Climate change is considered one of the major environmental challenges that humanity is facing. In Europe, the efforts to reduce greenhouse gas (GHG) emissions is visualized in the target of achieving net-zero GHG by 2050. To achieve this goal, one of the strategies of reducing GHG emissions that has been studied in different industries, is carbon capture and use (CCU). This technology captures the CO2 from different sources and use it to deliver new carbon-based products to the market. Hence, it creates the opportunity to create new products form CO2 that is otherwise emitted to the atmosphere.
The CCU principle could be applied in biogas systems to increase their performance. Raw biogas contains between 50 to 70% methane and around 30 to 50% CO2. In order to increase the energy content of the biogas, the CO2 can be removed from the gas stream in a process called biogas upgrading. Moreover, this is considered biogenic (green) CO2 and thus, it does not contribute to climate change. For that reason, this CO2 is commonly emitted to the atmosphere.
By combining CCU technology with biogas systems, the CO2 could be valorized into additional methane through methanation, a chemical reaction of CO2 and hydrogen. Even though there are some technological paths under development, a concrete application requires an extensive technical and environmental assessment, which is the aim of this project.
The outcome of this research will be the proposal of different set ups for the incorporation of methanation in real biogas plants, and a comprehensive assessment. For that, real data will be provided by biogas producers.
To identify potential technological pathways to incorporate the use of CO2 in biogas production through methanation and assess the environmental performance.
Proposed Research Questions
What technologies are the available for CO2 methanation in biogas plants? How does the inclusion of methanation of CO2 influence the economic and environmental performance of biogas plants?
Literature review, interviews, case studies, environmental system analysis.
The thesis project takes place within a research project on valorization of CO2 from biogas production, in collaboration with Scandinavian Biogas, Gasum, ST1 Biogas, Tekniska verken (Linköping) and Wärtsilä Biogas Solutions. Case studies will be performed at biogas plants belonging to one or more of these companies.
Master program related to sustainability. Knowledge of systems analysis.