Patent ID: 8679323

Claim:
A process for the production of middle distillates from a paraffinic feedstock, produced by Fischer-Tropsch synthesis, said process comprising: subjecting said paraffinic feedstock to hydrocracking and/or hydro-isomerization in the presence of a hydrocracking and/or hydro-isomerization catalyst, wherein said catalyst comprises: at least one hydro-dehydrogenating metal selected from the metals of group VIB and group VIII of the periodic table, wherein the metals of group VIII of are selected from iron, cobalt, nickel, and mixtures thereof, taken by themselves or in a mixture, and a substrate comprising at least one dealuminified Y zeolite having an initial overall atomic ratio of silicon to aluminum of between 2.5 and 20, a starting extra-lattice aluminum atom fraction by weight that is greater than 10%, relative to the total mass of the aluminum that is present in the zeolite, a starting mesopore volume, measured by nitrogen porosimetry that is greater than 0.07 ml.g −1 , and a starting crystalline parameter a o of the elementary mesh of between 24.38 Å and 24.30 Å, whereby said zeolite is modified by a process comprising: a basic treatment stage wherein said dealuminified Y zeolite is mixed with a basic aqueous solution, wherein said basic aqueous solution is a solution of basic compounds selected from alkaline bases and the strong non-alkaline bases, wherein said basic treatment stage is implemented at a temperature of between 40 and 100° C. and for a time period of between 5 minutes and 5 hours, and at least one heat treatment stage that is implemented at a temperature of between 200 and 700° C.; wherein, after being modified, the dealuminified Y zeolite has a mesopore volume, measured by nitrogen porosimetry, that is greater than at least 10% relative to the mesopore volume before modification.