Production of liquid hydrocarbons

A process for the conversion of hydrogen and one or more oxides of carbon to hydrocarbons, which process comprises:

• contacting hydrogen and one or more oxides of carbon with a catalyst in a reaction zone;
• removing from the reaction zone an outlet stream comprising unreacted hydrogen, unreacted one or more oxides of carbon and one or more hydrocarbons and feeding the outlet stream to a separation zone in which the outlet stream is divided into at least three fractions, in which;
• a first fraction predominantly comprises unreacted hydrogen, unreacted one or more oxides of carbon and hydrocarbons having from 1 to 4 carbon atoms;
• in which a portion of the first fraction is separated into C3-C4 fraction which comprises an increased concentration of C3-C4 hydrocarbons compared to the first fraction, and a lights fraction, which comprises an increased concentration of hydrogen, one or more oxides of carbon and C1-C2 hydrocarbons compared to the first fraction;
• a second fraction predominantly comprises hydrocarbons having 5 to 9 carbon atoms, at least a portion of which hydrocarbons having from 5 to 9 carbon atoms are olefinic;
• and
• a third fraction predominantly comprises hydrocarbons having 10 or more carbon atoms;
• characterised in that at least a portion of the second fraction is recycled to the reaction zone.