Abstract: Lubricating base oils having a high viscosity index, preferably at least 135, are manufactured by catalytic hydroisomerization of a hydrocarbonaceous feedstock, derived from a waxy crude oil, which feedstock has not been treated to remove a lubricating base oil fraction and which feedstock contains at least 30% by weight wax and has at least 80% by weight boiling above 300.degree. C. and at most 30% by weight boiling above 540.degree. C.

Abstract: Process for the manufacture of lubricating base oils from nitrogen-containing distillate and/or deasphalted oils by catalytic hydrotreatment followed by a dewaxing treatment, which comprises subjecting nitrogen-containing distillates and/or deasphalted oils to solvent extraction and subjecting the raffinate and/or the extract produced to a further treatment to obtain a low-nitrogen fraction and a high-nitrogen fraction and subjecting the low-nitrogen fraction from the extract and/or the high-nitrogen fraction from the raffinate to catalytic hydrotreatment.

Abstract: A process is disclosed for the manufacture of lubricating base oils from nitrogen-containing distillates and/or deasphalted oils by subjecting them to a catalytic hydrotreatment which may be followed by a dewaxing treatment, wherein distillates and/or deasphalted oils having a nitrogen content which numerically expressed exceeds the value f.multidot.P.sub.H2 .multidot.S.sub.v.sup.-1, wherein f is a constant relating to the viscosity of the final base oil, P.sub.H2 represents the hydrogen partial pressure in bar applied in the catalytic hydrotreatment and S.sub.v represents the weighted hourly space velocity in t/m.sup.3 .multidot.h at which the catalytic hydrotreatment is carried out, are subjected to a preceding solvent extraction.

Abstract: A process is disclosed for the preparation of a hydrocarbon mixture rich in aromatics from a gasoline boiling range hydrocarbon mixture low in aromatics which comprises catalytically reforming said hydrocarbon mixture followed by contacting the reformate with certain crystalline silicates at an elevated temperature.