The Role of Carbon Capture in a Net Zero Future

Carbon Capture, Use and Storage (CCUS): the process by which carbon dioxide emissions (produced by burning fossil fuels or by other chemical/biological processes) are trapped and then stored or used so that they cannot adversely affect the atmosphere. As global warming increases, the process of carbon capture is becoming more and more important to mitigate further harm. In fact, the International Panel on Climate Change (IPCC) has stated that it’s incredibly unlikely that global climate goals can be achieved without taking carbon dioxide from the air.[1] Furthermore, if we do overshoot the 1.5 degree target agreed in the Paris Climate Agreement, carbon capture will be even more important.[2]

The idea of carbon capture has been around for over 100 years in different forms. First used to separate carbon dioxide from methane gas, the technology has developed to have a greater emphasis on stopping carbon entering the atmosphere for climate reasons.[3]CCUS in its current form can still be viewed as a relatively new technology. However, with scientists stating that we are likely to surpass 1.5 degrees of global warming based on our current actions, it is imperative that we work to understand it further and employ it quickly to reduce the risks associated with this warming.

In this article, the Institute will explore the different types of CCUS, current carbon capture projects and the main advantages and disadvantages of using the technology.

Types of CCUS

The process of CCUS requires 3 main stages, separation and capture of the CO2, transportation and storage.

There are different ways in which carbon can be stored or used:

• Underground storage. This involves injecting carbon back into the earth, to occupy space in porous rock. If left undisturbed for a long time, the CO2 will eventually turn into rock itself. Gas can also be injected into depleted oil and gas reservoirs or into saline aquifers. These reservoirs generally need to be more than 1km underground to be used for this purpose.
• Natural storage. This method is cheaper and more widely used. CO2 can be put back into forests and swamps, or absorbed by algae. Microalgae grows rapidly in conditions unsuitable to many other plants; it can then use the absorbed carbon to photosynthesise; eventually the algae itself can be made into biofuel or animal feed.
• Manufacturing processes. Some projects are using CO2 taken from the atmosphere to help manufacture concrete, plastics and synthetic fuels. However, this method is less successful as both materials will eventually release the CO2 again as they degrade, plus plastic consumption brings its own problems in regards to the climate.

Current CCUS Projects

According to the International Energy Agency (IEA), there are currently over 500 CCS projects in development and approximately 40 in operation. Collectively, these projects are removing 45Mtco2 from the atmosphere annually.[4] Some of these projects include:

Zero Carbon Humber, UK (in development)

As part of their aim to achieve the UK’s first zero carbon region, Zero Carbon Humber are adopting a project involving shared pipelines across the region that will allow for carbon capture (as well as use of hydrogen as a fuel).[5]

Humber is particularly industrialised and one of the most carbon intensive clusters in the UK.[6]
They will use a saline aquifer located 90km offshore in the southern North Sea. It will be located approximately 1 mile (1.6km) below the seabed and has the potential to store very large amounts of CO2.[7]

They have submitted a £75 billion bid to raise the funds required, highlighting the huge economic deployment required to launch and operate CCUS projects.

In the UK more widely, 20 awards for carbon storage licenses were created in May 2023, equating to £20 billion worth of government support for CCUS projects. This will benefit projects across the whole country and it is hoped that these sites will eventually store 10% of the UK’s emissions.[8]

Citronelle Project – Alabama (in operation)

Storage in Citronelle began over a decade ago, in 2012. This is a large-scale project with hundreds of injection sites and involves long-term storage in saline reservoirs.[9] The project is located in an active oilfield and close to an electric plant. Over the last decade it has demonstrated breakthrough fibre optic technologies in its operations, which have gone on to be used in other projects. This highlights how successful projects can allow us to learn, improve the technology and benefit future CCUS.

More widely, the US has provided increased CCUS funding under the Infrastructure Investment and Jobs Act and Inflation Reduction Act, which will help future CCUS projects to become operational.[10]

Sleipner Project – Norway (in operation)

The world’s first industrial-scale CCS project[11], Sleipner has already been operating for nearly 30 years, since 1996. It has stored, on average, 1 million tonnes of CO2 each year according to data.[12] As with Citronelle, the experience and data generated by this long running project has been incredibly important in helping current and future projects to be realised.[13]Experience gained from Sliepner was even used to create EU Directive on geological storage of carbon dioxide in 2009.[14]

Project Greensand – Denmark (in operation)

This is a much newer project which came into operation in March 2023. Unlike other projects mentioned above, transporation of carbon has to take place over a much greater distance; CO2 from Belgium is transported via ship to a depleted oil field in the Danish North Sea.[15] As such it is an example of an international CCS value chain.[16] Project Greensand is expected to store 1.5 million tonnes of CO2 per year in 2025/2026 and up to 8 million tonnes of CO2 per year by 2030.[17]

Problems and Criticisms Regarding CCUS

Finance

CCUS projects are incredibly expensive to mobilise, as seen in the funding required for the Humber project detailed above. In addition, it is difficult to make a profit when using this technology, meaning that it is a less attractive venture for many companies.[18] However, if neighbouring countries collaborate on CCUS projects and share the cost of the required infrastructure, the cost can be brought down significantly using a collective approach. Examples of this can already be seen in action, such as with Project Greensand mentioned above.

