Biogas is an excellent renewable energy source that can be used for heating, electricity generation, and even fuel. By capturing and utilizing biogas produced during anaerobic digestion, we can reduce our reliance on fossil fuels and decrease greenhouse gas emissions. However, public concerns have been raised about odors coming from biogas plants. But is this perception aligned with reality?

To find out, we spoke with Themistoklis Sfetsas, a technical and quality control manager at Q-lab. With broad experience in biogas production, Themistoklis has examined plants in Greece for a long time, assessing their operations and their impact on people's lives. According to him, “If there is very good fermentation, usually the result is zero to very few smells”.

That said, unpleasant odors can occasionally appear, typically stemming from two sources: the organic waste itself and the anaerobic digestion process. Decomposing organic matter releases gases, including volatile organic compounds (VOCs), which, when discharged into the environment, can cause discomfort to surrounding communities. So, what’s the strategy here? Should we abandon biogas then? Not at all, we just need to find the correct perfume.

 

It’s all about the location

“When considering the environmental benefits of this technology for the treatment of biowaste, we realize it is good for our planet. Otherwise, the volume of methane released would be much higher, contributing significantly to atmospheric pollution”, Themistoklis emphasizes. In Greece, for instance, selecting the location for the construction of biogas plants is meticulously thought-through due to its critical importance.

These facilities are carefully designed and strategically positioned away from residential areas while also being in proximity to available biomass, according to Themistoklis. And the rest of the European Union seems to follow the same strategy.

But a portion of the population remains hesitant when it comes to having a plant nearby. Although, as the Greek expert emphasizes “allowing untreated manure from a livestock farming plant to remain untreated would present a far worse scenario than having these plants nearby”.

By harnessing the waste from livestock farming through biogas plants, we can effectively address the issue of odors while simultaneously converting waste into a valuable renewable energy resource. This exemplifies the concept of circularity, where waste is repurposed to create sustainable energy, contributing to a more environmentally friendly and efficient system.

Should any minor odors persist, solutions are already in motion to combat them. “Technological solutions such as biofilters could be implemented to further minimize any residual odors”, confirms Themistoklis. And there are other approaches to mitigate the unpleasant smells resulting from anaerobic digestion processes. These include preparing an odor management plan, identifying the source of the smells, implementing monitoring systems, and fostering open communication with local communities.

The latter is crucial, as society should be encouraged to embrace the environmental benefits of these digesters. As Themistoklis explains, it's a matter of enhanced communication. “The information should be disseminated by governments; otherwise, people might perceive it as originating from investment interests and entrepreneurs”, he states.

As we've learned, biogas not only helps manage organic waste but also lowers methane emissions from decomposing waste, provides a decentralized energy source, and produces digestate, the material remaining after anaerobic digestion, which is an excellent fertilizer for fields. Therefore, we need to improve communication to foster acceptance of these plants, and, in case of any residual odors, we'll apply some perfume – ahem, we mean effective measures – to keep this energy growing.

Published On: June 26, 2024

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