Can we bury carbon?

“Put simply, the concept of Carbon Capture and Storage is to capture CO₂ in the gas phase, liquefy it, transport it, and inject it into a reservoir in the ground where it can be stored safely and permanently”, says Olivier Point. Let’s take a closer look at each step.

Phase 1: How to capture CO₂ 

“Capture is happening at what we call the post-combustion stage and has been done for decades now in refineries all over the world”, Olivier explains. For this, chemical compounds named amines are used to capture CO₂ in a chemical reaction, one that can later be reversed to release the CO₂ and reuse the amines”, Olivier says. 

Phase 2: How to liquefy CO₂

To process the extracted gas, it is brought down to a specific temperature and pressure to be liquefied. It is also dehydrated. “The infrastructure needed for Carbon Capture and Storage is a capture and processing plant next to the industry or plant that emits CO₂”, Olivier says. It is then conveyed by a pipeline to a liquefaction unit where it is made ready to be further transported to a storage site. “Over the past few years, business models have changed and companies and industries that emit a lot of CO₂ are coming together to elaborate industrial hubs where they can share the infrastructure for capturing and processing CO₂ for more efficiency”, Olivier says.

Phase 3: How to transport CO₂

After the gas has been extracted, collected, and processed, it can be conveniently transported by any means we know for transporting liquefied gases: Trucks, trains, barges, ships, vessels, or pipelines. “CO₂ is no different from other liquefied gases, like ammonia or liquefied natural gas. Once liquefied, it can be transported over long distances”, Olivier explains.

Phase 4: How and where to store CO₂

“When the CO₂ gets injected, it is at the so-called dense phase, which means it has the viscosity of a gas and the density of a liquid”, Olivier explains. Experts like him try to find reservoirs to store the CO₂ safely, permanently, and cost effectively. Currently, most of the storage reservoirs can be found in the North Sea and are evaluated by the UK, Norway, Denmark, and the Netherlands. The CO₂ is stored in depths ranging from 800 to 2000 meters below the surface into rocks that are sealed.

Carbon Capture and Storage is a necessity, not an option. The International Energy Agency’s Sustainable Development Scenario envisions CCS accounting for 15% of the cumulative reduction in emissions, that’s 7.5 billion tons per year by 2050”
Olivier Point, geoscientist and senior project manager for CCS Solutions, OMV

Why is Carbon Capture and Storage an important technology?

The International Energy Agency’s net zero scenario targets involve CCS for 15% of the emissions reduction, that’s 7.5 billion tons per year by 2050. For Olivier, implementing the technology is not an option, but a necessity. “On the one hand, we cannot eliminate fossil fuels overnight, because energy demand is increasing. Goal 7 of the UN Sustainable Development Goals calls for an affordable, reliable and sustainable source of energy for all. So we still need fossil fuels during the energy transition. On the other hand, there are other industries that emit a lot of CO₂ like the cement industry and the steel industry. We need solutions to handle these emissions and Carbon Capture and Storage is a great option.”

Pressed on whether CCS is a false hope because it is too capital intensive, Olivier counters: “It’s far from being a scam. Like most other renewable energies, it is very capital intensive; that’s a fact. But the thing we need to understand is that CCS is a necessity not an option. Additionally, governments are enabling innovative and technological advancements via investment policies. Everyone has net zero targets and CCS is essential in meeting them.”

Oliver Point also joined the OMV Podcast "Rethinking Resources" to talk about CCS. Watch the whole recording here: