Patent ID: 7880043

Claim:
A method of treating a feedstock coming from a renewable source, comprising the following steps: a) hydrotreatment of said feedstock in the presence of a fixed-bed hydrotreating catalyst, said catalyst comprising at least one metal of group VIII and/or group VIB providing a hydrogenating a function and an amorphous alumina support, at a temperature of between 200 and 450° C., a pressure of between 1 MPa and 10 MPa and an hourly space velocity of between 0.1 h −1 and 10 h −1 and in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio is between 150 and 600 Nm 3 of hydrogen/m 3 of feedstock; b) separation from the resultant effluent coming from step a) of the hydrogen, gases and at least one liquid gas-oil base having a sulphur content of less than 10 ppm by weight, and subjecting at least one part of the liquid gas-oil base obtained from step b) to a separate hydroisomerization step in the presence of a hydroisomerization catalyst comprising: at least one hydrodehydrogenating element chosen from elements of Group VIB and Group VIII of the Periodic Table; a non-zeolitic support based on silica-alumina containing an amount of silica (SiO 2 ) of greater than 10% by weight and less than or equal to 80% by weight; a mean pore diameter, measured by mercury porosimetry, of between 20 and 140 Å; a total pore volume, measured by mercury porosimetry, between 0.1 ml/g and 0.6 ml/g; a total pore volume, measured by nitrogen porosimetry, of between 0.1 ml/g and 0.6 ml/g; a BET specific surface area of between 150 and 500 m 2 /g, a pore volume, measured by mercury porosimetry, in the pores of diameter greater than 140 Å of less than 0.1 ml/g; a pore volume, measured by mercury porosimetry, in the pores of diameter greater than 160 Å of less than 0.1 ml/g; a pore volume, measured by mercury porosimetry, in the pores of diameter greater than 200 Å of less than 0.1 ml/g, and a pore volume, measured by mercury porosimetry, in the pores of diameter greater than 500 Å of less than 0.1 ml/g, and with the provision that the hydroisomerization catalyst is different from the hydrotreatment catalyst.