Power

The process in which carbon dioxide is trapped and stored is also very power intensive, which has led some commentators to argue that many of the benefits of the process are negated. Studies have shown that it requires 1,200 kilowatt-hours of energy to remove a tonne of carbon from the atmosphere.[19] Considering the amount of carbon that requires capturing, this creates a huge demand for energy, potentially leading to further burning of fossil fuels, if renewables cannot provide the amount of energy required.

Draws Focus Away From Renewables

While the IPCC have previously acknowledged the importance of carbon capture, they have also issued warnings that we should not rely solely on this technology to avert climate disaster and that we should still be focusing on ways to move away from fossil fuels entirely, rather than mitigating the carbon dioxide that is released when using them.[20] As it stands, many oil and gas companies are using the existence of carbon capture to argue that they do not need to reduce or halt production.[21]

Performance

Finally, the Institute for Energy Economics and Financial Analysis (IEEFA) has argued that many carbon capture projects underperform, i.e. they have not removed the levels of CO2 from the atmosphere that they were expected to. They cite examples including: Shute Creek (US) underperforming by 36%, Boundary Dam (Canada) by 50% and Gorgon (Australia) by 50%. Out of 13 projects that they assessed during their study, only 2 were considered a success.[22]

Furthermore, they claim that CCUS projects are not generally being used to help the climate crisis, but that around ¾ of CO2 removed from the atmosphere is injected back into the ground in order to aid oil production.[23] However, many of their criticisms revolve around using carbon capture as the sole method of reducing carbon levels; whereas it is clear that if used in conjunction with other measures, including renewables, it can have a significant impact on achieving net zero targets.

Conclusion

CCUS projects will play a crucial role in our global decarbonisation efforts. However, as highlighted by the IPCC, we cannot rely on these projects alone. The technology itself still has a way to go in order to be as effective as required. In addition, significant finance needs to be mobilised to ensure the technology progresses and for projects to come into operation.

More importantly, we cannot simply rely on CCUS alone while failing to reduce our use of fossil fuels in general. A reduction in fossil fuels in conjunction with CCUS to mitigate the remaining effects appears to be an effective way forward, and we are seeing this with more and more projects coming into existence.

The benefit of using this technology to help reach net zero targets is that it has been in existence for decades. As such we know that it is safe and we can build further on its effectiveness from an existing level. By committing resources to CCUS projects across the world, we can benefit and learn from these to improve the process further and allow it to play its role in averting future climate disasters.

The Renewable Energy Institute is delighted to be launching their NEW Carbon Capture and Storage course this October as part of the Accredited Carbon Finance Consultant Expert Certificate. Click here to find out more about the course content and to secure your place!

Read Next: 6 reasons why hydropower is the most commonly-used renewable source of electricity

[1] https://www.globalcitizen.org/en/content/carbon-capture-use-and-storage-methods/

[2] https://www.theguardian.com/environment/2023/jun/06/carbon-capture-and-storage-is-no-free-lunch-warns-climate-chief-hoesung-lee

[3] https://ieaghg.org/docs/General_Docs/Publications/Information_Sheets_for_CCS_2.pdf

[4] https://www.iea.org/energy-system/carbon-capture-utilisation-and-storage

[5] https://www.zerocarbonhumber.co.uk/the-vision/

[6] https://www.zerocarbonhumber.co.uk/

[7] https://www.nationalgrid.com/stories/energy-explained/what-is-ccs-how-does-it-work

[8] https://www.nstauthority.co.uk/news-publications/news/2023/huge-net-zero-boost-as-20-carbon-storage-licences-offered-for-award/

[9] https://www.netl.doe.gov/sites/default/files/2018-11/Citronelle-SECARB-Project.PDF

[10] https://www.iea.org/energy-system/carbon-capture-utilisation-and-storage

[11] https://www.ice.org.uk/engineering-resources/case-studies/sleipner-carbon-capture-and-storage-project

[12] https://www.iea.org/reports/20-years-of-carbon-capture-and-storage

[13] As above

[14]https://www.ice.org.uk/engineering-resources/case-studies/sleipner-carbon-capture-and-storage-project

[15] https://www.iea.org/energy-system/carbon-capture-utilisation-and-storage

[16] https://www.projectgreensand.com/first-carbon-storage

[17] As above

[18] https://www.globalcitizen.org/en/content/carbon-capture-use-and-storage-methods/

[19] https://www.protocol.com/bulletins/direct-air-capture-energy-use

[20] https://www.theguardian.com/environment/2023/jun/06/carbon-capture-and-storage-is-no-free-lunch-warns-climate-chief-hoesung-lee

[21] As above

[22] https://ieefa.org/resources/carbon-capture-remains-risky-investment-achieving-decarbonisation

[23] As above