Copyright: PtX Lab Lausitz
Fraunhofer IEG and PtX Lab Lausitz develop direct air capture process for carbon capture approach using zeolites
Simply stopping the use of fossil fuels is not going to be enough to achieve the goals of the Paris Agreement. What is required are negative emissions, i.e. the physical removal of greenhouse gases like carbon dioxide (CO2) from the atmosphere. These kinds of solutions not only meet the carbon demand gap for the production of sustainable fuels and basic materials, but the carbon dioxide can also be stored for longer. Direct air capture (DAC) processes, where carbon is extracted from the air in the form of CO2, are a definitive solution here and play a central role in covering future demand for synthetic fuels based on green hydrogen (Power-to-Liquid, PtL), such as are required in the case of the aviation industry.
During a 13-month study, researchers from the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG and experts from PtX Lab Lausitz have investigated a method for capturing CO2 from ambient air. In the novel process, zeolite was used as the adsorption material. Another boundary condition for the study was the use of electrically powered heat pumps to supply the thermal energy required – which has a key role to play in all DAC processes. The aim was to develop a scalable, large-scale industrial DAC process based on established technologies with a high technology readiness level (TRL) plus process flows.
Large-scale industrial processes based on known technologies
The researchers managed to develop a process for carbon capture based on known technologies that is also a good fit for the conditions in Lusatia as a region, and which can be scaled arbitrarily using ‘numbering-up’ (i.e. simply adding more of the same sort of module). Alongside cost-effectiveness, the team also accounted in particular for the necessary resources in their investigations. Can the water needed be used in other processes? Is a carbon storage system required for linking to supplementary processes? How much energy is required and how large are pressure losses – and how can these be reduced? These and other questions were addressed by the experts in their search for answers.
To ensure a greenhouse gas-neutral energy supply, sustainable, closed carbon loops need to be set up in the years to come.
“To ensure a greenhouse gas-neutral energy supply, sustainable, closed carbon loops need to be set up in the years to come. Potential sources of sustainable carbon are biomass or CO2 harvested either from the atmosphere or from biomass,” explains Prof. Mario Ragwitz, Joint Institute Director of Fraunhofer IEG.
