Sulfothane™ - biogas desulphurization
Biogas is valuable renewable energy source receiving ever more attention. Biogas can be generated by the anaerobic treatment of industrial wastewaters, by the digestion of manure and other bio-wastes, and is released as landfill gas from covered landfill sites.
Depending on the biogas quality, desulphurisation, or the removal of sulphur compounds that occur in biogas in the form of sulphide (H2S), is necessary. The formation of sulphide and its concentration in biogas is determined by the type of substrate processed in anaerobic digestion. Sulphur can cause severe corrosion in boilers and engines utilizing biogas, and thus, significantly reduces the technology lifetime.
Description of Sulfothane™ technology
The Sulfothane™ process consists of two steps. First it resembles a chemical alkaline scrubber for H2S. Second the alkaline solution is continuously regenerated in a biological process using aerobic sulphur bacteria. This configuration avoids the problems of elemental sulphur clogging of the alkaline scrubber that are commonly found in conventional alkaline scrubbers. Theiologically recovered sulphur can easily be disposed for sulphuric acid production or as a fertiliser.
Main characteristic
- H2S removal efficiency up to 99%. The resulting H2S concentration in the treated biogas can be < 25 ppm
- No addition of air in biogas stream
- Very compact layout and small footprint
- Robust process, easily handling peak loads and fluctuating flows
- Short start-up time
- Small requirements of caustic, water and nutrients
- Clogging free scrubber so almost no maintenance (cleaning)