METHOD FOR PRODUCING MIDDLE DISTILLATES BY THE HYDROISOMERIZATION AND HYDROCRACKING OF FEEDSTOCKS OBTAINED FROM THE FISCHER-TROPSCH METHOD

摘要

Preparation of middle distillates from a paraffinic load produced by Fischer-Tropsch synthesis comprises the use of a hydrocracking/hydroisomerization catalyst comprising at least a hydro-dehydrogenating element, e.g. of VIB or VIII groups of periodic classification, 0.2-2.5 wt.% of oxides of phosphorus, boron or silicon and a non-zeolitic support containing silica-alumina (containing higher than 5 wt.% to = 95 wt.% of silica (SiO 2)). Preparation of middle distillates from a paraffinic load produced by Fischer-Tropsch synthesis comprises the use of hydrocracking/hydroisomerization catalyst comprising at least a hydro-dehydrogenating element e.g. of VIB or VIII groups of periodic classification, 0.2-2.5 wt.% of oxides of phosphorus, boron or silicon and a non-zeolitic support containing silica-alumina (containing higher than 5 wt.% to = 95 wt.% of silica (SiO 2)), where the catalyst has the characteristics of: an average porous diameter, measured by mercury porosimetry, of 20-140 Å; total porous volumes, measured by mercury and nitrogen porosimetries, of 0.1-0.5 ml/g; a Brunauer, Emmett and Teller specific surface area of 100-550 m 2>/g; a porous volume, measured by mercury porosimetry at pores of diameter higher than 140 Å, 160 Å, 200 Å and 500 Å, of lower than 0.1 ml/g; an X-rays diffraction diagram containing at least the principal lines characterized by at least one of transition aluminas e.g. alpha , rho , chi, eta , gamma , kappa, theta and delta aluminas and a packed filling density of catalysts higher than 0.75 g/cm 3>.