| 摘要 |
PURPOSE:To obtain a catalyst precursor to produce maleic acid anhydride by vapor phase oxidation of hydrocarbons having a specified carbon number and to improve the production yield, the life and reproducibility by using specified % phosphoric acid produced from ortho phosphoric acid seeds as a pentavalent phosphorus compd. to be used with a pentavalent vanadium compd. to constitute the precursor. CONSTITUTION:This catalyst precursor is used to produce maleic acid anhydride from hydrocarbons having 4 carbon atoms by vapor phase oxidation. The precursor is produced by the reaction of a pentavalent phosphorus compd. and a pentavalent vanadium compd. in an org. solvent which can reduce at least a part of the pentavalent vanadium compd. into quadrivalent vanadium. In this method, as to the phosphorus compd., phosphoric acid produced from orthophosphoric acid seeds is used in an amt. between >90% and <=96%. A mixture liquid of a 3-6C aliphatic alcohol and benzyl alcohol is used as the org. solvent. Further, iron or the like may be used as co-catalyst component. |
