Vapor phase oxidation of propylene to propylene oxide
AssigneeArco Chemical Technology, L.P.
InventorsRangasamy Pitchai, Andrew P. Kahn, Anne M. Gaffney
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Abstract
Propylene is converted to propylene oxide in a vapor phase oxidation process employing a silver catalyst supported on an alkaline earth metal carbonate and containing both a potassium salt such as potassium nitrate and a molybdenum promoter. The potassium salt and the molybdenum promoter may be simultaneously supplied by the use of a potassium salt of a molybdenum oxyanion. The efficiency of the process is greatly enhanced through the simultaneous inclusion of carbon dioxide and an organic halide in the feedstream. The feedstream need not contain a nitrogen oxide species such as NO to attain high propylene oxide selectivity.
Claims16
A supported silver catalyst useful for vapor phase epoxidation of propylene comprising (a) a support material, at least 50% by weight of which is an alkaline earth metal carbonate, (b) 25 to 60 weight percent silver, (c) 0.5 to 3 weight percent, calculated as potassium cation, of a salt selected from potassium nitrate and potassium nitrite, and (d) 0.05 to 2.5 weight percent, calculated as Mo, of a molybdenum promoter.
A supported silver catalyst useful for vapor phase epoxidation of propylene comprising (a) a support material, at least 50% by weight of which is an alkaline earth metal carbonate, (b) 25 to 60 weight percent silver, and (c) 0.5 to 3 percent by weight, calculated as potassium cation, of a molybdenum promoter derived from a potassium salt comprising potassium cation and a molybdenum oxyanion.
A supported silver catalyst useful for vapor phase epoxidation of propylene comprising a support material consisting essentially of calcium carbonate, 25 to 60 weight percent silver, 1.5 to 2.5 weight percent, calculated as potassium cation, of potassium nitrate, and 0.05 to 2.5 weight percent, calculated as Mo, of a molybdenum promoter derived from an oxyanionic compound of molbdenum.
A supported silver catalyst useful for vapor phase epoxidation of propylene comprising (a) a support material consisting essentially of calcium carbonate, (b) 25 to 60 weight percent silver, and (c) 1.5 to 2.5 weight percent, calculated as potassium cation, of a molybdenum promoter derived from a potassium salt of molybdate, dimolybdate, or paramolybdate.
Dependencies are inferred from the claim text.