The ZSW has been conducting research into CO₂ capture from the air for around 30 years and is one of the world’s leading research institutions in the field of Direct Air Capture (DAC). The institute develops and investigates both liquid-based and solid-based DAC processes.
In the field of liquid-based processes, methods using caustic soda (NaOH) and polyethyleneimine (PEI) have been developed, with prototypes achieving capture capacities of up to 10 kgCO₂/h. In particular, the PEI-based scrubbing process developed at ZSW is showing promising results in terms of reliability, cost-efficiency and scalability potential. In addition, continuous solid-based DAC concepts based on cellulose-immobilised amines have been developed and implemented as prototypes.
Specifically, the DACLab currently has around 10 test benches and pilot plants, ranging from sorbent characterisation on a laboratory scale to process validation on a kg/h scale. The test benches were designed, engineered and implemented in-house and can therefore be flexibly adapted to different research questions and customer requirements.
A particular focus of the DACLab is the investigation of various DAC technologies under realistic and globally varying climatic conditions. Whilst the expansion of renewable energy opens up many new sites for large-scale DAC plants, it often places considerable demands on DAC technologies, which react with varying degrees of sensitivity to fluctuations in temperature and humidity, depending on the specific technology. These factors have a decisive influence on efficiency, energy requirements and, ultimately, economic viability. With the aid of highly flexible air pre-conditioning, the DACLab can simulate almost any global climate situation – from dry desert climates to tropical humidity. The data obtained enables more precise process design, provides insights into site-specific limitations and creates a robust basis for technology comparisons and benchmarks.
In addition to developing its own DAC technologies and offering testing and consultancy services, the ZSW also promotes the establishment of networks and regional value creation. In the DAC-BW project, for example, a state-wide DAC network comprising around 40 companies and institutions was established to strengthen the development of DAC technologies in Baden-Württemberg.
