Protein feed and bioplastic from farm biogas
Methane-rich biogas is generated on farms, at landfills and wastewater treatment plants in anaerobic digestion of biological material. Until now, the processing of this type of gas into biomethane has only been viable on large biogas-producing sites; small biogas sources such as farms have remained largely unexploited.
The method developed by VTT enables reduction of emissions, increased use of biogas and improved protein self-sufficiency. It is based on the ability of methanotrophic bacteria to grow in aerobic conditions using methane as the source for carbon and energy. The technology presented here is targeted especially for farm use.
Protein content around 30%
Methanotrophic bacteria may contain polyhydroxybutyrate (PHB) – a natural substance in the cells that enables them to store energy. PHB can be used as a raw material for biodegradable packaging material, instead of oil-based and non-biodegradable plastics such as polypropylene (PP). The cell mass may contain up to 50% PHB, in which case the protein content is around 30%. PHB and protein can be separated by extraction from the dried cell mass.
The protein fraction could be used as an animal feed component. The production of single-cell proteins represents a good opportunity to improve protein self-sufficiency and reduce dependency on imported soymeal.
The production rate of microbial biomass still needs to be improved, which is expected to be accomplished during a couple of years of development work. In addition, the protein fraction’s suitability as a feed component needs to be tested.
Further information: Juha-Pekka Pitkänen, juha-pekka.pitkanen@VTT.fi, +358403569758.