Hydrocracking process and system including separation of heavy poly nuclear aromatics from recycle by oxidation

摘要

Hydrocracked bottoms fractions are treated to separate HPNA compounds and/or HPNA precursor compounds and produce a reduced-HPNA hydrocracked bottoms fraction effective for recycle, in a configuration of a single-stage hydrocracking reactor, series-flow once through hydrocracking operation, or two-stage hydrocracking operation. A process for separation of HPNA and/or HPNA precursor compounds from a hydrocracked bottoms fraction of a hydroprocessing reaction effluent comprises contacting the hydrocracked bottoms fraction with an effective quantity of a oxidizing agent to produce corresponding oxidized HPNA compounds and/or oxidized HPNA precursor compounds, and to form an oxidized hydrocracked bottoms fraction. The oxidized hydrocracked bottoms fraction is separated into an HPNA-reduced hydrocracked bottoms portion and an oxidized HPNA portion. All or a portion of the HPNA-reduced hydrocracked bottoms portion is recycled within the hydrocracking operation.