PROCESS FOR PRODUCING MIDDLE DISTILLATE FROM FISCHER-TROPSCH WAXES USING A CATALYST BASED ON A ZEOLITE MODIFIED BY A BASIC TREATMENT

摘要

The present invention describes a process for producing middle distillates from a paraffinic feedstock produced by Fischer-Tropsch synthesis, using a hydrocracking/hydroisomerization catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the metals from group VIB and from group VIII of the Periodic Table and a support comprising at least one dealuminated zeolite Y having an initial overall atomic ratio of silicon to aluminium of between 2.5 and 20, an initial extra-lattice aluminium atom weight fraction of greater than 10%, relative to the total weight of the aluminium present in the zeolite, an initial mesoporous volume measured by nitrogen porosimetry of greater than 0.07 ml.g^-1, and an initial lattice parameter a₀ of the unit cell between 24.38 Å and 24.30 Å, said zeolite being modified by a) a step of basic treatment consisting of mixing said dealuminated zeolite Y with a basic aqueous solution, and at least one step c) of heat treatment.