Synthesis of atmospheric distillate by Fischer-Tropsch reaction, includes fractionation and isomerizing hydrocracking to produce naphtha, gasoil and kerosene cuts

摘要

The process comprises the preparation of a synthesis gas from a liquid or gaseous hydrocarbon charge coupled with Fischer-Tropsch technology. Production of the atmospheric distillate comprises: (a) formation of a gaseous mixture containing H2 and CO in a ratio of 1.7:1 to 2.5:1 from the initial hydrocarbon charge; (b) conversion of the gaseous mixture from (a) at a high temperature and pressure and in the presence of a catalyst, to obtain a liquid effluent containing 5C minimum hydrocarbons, and a gaseous effluent comprising the non-converted fraction of (a) and CO2 ; (c) treatment of the gaseous fraction from (b) to partly eliminate CO2 and obtain a gaseous fraction depleted in CO2; (d) a primary fractionation stage of the liquid fraction from (b) in which a fraction FL1 (containing mainly 7C minimum hydrocarbons) and a light fraction FL2 (containing 6C maximum hydrocarbons) are obtained; (e) isomerizing hydrocracking stage at high temperature and pressure, in the presence of a catalyst and H2, of the fraction FL1 into a fraction F2 comprising a greater amount of branched chain compounds than in FL1; and (f) a second fractionating stage in which the light fractions FL2 from (d) and F2, from (e) are separated into a fraction containing 4C maximum hydrocarbons (final boiling point less than 37 deg C), a fraction having a final boiling point greater than 300 deg C, and an intermediate fraction of atmospheric distillate of boiling points between 5 and 370 deg C.