Carbon capture processes
Contents |
[edit] Introduction
Carbon capture is a process that can remove as much as 90% of the carbon dioxide (CO2) gas emitted from fossil fuel (coal, oil or gas) power stations which are the main source of anthropogenic CO2 emissions. But the process is also used in cement making and other industries, and can be used to extract carbon from the atmosphere.
Carbon capture has been used for decades by the oil and gas sectors, although long-term storage of CO2 is a relatively new activity. It is thought that carbon capture could achieve around 20% of the total greenhouse gas emissions reductions needed to achieve 2050 targets. It is seen as one of the few practical ways to efficiently decarbonise the industrial sector quickly.
[edit] Carbon capture and storage (CCS)
CO2 captured from industrial processes is captured for secure and indefinite storage. In the UK storage of large quantities of CO2 is likley to take place in offshore underground saline formations or depleted oil and gas fields.
Although at the time of writing there are around 17 operating CCS projects globally, there are no commercial-scale CCS projects in the UK, but relevant health and safety regulations exist for future operators to abide by.
There are three stages to carbon capture and storage:
- CO2 is trapped and separated from other gases.
- CO2 is transported to a storage site.
- CO2 is stored away from the atmosphere.
[edit] Trapping and separating CO2
There are three ways to extract CO2:
- Post-combustion capture - applied mostly to power plants, post-combustion capture involves capturing the CO2 from the flue gases produced by fossil-fuel combustion. Typically, chemical solvents are used to achieve this. The technology can be retrofitted to existing power plants.
- Pre-combustion - this process involves removing the CO2 before combustion takes place in chemical, fertilizer, gaseous fuel and power production processes. Rather than being combusted, fuel is ‘gassified’ to produce a synthetic gas (syngas). The carbon monoxide (CO) from this is converted to CO2 which, after the action of solvents, is freed from the hydrogen present.
- Oxy-fuel combustion - fossil fuel is burned in oxygen to produce a steam-CO2 mixture from which the CO2 is separated by cooling and compression. This is a relatively expensive process becuase of the amount of oxygen required, however it ensures that only around 10% of a power plant’s emissions enter the atmosphere.
It may also be possible to extract CO2 from ambient air (direct air capture), although it is more difficult than the aforementioned processes due to the lower concentration of the gas in air. Work on this is still at an early stage.
[edit] Transportation of CO2
Once captured, CO2 must be transported to suitable sites for permanent storage. Conveyance is mostly by pipeline as this is one of the cheapest methods for large volumes. CO2 can also be transported – eg by ships – to other locations for industrial use.
[edit] Storing CO2
The three techniques available for storing CO2 are:
- In deep geological formations.
- In deep ocean water.
- In the form of mineral carbonates (mineral storage).
For more information see: http://www.bgs.ac.uk/discoveringGeology/climateChange/CCS/howcanCO2bestored.html
[edit] Related articles on Designing Buildings
- Carbon dioxide capture and utilisation.
- Carbon capture and storage.
- Carbon emissions.
- Carbon footprint.
- Carbon Reduction Commitment Energy Efficiency Scheme.
- Climate change act.
- Climate change science.
- Government publishes 2021 guidance on carbon capture technologies.
- Greenhouse gases.
- Environmental impact.
- Ozone depleting substances.
- UK Climate Change Risk Assessment.
- Using CO2 to make construction products and materials.
Featured articles and news
C20 Society; Buildings at Risk List 2025
10 more buildings published with updates on the past decade of buildings featured.
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.