Selective acetylene hydrogenation
AssigneePhillips Petroleum Company
InventorsTin-Tack P. Cheung, Marvin M. Johnson, Scott H. Brown, Stan A. Zisman, James B. Kimble
Life of this patent
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Abstract
A catalyst composition comprising palladium, silver and a support material (preferably alumina) is contacted at a relatively low temperature (of up to about 60.degree. C.) with a liquid composition comprising an effective reducing agent (preferably an alkali metal borohydride, hydrazinc, formaldehyde, formic acid, ascorbic acid, dextrose, aluminum powder). Preferably, at least one alkali metal compound (more preferably KOH, RbOH, CsOH, KF) is also present in the liquid composition. An improved process for selectively hydrogenating acetylene (to ethylene) employs this wet-reduced catalyst composition.
Claims26
In a process for the selective hydrogenation of acetylene to ethylene which comprises mixing (a) a feed gas comprising acetylene and (b) hydrogen gas and contacting the mixture of (a) and (b) with (c) an effective catalyst composition, the improvement which comprises employing a catalyst composition which has been prepared by a method consisting essentially of the steps of:
- (1) contacting a solid composition comprising palladium, silver and an inorganic support material with a liquid reduction composition comprising (i) at least one reducing agent selected from the group consisting of alkali metal borohydrides, hydrazine, aldehydes containing 1-6 carbon atoms per molecule, ketones containing 1-6 carbon atoms per molecule, carboxylic acids containing 1-6 carbon atoms per molecule, aluminum metal and zinc metal, (ii) at least one non-reducing liquid component, and (iii) at least one dissolved alkali metal compound selected from the group consisting of alkali metal hydroxides and alkali metal fluorides, at a temperature of up to about 60.degree. C. for a time period of at least about 1 second, so as to produce a wet-reduced solid composition;
- (2) substantially separating said wet-reduced solid composition produced in step (1) from said liquid reduction composition;
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- (3) drying the substantially separated, wet-reduced solid composition obtained in step (2).
In a process for the selective hydrogenation of acetylene to ethylene which comprises mixing (a) a feed gas comprising acetylene and (b) hydrogen gas and contacting the mixture of (a) and (b) with (c) an effective catalyst composition, the improvement which comprises employing a catalyst composition which has been prepared by a method consisting essentially of the steps of:
- (1) contacting (a) a solid composition comprising palladium, silver and an inorganic support material with (b) a liquid reduction composition comprising (i) at least one reducing agent selected from the group consisting of alkali metal borohydrides, hydrazine, aldehydes containing 1-6 carbon atoms per molecule, ketones containing 1-6 carbon atoms per molecule, carboxylic acids containing 1-6 carbon atoms per molecule, sugars containing an aldehyde group, sugars containing an .alpha.-hydroxyketone group, aluminum metal and zinc metal, (ii) at least one non-reducing liquid component, and (iii) at least one dissolved alkali metal compound selected from the group consisting of alkali metal hydroxides and alkali metal fluorides, at a temperature of up to about 60.degree. C. for a time period of at least about 1 second, so as to produce a wet-reduced, solid composition;
- (2) substantially separating the wet-reduced solid composition produced in step (1) from said liquid reduction composition;
- (3) drying the substantially separated, wet-reduced solid composition obtained in step (2);
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- (4) heating the dried, wet-reduced solid composition obtained in step (3) in an oxidizing gas atmosphere at a temperature of about 300.degree.-700.degree. C. for a time period of at least about 10 minutes.
Dependencies are inferred from the claim text.