Abstract: A method for reusing rhenium from a donor spent epoxidation catalyst, the method comprising: providing a donor comprising spent epoxidation catalyst comprising rhenium, the donor having a cumulative alkylene oxide production of 0.16 kT/m3 of the spent epoxidation catalyst or more; contacting the donor with an aqueous liquid to produce rhenium-depleted donor and aqueous extract comprising extracted rhenium; separating the aqueous extract and the rhenium-depleted donor; and, using the extracted rhenium as a source of rhenium in a subsequent process.