Method of production of middle distillate from waxes fischer-tropsch using a catalyst based on zeolite modified by a basic treatment

摘要

This invention describes a process for the production of middle distillates from a paraffinic feedstock that is produced by Fischer-Tropsch synthesis, implementing a hydrocracking/hydroisomerization catalyst that comprises at least one hydro-dehydrogenating metal that is selected from the group that is formed by the metals of group VIB and group VIII of the periodic table and a substrate that comprises at least one dealuminified Y zeolite that has 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 aluminum that is present in the zeolite, a starting mesopore volume that is measured by nitrogen porosimetry that is greater than 0.07 ml.g1, and a starting crystalline parameter ao of the elementary mesh of between 24.38 and 24.30 , whereby said zeolite is modified by a) a basic treatment stage consisting in mixing said dealuminified Y zeolite with a basic aqueous solution, and at least one heat treatment stage c).