Abstract:
Metals in petroleum fractions have a deleterious effect on the refining equipment and catalyst. They corrode the equipment, plug the catalyst pores, and create irregularities in the system. With reference to today’s petroleum industry, the fast depletion of light crude has created the need to process heavier crudes with much higher metal content. Hence, the need to remove traces of harmful metals and restrict their accumulation in feed stocks has become a pressing issue. In this context, we review developments over the past decade in regard to the methods of metal removal with a focus on unconventional methods, such as the use of molecularly imprinted polymers, supercritical fluids, and irradiation. Other methods of demetallization discussed include the usage of nanocatalysts, micro-organisms, and certain solvents. The removal of vanadium and nickel were reviewed most, because of the abundance of these elements in the crude.