Ocean Alkalinity Enhancement (OAE)
Alkalinity production, solution conditioning and seawater chemistry.
Ocean Alkalinity Enhancement aims to increase seawater’s capacity to take up atmospheric CO₂. Alkalinity may be supplied through suitable mineral dissolution or chemical and electrochemical routes. Unlike a gas-extraction process, OAE generally aims to retain additional carbon in the ocean’s dissolved inorganic carbon pool.
Managing alkalinity without losing it to precipitation
Alkalinity and pH are related but are not the same measurement. The alkalinity source, its impurities, the receiving seawater and the mixing conditions all matter. Local chemical conditions can promote unwanted precipitation, so producing an alkaline solution and delivering a measurable carbon-removal outcome are distinct engineering and monitoring tasks.
Where Lenntech technologies may fit
| Technology or task | Potential role | Design consideration |
|---|---|---|
| BPMED | Evaluate production of acid and base from suitable salt solutions. | Feed purity, membrane selectivity and the destination of co-products matter. |
| NF and ion exchange | Investigate hardness or impurity control in selected feed streams. | Removing useful alkalinity or producing residuals may change the process balance. |
| Filtration and UF | Manage particles in process-water or solution-handling steps. | The intended dissolved and particulate fractions must be defined. |
| Precipitation control | Evaluate saturation and solids formation during conditioning and mixing. | Carbonate precipitation may reduce the alkalinity available for CO₂ uptake. |
What to evaluate during development
- Alkalinity source, concentration and impurity profile
- pH, total alkalinity, dissolved inorganic carbon and salinity
- Calcium/magnesium chemistry and precipitation potential
- Acid co-product handling, mixing, ecological assessment and monitoring
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 ocean alkalinity enhancement process or a guaranteed carbon-removal performance.
OAE is an emerging approach. Net removal depends on alkalinity retention, air–sea equilibration and the full process; an increase in local pH alone does not quantify carbon removal.
Discuss your OAE 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