Fluid Catalytic Cracking is used to convert the
high-molecular weight petroleum crude oils to lighter and more valuable
products such as gasoline. Magnesium oxide (MgO) is the main building
block for many SOx capturing catalysts as well as metals trapping
Several magnesium-based catalysts are used for
SOx absorption in the fluid catalytic cracking unit and releases the sulfur as
a hydrogen sulfide (H2S) for capture in the sulfur recovery unit as elemental
sulfur. SOx emissions can be reduced by 95% thus reducing the need
for crude oil pretreatment and wet scrubbing of FCC unit exhaust stack.
Magnesium-based catalysts are also used as a
metals trapping catalyst, mainly for vanadium and iron. Without the
addition of this catalyst, vanadium and iron will fill the porous sites of more
expensive zeolite-based catalysts.