Patent ID: 7776932

Claim:
A process for the production of liquid hydrocarbons by the Fischer-Tropsch process comprising a) for generating a synthesis gas essentially comprising carbon monoxide and hydrogen, b) Fischer-Tropsch synthesis from a supply comprising at least a portion of the synthesis gas, to produce an effluent comprising synthesized liquid hydrocarbons and at least one gaseous effluent, c) condensing the gaseous effluent obtained during b), d) separating the effluent condensed during c) to obtain a gaseous effluent enriched in carbon monoxide and hydrogen, an aqueous phase and liquid hydrocarbons, and e) recycling at least a portion of the enriched gaseous effluent obtained during d) to the Fischer-Tropsch synthesis b), wherein: 1) two molar ratio of concentrations, A 1 and A 2 , are determined between the hydrogen and the carbon monoxide (H 2 /CO), A 1 being the value of said ratio in the supply to the synthesis b), and A 2 being the value of said ratio in any of the gaseous effluents obtained during b) to e); 2) comparing ratios A 1 and A 2 ; and 3) adjusting the concentrations of hydrogen and/or carbon monoxide in the synthesis gas to keep the difference between the two ratios A 1 and A 2 substantially constant.