Carbon Capture and Storage: Technologies for trapping and storing CO2

Welcome to our article on carbon capture and storage (CCS), a groundbreaking technology that offers a compelling solution to combat climate change. As the world grapples with rising greenhouse gas emissions, CCS provides a way to capture and store carbon dioxide (CO2) from industrial processes, effectively reducing the amount of CO2 released into the atmosphere.

CCS is a critical tool in the arsenal of climate change mitigation strategies. By capturing CO2 emissions and storing them deep underground in geological formations, CCS significantly contributes to the global effort of reducing industrial emission levels. This process prevents carbon from being released into the atmosphere and helps prevent global warming.

The technology behind CCS is well-established and has been successfully used for over 45 years. It involves three key steps: capturing CO2 emissions, transporting them to storage sites, and injecting them into rock formations for long-term storage. These storage sites can include saline aquifers and depleted oil and gas reservoirs.

Implementing CCS worldwide has gained momentum, with increasing numbers of projects and facilities across the Americas, Europe, Asia-Pacific, and the Middle East. The growing interest in CCS demonstrates its effectiveness in reducing carbon emissions and creating a more sustainable future.

Key Takeaways:

• CCS technology captures and stores CO2 emissions from industrial processes.
• It helps reduce greenhouse gas emissions and combat climate change.
• CCS has been used successfully for over 45 years and is a proven technology.
• Storage sites for carbon emissions include saline aquifers and depleted oil and gas reservoirs.
• CCS implementation is growing worldwide, with projects in various regions.

How Does CCS Work?

The Carbon Capture and Storage (CCS) process involves three main steps: CO2 capture, transport, and storage.

CO2 Capture

In the first step of the CCS process, carbon dioxide is captured from industrial processes, such as power generation, steel production, and cement manufacturing. This is done using various technologies, including:

• Post-combustion capture: Removing CO2 from flue gases after the fossil fuel combustion process.
• Pre-combustion capture: Separating CO2 from fossil fuels before combustion.
• Oxyfuel combustion: Burning fossil fuels in an oxygen-rich environment to produce a concentrated CO2 stream.

Once the CO2 is captured, it undergoes a purification process to remove impurities and ensure its quality.

CO2 Transport

After capturing and purifying the CO2, it is transported to a storage site. This can be done through various methods, including:

• Pipelines: Building a network of pipelines to transport the CO2 to the storage site.
• Road Transport: Using specially designed tanker trucks to transport the CO2.
• Ship Transport: Loading the CO2 onto ships and transporting it by sea.

The choice of transport method depends on factors such as distance, volume, and infrastructure availability.

CO2 Storage

Once the CO2 reaches the storage site, it is injected deep underground into rock formations for long-term storage. The storage can occur in various types of geological formations, including:

• Saline Aquifers: Underground formations containing salty water and porous rock suitable for storing CO2.
• Depleted Oil and Gas Reservoirs: Underground reservoirs that were previously used for oil and gas extraction but are no longer productive.

The CO2 is injected into these formations at depths of at least 1km, where it is permanently stored. Over time, the CO2 is immobilized through several trapping mechanisms, including structural trapping, residual trapping, solubility trapping, and mineral trapping.

The CCS process ensures that captured CO2 is safely stored underground, reducing greenhouse gas emissions and helping to mitigate climate change.

Table 1 summarizes the steps involved in the CCS process and the corresponding technologies used:

What is CCUS and How is it Different from CCS?

CCUS, or Carbon Capture Utilisation and Storage, is a related concept to CCS. While CCS focuses on capturing and storing carbon emissions, CCUS takes it a step further by exploring ways to re-use the captured carbon in a variety of industrial processes. Instead of simply storing carbon, CCUS offers the potential to convert it into other valuable products such as plastics, concrete, or biofuel. This approach not only helps to reduce carbon emissions but also contributes to the circular economy by creating sustainable materials and fuels.

CCUS extends the environmental benefits of CCS by promoting the re-use of carbon, thereby minimizing waste and maximizing its value. By incorporating captured carbon into the production of plastics, concrete, and biofuel, CCUS demonstrates its potential to revolutionize industrial processes, making them more sustainable and eco-friendly.

Carbon Capture Utilisation and Storage in Industrial Processes

In the context of CCUS, industrial processes refer to various sectors such as manufacturing, energy production, and transportation. These sectors produce significant amounts of carbon emissions that can be captured and re-utilized to reduce their environmental impact.

