Carbon Capture
Select one of the first five illustrated technologies to open its detailed page. The remaining five routes are shown for context.
Water treatment and separation technologies for carbon capture and removal.
Explore ten routes for capturing CO2 from air and water, converting it into minerals, or storing carbon through biological processes. These introductory process flows show the main steps without the detail of an engineering flowsheet.
The first five routes highlight the strongest connections to water treatment, separation and mineral processing.
Carbon capture: water, separation and mineral routes
Direct Air Capture (DAC)
Captures CO2 from ambient air using solid sorbents or liquid solvents. Regeneration releases a concentrated CO2 stream for storage or use.
Air → Sorbent or solvent contactor → Regeneration → CO₂ for storage or use
Sorbent or solvent is recycled to the contactor.
Direct Ocean Capture (DOC)
Extracts dissolved inorganic carbon from seawater through chemical or electrochemical processing. CO2 is separated and the treated water is returned to the ocean.
Seawater → Pretreatment → pH adjustment → CO₂ separation
Treated water → Rebalancing → Return to ocean
Ocean Alkalinity Enhancement (OAE)
Adds alkalinity to seawater to increase its capacity to absorb atmospheric CO2. Carbon is held mainly as dissolved bicarbonate and carbonate.
Alkalinity source → Controlled seawater addition → Ocean CO₂ uptake
Electrochemical alkalinity generation, including BPMED, is one possible route.
Enhanced Rock Weathering (ERW)
Finely ground alkaline minerals react with CO2 and water. Weathering can form dissolved bicarbonate, which may be transported through waterways to the ocean.
Alkaline rock → Grinding and spreading → Reaction with CO₂ + water → Dissolved bicarbonate
Illustrative mineral source: basalt.
Mineral Carbonation
CO2 reacts with calcium or magnesium from suitable minerals or industrial residues to form stable solid carbonates.
CO₂ + Ca/Mg source → Carbonation reactor → Solid–liquid separation → Carbonate product
Water separation and reuse can form part of an aqueous process.
Biological carbon removal and storage
Bioenergy with CCS (BECCS)
Biomass absorbs CO2 as it grows. Energy conversion is combined with CO2 capture and geological storage.
Biomass → Energy conversion → CO₂ capture → Geological storage
Biochar
Pyrolysis heats biomass in low-oxygen conditions, producing carbon-rich biochar alongside gases and liquids. Biochar can be used in suitable soils or materials.
Biomass → Pyrolysis → Biochar → Soil or material use
Soil Carbon Sequestration
Land-management practices can increase soil organic carbon through plant residues, cover crops and reduced soil disturbance.
Plants → Roots and residues → Soil organic carbon
Afforestation / Reforestation
Trees capture CO2 through photosynthesis and store carbon in biomass and soils.
Atmospheric CO₂ → Photosynthesis → Carbon in trees and soil
Blue Carbon / Macroalgae
Coastal vegetation and seaweed take up CO2 as they grow. Coastal ecosystems can store carbon in biomass and sediments; long-term storage depends on the pathway.
Dissolved CO₂ → Coastal vegetation or macroalgae → Biomass → Storage pathway
Where water treatment fits
Depending on the process, relevant treatment steps may include ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), ion exchange (IX), electrodialysis (ED), bipolar membrane electrodialysis (BPMED), degassing, membrane contactors and precipitation. Their role depends on the feed composition, process chemistry and required water quality.
Contact Lenntech to discuss the water and separation steps in your carbon capture concept.
The diagrams are simplified route overviews, not complete process designs. Capturing or using CO2 does not by itself guarantee permanent removal. Net removal and storage duration depend on the full process, energy supply, carbon destination and monitoring.