By Dr. Michael Dent, IDTechEx
Carbon capture, utilization, and storage (CCUS), or carbon capture and storage (CCS), is a set of technologies used to strip carbon dioxide from industrial waste gases or directly from the atmosphere. Once the carbon dioxide is captured, it is either stored permanently underground (carbon storage) or it is used for a range of industrial applications (carbon utilization), such as CO2-derived fuels or building materials. CCUS technologies are likely to play a key role in the fight against climate change, with the UN estimating that CCUS could mitigate between 1.5 and 6.3 gigatonnes of CO2 equivalents per year by 2050.
The world has already taken its steps along this pathway. Over the last decade, the deployment of carbon capture technology has been steadily scaling up, with global carbon capture capacity reaching 40 million tonnes in 2020. Plans for more than 30 new CCUS facilities have been announced since 2017. If all these projects proceeded, global capture capacity would triple to around 140 million tonnes per year.
However, this is a drop in the ocean compared with global CO2 emissions, which reached 36 billion tonnes in 2019. Although global emissions are believed to have dropped to around 31 billion tonnes in 2020, stemming from the global slowdown in the wake of COVID-19, this is probably a blip in the wider picture, and global CO2 emissions are likely to continue growing over the next few years. For CCUS to have a meaningful impact on emissions in a timely manner, it will need to scale up hundreds of times compared with today’s levels.
CCUS technologies also face some major challenges that could hamper widespread deployment. Although each aspect of CO2 capture, utilization, and storage faces its own challenges, a common challenge facing all aspects of the industry is that of economics.
Separating out CO2 from a mixture of gases is costly. Although separation is fairly straightforward for waste streams with high concentrations of CO2, such as in natural gas processing or ammonia production, it becomes costlier as the relative amount of CO2 in the stream decreases. Capturing one tonne of CO2 from a flue gas stream in an average coal-fired power plant currently costs around $40-80. Capturing CO2 directly from the atmosphere can cost around $600. The energy requirements to capture the CO2 are also an issue – a coal plant equipped with CO2 capturing equipment can require about 25% more fuel to generate the same amount of power as one without it.
Once the carbon has been captured, there’s the challenge of what to do with it. Captured CO2 can either be stored underground or utilized for various industrial applications. Underground storage is by far the most widely used option, with most industrial-scale CCUS facilities using captured CO2 for enhanced oil recovery (EOR), where CO¬2 is injected into oil wells to boost productivity. This is somewhat problematic in its own sense, as it is essentially using CO2 to access more oil which will then be burned to give out CO2, but it also requires high oil prices to be commercially viable. The drop in oil prices stemming from the COVID-19 pandemic made EOR less viable in 2020, resulting in the Petra Nova facility’s closure in Texas, which was the world’s largest installation of CO2 capture on a power plant. Carbon pricing schemes and tax credits such as the 45Q scheme in the US can help make CO2 storage more viable, although such schemes are still in their early stages across much of the world.
Despite these challenges, progress in CCUS may be something the world can’t afford to ignore. Innovative companies across the world are working to overcome the challenges associated with CCUS, for example, through improved capture technology and the development of catalysts that can quickly and cheaply convert CO2 molecules into useful chemicals and fuels. The next few years could be essential in ensuring the future success of the industry. “Carbon Capture, Utilization and Storage 2021-2040,” a new report from IDTechEx, explores the technical and commercial factors that are key to ensuring the success of the industry.