How Does Carbon Capture Work?

Carbon capture is a cutting-edge and becoming increasingly crucial in the global fight against climate change.

Large volumes of carbon dioxide (CO₂), a significant greenhouse gas, are released into the atmosphere as a result of the world’s continued heavy reliance on fossil fuels for industrial production and energy, which contributes to global warming.

By keeping these pollutants from ever entering the environment, carbon capture provides a remedy.

What is Carbon Capture?

A process called carbon capture, sometimes referred to as carbon capture and storage (CCS) or carbon capture, utilisation, and storage (CCUS), aims to capture CO₂ at the point of emission, such as power plants, steel mills, cement plants, and chemical processing facilities, before it is released into the atmosphere.

After being captured, CO2 can be retained in deep-seated geological formations or utilised again in a variety of industrial processes, including increased oil recovery and synthetic fuels. Preventing these emissions from causing global warming is the goal.

How Does Carbon Capture Work?

A group of technologies known as Carbon Capture, Utilisation, and Storage (CCUS) is intended to lower carbon dioxide (CO₂) emissions from power production and industrial processes.

By keeping CO₂ out of the environment, CCUS helps mitigate climate change. The three main steps in the process—capture, transportation, and storage or utilization—are all essential to efficiently managing CO2.

• Capture
• Transportation
• Storage or Utilization

1. Capture

Capturing CO₂ from emission sources such as steel mills, cement factories, and power plants is the initial stage. There are multiple ways to accomplish this technically challenging phase. Fuel is transformed into a gas mixture before burning in pre-combustion capture, which is mostly utilised in coal gasification.

This process enables CO₂ to be separated from hydrogen, which is subsequently burned to produce energy. Common in traditional power plants, post-combustion capture entails removing CO₂ from flue gases following fuel combustion, usually with the use of chemical solvents such as amines that bind to CO₂.

Fuel is burned in pure oxygen instead of air in oxy-fuel combustion, which results in a flue gas that is mostly made up of CO₂ and water vapour, from which CO₂ is easily separated once the water condenses.

Although the cost, effectiveness, and applicability of each technology vary, post-combustion is the most popular since it works with the infrastructure that is already in place.

2. Transportation

For effective transportation, CO₂ is compressed into a thick, fluid-like form once it has been caught. Like natural gas pipelines, pipelines are the most widely used technology since they can transport large quantities across long distances.

CO₂ may be transferred by trucks or ships in areas without pipeline infrastructure, but this is less frequent and more expensive. To stop leaks and guarantee that CO₂ gets to its destination, safe and dependable conveyance is essential.

3. Storage or Utilization

The fate of captured CO₂ is decided in the last step. CO₂ is stored (or sequestered) by injecting it deep down, usually 1-2 km, into geological formations such as saline aquifers, unmineable coal seams, or exhausted oil and gas fields.

These locations were picked because of their impermeable caprock and porous rock, which permanently trap CO2. Monitoring makes sure there are no leaks. As an alternative, utilisation repurposes CO₂ for useful reasons.

CO₂ is injected into oil fields during enhanced oil recovery (EOR) to extract more oil while storing some CO₂ underground. Although these uses frequently have limited long-term storage capability, CO₂ can also be utilised to make polymers, concrete, synthetic fuels, and carbonated beverages.

Benefits of Carbon Capture

The advantages of carbon capture, utilisation, and storage (CCUS) include reducing emissions, addressing climate change, decarbonising industry, and creating economic opportunities. Because of these benefits, it is an essential instrument for accomplishing global climate targets and promoting environmental and economic sustainability.

• Climate change mitigation
• Supports industrial decarbonization
• Enables negative emissions
• Economic opportunities

1. Climate Change Mitigation

By removing carbon dioxide (CO₂) from significant sources, like as power stations and industrial sites, before it reaches the atmosphere, CCUS directly lowers greenhouse gas emissions.

By preventing CO₂ from contributing to global warming, CCUS helps mitigate climate change impacts such as rising temperatures, extreme weather, and sea-level rise. It’s particularly useful for high-emitting industries, where alternative low-carbon options are limited, assuring sustained progress toward net-zero ambitions.

