Gasum investigates making biogas from cargo ship wastewater

There are around 2,000 cargo ships with an estimated 25,000 seafarers sailing on the Baltic Sea at any given time. The greywater and sewage generated on these vessels can be legally discharged, but Gasum aims to see if this wastewater be used in the circular economy via the production of renewable biogas by participating in the Baltic Sea Action Group Ship Waste Action project. The project, which began last year in the port of HaminaKotka, aims to reduce loading in the Baltic Sea in conjunction with shipping.

Gasum has committed to receive ship-generated wastewater and biowaste as a feedstock for biogas, a renewable, low-emission fuel that is suitable for use in maritime transport when liquefied. The production process also produces recycled nutrients that can replace synthetic and virgin nutrient products in agriculture and industry. Both the production of biogas and the recovery and commercialisation of nutrients support security of supply and reduce dependence on imported raw materials.

“Gasum is a Nordic energy company and a strong circular economy actor. For us, Ship Waste Action is a great opportunity to promote circular economy solutions and to work for the good of the Baltic Sea. Cooperation with other actors is important to discharge ship-generated waste into a port from where it can be recovered for use. Besides renewable energy production, we want to promote the agricultural use of recycled nutrients created in the biogas process. We are using carbon footprints to assess the climate impacts of nutrient products in the project,” says Elina Saarivuori, Sustainability Manager, Gasum.

Other partners in the project include the Port of HaminaKotka, Kymen Vesi wastewater treatment plant, Autoyhtymä Vuorinen, shipping companies Meriaura and RABN, Essberger & Stolt Tankers, Utkilen and Maersk, as well as shipbrokers C&C Port Agency, Dahlberg’s Agency and GAC Finland.

Earlier this month, UPM became the first Finnish company, acting as a shipper and charterer, to discharge its ship-generated wastewater on land and utilise various circular economy solutions in wastewater treatment. For example, UPM is exploring opportunities to use recycled nutrients from ship-generated wastewater in its own wastewater treatment plants. This way, the company contributes to its own 2030 target of using only recycled nutrients in its wastewater treatment plants.

In addition to discharging wastewaters on land, UPM and the Baltic Sea Action Group will explore opportunities for discharging cargo hold washing waters on land for possible further reuse.