Biogas oxidation catalysts (BOC)

Biogas oxidation catalysts are used in gas-powered and dual-fuel engines that run on biogas, sewage gas or landfill gas.


  • Up to 90% of formaldehyde (CH2O) is converted into carbon dioxide (CO2) and water (H2O).
  • Over 90% of the carbon monoxide (CO) is converted into carbon dioxide (CO2).
  • Up to 90% of hydrocarbons (HC) are converted into carbon dioxide (CO2) and water (H2O).

If the fuel gas contains hydrogen sulphide (H2S) (i.e. there is no desulphurisation system), it is burnt to form sulphur dioxide (SO2) and sulphur trioxide (SO3). As catalyst poisons, these substances have a deactivating effect on the coating and undergo further oxidation in the catalys:

  • Sulphur dioxide (SO2) into sulphur trioxide (SO3)
  • Sulphur trioxide (SO3) into sulphur tetroxide (SO4)

If the exhaust gas is cooled to below the dew point after passing the catalytic converter, the sulphur dioxide (SO2) in the condensate will form sulphurous acid (H2SO3) and the sulphur trioxide (SO3) will form sulphuric acid (H2SO4). These substances have highly corrosive effects even on stainless steels and can damage the components installed downstream of the catalytic converter, e.g. the exhaust gas heat exchanger.
This is why Fischer BOC feature a special coating that is highly resistant to sulphur compounds and keeps the oxidation of sulphur oxides low. 

Our biogas oxidation catalysts are exclusively coated with platinum