Steam regeneration of phosphorus treated vanadium-phosphorus-oxygen catalysts
AssigneeDenka Chemical Corporation
InventorsGaylon T. Click, Bruno J. Barone
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Abstract
The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.
Claims16
In a method for regenerating a vanadium-phosphorus - oxygen vapor phase oxidation catalyst used in the production of maleic anhydride from n-C.sub.4 hydrocarbons containing P:V in an atomic ratio of 1/2 to 3:1 comprising contacting said catalyst with phosphorus compound of phosphorus halide, phosphorus oxyhalide, organic phosphines, organic phosphites, organic phosphates or mixtures thereof at a temperature in the range of about 0.degree. to 600.degree. C., whereby said catalyst exhibits a first yield wherein the improvement comprises thereafter contacting said catalyst with a flow of steam at a temperature in the range of about 300.degree. C. to about 600.degree. C. in an amount and for sufficient duration such that said catalyst exhibits a second yield greater than said first yield.
Dependencies are inferred from the claim text.