Rebuilt biogas plant with zero disturbing odor emissions

The combination of ozonation and selective adsorption removes all gas pollutants

VSS Biovoima Oy is a bioenergy company founded in 2016, active in the Säkylä industrial area – one of Finland’s most important food production areas. The company produces biogas and biodiesel from a combined plant for treatment of organic residues from the food industry. Their key industrial stages are a continuous dry anaerobic digestion process and a supercritical esterification process. The treatment capacity is about 20,000 tons per year of residues, producing 200 m3/h of raw biogas.


  • Name:

    VSS Biovoima OY

  • Location:

    Säkylä, Finland

  • Industry:

    Biogas and biodiesel production plant

  • Air flow:

    13 000 m3/h

  • Purpose:

    H2S and odor removal


  • 1 x Nodora ADS

  • 1 x Ozonetech RENA Pro B-series

  • Dimensions (HxWxD):

    2,070 x 760 x 1,160 mm

  • 1800 x 600 x 800 mm

  • Input power:

    1.7 kW

  • Noise level:

    55 dB

VSS Biovoima from outside

The biogas plant VVS Biovoima OY in Finland.

The problem

Since the company was recently founded, parts of the industrial site required significant rebuilding to be adapted to the new process requirements. H2S is a gaseous pollutant always present in biogas plants, either in the air of the ventilation system or in the biogas after the anaerobic digestion stage. VSS Biovoima OY decided to adopt a proactive approach, installing a treatment system for preventing any H2S and odor emissions.

The solution

Mellifiq was commissioned to design and install the whole treatment stage. We choose our most advanced Ozonetech system for air treatment – the RENA Pro B-series – combined with the Nodora ADS active filter, for a final air polishing. The Ozonetech and Nodora systems are designed to work in synergy, maximizing the range of pollutants removal. In addition, the Nodora filter ensures low pressure drops, a very important feature when designing ventilation systems.


Once more our combined system proved to keep up with the expectations. Immediately after injection, ozone started to decompose the pollutants, due to its fast reactivity. Thanks to the combination with Nodora, the final H2S removal had an average value of 95%, ensuring no odor problems for the surroundings. Due to expected changes in the process conditions, mild variations (± 2 %) of H2S removal were observed, confirming the effectivity of our system even in the most problematic situation.