44.01 ($6M for peridotite carbon mineralization)

44.01, a company founded in the United Kingdom in 2020, has developed a technology for permanently removing CO₂ from the atmosphere by mineralizing it in peridotite rock. By injecting CO₂-saturated water into an underground peridotite layer, the technology shortens the peridotite CO₂ mineralization process to 12 months. Once CO₂ has been mineralized, there is no need for high-pressure underground storage or risk of leaks. Peridotite is abundant across America, Europe, Asia, and Australasia, making the solution scalable. 44.01, in collaboration with Mission Zero, has won a $1 million milestone award in the XPRIZE Carbon Removal competition.

Challenges: carbon emissions and carbon mineralization

Carbon emissions

Since the early 1900s, carbon dioxide (CO₂) levels in the atmosphere have increased by 50% due to human activities. When fossil fuels (such as coal, oil, and natural gas) are burned for energy production, transportation, and industrial processes, CO₂ is released into the atmosphere. This excess CO₂ acts as a greenhouse gas, trapping heat and causing the air and ocean temperatures to rise. CO₂ emissions play a crucial role in driving climate change.

This warming effect has caused the global average temperature to rise by about 1.1 ºC since the pre-industrial period. This has led to rising in the frequency and intensity of extreme weather events, melting of polar ice caps and glaciers and rising sea levels, shifts in species ranges and increased risk of species extinction, agriculture and food security, and ocean acidification.

To mitigate these impacts, the Paris Agreement aims to limit global warming to well below 2 ºC above pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC) estimates that a “carbon budget” of about 500 GtCO₂, which corresponds to about ten years at current emission rates, provides a 66% chance of limiting global warming to 1.5 ºC.

Carbon mineralization

Natural weathering process converts atmospheric CO₂ into rocks, providing reliable, long-term storage. It has been found that the rate of natural carbonation of peridotite is surprisingly fast compared to other types of rock.

Peridotite rocks primarily consist of the silicate minerals olivine and pyroxene. They are the most common rock found in the Earth’s mantle and are especially abundant in Oman. They react with CO₂ and H₂O near the Earth’s surface to form hydrous silicates (serpentine), Fe-oxides (magnetite), and carbonates (calcite, magnesite, and dolomite) via the following chemical reactions:

Mg₂SiO₄ (olivine) + 2CO₂ → 2MgCO₃ (magnesite) + SiO₂ (quartz);

2Mg₂SiO₄ (olivine) + Mg₂Si₂O₆ (pyroxene) + 4H₂O → 2Mg₃Si₂O₅(OH)₄ (serpentine);

Mg₂SiO₄ (olivine) + CaMgSi₂O₆ (pyroxene) + 2CO₂ + 2H₂O → Mg₃Si₂O₅(OH)₄ (serpentine) + CaCO₃ (calcite) + MgCO₃ (magnesite)

One ton of mantle peridotite could solidify up to 500 kilograms of CO₂, whereas one ton of basalt could only solidify 170 kilograms. Therefore, peridotites are considered as promising reactants for converting atmospheric CO₂ to solid carbonate to mitigate climate change.

Mantle peridotite is typically found beneath the Earth’s crust, > 6 km below the seafloor and 40 km below the land surface. It is out of equilibrium with air and water at the Earth’s surface. The natural weathering of peridotite is slow and may take thousands of years to convert a considerable amount of CO₂ into carbonate rocks.

Accelerated weathering methods

Accelerated weathering aims to speed up chemical reactions between rocks, water, and air, thereby removing CO₂ from the atmosphere and storing it in solid carbonate minerals. There are two primary approaches to enhanced mineralization: in situ and ex situ mineralizations.

The in situ mineralization method drills deep wells and injects CO₂-rich fluids into suitable rock formations. The injected CO₂ reacts with rocks to form solid carbonate species, realizing underground geologic sequestration.

The ex situ mineralization methods mines fresh rocks, grind them into fine particles, and mineralize CO₂ at elevated pressure and temperature via industrial processes. Ex situ mineralization can be more expensive, costing as much as $600 per ton of CO₂, because it requires lots of fresh rock and energy to power the mineralization reaction.

44.01 Technology

44.01 has developed an in situ mineralization system to mineralize CO₂ into peridotite rock formations in a controlled and efficient manner, thus removing carbon permanently from the atmosphere. 44.01’s CO₂ mineralization system shortens the peridotite CO₂ mineralization process to 12 months. Powered by renewable energy, the system uses CO₂ gas from Direct Air Capture methods and mixes it with cold water to form a CO₂-rich solution. The CO₂-rich water is injected into peridotite rock formation and efficient mineralization reaction occurs by conversion peridotite into magnesite (MgCO₃) and calcite (CaCO₃).

44.01 CO₂ mineralization system

The diagram below depicts the in situ CO₂ mineralization system of 44.01.

The system includes a renewable energy system, a water storage tank, injection pumps, a tracer fluid system, a gas dissolution system, submersible pumps, a packer system, and a monitoring system.

Renewable energy

During daytime, wind and solar energy are used to power the system. Excess renewable energy is stored for operation at night.

Water storage tank

A submersible pump draws water from the water recovery wells into the water storage tank. The water storage tank can also receive water from other sources, such as seawater. The water storage tank dampens pressure fluctuation caused by natural changes in water levels in the water recovery well. Therefore, it enables the injection pumps to supply a stable pressure. The water storage tank is equipped with sensors that operate the submersible pump in the water recovery well automatically.

Injection pumps

A set of injection pumps pressurize the water steam from the water storage tank and inject it to the CO₂ injection well. The flow rates are adapted to the permeability of the injection zone.

