| abstract |
The invention concerns an improved method for making high-quality basic oils optionally with simultaneous production of high-quality middle distillates, comprising hydrotreatment steps, preferably hydrocracking, on Y or beta zeolite, atmospheric distillation. The effluent (which is not vacuum-distilled) is subjected to catalytic dewaxing, preferably on NU-10, EU-1, EU-13 zeolite or ferrierite. The method then comprises steps of hydrofinishing to hydrogenate the aromatics, preferably on a catalyst comprising at least one noble metal of group VIII, chlorine and fluorine, and steps of atmospheric and vacuum distillation. The properties of the oils and the middle distillates are enhanced (flow point, viscosity index, aromatic content) resulting even in to medicinal oils. |