Thiomargarita namibiensis with sulfur deposits on the outside (Source: MPI)
Thiomargarita namibiensis with sulfur deposits on the outside (Source: MPI)

Biological Desulfurization - H2S Removal

Biological desulfurisation utilizes the microbial process where microbes remove hydrogen sulfide (H2S) and convert it into sulfur.

With farm material and substrates low in protein desulfurization is handled by air injection into the gasholder. Microbes take the oxygen and convert hydrogen sulfide (H2S) into sulfur.

    • H2S  + O2 -> S2 + 2 H2O

Sulfur oxidizing bacteria perform that task. Being autothrophic these species oxidize hydrogen sulfide as a source of energy.

Air is normally injected into the biogas digester with a controlled compressor. The total air going into the digester should not exceed 2-5% of the biogas (volume) produced at any one time. Higher levels can lead to incendive and explosive gas mixtures.

Warning: Methane can form a highly incendive and explosive gas mixture in connection with air.

These installation should only be carried out by authorized and trained personal or companies.