Reforming Catalyst Technology
Hydrocarbon reforming is a basic chemical process used to develop synthesis gas used in the manufacture of hydrogen,
methanol and ammonia. The article includes such topics as hydrocarbon reforming, carbon forming reactions, catalyst
poisons, catalyst formulations and advanced catalyst shapes. Primary Reforming, Auto-Thermal Reforming, and
Pre-Reforming reactors are explained and limitations and problems are discussed.
Hydrocarbon Reforming with steam in the presence of catalyst has been an essential means for hydrogen production in
Chemical Industry since the 1930's. While the catalysts for operating plants have improved, the underlying principles of
operation have remained steadfast throughout time. In Primary and Pre-Reforming equipment, hydrocarbon is mixed with
steam at elevated temperatures and passed across catalysts supported within tubes in a fired heater or within a pressure
vessel. Competing simultaneous hydrocarbon reforming and water-gas-shift reactions occur on the active sites of the
catalyst, as follows:
Methane Reforming:
CH4 + H2O = CO + 3H2 +49.2 kcal/mole (Endothermic)
CH4 + 2H2O = CO2 + 4H2 +39.4 kcal/mole (Endothermic)
Water-Gas-Shift:
CO + H2O = CO2 + H2 -9.84 kcal/mole (Exothermic)
Higher hydrocarbons are first cracked catalytically to Olefines and Methane and then these primary products react further
with Steam yielding Hydrogen and oxides of Carbon. Thus, a mixture of H2, CO, CO2, CH4 and Water vapors is obtained,
the composition of which depends upon reaction chemical equilibria and catalyst activity, operating temperature and
pressure conditions and the ratio of steam to hydrocarbon feeding into the reformer. Over decades of design, operating
conditions for hydrocarbon reforming have become much more severe, intensifying the design requirements of the catalyst.
Earliest equipment operated at near atmospheric pressure, whereas modern reforming equipment can operate up to 40
atmospheres pressure. (588 psia, 4034 kPa, 41.3 kg/cm2 abs)