Catalyst for producing maleic anhydride
AssigneeChevron Research Company
InventorJonas P. Harrison
Life of this patent
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Abstract
A process for producing maleic anhydride which comprises partially oxidizing a hydrocarbon feed at a temperature in the range 300.degree.-600.degree. C by contacting said feed and an oxygen-containing gas with a catalyst comprising vanadium, phosphorus and silicon oxides prepared by steps comprising coprecipitating vanadium oxide and silica or a silica precursor. Preferably an organic silicon compound, especially an alkyl orthosilicate, is used to form the silica precipitate. Preferably the organic silicon compound is added so as to coprecipitate both during the reduction of the vanadium from a +5 oxidation state to a 3.5-4.6 oxidation state and also is added or is present so as to precipitate silica or a silica precursor simultaneously with the reaction of phosphoric acid with the reduced vanadium.
Claims5
A catalyst comprising oxides of vanadium, phosphorus, and silicon prepared by steps comprising:
- a. coprecipitating vanadium oxide and an alkyl orthosilicate in an organic medium to form a coprecipitate of vanadium oxide and silica or a silica precursor and wherein the alkyl groups of the alkyl orthosilicate have 1 to 10 carbon atoms;
- b. coprecipitating phosphorus either simultaneously with the vanadium oxide and alkyl orthosilicate coprecipitation or thereafter to thereby obtain the catalyst precursor;
- and
- c. calcining the catalyst precursor to thereby obtain the silica-containing catalyst.
Dependencies are inferred from the claim text.