METHOD OF TWO-STAGE THERMAL CRACKING WITH MULTI-STAGE SEPARATION SYSTEM Russian patent published in 2019 - IPC C10B55/00 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to delayed coking of heavy oil residues to obtain petroleum coke and light hydrocarbon products. Method envisages the following stages: a) the fresh hydrocarbon starting material is passed to the bottom section of the main fractionation plant and mixed with the internal recycle to produce the secondary hydrocarbon starting material; b) the secondary hydrocarbon feedstock is heated in the furnace to obtain hot starting material at the desired pre-cracking reactor inlet temperature; c) the hot starting material is passed at the desired temperature and pressure values to the pre-cracking reactor, in which the hot starting material undergoes soft thermal cracking reactions to obtain the produced stream of the obtained material; d) released flow of obtained material is introduced into first intermediate separator for separation of hydrocarbons in outlet flow of material into upper and lower fractions, wherein upper fraction consists of lighter products and gases, and lower fraction is divided into first part and second part; e) upper fraction is directed to main fractionation unit; f) first part of lower fraction is separated in second separation column operated in vacuum conditions to produce upper product and heavier product; g) the upper product obtained at step (f) is passed to the main fractionation unit; h) fractions of the heavier product are removed from the second separator of step (f) and passed to the main fractionation unit, wherein the heavier fractions consist of light vacuum gas oil (LVG) and heavy vacuum gas oil (HVG); i) a second portion obtained from the first intermediate separator in step (d) and the bottom product obtained from the second separation column at step (f) are mixed and heated in the furnace to the desired coking temperature to obtain a hot hydrocarbon stream; j) hot hydrocarbon flow is passed from furnace into pre-heated coke drum and k) vaporous products coming out of the coke drum are passed into the main fractionation column to obtain product fractions.

EFFECT: invention provides reduction of total output of coke.

19 cl, 8 dwg, 4 tbl