The Sabatier reaction involves hydrogen and carbon dioxide reacting at elevated pressures and temperatures (above 300°C) in the presence of a catalyst to produce methane and water. Catalysts may be nickel or ruthenium.
- CO2 + 4 H2 --> CH4 + 2 H2O + energy
- H = 165.0 kJ/mol
Such a reactor is not ultimately preferred to photosynthesis as a means to make use of CO2 inside a CELSS. However the Sabatier technique is perhaps favorable during the construction of a habitat on Mars for instance, where CO2 and H2O are available (H2O can be electrolyzed to make H2 and O2 gas), before plants can be established. CH4 (methane) can be used as fuel for heating, cooking, energy storage, and transportation.