Introduction

Carbon capture refers to a range of technologies and processes designed to prevent carbon dioxide (CO₂) emissions from entering the atmosphere. The goal is to mitigate climate change by reducing greenhouse gas concentrations. Carbon capture is essential for industries with high CO₂ emissions, such as power generation, cement, and steel manufacturing.

Historical Background

  • Early Awareness (1970s–1980s): The concept of capturing CO₂ emerged alongside growing concerns about global warming. Initial research focused on separating CO₂ from natural gas streams and flue gases.
  • First Demonstrations (1990s): The Sleipner gas field in Norway became the world’s first commercial CO₂ storage project in 1996, injecting CO₂ into deep saline aquifers.
  • Policy Influence: The Kyoto Protocol (1997) and subsequent international climate agreements emphasized the need for emissions reduction, spurring interest in carbon capture and storage (CCS).

Key Experiments and Milestones

1. Sleipner Project (Norway, 1996)

  • Injects ~1 million tonnes of CO₂ annually into a saline aquifer beneath the North Sea.
  • Demonstrated safe, long-term geological storage.

2. Weyburn-Midale Project (Canada, 2000)

  • Used CO₂ for enhanced oil recovery (EOR) and monitored underground behavior.
  • Provided data on CO₂ migration and containment.

3. Boundary Dam Power Station (Canada, 2014)

  • First coal-fired power plant retrofitted with full-scale CCS.
  • Reduced CO₂ emissions by over 1 million tonnes per year.

4. Petra Nova Project (USA, 2016)

  • Captured ~1.6 million tonnes of CO₂ annually from a coal plant.
  • Used CO₂ for EOR; project paused in 2020 due to economic factors.

Modern Applications

1. Industrial CCS

  • Cement and Steel Plants: Capture technologies are integrated to reduce process emissions.
  • Bioenergy with CCS (BECCS): Combines biomass energy production with CO₂ capture, resulting in net negative emissions.

2. Direct Air Capture (DAC)

  • Machines remove CO₂ directly from ambient air, independent of emission sources.
  • Companies like Climeworks and Carbon Engineering operate commercial DAC plants.

3. Carbon Utilization

  • Captured CO₂ is converted into products such as synthetic fuels, building materials, and chemicals.
  • Example: CarbonCure injects CO₂ into concrete, improving strength and reducing emissions.

Recent Breakthroughs

1. Advanced Sorbents and Membranes

  • Researchers have developed new materials that selectively capture CO₂ at lower energy costs.
  • Metal-organic frameworks (MOFs) and amine-based sorbents show promise for industrial-scale deployment.

2. Electrochemical Carbon Capture

  • Uses electricity to drive CO₂ separation, potentially integrating with renewable energy sources.
  • Offers higher efficiency and lower operational costs.

3. Large-Scale DAC Deployments

  • In 2021, Climeworks launched “Orca” in Iceland, the largest DAC plant, capable of capturing 4,000 tonnes of CO₂ per year.
  • The plant stores CO₂ underground by mineralizing it in basalt rock.

4. Ocean-Based Carbon Capture

  • New research explores enhancing natural ocean processes to absorb more CO₂.
  • Techniques include alkalinity enhancement and seaweed cultivation.

Recent Study:

In 2022, a study published in Nature (Smith et al., 2022) demonstrated that engineered minerals could accelerate oceanic CO₂ absorption, potentially removing billions of tonnes annually.
Source: Smith, S. et al. (2022). “Accelerated Oceanic Carbon Sequestration via Engineered Minerals.” Nature, 607, 489–495.

Real-World Problem: Climate Change and Emissions

  • Global Challenge: Fossil fuel combustion and industrial processes release over 35 billion tonnes of CO₂ per year.
  • Impact: Rising atmospheric CO₂ drives global warming, causing sea level rise, extreme weather, and ecosystem disruption.
  • Connection: Carbon capture technologies address the urgent need to reduce emissions from sectors where alternatives (like renewable energy) are currently impractical.

Latest Discoveries (2020 and Later)

  • Hybrid Capture Systems: Integration of physical and chemical separation methods for higher efficiency.
  • Biological Carbon Capture: Genetically engineered microbes and algae are being developed to absorb and convert CO₂ into useful products.
  • Policy and Economics: The U.S. Infrastructure Investment and Jobs Act (2021) allocated billions for CCS deployment, signaling increased government support.
  • Monitoring and Verification: Advances in satellite and sensor technologies allow real-time tracking of stored CO₂, improving safety and transparency.

Summary

Carbon capture technology has evolved from early experiments in gas separation to sophisticated systems capable of removing CO₂ from industrial sources and the atmosphere. Key milestones include the Sleipner and Weyburn-Midale projects, which proved the feasibility of geological storage. Modern applications span industrial CCS, direct air capture, and carbon utilization, with recent breakthroughs in materials science, electrochemical processes, and ocean-based solutions. These advances are vital in addressing climate change, especially for sectors where emissions are hard to eliminate. Ongoing research and policy support are accelerating deployment, with recent studies highlighting new pathways for large-scale CO₂ removal. Carbon capture remains a critical tool in the global effort to achieve net-zero emissions and protect ecosystems like the Great Barrier Reef, which are threatened by rising temperatures and ocean acidification.