2. Supports Industrial Decarbonization

Industries including cement, steel, and chemicals emit considerable CO₂ emissions due to their reliance on high-temperature operations or chemical reactions that inherently release CO₂. CCUS offers a workable solution to reduce carbon emissions in these challenging industries without involving total process changes.

Cement kilns and steel blast furnaces, for example, can continue to produce while adhering to climate standards by capturing CO₂, maintaining their economic viability in a low-carbon future.

3. Enables Negative Emissions

When combined with BECCS or DAC, CCUS can achieve negative emissions by removing CO₂ from the atmosphere. BECCS captures CO₂ from burning biomass, which already absorbs CO₂ during growth, resulting in a net reduction, while DAC extracts CO₂ directly from the air for storage or use.

These technologies are essential for offsetting residual emissions and reaching ambitious climate targets, like those outlined in the Paris Agreement.

CCUS encourages innovation in CO₂-based products, like synthetic fuels, concrete, and plastics, creating new markets. For instance, CO₂ utilisation in enhanced oil recovery creates income while storing CO₂ underground.

4. Economic Opportunities

In areas with CCUS infrastructure, these initiatives promote energy security and economic prosperity. Although issues like cost and scalability necessitate continual innovation and policy assistance, CCUS is a cornerstone of sustainable development by lowering emissions, facilitating industrial changes, and generating economic advantages.

Challenges and Criticisms

Some issues and objections impede the widespread implementation of carbon capture, utilisation, and storage (CCUS).

• Cost
• Energy intensive
• Storage risks
• Delayed transition

1. Cost

Cost is the main problem. With high capital expenses for capturing equipment and infrastructure like pipes, CCUS system installation and operation are costly.

Without significant subsidies or carbon pricing, retrofitting existing plants or constructing new facilities becomes less appealing due to the increased financial burden.

2. Energy Intensive

Additionally, the process uses a lot of energy. The energy required to run chemical solvents or compressors during CO2 capture, especially in post-combustion systems, is high, which lowers the overall efficiency of power plants or industrial facilities.

If derived from fossil fuels, this energy penalty can raise operating costs and partially counteract the emissions reductions that CCUS seeks to accomplish.

3. Storage risks

Storage risks raise additional worries. There is a slight chance that CO₂ injected into geological formations will eventually leak, contaminating groundwater or releasing stored CO₂ back into the atmosphere. Vigorous monitoring is necessary to ensure long-term site integrity, which raises expenses and public safety concerns.

4. Delay the Transition

Lastly, detractors contend that CCUS might postpone the switch to renewable energy. It might prolong the usage of fossil fuel facilities by making them seem cleaner, taking money away from renewable energy sources like solar or wind.

These difficulties show that to guarantee that CCUS supports decarbonisation initiatives rather than impedes them, strong regulations, technology developments, and a well-rounded strategy are required.

Where Is Carbon Capture Being Used?

Several nations are at the forefront of the global deployment of Carbon Capture, Utilisation, and Storage (CCUS), which aims to lower CO₂ emissions from industrial and electricity generation sources.

• United States
• Norway
• Canada
• The Middle East

1. The US

The two biggest CCUS projects in the US are the Illinois Industrial CCS project, which stores CO₂ from the manufacturing of ethanol underground, and Petra Nova in Texas, which captures CO₂ from a coal-fired power station for enhanced oil recovery (EOR).

2. Norway

Norway is a leader in this field; since 1996, the Sleipner and Snøhvit projects have used offshore geological formations to store more than 20 million tonnes of CO₂ beneath the North Sea.

3. Canada

One of the first coal-fired power stations in Canada to incorporate full-scale CO₂ collection is the Boundary Dam project in Saskatchewan. The captured CO₂ is either stored in deep saline aquifers or used for EOR.

4. Middle East

Projects like the Uthmaniyah complex in Saudi Arabia, which reuses CO₂ to increase oil output while storing it underground, are examples of how the Middle East is improving CCUS, especially for EOR.

5. Other Regions

Driven by climate goals and technological advancements, other regions, such as China, Australia, and the European Union, are also increasing CCUS in sectors like steel, cement, and hydrogen production.

