Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Patent
1990-01-22
1991-09-03
Shine, W. J.
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
B01J 2500
Patent
active
050455206
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a process for the production of catalysts, useful in the synthesis of methanol, to the catalysts so produced and to a process for the production of methanol using such catalysts.
BACKGROUND ART
Marsden et al. Industrial & Engineering Chemistry Product Research and Development, 19 551 (1980) were the first to show that an active low temperature methanol synthesis catalyst can be produced by leaching small particles of a Cu-Al-Zn alloy in sodium hydroxide solutions. In other studies, Friedrich et al. J. Catal. 80 1, 14 (1983) and Bridgewater et al. Appl. Catal. 7 369 (1983) using small particles, have investigated the effect of alloy composition on catalyst activity. This technique of catalyst preparation has been fully described in U.S. Pat. No. 4,349,464 and U.S. Pat. No. 4,366,260.
A recent study, Curry-Hyde et al. Appl. Catal. 29 31 (1987) has been concerned with the preparation of catalysts by the method described in the patents. In this study, an alloy of optimal composition was used to study preparation and characteristics of the Raney catalyst in pellet form. It was found that the long times required to leach the large particles had two detrimental effects on the nature of the catalyst. The first decreased the overall pellet surface area after long periods of leaching, whilst the second caused a decrease in the specific activity of the catalyst.
The decrease in pellet surface area was as a result of the physical rearrangement of copper crystallites in the porous copper whilst the alloy core was still being leached. The decreased activity resulted from decreases in zinc oxide concentrations on the copper surface. These were caused by secondary leaching effects on the zinc oxide that become significant at long leach times.
Previous investigations sought to improve the zinc oxide content in the leached Cu structures by changing the ZN content of the Al-Cu-Zn alloy, as described in Friedrich et al. J. Catal. 80 1, 14 (1983) and Bridgewater et al. Appl. Catal. 7 369 (1983).
DISCLOSURE OF INVENTION
Surprisingly, the present inventors have discovered an improved method for producing zinc oxide promoted Raney copper catalysts using a leaching/precipitation technique to give higher concentrations and improved distributions of zinc oxide in the catalytic material.
Accordingly, the present invention consists in a method for the production of a low temperature methanol synthesis catalysts composition suitable to synthesize methanol by the reaction of carbon monoxide or carbon dioxide of mixtures thereof with hydrogen, comprising forming an alloy containing 0 to 50 wt. % zinc, 30 to 75 wt. % aluminum, the balance being substantially all copper and extracting aluminum from the alloy using an effective concentration of zincate ions in an aqueous solution of an alkali metal hydroxide.
In a further aspect the present invention consists in a methanol synthesis catalyst produced by the foregoing method.
In a still further aspect the present invention consists in a process for the production of methanol comprising contacting a gaseous mixture of carbon monoxide or carbon dioxied, or mixtures thereof, and hydrogen with a catalyst according to the present invention.
It is believed that the extraction of the alloy in sodium zincate-sodium hydroxide solutions results in catalytic material with higher concentrations and improved distributions of ZnO after extracting, than the method described in U.S. Pat. No. 4,349,464 and U.S. Pat. No. 4,366,260 of extracting Raney alloys in sodium hydroxide solutions. The catalytic material prepared according to the present invention has both higher surface area and higher material activities than the catalytic material prepared by the previous invention.
The alloy from which the catalysts according to present invention are formed preferably comprises 0 to 20 wt. % zinc, 40 to 50 wt. % aluminum and 40 to 50 wt. % copper. Most preferably the alloy comprises 17 wt. % zinc, 39 wt. % aluminum and 44 wt. % copper.
Generally, the all
REFERENCES:
patent: 4349464 (1982-09-01), Wanwright et al.
patent: 4366260 (1982-12-01), Wainwright et al.
patent: 4436833 (1984-03-01), Broecker et al.
patent: 4843101 (1989-06-01), Klier et al.
Curry-Hyde et al "Preparation and Properties . . . " Applied Catalysis 29 (1987) pp. 31-41.
Tomsett et al. "Structural Changes . . . " Applied Catalysis 33(1987) 119-127.
Warwick et al "Zinc-Promoted Raney . . . " Prod. Res. & Dev. vol. 19 p. 551 12/1980.
Friedrich et al "Methanol Synthesis . . . " Jour. of Catalysis 80(1983) 1-13.
Friedrich et al "Methanol Synthesis . . . " Jour. of Catalyst 80(1983) 14-24.
Bridgewater et al "Methanol Synthesis over . . . " Applied Catalysis 7 (1983) pp. 369-382.
Bridgewater et al "A Comparison of Raney . . . " Applied Catalysis 28(1986) pp. 241-253.
Abstract #127494c "Catalyst and Method . . . " Catalysis, Kinetics vol. 100 1984, p. 405.
Curry-Hyde Henry E.
Wainright Mark S.
Young David J.
Shine W. J.
Unisearch Limited
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