Water-gas shift reaction

The water gas shift reaction, also briefly WGS is a method for reducing the carbon monoxide content in the synthesis gas and the production of hydrogen.

With the addition of steam, the CO reacts to form CO2 and H2. The reaction enthalpy of -41.2 kJ / mol is quite low. With increasing temperature, the chemical equilibrium of the reaction products shifts to the reaction educts. At about 700 ° C, the negative Gibbs free energy increases to 0 kJ / mol, at higher temperatures the reaction is no longer spontaneous.

At higher temperatures there is a rapid kinetics, but an unfavorable chemical equilibrium. Iron (III ) oxide catalysts to accelerate the reaction at low temperatures of 250 to 450 ° C. In chemical reactors, the shift reaction is often carried out in two stages: in a high -temperature and low -temperature shift stage (in short: HT and LT shift). The CO content can be so depending on the operation of the reactor to 0.6 to 1.5 vol - Lower %.

See also

  • Steam reforming
  • Water Gas
Chemical reaction engineering
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