Process for the refining of crude oil

1. A process for refining crude oil consisting essentially of:

sending the crude oil to a separation unit of the crude oil, the separation unit including at least one atmospheric distillation unit for separating various fractions of the crude oil, units for the conversion of heavy fractions, units for improving the quality of some of the fractions obtained in the atmospheric distillation unit by actions on the chemical composition of their constituents, and units for the removal of undesired components; wherein the step of sending the crude oil to the separation unit includes:

separating the crude oil into various fractions in the at least one atmospheric distillation unit, the heaviest fraction comprising an atmospheric distillation residue;

sending the atmospheric distillation fraction to the units for the conversion of heavy fractions, wherein the conversion units comprise at least one hydroconversion reactor in slurry phase or of the ebullated bed type, wherein hydrogen or a mixture of hydrogen and H 2 S is introduced in the presence of a nanodispersed hydrogenation catalyst;

separating non-converted asphaltene liquid from a gas phase obtained from an outlet of the hydroconversion reaction;

sending the separated, non-converted asphaltene liquid to a vacuum extraction to obtain products having a boiling point higher than 380° C.;

partially condensing the gas phase obtained either before or after the separation of non-converted asphaltene liquid to obtain products having a boiling point higher than 380° C.;

sending the products, having a boiling point higher than 380° C., back to said hydroconversion reactor so that the conversion products extracted can be distilled for at least 60% by weight at 380° C.; and

sending the products having at least 60% by weight at 380° C. and/or some of the fractions obtained from the atmospheric distillation unit to the units for improving the quality of the fractions by actions on the chemical composition of their constituents, and/or to the units for the removal of undesired components.

2. The process according to claim 1 , wherein the nanodispersed hydrogenation catalyst is based on a sulfide of Mo and/or Fe and/or W and/or Cr and/or Ni and/or Co and mixtures thereof.

3. The process according to claim 1 , wherein, when the hydroconversion reactor is of the ebullated bed type, a suitable heterogeneous, supported hydroconversion co-catalyst is also present.

4. The process according to claim 1 , wherein, when the hydroconversion reactor is in slurry phase, a suitable heterogeneous, supported hydroconversion co-catalyst is also present.

5. The process according to claim 3 , wherein the co-catalyst has particles of nanometric or micronic dimensions and is selected from cracking and/or denitrogenation catalysts.

6. The process according to claim 1 , wherein the distillation residue is sent to at least one hydroconversion reactor with solid accumulation in slurry phase, wherein one or more stripping phases are included, with a suitable hot stripping gas so as to obtain conversion products in vapour phase.

7. The process according to claim 1 , wherein the distillation residue is sent to a hydroconversion reactor with solid accumulation in slurry phase of the bubbling tower type, in the presence of a catalyst based on molybdenum so as to obtain conversion products in vapour phase directly in the reactor.

8. The process according to claim 1 , wherein the units for improving the quality of the fractions are selected from isomerization units and/or reforming units.

9. The process according to claim 1 , wherein the units for the removal of undesired components comprise desulfurization units.