By Alena, Winter 2022.

Norway, 1996: The site of the world’s first industrial-scale project dedicated to capturing carbon dioxide from the atmosphere and storing it underground. The Sleipner carbon capture and storage project was built to support gas field development by injecting removed carbon dioxide into sandstone formations underground rather than releasing it into the atmosphere. Since then, it has stored over sixteen million metric tons of carbon dioxide, becoming a benchmark for carbon capture and storage technology (CCUS). It continues to be a source of interest as we turn towards CCUS as a potential solution to climate change, one of the biggest challenges facing our world today.

You’ve likely heard about the dire consequences of climate change, from the worsening effects of natural disasters to the displacement of coastal communities due to changing ecosystems, as well as the importance of limiting the global temperature increase to 1.5 degrees. However, meeting that goal, as well as reaching net zero emissions by 2050, has proved to be a monumental task. 

Scientists and governmental organizations alike have identified carbon capture, use, and storage technologies (CCUS) as essential in the fight to reduce carbon dioxide levels in the atmosphere and slow down climate change. As of now, CCUS technologies have the potential to capture over 90% of carbon dioxide emissions from industrial and power plants that rely on fossil fuels [1].

But how exactly does carbon capture technology work, and is it enough to make a difference? When current renewable energy sources are still inefficient and the implementation is slow, can carbon capture technology be the stopgap for the major industrial polluters, or is it a diversion from the broader, structural economic change we need to address climate change? 

CCUS technology works in several different ways. There are three main methods to capture carbon dioxide at the source, based on when the combustion, or burning, of fossil fuels takes place. 

Pre-combustion carbon capture involves removing carbon dioxide from fuels before combustion occurs. Through this process, the fossil fuel reacts with steam and oxygen under high pressure and temperature to form a gas containing a mixture of carbon monoxide and hydrogen. The carbon monoxide in the gas is converted to carbon dioxide, which is later separated out [2]. 

On the other hand, post-combustion carbon capture uses chemicals to separate carbon dioxide out of flue gas, which is the material emitted from fossil fuel combustion that contains carbon dioxide, other pollutants, and particulate matter. The carbon-free gas is then released into the atmosphere, while the captured carbon is stored. Finally, oxy-fuel carbon capture involves combusting fossil fuels in pure oxygen, rather than air, which makes it easier and more cost-effective to separate carbon dioxide from flue gas [1]. 

Once carbon dioxide has been captured, it can be used for oil extraction or in the production of synthetic fuels and other materials. It can also be stored, usually deep underground in structures like oil and gas reservoirs, coal beds, or porous rock formations, where it can remain for thousands of years. In terms of controlling carbon dioxide levels in the atmosphere, this process is easier than taking carbon dioxide out of air that’s already been dispersed far from the original source [1].

Putting all of this together, CCUS technology appears to be a compelling way to help offset the environmental impact of the energy sector, as well as other areas where it is currently not feasible to switch completely to clean energy, such as the iron, steel, or cement production sectors [3]. Currently, the carbon capture facilities operating around the world are able to capture more than 40 million metric tons of carbon dioxide each year, and more projects are in development with the potential of doubling the number of active facilities by 2025  [1]. CCUS technology can also be added to existing industrial plants to drastically reduce emissions while still allowing them to operate [4].

But this solution is not without its drawbacks. Despite its potential, one of the major limitations is the cost of implementing CCUS technology. Although the overall cost for this technology, as well as costs for transporting and sequestering the carbon, depends on the industry, current subsidies for CCUS technology fall short of what’s necessary to make it economically competitive. Investment in CCUS technology, as well as its deployment, has also been slow, which has limited its overall impact. Moreover, the majority of the carbon that does get captured is often used to support oil production in a process known as enhanced oil recovery. While enhanced oil recovery can be helpful in providing a revenue source for CCUS technology in the absence of sufficient funding, the use of this oil would in turn undermine the purpose of this technology by contributing to even more emissions [5]. 

