Production of liquid fuels by a concatenation of processes for treatment of a hydrocarbon feedstock

A process for the production of liquid fuels starting from a solid feedstock containing biomass in which:

• a) the solid feedstock is subjected to a gasification stage so as to convert said feedstock into synthesis gas comprising carbon monoxide and hydrogen,
• b) the synthesis gas that is obtained in stage a) is subjected to a purification treatment that comprises an adjustment to increase the molar ratio of hydrogen to carbon monoxide, H2/CO, up to a predetermined value,
• c) the purified synthesis gas that is obtained in stage b) is subjected to a conversion stage that comprises the implementation of a Fischer-Tropsch-type synthesis so as to convert said synthesis gas into a liquid effluent and a gaseous effluent,
• d) the liquid effluent that is obtained in stage c) is fractionated so as to obtain at least two fractions that are selected from the group that consists of:
• a gaseous fraction, a naphtha fraction, a kerosene fraction and a gas oil fraction, and
• e) at least a portion of any naphtha fraction obtained in step d) is recycled in gasification stage a).