Biogas & RNG Online – March 2026
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Is it important to measure oxygen?
Is it important to measure oxygen?
Oxygen measurements needed in the industry for Biogas and RNG, how it is done?
- 7 Replies
@ametek David, any insights on why it is important and how it works?
HI Natalia and great question on why O2 measurement is important in Biogas/RNG industry. There are 2 critical O2 measurement challenges that the Barben OXYvisor solves. First challenge; methanogenic bacteria that is used in the digestor can’t survive in the presence of O2, therefore monitoring the levels is crucial since any increase in O2 can be detrimental in the digester structure. Second challenge; is low explosive limits (LEL) of O2 measurement to provide safety checks in order to avoid exceeding these O2 levels limits. The Barben OXYvisor Optical analyzer, which uses Optical Quench Luminescent, is great for measuring O2 and solves these 2 challenges due to no interference due to moisture, H2S, CO2, & other contaminant gases. Hope this helps and please feel free to ask any more questions!
David, thank you so much for sharing this information. Do you know if natural gas utilities have standards for oxygen content for natural gas and for RNG?
Depends on the natural gas pipeline company, but max oxygen content seems to be around .0.2% to 0.4% by volume. RNG seems to have stricter limits, <= 1.0% by volume, even some trends toward Ultra-trace oxygen limits down to <= 0.005% (50ppm). The limits are based around minimizing risk of corrosion.
David, thank you for these details and the last question: overall for RNG projects, do projects have to reduce oxygen content or typically it comes within norms? Basically, apart from monitoring oxygen, should projects have the technology to reduce it?
Oxygen in the liquid-phase is a non-starter. If there is oxygen then it is not anaerobic!
In the biogas phase, oxygen must be carefully considered. If there is any oxygen measured, was it added for a purpose or does it signal a leak to be investigated?
Of course, at high range is the fire and explosion risk.
A low level of oxygen is needed if you have a biodesulfurization system. The trade-off is the generation of sulfuric acid and the slow degradation of materials. Too much O2 and you can have RNG quality issues or even be rejected from grid injection.
Oxygen can cause corrosion in RNG pipelines, so it is tightly restricted. Most RNG projects must meet a certain O2 spec, usually much lower than what is in raw biogas. Regarding oxygen reduction / removal methods, I can’t really speak on this topic but it would be needed and I believe there are technologies out there for deoxygenation.
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