Emerging Technologies in Carbon Capture

In the fight against climate change, emerging technologies in Carbon Capture, Utilization, and Storage (CCUS) are important for reducing atmospheric CO₂ levels. By focusing on emissions from the atmosphere and industrial sources, these creative solutions provide long-term ways to slow down global warming.

We examine three important new technologies below: CO₂-to-Products, Mineralisation, and Direct Air Capture (DAC).

• Direct Air Capture (DAC)
• Mineralization
• CO₂-to-Products

1. Direct Air Capture (DAC)

Direct Air Capture is a revolutionary device that recovers CO₂ directly from the ambient air, tackling diffuse emissions that existing capture systems cannot. DAC systems suck air through solid sorbents (like amine-functionalized materials) or chemical solutions (such liquid solvents like potassium hydroxide) using big fans.

A concentrated CO₂ stream for storage or use is produced when these materials selectively bind CO₂, which is subsequently released through heating or other procedures. Pilot facilities are proving the viability of DAC, which is being pioneered by firms like Climeworks and Carbon Engineering.

The high energy requirements and expenses of DAC, which are now between $500 and $600 per tonne of CO2 extracted, present difficulties, though. With estimates indicating $100–200 per tonne by 2030, innovations in material efficiency and the incorporation of renewable energy are bringing costs down.

2. Mineralization

By turning CO₂ into solid minerals like calcium or magnesium carbonate, mineralization provides a long-term solution for CO₂ storage. In the presence of water, this process entails the reaction of CO₂ with naturally occurring minerals such as olivine, basalt, or industrial byproducts like steel slag.

The reaction can be increased industrially in a matter of hours or spontaneously over generations. Successful projects include Iceland’s Carbfix, which injects CO₂ into basalt formations and allows it to mineralize in as little as two years.

Mineralisation has enormous geological potential—global basalt reserves might store millennia’ worth of emissions, yet is environmentally benign and leak-proof.

The requirement for appropriate water and rock formations, as well as the expense of electricity for expedited operations, are obstacles. Optimising reaction rates and investigating ex-situ uses, such as mineralising CO₂ in concrete, are the main areas of research.

3. CO₂-to-Products

CO₂-to-Products technologies generate economic incentives for capture by converting captured CO₂ into valuable commodities. Carbon-negative concrete, polymers, chemicals, and synthetic fuels (such as methanol and jet fuel) can all be made from CO₂.

These conversions are made possible by biological techniques (such as the use of algae), photocatalysis, or electrochemical processes.

Companies such as CarbonCure, for example, inject CO₂ into concrete, where it mineralises and strengthens the material while permanently retaining CO₂. Additional uses include the manufacture of consumer goods, plastics, and carbon-neutral aviation fuels.

While scalable, many CO₂-to-products processes are energy-intensive, and markets for some products (e.g., specialty chemicals) are limited. Advances in catalysis and renewable energy are improving profitability, with the global market for CO₂-derived goods predicted to reach $1 trillion by 2030.

The future of Carbon Capture, Utilization, and Storage (CCUS) looks promising as a cornerstone of global climate initiatives aiming for net-zero emissions by 2050. Technological developments such as mineralisation, CO₂-to-products, and direct air capture are increasing productivity and cutting expenses.

Adoption is being fuelled by rising investments, encouraging laws like the US 45Q tax credit, and carbon pricing. CCUS may trap 7.6 Gt of CO₂ per year by 2050, according to the International Energy Agency.

However, public acceptance, increased infrastructure, and reasonably priced sustainable energy are necessary for scaling. CCUS will be essential to decarbonising industry and reducing climate change with international cooperation.

Conclusion

In the end, carbon capture is an essential component of a larger approach that also involves energy efficiency, renewable energy, and behavioural change; it is not a panacea. It offers a possibility to reach net-zero emissions, reducing the negative effects of climate change and limiting the increase in world temperatures.

Furthermore, despite CCUS’s potential as a decarbonisation tool for difficult-to-abate industries, issues including high costs, energy intensity, and public acceptance of storage sites still exist.

Its adoption is being fuelled by technological advancements and regulatory assistance, with projects all around the world showcasing its ability to reduce emissions.

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