Phosphorous/vanadium oxidation catalyst
AssigneeScientific Design Company, Inc.
InventorArie Bortinger
Life of this patent
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Abstract
An improvement in the oxidation catalyst used for the partial oxidation of n-butane and containing vanadium and phosphorus, zinc, lithium and molybdenum mixed oxides which comprises adding the molybdenum as a compound which is dissolved in a solvent during the manufacture of the catalyst.
Claims23
In a method for preparing a molybdenum containing phosphorus/vanadium mixed oxide oxidation catalyst comprising reducing vanadium in the +5 valence state in a substantially anhydrous organic medium to a valence of less than +5 and digesting said reduced vanadium and a modifier comprising molybdenum in concentrated phosphoric acid wherein the improvement comprises adding said molybdenum as a solution of molybdenum compound prior to said digesting.
A method for preparing a phosphorus/vanadium/zinc/lithium/molybdenum mixed oxide oxidation catalyst comprising the steps of:
- admixing a +5 valence vanadium compound with an organic solvent, contacting said mixture with gaseous HCl until the valence of vanadium is reduced to less than +5 at a temperature in the range of 35.degree. to 60.degree. C.,
- adding a zinc compound, a lithium compound and a solution of a molybdenum compound to said organic solvent containing said vanadium having a valence of less than +5,
- digesting said reduced vanadium, zinc compound, lithium compound and molybdenum compound in concentrated phosphoric acid of about 98 to 101% H.sub.3 PO.sub.4 by a first reflux step,
- removing a first portion of said organic solvent from said digested mixture by distillation,
- digesting said organic solvent in a second reflux step,
- removing a second portion of said organic solvent from said digested mixture by distillation to form a slurry of mixed oxides and organic solvent,
- recovering a dried mixed oxide composition and heating said dried mixed oxide composition at a temperature in the range of 200.degree. to 400.degree. C. for a sufficient period to improve the catalytic properties of the composition.
A method for preparing a phosphorus/vanadium/zinc/lithium/molybdenum mixed oxide oxidation catalyst comprising the steps of:
- admixing a +5 valence vanadium compound with an organic solvent, contacting said mixture with gaseous HCl until the valence of vanadium is reduced to less than +5 at a temperature in the range of 35.degree. to 60.degree. C.,
- adding a zinc compound, a lithium compound to said organic solvent containing said vanadium having a valence of less than +5,
- digesting said reduced vanadium, zinc compound, lithium compound and molybdenum compound in concentrated phosphoric acid of about 98 to 101% H.sub.3 PO.sub.4 by a first reflux step,
- removing a first portion of said organic solvent from said digested mixture by distillation,
- adding a solution of a molybdenum compound to said digested mixture,
- digesting said organic solvent in a second reflux step,
- removing a second portion of said organic solvent from said digested mixture by distillation to form a slurry of mixed oxides and organic solvent,
- recovering a dried mixed oxide composition and heating said dried mixed oxide composition at a temperature in the range of 200.degree. to 400.degree. C. for a sufficient period to improve the catalytic properties of the composition.
Dependencies are inferred from the claim text.