Process for the production of synthesis gas
Process and system for the production of synthesis gas from a hydrocarbon feed stock comprising the steps of endothermic and/or adiabatic catalytic steam reforming and autothermal steam reforming in series, wherein the steam reforming is carried out in one or more endothermic stages in series or in one or more adiabatic steam reforming stages in series with intermediate heating of feed stock gas leaving the adiabatic reforming stages and wherein carbon monoxide containing gas characterised by having a molar ratio of hydrogen to carbon of less than 4.5 is added prior to at least one of the endothermic or adiabatic steam reforming stages and/or prior to the autothermal steam reforming step.
1. A steam reforming system for use in a process for the production of synthesis gas from a hydrocarbon feed stock comprising:
optionally a pre-reformer for adiabatic pre-reforming of the feed stock;
at least a first and last adiabatic catalytic steam reformer and/or a reformer for endothermic catalytic steam reforming;
means for intermediate heating of the feed stock between the at least first and last adiabatic steam reformer;
a down stream autothermal steam reformer connected in series with the reformer for endothermic steam reforming or with the last adiabatic steam reformer; and
means for addition of a carbon monoxide containing gas between the at least first and last adiabatic reformer and/or between the reformer for endothermic catalytic steam reforming and the autothermal reformer,
wherein the means for addition of the carbon monoxide containing gas is a tail gas recycle line from a Fischer-Tropsch synthesis gas and/or a Fischer-Tropsch product work-up unit.