Process and apparatus for producing gas products using a shift converter

The invention relates to a process and to an apparatus for producing a hydrogen-containing gas product in a first modification (7) or a second modification (14) having a lower hydrogen content than the first modification, wherein a synthesis gas (1) containing steam, carbon monoxide and hydrogen and provided with a steam/carbon monoxide ratio (S/CO ratio) between 1.8 and 2.5 mol/mol is treated using a shift converter (S) to obtain an intermediate product (3, 12) from which water and acid gases are separated in each case to obtain the hydrogen-containing gas product (7, 14). The characteristic feature here is that the synthesis gas (2) is supplied to the shift converter (S) in the form in which it is provided to obtain the gas product in the first modification (7), while the ratio of steam to carbon monoxide in the synthesis gas (11) is adjusted to a value between 0.1 and 0.6 mol/mol by the removal of water upstream of the shift converter (S) to obtain the gas product in the second modification (14).