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The Understand Energy Learning Hub is a cross-campus effort of the Precourt Institute for Energy.

Carbon Capture

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Fast Facts About
Carbon Capture, Utilization, and Storage

Carbon Capture, Utilization, and Storage (CCUS) is the process of capturing CO2 and then using the CO2 or sequestering it. Both the International Energy Agency (IEA) and Intergovernmental Panel on Climate Change (IPCC) predict CCUS will be a necessary tool to reach net zero carbon emissions and keep global warming to 1.5 °C or 2 °C above pre-industrial levels.

CO2 is naturally removed from the air through our environment by forests, soils, oceans, and wetlands. Carbon dioxide removal (CDR) enhances these biological processes and uses technology to remove additional CO2 from the atmosphere. CCUS uses technology to minimize the emissions from industrial processes by capturing the CO2 before it is released into the atmosphere.

CCUS is still in the early stages of commercialization and remains an expensive form of reducing carbon emissions. The prices range from US$13 to $300+ per ton depending on the source of CO2. The foundations of CCUS stem from CO2 injection as a part of enhanced oil recovery (EOR), which has been used as a method of oil production for over 50 years (learn more about EOR on our Drilling, Completing, and Producing from Oil and Natural Gas Wells page).

CCUS is far from where it needs to be to contribute significantly to carbon reductions—targets are over 100x more than what is being captured today. However, the industry is growing rapidly and is projected to continue its growth.

Carbon Management Includes Natural and Technological Solutions

Diagram showing carbon dioxide removal, carbon capture, utilization, and storage

Components of Carbon Management

Carbon Dioxide Removal (CDR)

Technologies and natural solutions that enable the reduction of CO2 emissions from the atmosphere by capturing it from ambient air and using it or storing it. Because of the low concentration of CO2 in the atmosphere, this is very difficult to achieve.

Examples of CDR Technologies

Direct Air Capture (DAC): A technological type of CDR that uses large fans to capture CO2 from ambient air

Reforestation/Afforestation: A natural type of CDR – planting trees or using other biological methods to reduce the amount of CO2 in the atmosphere

Carbon Capture

Technologies that enable the reduction of CO2 emissions from higher concentration sources of CO2 such as power plants and refineries by capturing it and either using or storing it.

Examples of Carbon Capture Technologies

Post-Combustion: Separating the CO2 from the other exhaust of a combustion process

Pre-Combustion: Gasifying fuel and separating out the CO2

Oxy-Fuel Combustion System: Fuel is burned in a nearly pure-oxygen environment in order to create a concentrated stream of CO2 emissions to capture

Carbon Utilization

Using the carbon from either carbon capture or CDR for a product that either stores or re-releases the carbon (when burned). The carbon utilization industry is much smaller than the storage of CO2.

Examples of Carbon Utilization Products

Liquid fuels which are then burned and the carbon is re-released into the atmosphere

Plastics, chemicals, and other materials

Carbon Storage

The long-term sequestration of captured CO2.

Examples of Carbon Storage

Underground geologic formations: (e.g., oil reservoirs)

Rocks: (e.g., basalt)

Natural systems: (e.g., soils, trees, ocean, kelp)

Other parts of the carbon removal process include compressing and transporting the carbon through pipelines or via ship, and monitoring the storage sites to ensure no leakage of CO2.

Global Status

operating projects* with
in planning or construction. Capture sources are generally gas cleanup, ammonia production, steel manufacturing, ethanol production, power plants

43 Mt CO2 / year
being captured currently. If all planned projects go forward, the total injection capacity would increase by
200 Mt CO2 / year

Record high of
$6.4 billion invested in CCUS in 2023, more than
the 2022 investment.

*Current projects generally cluster in the US, Western Europe, Asia-Pacific, and the Gulf Coast (Saudi Arabia and UAE).

CCUS Needed for Sustainable Development

Treemap showing 43 Mt CO2/year being captured now. The world has promised to capture 3000 Mt CO2/year by 2050 in stated policies. 6600 Mt CO2/year is the amount needed to capture by 2050 in the IEA Sustainable Development Scenario.
Treemap of the current state of carbon capture around the world compared to 2050 goals. Demonstrates how large the difference is between what is currently being captured, what has been promised to be captured, and what will need to be captured for sustainable development (about 153x what is being captured now).

Red: Amount of CO2 being captured now
Blue: Amount of CO2 the world has promised to capture by 2050 in stated policies
Green: Amount of CO2 needed to capture by 2050 in the IEA Sustainable Development Scenario

CCUS Can Help Reduce "Difficult to Eliminate Emissions"

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Cost of Capture Increases with Lower CO2 Concentrations

High Concentration Sources (100% CO2)

  • Hydrogen and ammonia production
  • Biomass fermentation for ethanol production

US$13 - $35 per ton of CO2 captured

Medium Concentration Sources (3-35% CO2)

  • Coal steam turbines
  • Cement kiln

US$40 - $120 per ton of CO2 captured

Low Concentration Sources (<1% CO2)

  • Air

US$134 - $342 per ton of CO2 captured

CCUS prices are falling, and that trend is expected to continue (e.g., planned CCUS projects for coal power plants will cost less than half as much per tonne as the first projects, which were built less than a decade ago). According to the IEA, for industry sectors such as cement and steel production, CCUS is the least-cost low-carbon option, increasing costs by less than 10%.


  • Shown to be necessary by recent IPCC and IEA reports in order to keep warming to 1.5 °C
  • Supported by institutions such as fossil fuel companies
  • A lot of policy, in the US and globally, supporting these efforts (e.g., 45Q tax incentive, Norwegian carbon tax)
  • Helps to take away the effect of emissions from “difficult to reduce” sources


  • Potential risks of worker safety, groundwater quality degradation, induced seismicity, and ecosystem degradation
  • High costs, especially for CDR because of how dilute CO2 is in the atmosphere
  • Difficult questions such as who bears the cost of capture and where the money comes from
  • Facilitates the continuation of non-renewable sources which may have other harmful effects such as air pollution

Updated October 2023

Before You Watch Our Lecture on
Carbon Capture

We assign videos and readings to our Stanford students as pre-work for each lecture to help contextualize the lecture content. We strongly encourage you to review the Essential videos below before watching the Carbon Capture lecture. Include selections from the Optional and Useful list based on your interests and available time.


Optional and Useful

Our Lecture on
Carbon Capture

This is our Stanford University Understand Energy course lecture on carbon capture and storage. We strongly encourage you to watch the full lecture to understand how carbon capture works and to be able to put this complex topic into context. For a complete learning experience, we also encourage you to watch the Essential videos we assign to our students before watching the lecture.

Franklin Orr

Presented by: Lynn Orr, PhD; Keleen and Carlton Beal Professor In Petroleum Engineering, Emeritus, Energy Science & Engineering, Stanford University
Recorded on: November 9, 2022   Duration: 47 minutes

Table of Contents

(Clicking on a timestamp will take you to YouTube.)
0:00 Why Carbon Capture and Storage?
7:35 How Carbon Capture and Storage Works
42:45 Risks of Carbon Capture and Storage
44:56 Future of Carbon Capture and Storage

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Additional Resources About
Carbon Capture

Stanford University