The process of CO2 capture involves capturing the carbon dioxide produced by industrial processes or energy production and storing it securely to prevent its release into the atmosphere. This method is expected to help us decrease greenhouse gas emissions and combat climate change. Various technologies are utilized to absorb CO2, and the transportation and storage of this gas are also crucial aspects to consider. Recently, the topic was discussed at a round table during the HyPorts exhibition in Marseille, France that we attended.
Sequestration has been identified as one of the strategies, alongside the development of renewable energy sources, to reduce the levels of greenhouse gasses in the atmosphere. This approach is crucial in the fight against climate change and the fulfillment of climate commitments. Numerous countries have indeed committed to achieving carbon neutrality by 2050.
According to the International Energy Agency (IEA), our planet must capture four billion tons of CO2 annually by 2035 and 7.6 billion tons by 2050 (equivalent to 20% of current emissions) to reach carbon neutrality. Achieving these targets is a daunting task that requires significant investment in technology and infrastructure.
Currently, the amount of CO2 captured each year is approximately 440 million metric tons, of which 230 million are primarily utilized for urea production for fertilization (130 million Mt) and enhanced oil recovery (80 million Mt). However, these efforts must be scaled up drastically to meet the IEA’s targets and achieve carbon neutrality.
1/ What is the Purpose of CO2 Capture?
The primary reason for capturing CO2 is the staggering amount of this greenhouse gas in the atmosphere.
According to the French Ministry of Environment, in 2019,
“CO2 emissions reached 38.0 billion tonnes, a 2.4-fold increase since 1970. These emissions are 39% from coal combustion, compared to 30% from oil and 19% from natural gas. The remaining 12% is related to industrial processes (e.g. the transformation of limestone into lime to produce cement).”
According to Fabrice Del Corso, production expert at French industrial gases supplier Air Liquide
“When CO2 is utilized, it often returns to the atmosphere quickly, making CO2 sequestration crucial to prevent its permanent release into the atmosphere.”
In addition to environmental concerns, there is also a financial incentive for capturing CO2. The cost of the carbon tax on the European market has increased significantly from €14.50 in 2015 to more than €80 per tonne currently, and it is projected to reach €100 per tonne by 2030.
Capturing and storing CO2, on the other hand, costs between €50 and €200 per tonne, depending on the specific figures. This makes the capture of CO2 economically attractive to certain industrial companies subject to the carbon tax.
CO2 capture can be divided into two objectives: carbon capture, utilization, and storage (CCUS) and carbon capture and utilization (CCU).
According to Adrien Allet, a member of the Club CO2 which gathers various players in the industry to discuss solutions,
“CCS aims to prevent the addition of CO2 to the atmosphere by storing it underground sustainably. CCU aims to provide societal services without using new fossil molecules but by using already emitted CO2.”
For the Club CO2, the capture, geological storage, and valorization of CO2 (CSCV) would make it possible to capture 90% of the emissions from the world’s largest CO2 emitters. It is estimated that the technology of capture and geological storage could contribute up to 19% to the overall reduction of greenhouse gas emissions by 2050.
2/ Which CO2 to Capture?
When it comes to capturing CO2, certain areas are more promising than others.
David Lefranc, Director of Development and Environment at the Grand Port Maritime of Dunkirk in northern France, notes that the industrial port area of Dunkirk produces a staggering 14 million tonnes of CO2 per year – equivalent to 20% of France’s total emissions.
“This is mainly due to the presence of the industrialist ArcelorMittal but also other industrial companies, so there is a real potential.”
Adrien Allet agrees that port areas are a prime location for CO2 capture:
“Industrial port areas are interesting because they have CO2 emitters present in these areas. We can therefore collect the CO2 there, centralize it and send it to its final and definitive destination in underground storage.”
The captured CO2 can also be put to use, such as in the creation of alternative maritime fuels that use hydrogen and CO2 to decarbonize the shipping industry.
The emissions of CO2 from ships are a significant contributor to global greenhouse gas emissions. A ship’s engine, which is typically powered by diesel, emits between 3% to 6% of CO2. Current methods for capturing CO2 on ships typically involve absorption technologies, as cryogenic processes are not yet effective for these densities of CO2.