1. Plastics: The re-use of carbon captured from industrial processes in the production of plastics can help reduce the dependence on fossil fuels and mitigate the environmental consequences associated with plastics production. By incorporating captured carbon into the manufacturing process, CCUS can contribute to the development of more sustainable and eco-friendly plastic materials.
2. Concrete: Incorporating captured carbon into the production of concrete offers a promising solution for reducing carbon emissions in the construction industry. By replacing a portion of the traditional cement used in the production process with carbon captured from industrial emissions, CCUS can help create greener and more sustainable construction materials.
3. Biofuel: In the quest for alternative energy sources, CCUS can play a crucial role in the development of biofuels. By utilizing captured carbon as a feedstock for biofuel production, CCUS enables the creation of cleaner and more sustainable fuels that can help reduce greenhouse gas emissions in the transportation sector.

The Circular Economy and CCUS

CCUS aligns with the principles of the circular economy by transforming captured carbon into valuable products. Instead of treating captured carbon as waste, CCUS repurposes it, creating a closed loop where carbon emissions are captured, utilized, and stored.

“CCUS has the potential to not only reduce carbon emissions but also contribute to the circular economy by creating valuable products from captured CO2.”

By re-using carbon in industrial processes, CCUS reduces the reliance on virgin resources and mitigates the need for additional carbon emissions. This approach fosters sustainability, promotes resource efficiency, and encourages the regeneration of materials, enabling a more circular and sustainable economy.

Current Deployment and Development of CCS

According to the Global CCS Institute, there are currently 194 large-scale CCS facilities worldwide. These facilities capture and store carbon emissions from various industries. The number of CCS facilities has been increasing, with 61 new projects added to the pipeline in 2022.

These projects are distributed globally, with 94 in the Americas (including 80 in the U.S.), 73 in Europe (including 27 in the UK), 21 in Asia-Pacific, and 6 in the Middle East. The total CO2 capture capacity of all CCS facilities under development has grown by 44% in 2022.

CCS facilities play a crucial role in reducing greenhouse gas emissions and mitigating climate change. By effectively capturing and storing carbon emissions, these facilities contribute to the global effort to achieve a sustainable future.

CCS facility deployment and development are key drivers of the transition towards a low-carbon economy. These projects not only offer environmental benefits but also create opportunities for economic growth and technological advancement.

Global Distribution of CCS Facilities

The table above illustrates the distribution of CCS facilities across different regions.

CCS technology represents a significant milestone in addressing climate change. The increasing number of CCS facilities in various parts of the world demonstrates the growing global commitment to reduce greenhouse gas emissions and transition to a low-carbon future.

With ongoing development and expansion of CCS projects, the potential impact on emission reduction and climate change mitigation is substantial. The continuous growth of CCS facilities highlights the importance of this technology in achieving global sustainability goals.

Safety of CCS

Carbon Capture and Storage (CCS) is a technology that has been proven safe and reliable over decades of commercial scale operation. The Global CCS Institute confirms that all components of CCS are well-established technologies that have been widely used in real-world applications. From the capture of carbon dioxide (CO2) to its transportation and storage, every step of the CCS process has been implemented and continuously improved with a strong focus on safety.

CCS projects undergo rigorous safety assessments and adhere to strict guidelines to ensure the secure and reliable storage of carbon emissions. These assessments include comprehensive risk assessments, monitoring protocols, and emergency response plans to mitigate any potential risks associated with CO2 storage.

“The storage of CO2 has been proven to be safe and effective through decades of experience in commercial scale operations. Extensive research and monitoring have demonstrated that the injected CO2 remains securely trapped deep underground, reducing the risks of leakage or any adverse environmental impacts.”

CCS technology has been successfully deployed in various countries worldwide, contributing to the reduction of greenhouse gas emissions and the mitigation of climate change. Its proven track record and continuous improvement make CCS a reliable and trusted solution for achieving carbon reduction targets.

Table: Snapshot of CCS Safety Measures

CCS ensures the safe storage of CO2 by utilizing various trapping mechanisms within suitable storage formations. These mechanisms include structural trapping, where CO2 is physically trapped in rock layers and faults, as well as residual trapping, solubility trapping, and mineral trapping, which further secure the stored CO2 underground.

With its proven technology and decades of commercial scale operation, CCS offers a reliable and effective pathway for reducing carbon emissions and addressing climate change challenges.

Storage Mechanisms in CCS

Carbon dioxide is trapped underground in Carbon Capture and Storage (CCS) through various mechanisms that ensure its long-term storage and prevent its release back into the atmosphere.

