FIELD: oil and gas industry.
SUBSTANCE: method used for obtaining middle distillates based on the mixture of paraffin hydrocarbons obtained by Fischer-Tropsch synthesis involves the following subsequent stages: a) separation at least of light gas fraction C4-, which has final boiling temperature of less than 20°C, from the flow leaving the Fischer-Tropsch synthesis plant in order to obtain only heavy liquid fraction C5+, which has initial boiling temperature of 20 to 40°C; b) hydrogenation of non-saturated compounds of olefinic type at least of some part of heavy fraction C5+ in presence of hydrogen and hydrogenation catalyst at the temperature of 100 to 180°C, at total pressure of 0.5 to 6 MPa with volumetric hourly velocity of 1 to 10 h-1 and at supply of hydrogen, which corresponds to volumetric "hydrogen/hydrocarbons" ratio of 5 to 80 nl/l/h; c) hydroisomerisation/hydrocracking of the whole hydrogenated liquid fuel of stage b), without implementation of the pre-separation stage in presence of hydrogen and catalyst of hydroisomerisation/hydrocracking; d) distillation of the flow subject to hydrocracking/hydroisomerisation, which has been obtained at stage (c) in order to obtain at least fractions of kerosene and gas oil, and residual fraction. Obtained gas oil has the flow point below 0°C, cetane number exceeds 60, kerosene has setting point of not more than -35°C, and height of smokeless flame exceeds 25 mm.
EFFECT: improvement of gas oil properties.
14 cl, 3 dwg
