Direct Air Capture
Direct air capture (DAC) is a process for extracting carbon dioxide (CO2) directly from ambient air.
The basic principle is that ambient air flows through a separator that removes part of the CO2. The result of the process is pure CO2, which can then be used for various purposes.
PlasmaAir AG is developing and building a pilot plant for the separation of CO2 from ambient air in cooperation with the ZSW (Center for Solar Science). This will serve as a technology demonstrator and produce approximately 10 kg/h of highly concentrated CO2. The further utilization of the CO2 is application-oriented, but not the task of the current project.
Possible recycling routes:
- Synthetic fuels
- Basic materials for the chemical industry
- Storage in underground reservoirs
- and much more
Which later use will establish itself first on the market depends on the cost and purity of the CO2 extraction process. Determining these parameters is one goal of this pilot plant.
The process
The process used is an absorption-desorption process. In the absorption process, carbon dioxide is separated from the gas phase by a liquid (absorbent) from the ambient air. An amine-water mixture is used as the absorbent. The liquid phase is introduced in cross flow to the gas phase inside the column. The CO2 from the ambient air is absorbed by the liquid. In a desorber operated parallel to the absorption process, the CO2 is separated on the liquid and is available for further use in a highly concentrated and highly pure form.
Absorptionswäscher sind oftmals Bestandteil komplexer Anlagen, sie müssen die gesetzlichen Bestimmungen erfüllen und gleichzeitig optimale Wirtschaftlichkeit und zuverlässigen Betrieb garantieren. Die Wirtschaftlichkeit wird auf Grund der weiter steigenden Kosten für die Entsorgung von Reststoffen entscheidend verbessert, wenn es gelingt, die Absorptionsanlagen so in die technologischen Verfahren zu integrieren, dass entweder ein Kreislaufbetrieb gewährleistet werden kann, oder dass die entstehenden Reststoffe in einer kostengünstig zu entsorgenden Form anfallen.