Method and device for carrying out a water-gas shift reactor

A process for performing a water gas shift reaction, comprising:

• reacting raw synthesis gas in the presence of steam and at least one water gas shift catalyst to convert carbon monoxide into carbon dioxide and to form hydrogen,
• wherein the raw synthesis gas is initially passed through at least one unit for high-temperature CO conversion and subsequently, downstream thereof, passed through at least two units for low-temperature CO conversion,
• wherein after passing through the at least one unit for high-temperature CO conversion the synthesis gas stream is divided into at least two substreams,
• wherein the first substream is passed through a first unit for low-temperature CO conversion wherein the first substream comprises a proportion of 95% by volume to 65% by volume of the total synthesis gas stream after the high-temperature CO conversion and the second substream is passed through a second unit for low-temperature CO conversion wherein the second substream comprises a proportion of 5% by volume to 35% by volume of the total synthesis gas stream after the high-temperature CO conversion, wherein both units for low-temperature CO conversion are arranged in parallel relative to one another.