The feed materials natural gas, liquid gas or naphtha are endothermically converted with water steam into synthesis gas in catalytic tube reactors. Process heat as well as flue gas are used for the steam generation.
Linde is a leading supplier of steam reformer plants with more than 200 constructed units producing capacities of synthesis gas from 1,000 to over 120,000 Nm³/h of.
The desulfurized hydrocarbon feed is mixed with superheated process steam in accordance with the steam/carbon relationship necessary for the reforming process.
After that, this gas mixture is heated up and then distributed on the catalyst-filled reformer tubes. The gas mixture flows from top to bottom through tubes arranged in vertical rows. While flowing through the tubes heated from the outside, the hydrocarbon/steam mixture reacts, forming hydrogen and carbon monoxide in accordance with the following reactions:
CnHm + n H2O => n CO + ((n+m)/2) H2 (1)
CH4 + H2O <=> CO + 3 H2 (2)
CO + H2O <=> CO2 + H2 (3)
To minimize the methane content in the synthesis gas while simultaneously maximizing the H2 yield and preventing the formation of elemental carbon and keeping it from getting deposited on the catalyst, the reformer is operated with a higher steam/carbon relationship than theoretically necessary.
As the heat balance for the main reactions (1) - (3) is endothermic, the required heat must be produced by external firing. The burners for the firing are arranged on the ceiling of the firing area between the tube rows and fire vertically downward. The residual gas from the pressure swing adsorption unit as well as heating gas from battery limits is used as fuel gas.
The flue gas is then cooled down in a convection zone, generating steam.