IMPROVED METHOD OF HEAVY RAW MATERIAL CONVERTING INTO MIDDLE DISTILLATES WITH PRELIMINARY TREATMENT BEFORE SUPPLY TO CATALYTIC CRACKING PLANT

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to method of heavy raw material converting. Method of middle distillates producing from heavy raw material (1) of vacuum gas oil type or atmospheric distillation residues is successively carried out in 4 stages, containing: a) preliminary treatment (PRET) stage, which is carried out on hydrocracking or hydraulic processing plant, which enables to reduce amount of sulphur and nitrogen-containing impurities in raw material, as well as amount of diolefins, during which gasoline fraction C5-160 °C (3) is produced, middle distillate (4) first fraction with boiling point temperature range of 160-360 °C and part (5), called non-converted, which has essentially same boiling point temperature range, as initial heavy raw material, b) said non-converted part (5) catalytic cracking (FCC) stage, taken from preliminary treatment (PRET) stage, during which dry gases fraction (7) is produced used as fuel, fraction C3 (8), fraction C4 (9), gasoline fraction C5-160 °C (10) and second middle distillates fraction (11), wherein gasoline fraction (10) is supplied to cleaning (PUR) plant, c) oligomerization (OLG) stage, to which fraction C3 (8) is supplied, fraction C4 (9), taken from catalytic cracking plant, and gasoline fraction (10') from cleaning plant (PUR), and during which fraction C3/C4 (14) is produced, gasoline fraction C5-160 °C (15), which are added to gasoline pool, and third middle distillates fraction (16), which is supplied to hydraulic treatment (HDT) plant, d) complete hydrogenation (HDT) stage of middle distillates fraction (16) taken from oligomerization stage, to achieve compliance with requirements for commercially distributed gas oil.;EFFECT: higher selectivity by middle distillates compared to petrol and their increased yield.;9 cl, 10 tbl, 1 dwg, 2 ex