Is it safe? Yes, and we’ve being doing it for decades. Storage sites are carefully selected only after rigorous analysis to ensure they’re geologically suitable. Once injected, the CO2 is capped by an impermeable seal of rock to prevent any potential leakage. The storage sites are thousands of feet underground, far below drinking water supplies, and they’re constantly monitored for any potential changes.
What else can be done with CO2? Once captured, some CO2 can be utilized instead of stored – which is why you sometimes hear the term “carbon capture, utilization, and storage,” or CCUS for short. One common use today is enhanced oil recovery. Some more innovative options are being developed – such as using CO2 to make eFuels, or turning it into a mineral for use in building materials or industrial processes. But for now, these options are still at a very small scale – and a very high cost.
ExxonMobil is a global leader in carbon capture and storage, or CCS: We have more than 30 years’ experience and have captured more man-made CO2 than any other company.
And we’re scaling up even further. We’ve announced several CCS projects, including one at our Baytown complex and ones for CF Industries, Linde and Nucor. In fact, the total CO2 we’ve agreed to transport and store for our customers has reached 5 million metric tons per year. That’s equivalent to replacing about 2 million gasoline-powered cars with electric vehicles, which is roughly equal to the total number of EVs on U.S. roads today.
But we’ll need to scale up carbon capture and storage much more if we’re going to meet the world’s climate goals, because it’s one of the few options for significantly reducing emissions from the heaviest-emitting sectors: power generation, commercial transportation, and heavy industries like steel and cement.
As the IEA says, carbon capture and storage “will need to be a key pillar in successful clean energy transitions.”
Have more questions? Check out these FAQs from the U.S. National Energy Technology Laboratory or this IEA report, which contains more details about capacity and safety, and has some great charts.
Prasanna Joshi is vice president for ExxonMobil Low Carbon Solutions technologies.
