Promoted during COP28 in Dubai, it is a technology increasingly used by States as part of their climate policy. And France is no longer an exception. After presenting its carbon capture and storage (CCS) roadmap last summer, the government is accelerating.
This technique consists of trapping the CO2 emitted by factories at the source, then storing it in geological formations underground or under the sea, so that it is not released into the atmosphere. The mining law reform project presented on Friday April 12 provides for the possibility of reconverting unexploited oil or gas wells into CO2 storage wells.
Several projects in preparation
If Paris has already signed partnership agreements with Denmark and Norway in order to send and then store CO2 in the subsoils of the North Sea, ultimately the idea is to do the same thing in the wells of the south of the Paris Basin and New Aquitaine. Several projects are in preparation, such as the Lacq gas field (Pyrénées-Atlantiques), supposed to store a million tonnes of CO2 by 2030, and which is already causing an outcry from many local associations.
Qualified both as “key lever for the decarbonization of French industry” and of “solution of last resort”this technology is presented by the government as one of the solutions to achieve carbon neutrality in 2050. The objective is to capture between 4 and 8.5 million tonnes of CO2 per year by 2030, then between 15 and 20 million tonnes of CO2 per year by 2050, or a quarter of the annual emissions of French industry.
A judged objective ” ambitious “ by the High Council for the Climate. In an opinion delivered in November 2023, he considered that the CSS could serve as a lever in the National Low Carbon Strategy for 2050, but also considered that “given its limitations”this technology should be reserved for sectors where decarbonization solutions are limited, such as for the manufacture of cement.
Numerous technical and financial obstacles
Today, the limits of CCS are primarily technical. According to a study published in 2022 by The Institute for Energy Economics and Financial Analysis (IEEFA), of the thirty carbon capture and storage installations identified in the world, most have not achieved their objectives. These capture and store 40 million tonnes per year, or less than 0.1% of global greenhouse gas emissions. And above all, very far from the 7.6 billion tonnes that would need to be captured by 2050 to achieve carbon neutrality, according to the scenarios of the International Energy Agency (IEA).
The costs of these devices, which consume a lot of water (2 to 4 m3 of water required per tonne of CO2 captured) and energy, represent another significant obstacle to their deployment.. “Today, the price of a tonne of CO2 avoidedin industryis estimated at €250 per tonne”, observes Pierre Gilbert, climate prospective consultant at the Rousseau Institute, according to whom “the risks of CO2 leaks must not be forgotten”.
And then France is not a major producer of hydrocarbons, the storage potential must also be taken into account. Ademe considers that this is “limited” and only applicable to certain industrial sites located in three areas, around Dunkirk, Le Havre and Lacq.
Capturing emissions directly into the atmosphere
Alongside CCS, other solutions no longer make it possible to avoid emissions but to directly remove the CO2 already present from the atmosphere. These so-called “negative” emissions bring together several techniques for eliminating carbon dioxide and are considered essential to limit warming to 1.5°C to 2°C by 2100, according to the IPCC (Intergovernmental Group of Experts). on climate change).
On the one hand, tree planting or soil restoration aim to improve existing natural carbon sinks (forests, oceans, soils, etc.). On the other hand, technological solutions such as direct air carbon capture and storage (Daccs), where the CO2 in the ambient air is filtered using huge fans, before inject it into the basement.
There is also bioenergy with carbon capture and storage (Beccs), which consists of growing trees or fast-growing plants so that they capture CO2. This biomass is then burned to produce energy, and the carbon dioxide from the combustion is recovered and stored in deep geological formations. However, these two technologies are much less advanced than CSS.
Reforestation, the main source of CO2 elimination
According to the IPCC, global needs for carbon dioxide elimination are between 5 and 16 billion tonnes of CO2 per year in the second half of the 21st century. However, for the moment, only 2 billion tonnes are eliminated each year by human activities, mainly through reforestation.
While recognizing that Beccs and Daccs could be used “as a last resort solution to achieve carbon neutrality”the High Council for the Climate considers that their use “must for the moment be limited to a minimum necessary contribution”. The reason: like CSS, these technologies require a lot of water, energy, and are very expensive.
If France's contribution is today almost zero in terms of carbon elimination, 30 start-ups launched the French Association for Negative Emissions (Afen) at the beginning of April in order to structure a new sector.
