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FCC slurries
Modern refineries use the fluid catalytic cracking (FCC) process, which converts residual petroleum products into more valuable gasoline, diesel fuel and gas oil in atmospheric and vacuum distillation units at refineries. In this case, long chain hydrocarbons are cleaved using aluminum and silicon based catalysts, the particles of which are submicron in size.
FCC devices produce a by-product - distillation bottom products like aromatic and high-viscosity oils, most often in the form of complex oil emulsions. However, such suspensions of oil products have their value and are used as feedstock for the production of bunker fuel (blended) by companding. FCC sludge can be recycled and used as refinery feedstock, and also marketed as a feedstock for pure carbon production or as refinery fuel.
The key to upgrading the FCC sludge to a higher quality product is the removal of catalysts such as aluminum and silicon and other ash forming elements. High speed disc separators from GEA are used to effectively remove these contaminants.
Cleaning with centrifugal separators from GEA showed a separation efficiency of 90% for particles smaller than 5 microns. The FCC sludge becomes a valuable product, which provides additional profit for the refinery.