Structural Trapping

In this process, CO2 is physically trapped within rock layers and faults, creating a structural barrier that prevents its movement out of the storage formation. The rocks act as a natural containment system, confining the CO2 within their geological structures.

Residual Trapping

Residual trapping occurs when some of the CO2 is left behind and held within the pore spaces between rock grains as the CO2 plume migrates through the rock. This trapping mechanism ensures that a significant portion of the injected CO2 remains confined within the storage formation.

Solubility Trapping

During solubility trapping, a portion of the injected CO2 dissolves into the brine water present in the rock’s pore spaces. This dissolved CO2 forms a stable solution with the water, preventing its escape from the storage formation.

Mineral Trapping

Mineral trapping occurs when the dissolved CO2 reacts with minerals present in the rock, resulting in the formation of solid carbonate minerals. These mineral formations, such as carbonates, provide a permanent storage solution for the captured CO2, ensuring its long-term containment.

By employing these various trapping mechanisms, CCS technology enables the safe and effective storage of carbon dioxide underground. These mechanisms work in conjunction to provide multiple layers of containment, ensuring the permanent storage of captured CO2 and contributing to the reduction of greenhouse gas emissions.

Characteristics of a Subsurface Carbon Storage Complex

When assessing a storage site for Carbon Capture and Storage (CCS), several key characteristics are taken into consideration. These factors play a crucial role in determining the suitability of a subsurface complex for large-scale CO2 storage.

1. Storage Resource

Storage resource refers to the available space within porous and permeable sedimentary formations to accommodate significant volumes of compressed CO2. These formations should have the capacity to securely store CO2 for extended periods.

2. Injectivity

Injectivity refers to the rate at which CO2 can be effectively injected into the subsurface reservoir. This parameter relies on the permeability of the formation and impacts the efficiency and speed of CO2 injection.

3. Integrity

Integrity is a fundamental consideration when evaluating a storage site. It refers to the ability of the subsurface complex to confine CO2 safely within a defined volume and prevent any leakage or migration. Ensuring the integrity of the storage complex is crucial to mitigate any risk of CO2 escaping back into the atmosphere.

4. Depth

The depth of the storage zone is an essential factor. It is necessary for the storage zone to be at a sufficient depth and pressure to ensure supercritical CO2 storage. Achieving supercritical conditions allows for higher CO2 densities, maximizing the storage capacity of the subsurface formation.

By carefully assessing these characteristics, experts can determine the feasibility and suitability of a subsurface storage complex for large-scale carbon capture and storage activities.

Example Table – Characteristics of Subsurface Carbon Storage Complexes

Assessing these characteristics is crucial in identifying and selecting suitable subsurface complexes for Carbon Capture and Storage (CCS) projects. This ensures the safe and effective storage of CO2 emissions, ultimately contributing to the global effort in mitigating climate change.

Different Storage Types for Geologic CCS

In carbon capture and storage (CCS), there are various types of storage formations that can be utilized for geologic storage. These formations can be found both onshore and offshore, offering unique opportunities and challenges for CCS deployment.

Onshore Storage

Onshore storage refers to the storage of carbon emissions in geological formations located on land. This can include saline formations, which are underground reservoirs of saltwater that have the potential to store large volumes of CO2. Saline formations are widely considered to be one of the most promising options for onshore storage due to their abundance and capacity for long-term storage.

Additionally, geologic formations such as oil and natural gas reservoirs can also be utilized for onshore storage. These formations, which have previously held oil and gas reserves, can provide suitable storage space for captured CO2.

Other onshore storage options include unmineable coal seams, organic-rich shales, and basalt formations. These formations present unique challenges but also offer potential for CCS deployment.

Offshore Storage

Offshore storage involves the storage of carbon emissions in geological formations located beneath the seabed. Offshore storage offers advantages such as larger storage capacity and the potential for proximity to CO2 emitting sources, particularly in coastal areas.

Similar to onshore storage, offshore storage can occur in saline formations, which are abundant in offshore areas. These formations have the potential to store significant amounts of CO2 and can contribute to the long-term storage of carbon emissions.

Oil and gas reservoirs can also be utilized for offshore storage. Depleted oil and gas reservoirs, which have already been used for hydrocarbon extraction, offer the opportunity for repurposing and storing captured CO2.

