DOUBLE-STAGE METHOD OF SATURATION OF AROMATIC DIESEL FUEL COMPOUNDS USING INTERMEDIATE STEAMING AND BASIC METAL CATALYST Russian patent published in 2018 - IPC C10G45/50 C10G65/08 C10G65/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for improving the properties of a distillate feedstock characterized by nitrogen concentration, a concentration of polyaromatic compounds and a cetane index. Method for improving the properties of a distillate feedstock characterized by nitrogen concentration, a concentration of polyaromatic compounds and a cetane index includes: introducing said distillate feedstock into contact with a first catalyst which is a basic metal catalyst in the sense that it contains a metal from Group VIII, which is either cobalt or nickel, or a combination thereof, or a metal from Group VI, which is either molybdenum or tungsten, or a combination thereof, or a combination of any of said Group VIII metal and any of said Group VI metal deposited on the material, characterized by a large specific surface area, which is preferably an inorganic oxide such as silica, alumina, silica-alumina or a combination thereof contained in the first reaction zone, for hydrodenitrogenation of organic nitrogen-containing compounds and saturation of polyaromatic compounds, wherein said first reaction zone functions in conditions suitable for hydrodenitrogenation and saturation of polyaromatic compounds, and obtaining, from said first reaction zone, a processed product, characterized by a reduced nitrogen concentration with respect to said nitrogen concentration in the feed and a reduced concentration of polyaromatic compounds with respect to said concentration of polyaromatic compounds in the feedstock; bypassing the processed effluent into an interstage high pressure stripper comprising a stripping column vessel that defines a lower section including the stripping zone and an upper section including a phase separation zone, and introducing said processed product to said upper section of said stripper vessel and obtaining from said lower section a stripped liquid fraction and obtaining from said upper section a gaseous fraction; introducing said stripped liquid fraction into contact with a second catalyst contained in the second reaction zone to saturate the mono-aromatic compounds, said second reaction zone functions in conditions suitable for saturation of mono-aromatic compounds, and obtaining from the second reaction zone a product of the reactor, wherein said second catalyst comprises a basic metal catalyst, containing either a nickel component or a cobalt component and either a molybdenum component or a tungstic component supported on an inorganic oxide support, and wherein said reactor product comprises a distillate portion characterized by an improved cetane index with respect to the cetane index for said distillate feedstock; passing said reactor product into a separator to separate said reactor product into a hydrogen portion and a dearomatized distillate portion; and introducing said first hydrogen part into a lower section of said stripper vessel.

EFFECT: ensuring the processing of middle distillate feedstock for obtaining final commercial diesel fuel, characterized in a suitable high cetane index for the use case.

4 cl, 1 dwg