Continuous oil recovery process from spent oily solid material
AssigneeDesmet USA, Inc.
InventorsWilliam Blake Hendrix, Timothy Kemper, Marc Kellens
Life of this patent
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Abstract
A process for the treatment of oily hazardous solid materials such as for example spent bleaching earths. The process allows a safe and economical recovery of typically about 85% to 95% of the residual oil contained in such oily hazardous solid materials and transforms those ones into inert materials safe to transport, store, dispose of, or even makes them valuable for some applications. The process includes the production of a transportation slurry and at least one extraction slurry. The at least one extraction slurry is separated in at least one centrifuge decanter.
Claims13
A continuous process for the recovery of 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 in a first extraction vessel 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 a first centrifuge decanter, said first centrifuge decanter separating said agitated first 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 a sludge with a non-polar solvent or miscella containing a non-polar solvent in a further extraction vessel to produce a further extraction slurry, agitating said further extraction slurry, and feeding said agitated further extraction slurry to a further centrifuge decanter, said further centrifuge decanter separating said agitated further extraction slurry into a liquid miscella and a further sludge having at least 40% solid content, wherein the last extraction cycle produces a 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, a liquid non-polar solvent, and
- f) evaporating a remaining portion of the non-polar 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, a further liquid non-polar solvent.
Dependencies are inferred from the claim text.