FIELD: chemistry.
SUBSTANCE: invention relates to methods for hydroprocessing hydrocarbon feedstock, wherein the method, in particular, comprises (a) contacting the hydrocarbon feedstock with hydrogen and a first diluent to form a first liquid feed, wherein hydrogen is dissolved in said first liquid feed, and wherein the hydrocarbon feed is a light cycle oil (LCO) having a polyaromatic compound content greater than 25% by weight, a nitrogen content greater than 300 parts per million by weight (wppm) and a density greater than 890 kg/m3 at 15.6°C at 15.6°C; (b) contacting the first liquid feed mixture with a first catalyst in a first liquid-full reaction zone to produce a first effluent; (c) recycling a portion of the first effluent for use as all or part of the first diluent in step (a); (d) separating ammonia and optionally other gases from the portion of first effluent not recycled, to produce a second effluent having a nitrogen content less than 100 wppm; (e) contacting the second effluent with hydrogen and a second diluent to produce a second liquid feed, wherein hydrogen is dissolved in said second liquid feed; (f) contacting the second liquid feed with a second catalyst in a second liquid-full reaction zone to produce a third effluent having a density less than 865 kg/m3 at 15.6°C and a polyaromatic compound content less than 11% by weight; (g) recycling a portion of the third effluent for use as all or part of the second diluent in step (e); and (h) taking the portion of the third effluent not recycled as a product stream, wherein the first catalyst is a hydrotreating catalyst and the second catalyst is a ring opening catalyst.
EFFECT: advantage lies in the fact that LCO feed is converted to diesel fuel with a high yield of the product with a small loss of hydrocarbon for the formation of naphtha.
15 cl, 2 dwg, 6 tbl, 4 ex