Tracer fluid system

The tracer fluid is injected into the pressurized water stream using a set of dosing pumps. The tracer is used to monitor the reactivity of the peridotite to mineralize the injected CO₂. The tracer is fluorescein. It is also possible to use natural tracers such as stable carbon, strontium, magnesium and calcium isotopes.

Gas dissolution system

The gas dissolution system maximizes the gas-water contact surface area and ensures rapid, complete CO₂ dissolution. This system is placed after the injection pumps because higher pressures increase the solubility of gasses. The system dissolves gas with a bubble diameter less than 100 µm.

Submersible pump 1

The submersible pump draws water from the isolated injection interval and for sampling purposes.

Packer system

The packer system is connected to the head of the injection well through a non-corrosive pipe. It is installed just above the injection zone and hydraulically isolates the column for injection of CO₂-rich water into the peridotite rock formation. The packer is equipped with sensors to monitor hydraulic pressures of the column above and below the packed off interval, as well as the packer pressure.

Submersible pump 2

The submersible pump 2 is installed in the water recovery well at depth. It draws water from the well into the water storage tank to be used for injection purposes.

Monitoring system

The monitoring system (not shown) monitors pH, total dissolved solids, electrical conductivity, temperature, and oxidation reduction potential of water samples from wells. Monitoring system also monitors the change of the molar ratio of CO₂ to tracers, which indicates CO₂ abatement.

How does 44.01 technology work?

The process begins by identifying a suitable location with a peridotite layer at least 0.5 km thick.

A CO₂ injection well is drilled into this peridotite layer. The well should be between 0.8 to 1.2 km deep and fitted with a well casing that is perforated at the targeted injection zone for peridotite mineralization in the geological formation.

Alongside the injection well, a water recovery well is drilled with hydraulic connection between the two boreholes.

The geologic formation is pretreated with an aqueous solution, such as an aqueous acidic solution, before the CO₂-rich water is injected therein. Pretreatment enhances CO₂ mineralization by forming voids and crevices within the geologic formation, thereby enhancing fluid flow through the formation and activating the peridotite formation for reaction with CO₂.

The gas dissolution system dissolves CO₂ gas in the pressurized water stream at 5 ºC. CO₂ can be dissolved in greater quantities at cooler temperatures. CO₂-rich water is injected through the injection borehole well head into the target injection zone.

The injected CO₂-rich water is dispersed through the annulus within the peridotite formation, where the dissolved CO₂ reacts in situ with the peridotite rocks according to the following chemical reaction:

Mg₂SiO₄ (olivine) + CaMgSi₂O₆ (pyroxene) + 2CO₂ + 2H₂O → Mg₃Si₂O₅(OH)₄ (serpentine) + CaCO₃ (calcite) + MgCO₃ (magnesite)

Tracers are used to monitor the change of molar ratio of tracers to CO₂. At the injection well, the tracer-to-CO₂ ratio is maintained at a constant value, whereas changes in this ratio at the water recovery well indicate CO₂ abatement via reaction with peridotite.

Monitoring of both the injected CO₂-rich water on the surface and the hydraulic pressures at the injection interval is continuously logged for analysis using sensors and a data acquisition system.

After the CO₂-rich water passes through the peridotite, the water recycled from the water recovery well contains little CO₂. The water is cooled via an evaporative cooling process after returning to the surface.

As peridotite formation becomes saturated with CO₂, the efficiency of further CO2 fixation decreases. It is then advantageous to relocate the injection of CO₂-rich water.

44.01 Patent

US20230038447A1 System and method for permanent carbon dioxide sequestration using a renewable energy source

44.01 Products

Carbon offset credit market

The market value of carbon offset credits varies widely. In current carbon markets, the price of one carbon credit can range from a few cents per metric ton of CO₂ emissions to $15/mtCO₂e (metric tons of CO₂ equivalent) or even $20/mtCO₂e. However, the voluntary carbon offset market, which was worth about $2 billion in 2021, is projected to grow to $10-40 billion by 2030, transacting 0.5-1.5 billion tons of CO₂ equivalent, as opposed to the current 500 million tons. The total value of carbon credits produced and sold to help companies and individuals meet their de-carbonization goals could approach $1 trillion as soon as 2037.

44.01 products

44.01 creates and sells valuable carbon credits for every ton of CO₂ mineralized. 44.01 is currently conducting two pilot projects aimed at mineralizing CO₂ and reducing its presence in the atmosphere:

Fujairah Pilot Project:

44.01 has partnered with Abu Dhabi National Oil Company (ADNOC), Fujairah Natural Resources Corporation (FNRC), and renewable energy company Abu Dhabi Future Energy Company (Masdar) to pilot its technology of mineralizing CO₂ into rock in the United Arab Emirates (UAE). This initiative is the first carbon-negative project by an energy company in the Middle East and the first peridotite mineralization project to utilize seawater. The project is due to start in January 2023 and will use 44.01’s Earthshot prize-winning technology.

Al Qabil Project:

44.01 has signed a concession agreement with Oman’s Ministry of Energy and Minerals for the world’s first commercial-scale peridotite mineralization project, which will begin in 2024 in the Hajar mountains. The project will take place at a site in Al Qabil, where 44.01 has already completed a successful pilot project to prove that their process is effective, safe, and permanent. The company will take CO₂ captured from the atmosphere or from industrial processes, dissolve it in water, and then inject it into peridotite formations deep underground, where it will mineralize, or turn into rock, meaning it can never escape back into the atmosphere.