CO2 capture, an asset to achieve our climate objectives

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[EN VIDÉO] COP25: the concentration of CO2 in the atmosphere over 15 years
Using data collected on Earth and from space, NASA has compiled the increase in carbon dioxide concentration and its global distribution over fifteen years. At the end of the measurements in 2015, the maximum reached 402 ppm; today we are at 418 ppm.

” The CO storage2, it’s good. Sobriety is even better. » This is what Pierre Toulhoat told us, retired from his position as scientific director of the Bureau of Geological and Mining Research (BRGM) and member of the Academy of Technologies, more than a year ago. As he deciphered for us the challenges of what the experts call CCS – for capture and geological storage carbon.

He specifically addressed the storage stage. His speciality. And today, it’s Florence Delprat-Jannaud, head of the CSC program atPFI Energies nouvelles (IFPEN), which confirms this. “CCS technologies should in no way distract us from the essentials: efficiency and sobriety. » With it, we will more specifically address the issue of carbon dioxide capture (CO2). Her specialty.

Why ? First, because at the start of 2022, the Intergovernmental Group of Experts on the Evolution of the climate (IPCC) relaunched the urgency of deploying these technologies. Announcing that we were no longer in a position to do without it, if we still hope limit global warming at 1.5°C. Then because some Tech giants have just launched the Frontier initiative, a market guarantee that aims to accelerate the development of carbon capture technologies by guaranteeing future demand for them.

“There are already technologies that work well”, assures us Florence Delprat-Jannaud. She mainly wants to talk about solutions that capture CO2 in factory fumes. Those of heavy industry, which does not currently have alternative technologies to reduce its carbon footprint.

CO capture technologies2 already exist

“Capture of “post-combustion” fumes consists of recovering the CO2 by washing these fumes with a solvent », explains the head of the CCS program at IFPEN. These technologies have been used for a long time to treat gas fossil and have been adapted to capture CO2 industrial fumes. The problem is that they are expensive and consume a lot of energy. But the project “3D” which has just entered its phase demonstrator industrial » could change that. And help decarbonize industries high CO emitters2. Thanks to a solvent selected for its efficiency, its competitiveness, itssustainability and the energy savings it should make possible. A first industrial unit could be operational on the production site of steel of AcelorMittal, in Dunkirk, from 2025. With the aim of capturing more than one million tonnes of CO2 every year.

Other CO capture solutions2 existing systems, one can cite precombustion capture. The idea is to directly produce a combustible of carbon. An idea that only applies to a few industries. “And that should be considered at the time of the constructionFrom the factory “, explains Florence Delprat-Jannaud. CO capture2 can also be done by oxyfuel . “To increase the concentration of CO2 in the fumes and thus facilitate its capture, we carry out acombustionin pure oxygen and no longer in air. But again, producing pure oxygen is expensive. »

“We are also working on more innovative processes, such as chemical loop combustion. It could hit the market by 2028”, explains Florence Delprat-Jannaud. On the other hand, theCO capture technologies2 straight into the atmosphere , they are not ready on a large scale. From concentrations of around 10% – that’s already low -, we go to concentrations of around 0.04% – that’s tiny, even if it’s still far too much from a greenhouse effect point of view . This makes the capture operation much more delicate. However, around fifteen projects have been launched around the world. “But capturing CO2 in the air is absolutely not economically viable today. »

Costs still high, but just waiting to come down

That’s to say ? “Capturing CO2 in factory fumes, it now costs between 50 and 180 euros per ton, depending on the situation. The capture stage accounts for 50 to 70% of this sum. Compression and transport, each for 10%. The rest goes to storage”explains Florence Delprat-Jannaud. “But for direct capture in the atmosphere, it’s something else entirely. We are talking about costs between 300 and 800 euros per ton of CO2 picked up. »

Costs which should generally decrease when the volumes treated will increase. With the evolution of technologies, too. According to IFPEN’s CCS program manager, “there is not a minute to lose. We must work to develop different capture solutions. And in parallel, we must also study the storage possibilities for this CO2. »

Because there is doubt about it? “There is no doubt about the extent of underground storage possibilities. In Europe, the capacity is of the order of 500 gigatonnes, which is equivalent to a hundred years of emission – on the basis of emissionsof 2019 », tells us Florence Delprat-Jannaud. But each of the potential reservoirs will have to go through a fairly precise characterization stage before being used, in order to know exactly what volume it can receive. Or to check hissealing. And to develop long-term monitoring technologies. “For old tanks of hydrocarbons , it takes a few years. But for saline aquifers which have not yet been explored by the oil industry, it takes about ten years. »

What should be remembered is therefore that if research still has work to do, there are already technologies for capturing CO2 mature ones that could help us decarbonize industry above all. By 2070, the International Energy Agency estimates that CCS will offset the emission of 9.5 billion tonnes of CO2. Enough to contribute 15% to the effort needed to save our climate. But for that, “We must act today. Implement CCS solutions in heavy industry, in particular. And start limiting what experts call incompressible emissions. To support the efforts ofreduction of greenhouse gas emissionswhich must, moreover, continue to be granted”concludes for us Florence Delprat-Jannaud.

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