The installation of a carbon capture system on a large ship could potentially reduce its emissions, but there are significant challenges to overcome, Pascal GAIOR, Commercial Director at SOFRESID ENGINEERING explained:
“One major challenge is the volume of CO2 to be stored, which is around 3 times greater than that of the fuel. For instance, a ship with a fuel storage capacity of 10,000 cubic meters would need to store 30,000 cubic meters of CO2 in a liquefied form if it were to consume all of its fuel. This presents significant logistical challenges in terms of storage and transportation.”
3/ What are the Carbon Capture Technologies?
The technologies used to capture CO2 can be classified into four main types. Currently, only one of these technologies is widely used and mature enough to capture millions of tons of CO2 annually.
Post-combustion Capture
Post-combustion capture is a method that captures CO2 after the combustion of fossil fuel sources like coal, natural gas, or oil. Solvents, like ammonia and monoethanolamine, are used to capture CO2. The captured CO2 is then separated from the solvent through a heating process in a regeneration tower. Although this method is mature and commonly used in fossil fuel power plants, it requires significant energy, mainly due to the high temperature it requires.
Pre-combustion Capture
Pre-combustion capture is used to capture CO2 before fossil fuel combustion. The fossil fuel is transformed into a synthesis gas containing hydrogen and CO2. The CO2 is then separated from the syngas for storage. This method is often used to produce hydrogen from natural gas.
Oxy-fuel Capture
Oxy-fuel capture requires the burning of fossil fuels in a pure oxygen atmosphere. This produces concentrated CO2 smoke, which can be captured and stored.
Biological Capture
Biological capture involves the use of plants and algae to absorb CO2 from the atmosphere through photosynthesis. This method is still in development, but it shows promise as a renewable energy source.
4/ How is Captured CO2 Stored?
Once captured, CO2 can be stored in different ways.
Geological Storage
Geological storage is the most common method of storing CO2. It consists of capturing CO2 from industrial processes or energy production, compressing it, and then transporting it to a geological storage site where it is injected into deep geological formations, -800 meters, such as saline aquifers, porous rock formations, or former oil and gas fields. CO2 is stored as a supercritical gas or dissolved in underground fluids, which keeps it in a stable state and prevents its release into the atmosphere. However, the geological formations must be deep and tight enough to ensure that the CO2 remains trapped for hundreds or thousands of years.
According to Pascal GAIOR, Sales Director of SOFRESID ENGINEERING
“CO2 comes from the oil fields, the idea is to put it back in. In an offshore oil field, in shallow waters, why not store with a steel or concrete GBS, buffer storage of liquefied CO2 at -60° 5 to 6 bars? There are already CO2 transport ships under construction. They are small ships, with 7500 tonnes of capacity per ship. A rotation of these ships allows us to consider up to 6 million tonnes processed by such an installation at sea with reinjection into the subsoil. In the North Sea and in the Arctic, this type of deployment is conceivable.”
Products Storage
CO2 can also be stored in products. For example, CO2 is used in the production of carbonated beverages and is therefore stored as a dissolved gas in the beverages. However, this storage method is limited to specific applications. In addition, once used, the CO2 is released back into the atmosphere.
RELATED ARTICLE
Oceanic Storage
Oceanic storage consists of injecting CO2 into the deep waters of the ocean. This storage method is still at an experimental stage and raises significant environmental concerns.
E-Fuel Storage
Finally, the captured CO2 can be used for industrial purposes, such as the production of synthetic fuels or construction materials.
5/ What Are the Most Successful Projects Currently?
A recent report by the Global CCS Institute shows that there has been a 44% increase in the number of CCS projects worldwide in just one year. Currently, there are almost 200 CO2 capture and storage (CCS) initiatives, with 30 already in operation and 164 in different stages of development. The most advanced CCS projects are being carried out in northern European (Iceland, Norway, the Netherlands, the United Kingdom, and Denmark), the United States, and Australia.
