Every second of the day, an extensive amount of greenhouse gases (mostly carbon dioxide) are emitted into the atmosphere by power plants, heavy industries, cars and other manmade sources. To tackle the provoked global climate change and stay under the 1.5ºC warming advised by the IPCC1, there need to be effective solutions to reverse the impact of human induced emissions. In fact, this innovative technology exists—it is called “carbon capture”. While still under development, carbon capture is a very promising large-scale carbon initiative and has many variants and applications.
Types of Carbon Capture
- Carbon Capture and Storage (CCS) is the process of capturing carbon from point sources, such as fossil fuel power plants or heavy industries’ factories, and sequestrating it under a rock formation. In 2019, the Global CCS Institute reported that there were 51 large-scale CCS facilities around the world, of which 19 are currently operating (the rest are still under development)2. They stored more than 260 million tons of carbon in total according to 2019 data3. As a comparison, CO2 emissions exceeded 35 billion tonnes in 20174.
- Direct Air Capture (DAC) is the capture of carbon not from point sources but directly from the air5. This developing technology would complement CCS by offsetting the CO2 emitted by, for instance, cars or cattle.
- Carbon Capture and Utilisation (CCU) captures carbon to then use it for other means, such as carbon-neutral fuel production or enhanced oil recovery5 (see next section).
Some applications of Carbon Capture
- Carbon-neutral fossil energy can be obtained if the CCS technology is applied to fossil fuel power plants and the emission of carbon is thereby offset by its storage6.
- Enhanced Oil Recovery (EOR) injects captured carbon into the rock formations trapping oil, to facilitate oil extraction in wells. This method allows this carbon to be both utilized and stored, as it is eventually trapped in rock pores3. EOR represents the biggest part of the total stored carbon as of today.
- Bioenergy and Carbon Capture and Storage (BECCS) takes biomass made by photosynthesis to either combust it or convert it into biofuel. The carbon emitted during the process is captured and stored, while the biofuel or bio-energy is used by consumers8.
Perspectives for the Future
Carbon capture technologies give a lot of room for research of new innovative ways to use or store CO2. Since they are profitable, they can be more realistically implemented than if storing carbon didn’t provide any short-term benefits. However, most of the initiatives are carbon neutral, not carbon negative. The US currently has the most carbon capture initiatives thanks to help given by its Department of Energy9. In the future, there might be further government help around the world for more large-scale carbon negative capture projects.
1 Summary for Policymakers. In: An IPCC Special Report on Global Warming of 1.5°C. Intergovernmental Panel on Climate Change, 2018; 7-10.
2 Global Status of CCS 2019: Targeting Climate Change. Global CCS Institute. 2019; 18.
3 Global Status of CCS 2019: Targeting Climate Change. Global CCS Institute. 2019; 30.
4 Richtie H, Roser M. CO2 and Greenhouse Gas Emissions. Our World in Data, 2020.
5 Global Status of CCS 2019: Targeting Climate Change. Global CCS Institute. 2019; 63.
6 Global Status of CCS 2019: Targeting Climate Change. Global CCS Institute. 2019; 12.
7 Risk analysis for CO2 sequestration at enhanced oil recovery sites. Los Alamos National Laboratory, 3 April 2017
8 Bioenergy and Carbon Capture and Storage. Global CCS Institute. 2019; 3-4.
9 Global Status of CCS 2019: Targeting Climate Change. Global CCS Institute. 2019; 39.