FIELD: chemistry.
SUBSTANCE: invention relates to a method for increasing middle distillate production and quality from a hydrocarbon feed. Method includes: a) delivering a partially-regenerated catalyst or a fully- regenerated catalyst, having MAT activity (MAT - microactivity) from 30 wt% to 65 wt%, to a first riser reactor and fully- regenerated catalyst having MAT activity from 50 wt% to 80 wt%, to a second riser reactor; b) cracking first feed in first riser reactor, where catalyst has carbon content on regenerated catalyst (CRC) of 0.2 wt% to 0.5 wt%, to obtain a first cracked product and spent catalyst; c) separating said first cracked product including a middle distillate from said spent catalyst in a single reactor vessel; d) recovering said first cracked product including said middle distillate and separating uncracked bottoms from said first cracked product; e) cracking second feed containing uncracked bottoms from step (d) in second riser reactor to produce a second cracked product; f) separating second cracked product including LHG and middle distillate from spent catalyst in said single reactor vessel; and g) passing spent catalyst from first and second riser reactors to a single two-stage catalyst regenerator device, where spent catalyst is partially regenerated in first stage of said two-stage catalyst regenerator to obtain said partially regenerated catalyst and part of said partially regenerated catalyst is fed into second regeneration stage of said two-stage catalyst regenerator to obtain fully regenerated catalyst, said catalyst regeneration device provides said partially regenerated catalyst and said fully regenerated catalyst, having a different MAT activity. Invention also relates to a system.
EFFECT: use of present method enables to maximise production required product.
32 cl, 6 dwg
