Abstract: Process for the manufacture of lubricating base oils wherein a hydrocarbon feedstock is catalytically treated in the presence of hydrogen at elevated temperature and pressure and wherein at least part of a heavy fraction of the material obtained is subjected to dewaxing, in which process a hydrocarbon feedstock is used containing flashed distillate produced via a residue conversion process.

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: Lubricating base oil compositions having improved stability comprise a major amount of a base oil which has been prepared from a vacuum distillate (VD) or deasphalted oil (DAO) by severe hydrotreating optionally in combination with solvent refining, and a minor amount of an oil which has been prepared from a VD or DAO by a combination of mild hydrotreating and solvent refining.

Abstract: Middle distillate hydrocarbons are produced from feed mixtures of carbon monoxide and hydrogen by contacting said feed at elevated temperature and pressure in a first stage with certain impregnated catalysts and contacting at least the middle distillate fraction of the product of the first stage in the presence of hyrogen with a catalyst containing at least one metal having hydrogenation activity supported on a porous carrier.