Alkali Process to Removal of Vanadium and Molybdenum From Spent Hydrodesulfurization Catalyst
Molybdenum-containing catalysts are used in petroleum-refining industries for hydrodesulfuration processes.
These catalytic processes generate huge quantity of spent catalyst. With the increasing demand of metal values and
environmental awareness, spent catalysts can serve as a secondary source for metal recovery. Extractive removal of
molybdenum and vanadium were carried out from spent hydrodesulfurization (HDS) catalyst, in presence of an alkaline
solution, to change vanadium and molybdenum into water-soluble compounds. Various parameters such as temperature,
time, and NaOH addition have been studied extensively. Additionally, conditions for the maximum recovery of molybdenum
and vanadium have been established; at 100 °C, with a retention time of 12 h, and using 5 wt.% NaOH solution, it was
possible to extract 95% of molybdenum and vanadium from the spent catalyst.
Indexterms- spent hydrodesulfurization (HDS) catalyst,removal, molybdenum and vanadium.