CCUS technology has also failed to live up to carbon storage projections on a broader scale. The storage capacity of currently active CCUS facilities is orders of magnitude less than estimations of what is needed for us to reach net zero emissions, which can be as much as 1.8 metric gigatons of captured carbon dioxide per year in some scenarios [6]. Moreover, project failures have undermined the effectiveness of CCUS technology. For example, the Petra Nova plant in Texas, which received a $190 million grant from the U.S. government, consistently had outages and fell short of carbon capture targets before being shut down [7]. Some argue that CCUS technology as a whole is only masking the root of the problem by enabling further carbon dioxide emission, and diverting attention—and investment—away from the transition to renewable energy sources that will actually make a difference in reducing emissions.

So where is CCUS technology headed? It won’t be the end-all-be-all for climate change mitigation, and it will have to be used in conjunction with other technological and natural processes such as renewable energy and reforestation if we truly want to reach net zero emissions. The costs associated with building infrastructure for CCUS technology and for transporting and storing the carbon are high, and the money to support it won’t come out of thin air; this issue is something that must instead be addressed by financially incentivizing CCUS technology use, such as through increasing the price of emitting carbon dioxide into the atmosphere [3].

Nonetheless, scientists continue to make improvements in the technology today, increasing its efficiency and lowering its costs. Plans for the construction of one hundred more CCUS facilities were announced in 2021 [1]. In the US, the Biden administration has also identified CCUS as one of the most promising methods for removing carbon from the atmosphere. Currently, companies that use CCUS technology can receive a tax credit of $50 per ton of captured carbon and $35 per ton of captured carbon used for enhanced oil recovery [8]. A greater carbon tax would support a more widespread use of—and innovation in—the technology. Although there is still a long way to go, with the right economic support and innovation, CCUS technology could play a significant role in getting us to carbon neutrality. Its role in the long term, especially in relation to renewable energy, however, remains to be seen. 

 

[1] “Carbon Capture.” Center for Climate and Energy Solutions, May 27, 2021. ​​https://www.c2es.org/content/carbon-capture/.

[2] “PRE-COMBUSTION CO2 CAPTURE.” National Energy Technology Laboratory. Accessed February 28, 2022. https://netl.doe.gov/coal/carbon-capture/pre-combustion.

[3] IEA. “A new era for CCUS.” International Energy Agency. IEA. Accessed February 18, 2022. https://www.iea.org/reports/ccus-in-clean-energy-transitions/a-new-era-for-ccus.

[4]] Clifford, Catherine. “Carbon capture technology has been around for decades — here’s why it hasn’t taken off.” Consumer News and Business Channel, January 31 2021. https://www.cnbc.com/amp/2021/01/31/carbon-capture-technology.html. 

[5] “Carbon Capture and Storage: Pros & Cons.” The Climate Connection, April 13, 2021. https://theclimateconnection.org/carbon-capture-and-storage-pros-cons/. 

[6] Moch, Jonathan M., Xue, William, Holdren, John P. “Carbon Capture, Utilization, and Storage: Technologies and Costs in the U.S. Context.” Belfer Center for Science and International Affairs, January 2022. https://www.belfercenter.org/publication/carbon-capture-utilization-and-storage-technologies-and-costs-us-context. 

[7] Groom, Nichola. “Problems plagued U.S. CO2 capture project before shutdown: document.” Reuters, August 6, 2020. https://www.reuters.com/article/us-usa-energy-carbon-capture/problems-plagued-u-s-co2-capture-project-before-shutdown-document-idUSKCN2523K8.

[8] Douglas, Leah. “Factbox: Biden administration sees carbon capture as key tool in climate fight.” Reuters, February 7, 2022. https://www.reuters.com/business/environment/biden-administration-sees-carbon-capture-key-tool-climate-fight-2022-02-07/.