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Mixed waste generated in homes typically contains 35-40% biodegradable waste such as food scraps and kitchen paper that is not of significant use at incineration plants in terms of energy production. A larger proportion of waste can be recovered for energy by utilizing biodegradable fractions in biogas production.

Gasum, Lounais-Suomen Jätehuolto and Lounavoima are partnering in a joint project to explore the opportunity to build a waste pre-processing system that will enable the utilization of biodegradable fractions in biogas production to make fuel for transport.  The pre-processing equipment would also enable the removal of other waste fractions such as recyclable metal from waste suitable for incineration.

The separation of biodegradable fractions from mixed waste will not eliminate the need for separate collection of biowaste. Instead, it will supplement existing solutions.

"The best alternative would be no biowaste ending up in mixed waste and all biowaste being delivered via separate collection directly to biogas plants.  However, the separate collection of biowaste does not make that much sense in areas with mainly detached and semi-detached homes or in sparsely populated areas as the volumes per household are low in relation to the collection costs. For as long as there is biodegradable waste ending up in mixed waste, it is important to find solutions on how to utilize it," says Ari Suomilammi, Director, Circular Economy Finland, Gasum.

Increased biogas production plays a major role in action to reach transport emission reduction targets

Reaching the climate targets set requires significant increases in renewable energy production and, consequently, new collaboration models and solutions. Biogas is a local and renewable fuel that can help cut greenhouse gas emissions from transport by up to 85 percent.

- The Waste-to-Energy plant’s annual volume of 120,000 tonnes of incinerable waste could provide feedstock for the production of more than 40 GWh of biogas – enough to fuel around 4,000 cars for a year, says Ari Suomilammi.

Gasum has made a strong commitment to transport emission reduction targets by building the Nordic filling station network for heavy-duty road vehicles and offering consumers biogas at Gasum's filling stations in Finland.

A biogas plant is being planned in conjunction with the project, but no construction investment decision has yet been made and the type of collaboration between the partners involved in the project will be specified further later on this year. The feasibility study involves a comparison of the suitability of the Topinoja, Turku, and Korvenmäki, Salo, waste treatment centers for waste pre-processing and biogas production. Gasum will continue the planning of similar projects with other eco-power plants, too.