Norway
One of the most promising projects is the Northern Lights initiative in Norway, which plans to become the largest CO2 transport and storage infrastructure under the sea in Europe. Equinor, Shell, and Total are collaborating on this geoengineering pilot project, which is set to become operational in 2024.
Denmark
Denmark has also recently launched its first carbon dioxide (CO2) storage site in the North Sea through the “Greensand” project. The pilot phase of this project aims to store carbon dioxide under the North Sea, using an old oil field.
France
In the Pyrenees, the Pycasso project is set to establish a Franco-European CO2 storage cluster. The project will employ the chemical absorption process by amines, a technique typically used to treat a 300-megawatt power plant, and is expected to produce two million tonnes of CO2 per year, according to Pascal GAIOR, Sales Director of SOFRESID ENGINEERING.
However, the future European hub in Dunkirk, which plans to capture, condition, transport, and store ten million tonnes of CO2 per year, will not be operational until 2035.
Although all of the current projects including the one mentioned above will allow for the capture and storage of 244 million tonnes of CO2 per year, this falls far short of the International Energy Agency’s goal of capturing and storing around 1.2 billion tonnes of CO2 per year by 2030, as noted by the Global CCS Institute.
6/ Who Are the Top 10 Carbon Capture Companies?
Energy Digital Magazine, the digital community for the oil & gas, utilities, and renewables energy industry, has ranked the top 10 carbon capture companies by the number of metric tons of CO2 captured. (Date: February 2023).
1) Carbfix (Iceland)
This Icelandic company established in 2006, specializes in CCS technology. Instead of storing CO2 as a gas, they dissolve it in water and inject the resulting solution into basaltic rock formations, where it reacts with minerals to solidify into a mineral form. Their lifetime carbon capture capacity is 1 billion metric tons of CO2 per year.
2) CarbonFree (USA)
CarbonFree captures 800 million metric tons of CO2 per year from stationary emitters and uses patented technologies to convert it into carbon-negative chemicals. Their products, SkyCycle™ and SkyMine®, create chemicals including sodium bicarbonate, precipitated calcium carbonate, and hydrochloric acid.
3) Quest Carbon Capture & Storage (Canada)
The facility captures and stores up to 1 million metric tons of CO2 emissions per year from the Scotford Upgrader in Alberta, Canada. The post-combustion capture process is used to transport the captured CO2 via pipeline and store it in a saline reservoir deep underground.
4) Carbon Engineering (USA)
Carbon Engineering uses a liquid DAC (direct air capture) technique, trapping CO2 with a potassium hydroxide solution. They plan to build a megaton-scale plant in the Permian Basin in the U.S. that is expected to capture 1 million metric tons of CO2 annually, starting in 2024.
5) Aker Carbon Capture (Norway)
Aker Carbon Capture uses their own proprietary technology to capture CO2 from waste flue gasses generated by industries such as oil refineries and cement plants. They capture 400,000 metric tons of CO2.
6) Carbon Clean (The UK)
Founded in 2009, Carbon Clean developed a proprietary solvent that captures CO2 from power plants and cement factories. The captured CO2 is separated, compressed, and can be reused or sequestered underground. Their carbon capture is 335,745 metric tons per year.
7) LanzaTech (New Zealand)
Founded in 2005, LanzaTech captures waste gasses and converts them into valuable chemicals and fuels using microorganisms. Their carbon capture is 150,000 metric tons per year.
8) CO2 Solutions
Developed by Saipem in 1997, CO2 Solutions uses enzymes to capture carbon dioxide from industrial emissions at a lower cost than traditional methods, without using toxic chemicals or producing harmful byproducts. Their carbon capture is 11,000 metric tons per year.
9) Climeworks (Switzerland)
Founded in 2009, Climeworks uses DAC technology to extract carbon dioxide from the atmosphere. Their carbon capture is 4,000 metric tons per year.
10) Global Thermostat
Founded in 2010, Global Thermostat uses a patented process that involves an adsorbent material that is regenerated by low-grade heat, and the CO2 is compressed for use in various applications. Their carbon capture is 4,000 metric tons per year.
