Sulfur removal from residual fuel oil has received increasing attention in
recent years mainly for the preparation of clean feedstocks for downstream
conversion units and to meet the new specifications for petroleum products.
This review presents discussion of non-conventional methods of fuel oil de
sulfurization other than hydrodesulfurization (HDS). These methods include
oxidation, electrochemical, sodium, alkali, chemical treatment, and biodesu
lfurization.