Abstract: A silica-alumina material, its preparation and application thereof are provided. The silica-alumina material has a SiO2/Al2O3 molar ratio of 0.8-1.5, and has a lamellar structure with an average length of 0.5-2 ?m and an average thickness of 30-80 nm, and its calcined form has a specific XRD pattern. The silica-alumina material has the characteristics of large pore volume, two-stage gradient pore channels of mesopores and macropores, as well as high B acid content as in molecular sieve, and shows crystal characteristics of a molecular sieve, and low impurity content, and thus is suitable for use as a carrier for catalytic materials, particularly a carrier for heavy oil hydrogenation catalysts.

Abstract: A pseudo-boehmite has a dry basis content of 55-85 wt % and contains a phosphoric acid ester group. The sodium oxide content is not greater than 0.5 wt %, and the phosphorus content (in terms of phosphorus pentoxide) is 1.2-5.7 wt %, relative to 100 wt % of the total weight of the pseudo-boehmite. The pseudo-boehmite has a low sodium content.

Abstract: A heavy oil hydrotreating system has a prehydrotreating reaction zone, a transition reaction zone, and a hydrotreating reaction zone that are connected in series successively, sensor units, and a control unit. In the initial reaction stage, the prehydrotreating reaction zone includes at least two prehydrotreating reactors connected in parallel, and the transition reaction zone includes or doesn't include prehydrotreating reactors; in the reaction process, the control unit controls material feeding to and material discharging from each prehydrotreating reactor in the prehydrotreating reaction zone according to pressure drop signals of the sensor units, so that when the pressure drop in any of the prehydrotreating reactors in the prehydrotreating reaction zone reaches a predetermined value, the prehydrotreating reactor in which the pressure drop reaches the predetermined value is switched from the prehydrotreating reaction zone to the transition reaction zone.

Abstract: A heavy oil hydrotreating system has a prehydrotreating reaction zone, a transition reaction zone, and a hydrotreating reaction zone that are connected in series successively, sensor units, and a control unit. In the initial reaction stage, the prehydrotreating reaction zone includes at least two prehydrotreating reactors connected in parallel, and the transition reaction zone includes or doesn't include prehydrotreating reactors; in the reaction process, the control unit controls material feeding to and material discharging from each prehydrotreating reactor in the prehydrotreating reaction zone according to pressure drop signals of the sensor units, so that when the pressure drop in any of the prehydrotreating reactors in the prehydrotreating reaction zone reaches a predetermined value, the prehydrotreating reactor in which the pressure drop reaches the predetermined value is switched from the prehydrotreating reaction zone to the transition reaction zone.