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US 4,537,751 AGranted
Treatment of alumina-base catalysts
AssigneeChevron Research Company
InventorPaul J. Marcantonio
Life of this patent
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Abstract
Particulate alumina-base catalysts are treated to recycle the alumina by a two-step process: the first step involving conversion of the alumina to aluminum sulfate by reaction with gaseous sulfur trioxide, and the second step involving conversion of the aluminum sulfate to an aluminum hydroxide compound by reaction with an aqueous hydroxide. Both reactions are topochemical, and the aluminum hydroxide compound is prepared in particulate form.
Claims12
A process for the treatment of spent particulate alumina-base catalysts, comprising:
- (a) treating the particles of catalyst with gaseous sulfur trioxide at a temperature of from 350.degree. to 550.degree. C. to cause a first reaction converting at least a substantial portion of the alumina present inthe catalyst to aluminum sulfate;
- and
- (b) treating the particles produced in step (a) with an aqueous solution of the hydroxide of a cation having a soluble sulfate salt at a pH of 9 to 12 to cause a second reaction converting at least a substantial proportion of the aluminum sulfate to an aluminum hydroxide.
A process for the treatment of spent particulate alumina-base catalyst comprising
- (a) treating the particles of catalyst with aqueous sulfur trioxide at a temperature of from 350.degree. to 550.degree. C. to cause a first reaction converting at least a substantial portion of the alumina present in the catalyst to aluminum sulfate;
- and
- (b) treating the particles produced in step (a) with an aqueous solution of the hydroxide of a cation having a soluble sulfate salt, which aqueous solution also contains carbonate and bicarbonate ions, at a pH of 9 to 12, to cause a second reaction converting at least a substantial proportion of the aluminum sulfate to an aluminum hydroxide carbonate.
Dependencies are inferred from the claim text.