalytic converter.
A method of regenerating a catalytic converter having an accumulation of one or more iron compounds, comprising:
- (i) treating the catalytic converter with a substantially aqueous alkaline solution, said aqueous alkaline solution comprises an antioxidant wherein the antioxidant comprises substituted phenols, hydroquinones, catechols, aliphatic mercapto compounds, araliphatic mercapto compounds, aromatic mercapto compounds, dithiocarbonates, enediols, phosphites, phosphonates, or combinations thereof;
- (ii) removing at least a portion of the one or more iron compounds accumulated on the catalytic converter;
- (iii) washing the catalytic converter with water or an aqueous solution;
- (iv) at least partially drying the catalytic converter;
- (v) impregnating the catalytic converter with at least one NOx removal catalyst with catalytic active metals to provide a regenerated catalytic converter.
Dependencies are inferred from the claim text.