Hydrocracking process with recycle, comprising adsorption of polyaromatic compounds from the recycled fraction on an adsorbant based on silica-alumina with a controlled macropore content

An improved hydrocracking process with a recycle, having a step for eliminating polyaromatic compounds from at least a portion of the recycled portion by adsorption on an adsorbent based on alumina-silica (i.e. comprising alumina and silica) with a mass content of silica (SiO2) of more than 5% by weight and 95% or less;

• said alumina-silica having:
• a sodium content of less than 0.03% by weight;
• a total pore volume, measured by mercury porosimetry, in the range 0.45 to 1.2 ml/g;
• a porosity such that:
• i) the volume of mesopores with a diameter in the range 40 Å to 150 Å and a mean pore diameter in the range 80 Å to 140 Å represents 30-80% of the total pore volume measured by mercury porosimetry;
• ii) the volume of macropores with a diameter of more than 500 Å represents 20-80% of the total pore volume measured by mercury porosimetry;
• a BET specific surface area in the range 200 to 550 m2/g;
• and
• an X ray diffraction diagram which contains at least the principal characteristic peaks of at least one of the transition aluminas included in the group composed of alpha, rho, khi, eta, gamma, kappa, theta and delta aluminas.