Desulphurisation Additives

Iron-based additives are supplied in powder form and are primarily composed of iron oxides and iron hydroxides (e.g. FeO (Wüstite), Fe₂O₃ (Hematite), FeOOH (Goethite)). These additives react with hydrogen sulphide (H₂S) during anaerobic digestion, reducing sulphur levels directly within the process.

Desulphurisation solutions we provide

H₂S needs to be removed from the gas in situations where the gas goes to the grid as well as in situations where the gas is burned in a CHP to produce power and heat. The H₂S lowers the acidity of the gas, whereby the lifetime of the oil and the equipment is significantly reduced.

It is also known that H₂S hinders the process of methanogenesis, thereby also displacing trace elements necessary for methanogenic bacteria. This results in a significant drop in biogas production. Therefore, the target should be to put a desulphurisation process in place that allows the anaerobic bacteria to focus on methane production.

Besides additives, we also provide “end-of-pipe” solutions, whereby the gas is cleaned from H₂S and/or other impurities: see Activated Carbon and Filter Media. The best solution for your process depends on many factors and plant-specific circumstances, and they co-exist in many cases. We can go through the pros and cons with you in a free-of-charge consultation.

The iron additives

FeSfix®-Red Reactive

Iron hydroxide based on FeOOH and Fe₂O₃, containing 50% iron (Fe) and featuring a high surface area (BET > 38 m²/g) for enhanced reactivity.

FeSfix®-Red

Iron oxide product primarily composed of FeOOH, with a significant proportion of Fe₂O₃, containing approximately 50% iron (Fe).

FeSfix®-Red Plus

High-quality, fast-reacting iron oxide with >80% Fe₂O₃, containing 55% iron (Fe). Available in particle sizes of 1 µm, 25 µm and 50 µm.

The products can be supplied in 1 ton big bags or in 25 kg biodegradable paper bags. Other weights can be supplied upon request.

Benefits

Sulphur leaves the system via the digestate as iron sulphide and is a valuable sulphur fertiliser.
Trace elements are more available for the bacteria to do the methanogenesis.
No corrosive effects on concrete and metal parts compared to other liquid based iron products such as ferric chloride.
The product is relatively harmless, which provides safe handling; especially the paper bags provide a dust free and “no contact” solution.
Low dosage per day due to the high iron content, and no dilution of the digester content.