Abstract: A process for deasphalting and demetallizing petroleum vacuum distillation residues using dimethylcarbonate (DMC) in the presence of an overpressure of carbon dioxide (CO.sub.2) and comprising:mixing a vacuum distillation residue with dimethylcarbonate (DMC) under a pressure of CO.sub.2, under temperature and pressure conditions such as to maintain the DMC in a prevalently liquid state, and forming a homogeneous solution with the deasphalted oils;cooling the entire system to a temperature such as to form three phases;then venting the gas at this temperature;recovering a deasphalted and partly demetallized primary oil from the light phase;recovering a deasphalted and partly demetallized secondary oil from the intermediate phase;f) recovering the used DMC for its possible reuse.

Abstract: A continuous process for deasphalting and demetallating a residue from crude oil distillation, by means of dimethyl carbonate as extraction solvent, comprises:mixing a residue from crude oil distillation with a recycled liquid stream containing oil and dimethyl carbonate, in order to produce a homogeneous solution;cooling said homogeneous solution and separating a refined light, liquid, phase; an extracted middle phase; and a heavy phase containing asphaltenes;recovering a primary, deasphalted/demetallated oil from said light phase;partially recycling said middle phase to the mixing step, and recovering a secondary deasphalted oil from the residual fraction;recovering asphaltenes from said heavy phase.

Abstract: A process is described for deasphalting and demetalating crude petroleum, or a fraction thereof, containing asphaltenes and metals, in which:said crude petroleum or its fraction is brought in to contact with an organic carbonate, the operation being conducted in the homogeneous liquid phase, until a solid residue rich in asphaltenes and asphaltenic metals precipitates; and said solid residue is separated from the homogeneous liquid phase.After separating, the solid, the homogeneous liquid phase can be cooled to separate an oil-rich refined liquid phase from the extracted liquid phase rich in organic carbonate. The separation of the extracted and refined liquid phases can also be achieved by adding a liquid solvent which is more polar than the carbonate, with or without cooling.