Method of regenerating used catalyst

Abstract

[Problem] Provided is a method for regenerating a catalyst, the method decreasing the SO2 oxidation rate, which has been increased by Fe and V compounds, of a spent denitration catalyst to an extremely low level, and improves the oxidation activity of the catalyst for metal mercury by the regeneration treatment. [Solving Means] A method for regenerating a catalyst, including steps of immersing a spent denitration catalyst composed mainly of titanium oxide in (a) a mixed aqueous solution containing phosphate ions and oxo-acid ions of one or more elements selected from vanadium (V), molybdenum (Mo), and tungsten (W), (b) a heteropoly acid compound aqueous solution containing phosphorus and one or more elements selected from V, M, and W, or (c) a mixed aqueous solution containing a phosphate compound and a vanadyl compound, and then drying the catalyst.

Dependencies are inferred from the claim text.