Carbon Capture Technology: Engineering Solutions for a Warming Planet
Discover how direct air capture, point-source technologies, and geological storage are fighting climate change through innovative carbon capture solutions.
Carbon Capture Technology: Engineering Solutions for a Warming Planet
Welcome to the BKIS Science Desk. As global temperatures rise and extreme weather events intensify, the mathematics of climate change have become starkly clear. Merely reducing future emissions is insufficient; we must also address the legacy carbon dioxide already accumulated in the atmosphere. Enter carbon capture technology—a suite of engineering approaches designed to trap, utilise, or permanently store CO₂. Some dismiss these technologies as excuses for continued fossil fuel use. Others see them as essential tools in a multi-pronged climate strategy. Today, we examine the science, the economics, and the controversies surrounding carbon capture.
How Carbon Capture Works
Carbon capture technology spans two broad categories: point-source capture, which removes CO₂ from industrial emissions before they reach the atmosphere, and direct air capture (DAC), which extracts CO₂ already dispersed in ambient air.
Direct Air Capture Explained
Direct air capture facilities function like mechanical trees. Large fans draw air through contactors containing liquid solvents or solid sorbents that bind with CO₂ molecules. Heat is then applied to release the captured CO₂ in concentrated form, which can be stored or utilised. Leading companies in this space include Climeworks (Switzerland), Carbon Engineering (Canada), and Global Thermostat (United States).
The principal challenge is thermodynamic: CO₂ constitutes only 0.04% of atmospheric air. Concentrating such a dilute gas requires substantial energy. For DAC to deliver genuine climate benefits, that energy must come from renewable or nuclear sources.
Point-Source Capture
Point-source capture is technologically mature and already deployed at scale. Facilities attached to power plants, cement factories, and refineries capture CO₂ from concentrated exhaust streams using amine solvents or membrane separation. The Boundary Dam project in Saskatchewan, Canada, and Petra Nova in Texas demonstrated the feasibility of post-combustion capture on coal-fired power stations.
The cement and steel industries are particularly interested in point-source capture because these sectors are difficult to decarbonise through electrification alone.
Storage and Utilisation
Captured carbon must go somewhere. Two pathways dominate: geological storage and utilisation.
Geological Sequestration
The most permanent solution is geological sequestration—injecting compressed CO₂ deep underground into porous rock formations capped by impermeable layers. Depleted oil and gas fields and deep saline aquifers offer vast storage potential. The Intergovernmental Panel on Climate Change estimates that global geological storage capacity exceeds 10,000 gigatonnes of CO₂.
The Sleipner project in the North Sea has successfully stored over 16 million tonnes of CO₂ beneath the seabed since 1996, providing a proof of concept for safe, long-term containment.
Carbon Utilisation
Alternatively, captured CO₂ can become a feedstock for valuable products. Carbon utilisation applications include synthetic fuels, building materials (such as carbon-negative concrete), plastics, and chemicals. While these markets are promising, most utilisation pathways release CO₂ back into the atmosphere eventually, limiting their climate benefit compared to permanent storage.
Leading Projects Worldwide
Around the globe, carbon capture projects are proliferating:
- Orca (Iceland): Climeworks’ facility captures 4,000 tonnes of CO₂ annually, powered entirely by geothermal energy.
- Mammoth (Iceland): A scaled-up successor to Orca with capacity for 36,000 tonnes per year.
- Northern Lights (Norway): A transport and storage network receiving CO₂ from industrial sites across Europe.
- Drax Power Station (UK): Developing bioenergy with carbon capture and storage (BECCS), potentially generating negative emissions.
Cost and Energy Challenges
The Achilles’ heel of carbon capture is cost. Current estimates suggest direct air capture costs between £200 and £600 per tonne of CO₂ removed—far above the social cost of carbon or prevailing carbon prices. Point-source capture is cheaper, typically £40–£100 per tonne, but still adds significant expense to industrial operations.
Learning curves observed in solar and battery technologies suggest costs could fall substantially with deployment scale. Government subsidies, carbon pricing, and procurement mandates will be essential to bridge the gap.
The Role of Policy and Incentives
Carbon capture does not exist in a vacuum; its viability depends on policy frameworks. The United States Inflation Reduction Act offers tax credits of up to $180 per tonne for direct air capture, catalysing massive investment. The UK government’s Power BECCS and Industrial Carbon Capture business models aim to create revenue certainty for developers.
Critics argue that carbon capture funding diverts resources from renewables and energy efficiency. Proponents counter that some emissions are unavoidable, and legacy carbon removal is indispensable for meeting Paris Agreement targets.
Conclusion
Carbon capture technology is neither a silver bullet nor a dangerous distraction. It is one component of a comprehensive climate response that must include emission reduction, ecosystem restoration, and societal adaptation. The technology works; the questions now concern scale, cost, and governance.
For authoritative updates, consult the Global CCS Institute’s status reports and the IEA’s carbon capture tracking.
Thank you for listening to BKIS Radio. The future of our atmosphere may depend, in part, on the machines we build today.