Table: Comparison of storage formations for onshore and offshore geologic CCS

Choosing the most suitable storage formation for geologic CCS depends on various factors such as the available capacity, proximity to CO2 emitting sources, and the geological conditions of the site. Saline formations and depleted oil and gas reservoirs are currently the most commonly utilized storage options, but ongoing research and development are exploring the potential of other formations for CCS deployment.

The Role of CCUS in Clean Energy Transitions

CCUS, or Carbon Capture Utilisation and Storage, plays a crucial role in clean energy transitions by addressing the challenges of reducing carbon emissions in various sectors. It enables the retrofitting of existing power plants and industrial facilities, allowing them to become more environmentally friendly and sustainable.

One of the key benefits of CCUS is its ability to tackle emissions in hard-to-abate sectors such as cement, steel, and chemicals. These industries produce a significant amount of carbon emissions and are challenging to decarbonize using conventional methods. By implementing CCUS technologies, these sectors can significantly reduce their carbon footprint and contribute to global emission reduction targets.

Furthermore, CCUS is essential for low-carbon hydrogen production. Hydrogen has emerged as a clean and versatile fuel source that can replace fossil fuels in various sectors, including transportation and heating. By capturing and storing carbon emissions from hydrogen production, CCUS ensures that the hydrogen produced is truly low-carbon, further contributing to decarbonization efforts.

Another important aspect of CCUS is its role in balancing unavoidable emissions. While transitioning to a low-carbon economy is crucial, certain sectors will continue to generate emissions that are difficult to abate or unavoidable. CCUS technology allows for the capture and storage of CO2 from these sources, effectively removing carbon from the atmosphere and offsetting these emissions.

CCUS technologies are instrumental in achieving net-zero emissions and mitigating the impacts of climate change. Retrofitting existing plants, addressing hard-to-abate sectors, enabling low-carbon hydrogen production, and balancing unavoidable emissions are key components of a comprehensive clean energy transition strategy.

CCUS enables the retrofitting of existing power plants and industrial facilities, reducing emissions in hard-to-abate sectors, facilitating low-carbon hydrogen production, and balancing unavoidable emissions.It plays a critical role in achieving net-zero emissions and mitigating the impacts of climate change.

Examples of CCUS Implementation:

CCUS technologies have been successfully deployed in various projects around the world. Some notable examples include:

• Gorgon Project, Australia: This project captures and stores CO2 from natural gas production, preventing approximately 5 million tonnes of CO2 from being released into the atmosphere annually.
• Boundary Dam Power Station, Canada: This power plant retrofitted with CCUS technology captures approximately 90% of its CO2 emissions, making it one of the world’s largest post-combustion carbon capture plants.
• Sleipner Field, Norway: The Sleipner Field has been injecting captured CO2 into a saline aquifer since 1996, effectively storing over 20 million tonnes of CO2.

Benefits of CCUS:

The adoption of CCUS technologies offers several benefits:

1. Emission Reduction: CCUS allows for the significant reduction of carbon emissions in hard-to-abate sectors, contributing to global climate change mitigation efforts.
2. Sustainable Industrial Practices: By retrofitting existing plants and industrial facilities, CCUS enables the transition to more sustainable and environmentally responsible practices.
3. Low-Carbon Hydrogen: CCUS plays a critical role in the production of low-carbon hydrogen, which can serve as a clean fuel source for various sectors.
4. Climate Change Adaptation: CCUS technology helps balance unavoidable emissions, removing CO2 from the atmosphere to offset emissions that are difficult to abate.

Conclusion

Carbon Capture and Storage (CCS) is a critical technology in the fight against climate change. By enabling the capture and storage of carbon emissions from industrial processes, CCS plays a crucial role in reducing greenhouse gas emissions and mitigating climate change. With numerous projects worldwide and a growing deployment of CCS facilities, this proven technology is leading the way towards a more sustainable future.

CCS offers opportunities for industrial decarbonization and clean energy transitions. As we combine CCS with other mitigation efforts, we can achieve significant emission reductions and make progress towards our climate goals. By capturing and storing carbon emissions, CCS helps us to address the challenge of climate change on a global scale.

As we move forward, it is essential to continue developing CCS and exploring related concepts like Carbon Capture Utilisation and Storage (CCUS). These innovations present us with the opportunity to not only reduce carbon emissions but also create valuable products from captured CO2, contributing to a circular economy.

Carbon Capture and Storage is a game-changing technology that supports climate change mitigation and emission reduction. By implementing CCS and embracing its potential, we can pave the way for a sustainable and low-carbon future that safeguards our planet for generations to come.