FeSfix is the latest generation's preparation in powder form, developed in cooperation with German scientific institutions. It works on the basis of the iron oxides (FeO, Fe203 ) which binds hydrogen sulphide (H2S) contained in ferments during the process of anaerobic fermentation in biogas plants (Fig. 2).


FeO + H2➙ FeS + H2O
2H2S + O2  2S + 2H2O   adding the air
2Fe3+ + 3S2- = 2FeS + S

Additional desulphurisation methods using the principle of adsorption by activated carbon do not constitute an economically optimal way. It is well known that H2S has got a hampering effect on the process of methanogenesis, and H2S also displaces trace elements necessary for methanogenic bacteria. This results in a significant drop in biogas production. Therefore, it is best to place the actual biogas desulphurisation process in the process of anaerobic fermentation.

Benefits of using FeSfix:

  • Formation of sulphides already in ferments and prevention of generation of increased amounts of H2S.
  • The process of methanogenesis is no longer hampered by a high concentration of H2S.
  • Limitation of corrosive effects on concrete and metal parts of equipment.
  • Improved availability of trace elements to bacteria and the associated higher biogas yield.
  • There is no ferment salinity as in the case of using toxic iron chloride (FeCl2).
  • FeSfix does not contain the highly toxic CrVI when compared with other preparations (ferrous hydroxide).
  • The actual sulphur remains in the digestate and is then applied to the soil as a valuable sulphur fertiliser.
  • A great benefit is the high content of trace elements (Co, Ni, Cu, Mn, Zn,B,V,Al) in the FeSfix preparation which optimises the process of anaerobic fermentation.
  • Nickel is a major component of the F420 and F430 coenzymes (Fig. 1) which are important carriers of hydrogen in the process of methanogenesis.
  • The resulting separate becomes a valuable substrate for growing mushrooms thanks to increased sulphur and iron content.
  • Reduced dosage of trace elements and the associated financial savings.
  • FeSfix contains 50% Fe which means low daily doses compared to other preparations of Fe(OH)3, Fe(OH)2, FeCl2  where iron concentration ranges between 9 and 30 %.
  • The cheapest, most effective way of biogas desulphurisation and ferment stabilisation in the market.