Regeneration of spent supported metal catalysts
AssigneeHeadwaters Nanokinetix, Inc.
InventorsBing Zhou, Michael Rueter
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Abstract
A method for regenerating spent supported metal catalysts comprising treating the spent catalyst with an organo-metallic complex forming agent having an ionization constant pK1 of at least 2.5. The catalyst activity is restored to an activity level near to or greater than the fresh catalyst. The regeneration method is particularly useful for regenerating spent palladium catalysts on an alumina support as utilized for the hydrogenation of ethyl anthraquinone (EAQ) in the production of hydrogen peroxide.
Claims25
A method for regenerating a used supported metal catalyst, comprising:
- (a) providing a used metal catalyst comprising a support and at least one catalytically active metal comprising metal particle clusters attached to the support;
- (b) contacting the used supported metal catalyst with at least one organo-metallic complexing agent having an ionization constant pK1 of at least about 2.5;
- and
- (c) breaking down the metal particle clusters and relocating the at least one catalytically active metal as smaller metal particles on the support to yield a regenerated supported metal catalyst.
A method for regenerating a used catalyst having supported metal catalyst particles comprising:
- a) calcining the used catalyst in air;
- and
- b) contacting the calcined catalyst from a) with at least one organo-metallic complexing agent, whereby the used catalyst is regenerated to a catalytic activity level in a range of 90-103% compared to fresh catalyst activity.
A method for regenerating a spent supported metal catalyst comprising:
- contacting the spent supported metal catalyst with at least one organo-metallic complexing agent having an ionization constant pK1 of at least about 2.5 under conditions sufficient to regenerate the spent supported metal catalyst,
- wherein the organo-metallic complexing agent comprises an organic chelating agent, wherein said organic chelating agent comprises:
- (i) one or more aliphatic or aromatic mono, di, and/or tribasic carboxylic acids selected from the group consisting of glycolic acid, malonic acid, tartaric acid, citric acid, succinic acid, glutaric acid, glycine, salicylic acid, isophthalic acid, 2-aminobenzoic acid, and their salts;
- and/or
- (ii) one or more phosphonate compounds including amine tri(methylanephosphonic acid) (ATMP), 1-Hydroxy-1,1-diphosphonic acid (HEDP), diethylenetriamine penta (methylphosphonic) acid, and their salts.
Dependencies are inferred from the claim text.