Method of regenerating SCR catalysts, fully or partially deactivated, and method of utilization of cleaning solutions used during regeneration

The present invention relates to a process for the regeneration of a completely or partially deactivated and calcined SCR catalyst, in particular of the stainless steel lattice or honeycomb type plate containing anatase form of titanium dioxide (TiO2), mixed with active metal oxides: vanadium oxide V2O5, tungsten oxide WO3 or molybdenum oxide MoO3, the regenerated SCR catalyst being immersed, preferably completely, in one or separately and in any order in two or three or four multicomponent cleaning solutions having the following composition: solution I containing 0.1-99.7% by weight CH3COOH and/or 0.1 - 99.7% by wt. glycerin, and/or 0.1-99.7% by wt. acetone, and/or 0.1-99.7% by wt. Na2S2O3; solution II containing 0.1-99.7% by weight CH3COOH and/or 0.1 - 99.7% by wt. H2SO4, and/or 0.1-99.7% by wt. H3PO4, and/or 0.1-99.7% by wt. (COOH)2 · 2H2O; solution III containing 0.1 - 99% by wt. NaOH and 1-99.9% by wt. H2O2; solution IV containing 0.1-99.9% by wt. CH3COOH and 0.1 - 99.9% by wt. H2O, where the immersion time is at least 30 minutes for each solution I - IV, each immersion step in a certain solution is followed by immersion of the catalyst in water, preferably distilled, for at least 5 minutes, and after completion of the last immersion step of the catalyst in water followed by drying at from 0 to 600 ° C for at least 5 minutes and the cleaning solutions used during regeneration are preferably recycled.