MULTISTAGE METHOD OF CRACKING AND STEAM STRIPPING AT FCC PLANT Russian patent published in 2015 - IPC C10G11/18 B01J8/24 

FIELD: oil and gas industry.

SUBSTANCE: this invention is related to catalytic cracking in fluidised bed and contains the following stages: stage of hydrocarbon material reaction in fluidised bed of catalyst in conditions of upward or downward stream; stage of coked catalyst grains stripping for the purpose of their separation from cracked fractions and steam stripping of coked catalyst grains; stage of coked catalyst grains regeneration in one or several steps, at that regenerated catalyst grains collected at the output are returned at the stage of reaction to input of the fluidised bed, at that the above method of catalytic cracking in the fluidised bed includes at stage of stripping/steam stripping the multistage method for cracking and steam stripping of the fluidised mix of hydrocarbons and coked catalyst grains, at that the above multistage method includes at least one stage of cracking and steam stripping upon separation of the coked catalyst grains and cracked fractions. According to the invention the above method in fluidised bed is carried out in the mode of maximum increase in distillates yield, the above multistage method of cracking and steam stripping includes at least two stages of cracking of at least one hydrocarbon flow at separated coked grains of the catalyst, upon the above two stages at least two stages of the above grains steam stripping is performed, moreover before each cracking stage the steam stripping stage is performed; at the first cracking stage at least one hydrocarbon is introduced as selected from obtained benzene or any fraction with boiling temperature less than or equal to 220°C, at the second cracking stage products with boiling temperature above 350°C of HCO type or suspensions collected at stage of hydrocarbons fractionation in the method of catalytic cracking in the fluidised bed are introduced, at that these two stages are separated by steam stripping stage. This invention is also referred to the device for separating and steam stripping.

EFFECT: increased yields of olefins and basic diesel fuel.

15 cl, 3 ex, 3 tbl, 5 dwg