Processing of bioplastics in biogas production: a forward-looking waste management solution

Biogas and biomethane are generated from different types of organic residues, turning waste into a valuable resource. A recent study shows that the increasing amount of compostable bioplastics in our waste can be collected and processed with no ecological risk to produce biogas, supporting the development of renewable energy in Europe.

EU countries are required to reuse and recycle at least 55% of their municipal waste by 2025, 60% by 2030 and 65% by 2035.[1] The biogas sector is already contributing to reach this target by producing renewable energy from collected local bio-waste. According to the EBA Statistical Report 2022, organic municipal solid waste is the second biggest source of biomethane production in Europe.

Biodegradable bioplastics could represent 8 – 10% of organic municipal solid waste in the coming years.[2] “The increasing use of bioplastics and their disposal within the organic fraction of municipal solid waste are a critical component for the future of waste management. To promote a circular economy, they need to be recovered to produce new materials and/or energy.”, explains Gabriella Papa, EBA Technical and Project Officer and co-author of this study.

The study “Anaerobic digestion of organic waste allows recovering energy and enhancing the subsequent bioplastic degradation in soil” illustrates that the processing of bioplastics through anaerobic digestion contributes to prevent bioplastics accumulation and reduce their leakage into the environment. According to the paper, the residual bioplastic remaining in the digestate, a co-product of biogas production used as organic fertiliser, does not accumulate in soils. The figures show that bioplastics degrade between 50% and 70% in the soil after 120 days, and are fully biodegradable within less than two years. This digestate can therefore be used as fertiliser in agricultural soils without ecological risks.

In addition, the degradation of bioplastics via anaerobic digestion also contributes to the energy recovery of waste by producing renewable energy for our households and industries.

Ultimately, this approach meets the EU’s objective to achieve a circular economy by 2050[3]. The treatment of bioplastics via anaerobic digestion to produce biogas can enable cities and regions to develop integrated circular city concepts and make optimal use of their resources.

“The insights gained from this study have a positive impact on organic municipal solid waste valorisation strategies. The processing of bioplastic waste in anaerobic digestion for biogas production appears a promising solution for both renewable energy production and reduction of bioplastic leakage.”, concludes Gabriella Papa.

[1] https://www.europarl.europa.eu/news/en/headlines/society/20180328STO00751/eu-waste-management-infographic-with-facts-and-figures

[2] The role of waste management in reducing bioplastics’ leakage into the environment: A review https://www.sciencedirect.com/science/article/abs/pii/S0960852421007999?via%3Dihub. Degradation of bioplastics in organic waste by mesophilic anaerobic digestion, composting and soil incubation https://www.sciencedirect.com/science/article/abs/pii/S0956053X21004414?via%3Dihub

[3] https://environment.ec.europa.eu/strategy/circular-economy-action-plan_en#:~:text=The%20EU’s%20transition%20to%20a,entire%20life%20cycle%20of%20products