Carbon capture and storage

This article is about removing CO2 from industrial flue gas. For processes that remove and sequester CO2 from the atmosphere, see Carbon dioxide removal.
In CCS, carbon dioxide is captured from point sources such as ethanol plants. It is usually transported via pipelines and then either used to extract oil or stored in dedicated geologic formations.

Carbon capture and storage (CCS) is a process in which carbon dioxide (CO2) from industrial installations is separated before it mixes with the atmosphere, then transported to a long-term storage location.[1]: 2221  In CCS, the CO2 is captured from a large point source, such as a natural gas processing plant and typically is stored in a deep geological formation. Around 80% of the CO2 captured annually is used for enhanced oil recovery (EOR), a process in which CO2 is injected into partially-depleted oil reservoirs in order to extract more oil and then is left underground.[2] Since EOR utilizes the CO2 in addition to storing it, CCS is also known as carbon capture, utilization, and storage (CCUS).[3]

Oil and gas companies first used the processes involved in CCS in the mid 20th century. Early versions of CCS technologies served to purify natural gas and to facilitate oil production. Subsequently, CCS was discussed as a strategy to reduce greenhouse gas emissions.[4][5] Around 70% of announced CCS projects have not materialized.[2] As of 2023, 40 commercial CCS facilities are operational[6] and collectively capture about one thousandth of anthropogenic CO2 emissions.[7] CCS facilities typically require capital investments of up to several billion dollars, and CCS also increases operating costs.[8] Plants with CCS require more energy to operate, thus they typically burn additional fossil fuel and increase the pollution from extracting and transporting fuel.

In strategies to mitigate climate change, CCS plays a small but critical role. Other ways to reduce emissions such as renewable energy, electrification, and public transit are less expensive than CCS and also much more effective at reducing air pollution. Given its costs and limitations, CCS is envisioned to be most useful in specific niches. These niches include heavy industry, plant retrofits, natural gas processing, and electrofuel production.[9]: 21–24  In electricity generation and hydrogen production, CCS is envisioned to complement a broader shift to renewable energy.[9]: 21–24  CCS is a component of bioenergy with carbon capture and storage, which can under some conditions remove carbon from the atmosphere.

The effectiveness of CCS in reducing carbon emissions depends on the plant's capture efficiency, the additional energy used for CCS itself, leakage, and business and technical issues that can keep facilities from operating as designed. Many large CCS implementations have sequestered far less CO2 than originally expected.[10] Additionally, there is controversy over whether CCS is beneficial for the climate if the CO2 is used to extract more oil.[11] Fossil fuel companies have heavily promoted CCS, framing it as an area of innovation and cost-effectiveness.[12] Many environmental groups regard CCS as an unproven, expensive technology that will perpetuate dependence on fossil fuels and distract from more effective ways to reduce emissions.[13] Other environmental groups support the use of CCS under certain circumstances.[14]

Almost all CCS projects operating today have benefited from government financial support, usually in the form of grants.[15]: 156–160  Countries that are developing programs to support or mandate CCS technologies include the US, Canada, Denmark, China, and the UK.[16][17]

  1. ^ IPCC, 2021: Annex VII: Glossary [Matthews, J.B.R., V. Möller, R. van Diemen, J.S. Fuglestvedt, V. Masson-Delmotte, C.  Méndez, S. Semenov, A. Reisinger (eds.)]. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 2215–2256, doi:10.1017/9781009157896.022.
  2. ^ a b Zhang, Yuting; Jackson, Christopher; Krevor, Samuel (28 August 2024). "The feasibility of reaching gigatonne scale CO2 storage by mid-century". Nature Communications. 15 (1): 6913. doi:10.1038/s41467-024-51226-8. ISSN 2041-1723. PMC 11358273. PMID 39198390. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
  3. ^ Cite error: The named reference :1132 was invoked but never defined (see the help page).
  4. ^ Metz, Bert; Davidson, Ogunlade; De Conink, Heleen; Loos, Manuela; Meyer, Leo, eds. (March 2018). "IPCC Special Report on Carbon Dioxide Capture and Storage" (PDF). Intergovernmental Panel on Climate Change; Cambridge University Press. Retrieved 16 August 2023.
  5. ^ Ketzer, J. Marcelo; Iglesias, Rodrigo S.; Einloft, Sandra (2012). "Reducing Greenhouse Gas Emissions with CO2 Capture and Geological Storage". Handbook of Climate Change Mitigation. pp. 1405–1440. doi:10.1007/978-1-4419-7991-9_37. ISBN 978-1-4419-7990-2.
  6. ^ Cite error: The named reference :26 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference :22 was invoked but never defined (see the help page).
  9. ^ a b IEA (2020), CCUS in Clean Energy Transitions, IEA, Paris Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
  10. ^ Cite error: The named reference :14 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference :113 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference :27 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference :73 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Corry & Riesch 20123 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference :44 was invoked but never defined (see the help page).
  16. ^ "2022 Status Report". Global CCS Institute. Page 6. Retrieved 21 September 2023.
  17. ^ "CCUS Net Zero Investment Roadmap" (PDF). HM Government. April 2023. Retrieved 21 September 2023.