Continuous oil recovery process from spent oily solid material

A process for the recovery of the residual oil contained in spent bleaching earths (SBE) comprising the steps of:

• a) producing a transportation slurry in a non-regulated area by mixing said SBE with oil,
• b) conducting said transportation slurry from said non-regulated area to a solvent extraction regulated area and mixing said transportation slurry with a non-polar solvent and/or a miscella containing a non-polar solvent to produce a first extraction slurry, said first extraction slurry being agitated to extract at least a fraction of the oil contained in said SBE,
• c) feeding the agitated first extraction slurry to at least one centrifuge decanter, said at least one centrifuge decanter separating said first agitated extraction slurry into at least a liquid full miscella and a first sludge, said first sludge having at least 40% solid content,
• d) submitting the first sludge to a number of extraction cycle(s) to obtain de-oiled SBE containing less than 2% residual oil on a dry basis, each extraction cycle consisting of blending the first sludge with non-polar solvent or miscella containing non-polar solvent to produce an extraction slurry, agitating said extraction slurry, and feeding said agitated extraction slurry to at least one centrifuge decanter, said at least one centrifuge decanter separating said agitated extraction slurry into a liquid miscella and a final sludge having at least 40% solid content, the final sludge comprising the de-oiled SBE containing less than 2% residual oil on a dry basis,
• e) evaporating the non-polar solvent of said liquid full miscella of step c) to recover glyceridic oil and, after condensation, the liquid non-polar solvent,
• f) evaporating the solvent of said de-oiled SBE containing less than 2% residual oil of step d) to recover de-oiled and desolventized SBE and, after condensation, the liquid non-polar solvent.