METHOD FOR HYDROTREATING GAS OIL IN REACTORS IN SERIES WITH HYDROGEN RECIRCULATION Russian patent published in 2018 - IPC C10G45/02 C10G65/16 C10G65/08 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for hydrotreating a hydrocarbon feedstock comprising sulphur and nitrogen compounds, which comprises the following steps: a) separating (SEP) hydrocarbon feedstock into a fraction rich in heavy hydrocarbon compounds and a fraction rich in light hydrocarbon compounds, b) performing a first hydrotreating step, bringing into contact the fraction rich in heavy hydrocarbon compounds, and a hydrogen-containing gas stream with a first hydrotreating catalyst in first reaction zone (Z1) to produce a first desulphurised effluent containing hydrogen, H₂S and NH₃, c) separating (D1) the first effluent into a first gas fraction containing hydrogen, H₂S and NH₃, and a first liquid fraction, d) purifying (LA) the first gas fraction to produce a hydrogen-rich stream, e) mixing a fraction rich in light hydrocarbon compounds with the first liquid fraction obtained in step c) to obtain a mixture, e) performing a second hydrotreating step, bringing into contact the mixture obtained in step e) with at least a portion of the hydrogen-rich stream obtained in step d), with a second hydrotreating catalyst in second reaction zone (Z2) to obtain a second desulphurised effluent containing hydrogen, NH₃ and H₂S, g) separating (D2) the second effluent into a second gas fraction containing hydrogen, H₂S and NH_3, and a second liquid fraction, h) recirculating at least a portion of the second gas fraction containing hydrogen, H₂S and NH₃, from step b) as a gas stream containing hydrogen.

EFFECT: object of the invention is to optimise the process in order to reduce sulphur and nitrogen content of the processed feedstock.

12 cl, 6 dwg, 2 ex