Terpenes and Siloxanes

Activated carbon filtration is an effective way to purify biogas of siloxanes, which generate abrasive silica when combusted in downstream machinery such as combined heat and power (CHP) engines. DESOTEC filters are ideal for the task, and can handle the discontinuous gas flows and varying concentrations typical of biogas applications. Biogas from wastewater treatment plants (WWTPs) is highly likely to contain siloxanes, which are found in cosmetics, deodorants, water repellents, food additives, soaps and other products. 

Activated carbon is recognised as the Best Available Technology (BAT) to purify biogas of terpenes, which can cause an odour nuisance at high concentrations and corrode downstream equipment. Terpenes are generated by the fermentation of green waste or derived biosynthetically from isoprene in cosmetic fragrances, so may be present in high concentrations in biogas. DESOTEC filters can be used as part of the process of upgrading biogas into biomethane for injection into the national grid, or conversion into compressed natural gas (CNG) or liquefied natural gas (LNG). 

Biogas production is governed by odour and air quality legislation that is likely to become more stringent in the coming years – but activated carbon is a reliable technology to future-proof your business. DESOTEC offers advice and expertise along with modular filtration technology that can be expanded to suit changing parameters or regulations. Our solutions also enable you to meet the terms of manufacturers’ warranties for downstream equipment. Compliant waste handling is included in our service, sparing your company hassle and enabling you to focus on producing renewable energy. 

Activated carbon is recognised as the Best Available Technology for biogas purification, and is often the most cost-effective and sustainable option – especially in the following situations:

• Where production is discontinuous, activated carbon is generally more cost-effective than alternatives such as thermal oxidisers (RTOs).
• If space is tight, DESOTEC filters have a smaller footprint than most alternatives.
• For short-term usage, our filters are mobile and rental – unlike more permanent installations such as RTOs.
• If treatment is needed immediately, our filters can be delivered fast and are plug-and-play – some alternatives have a lengthy lead-in time.
• If your needs might change in the future, our systems are modular – other technology might be less adaptable.
• If flow rates, concentrations and compounds are changeable, activated carbon is generally more versatile than alternatives. 

DESOTEC is keen to help customers find the best treatment for their needs, and our experts will tell you if they think another technology might be more suitable than activated carbon.

Activated carbon is a very versatile technology, so there are many ways to optimise set-ups – e.g. placing filters in series, using different carbon grades, or combining filters with complementary technology such as scrubbers.

DESOTEC solutions offer a low total cost of ownership (TCO): capex costs are minimal, and testing, maintenance, upgrading and ongoing support are included in our service. Sustainable carbon waste handling is also included,  with carbon reactivated for reuse wherever possible at our state-of-the-art facilities. This cuts your costs and further closes the loop in renewable energy production, boosting sustainability.