Direct Air Capture (DAC)
Water and chemical-system support for capturing CO₂ from ambient air.
Direct Air Capture brings ambient air into contact with a material that binds carbon dioxide. Liquid-solvent systems and solid-sorbent systems use different regeneration methods to release a concentrated CO₂ stream. The capture technology determines the water balance, chemical inventory and utility requirements.
Supporting the capture process
Lenntech’s role can centre on the water and separation systems around a developer’s capture process: preparing make-up water, conditioning recirculating streams and evaluating opportunities for water or chemical recovery. These supporting systems should be designed around the selected sorbent or solvent, rather than treated as a universal DAC package.
Where Lenntech technologies may fit
| Technology or task | Potential role | Design consideration |
|---|---|---|
| UF | Remove suspended solids from suitable water feeds or water-reuse streams. | UF does not separate CO₂ directly from air. |
| RO and ion exchange | Prepare water to the quality needed for utilities or chemical make-up. | Compatibility and required purity depend on the capture process. |
| NF, ED and BPMED | Investigate separation or chemical recovery from suitable aqueous salt streams. | These are process-dependent options, not required stages in every DAC system. |
| Water reuse and degassing | Evaluate suitable condensate, rinse-water or utility-water recovery opportunities. | Water consumption and recovery must be assessed across the complete site. |
What to evaluate during development
- Capture chemistry, regeneration method and operating cycle
- Make-up water source, seasonal temperature and water quality
- Composition of condensate, purge and recirculating streams
- Fouling, scaling, chemical compatibility and reject management
Developing the water and separation steps
Lenntech supports water and brine treatment development through laboratory evaluation, pilot testing and engineering support. For this application, potential treatment steps can be evaluated using representative streams and clearly defined separation objectives.
The scope described here is enabling water and process support. It does not represent a proprietary Lenntech direct air capture process or a guaranteed carbon-removal performance.
Capture is only one part of carbon removal. A net-removal assessment also considers energy, materials and the eventual storage or use of the CO₂.
Discuss your DAC project
A process outline, available water analyses and the desired separation outcomes can help frame the discussion. Contact Lenntech to explore the water-treatment scope for your concept.
Discuss water and separation requirements