Potential for the valorization of carbon dioxide from biogas production in Sweden

Biogas solutions offer many advantages to improve sustainable development, but there is still untapped potential in its environmental performance. During biogas upgrading, CO2 is separated from the gas to deliver a flow with high methane concentration and thus high energy content. In this practice, CO2 is commonly emitted to the atmosphere without contributing to a net addition of climate gases because of its biological origin, being a missed opportunity for carbon capture. In this paper, CO2 valorization is an option that has been evaluated using a qualitative and quantitative approach, taking Sweden as an example. Results showed that around 140 kt of CO2 can potentially be captured and utilized from biogas upgrading, which can significantly increase in future scenarios. If CO2 were turned into methane using power-to-gas technology, an additional 35% of biogas could be produced in the short term, meaning up to additional 0.7 TWh in 2020. By 2050, around 600 to 1600 kt of CO2 could be available, depending on how well the biogas production develops and how much of the biogas is upgraded, resulting in up to 6.2 TWh of biomethane. The qualitative assessment suggested that only minor modifications in the upgrading process are required for this practice. Biogas actors are interested in getting involved in valorization projects that enhance their circular business and avoid carbon lock-in mainly to improve the environmental performance of biomethane. Moreover, the application of CO2 valorization requires collaboration with different actors to integrate current CO2 demand or innovative transformation technologies.

Automated summary

Biogas solutions have untapped potential in improving sustainable development, particularly in terms of environmental performance. This paper examines the option of CO2 valorization in biogas upgrading, using Sweden as an example. The results show that capturing and utilizing CO2 from biogas upgrading can significantly increase the production of biomethane. By turning CO2 into methane, an additional 35% of biogas could be produced in the short term and up to 6.2 TWh of biomethane by 2050. Collaboration with different actors and minor modifications in the upgrading process would be necessary for CO2 valorization. Biogas actors are interested in valorization projects to enhance their circular business and improve the environmental performance of biomethane.