Prometheus has developed a 100% electrochemical process to transform atmospheric CO2 to long-chain hydrocarbons.
Prometheus has developed a proprietary electrochemical process that converts carbonate salts in water and electricity into energy dense liquid hydrocarbon fuels. This allows for the capture of CO2 from the air or from power generation exhaust into water as carbonate, which can be stored indefinitely. Once renewable energy is available, the carbonate can then be converted into fuel. This asynchronous carbon capture and fuel production is key to using this technology for zero emission energy storage. It also means that capturing CO2 from the air has a very low cost – no energy is needed to desorb it back to gas, because the carbonate is the form of carbon that is used in the electrochemical process.
The conversion of carbonate into kerosene (diesel and jet fuel) in water at room temperature and atmospheric pressure is a revolutionary breakthrough in electrochemistry.
Previously, using electricity to make fuels required the use of the Fischer Tropsch process, which converts CO2 and hydrogen at high pressure and temperature into hydrocarbons. This previous technology has very high capital and operating costs, and so cannot make commodity market priced fuels. Because it must use CO2 gas, it also could not be used for energy storage as the Prometheus process can. The Prometheus carbonate to kerosene process does not use hydrogen (H2), and does not use high temperature or pressure, a key reason the costs of the technology are so low. It enables an energy storage system capable of storing thousands of hours of energy — enough to absorb surplus renewables and dispatch firm electricity for weeks or months at a time — at under $5/kWh in capital cost, a fraction of the cost of competing long-duration technologies
Storage cost
Our DAC draws in large volumes of air through an enclosed high-pH waterfall that flows down a mesh grid, absorbing CO2.
High-pH water converts CO2 to carbonate (CO3) salt. The water and CO3 salt solution is sent directly to our hydrocarbon electrolyzer, the “Faraday Reactor.”
Inside the Faraday Reactor, CO3 salt from our DAC is turned directly into hydrocarbon fuels, utilizing low-cost proprietary catalysts and renewable electricity. Our system operates at room temperature and atmospheric pressure.
The only outputs of the Faraday Reactor are oxygen released into the atmosphere, and our zero-net-carbon kerosene (diesel and jet fuel).
Reviewed and validated one year of DAC-to-methanol pilot data. Confirmed fully integrated system from direct air capture to finished fuel. Observed kerosene pathway running on a single commercial-scale cell.
Drew methanol samples sent to external lab — 99.99% purity confirmed. Confirmed direct DC coupling to off-grid solar. No expensive power electronics required.
GC graph shows Prometheus diesel hydrocarbon distribution (C8–C19 range) comparable to fossil diesel.
Prometheus paraffinic kerosene FTIR spectrum closely matches fossil alkane reference.
Prometheus methanol FTIR spectrum matches Sigma (fossil methanol) reference — identical O-H, C-H, and C-O absorption peaks.
AmSpec, Houston TX
Prometheus Methanol 10-2-25 (Metal Can) Submitted Sample
IMPCA001II — Methanol Purity (On Dry Base): 99.99 %wt
Carbon Isotope Analysis – Unique Fuel Fingerprint
Prometheus methanol FTIR spectrum matches Sigma (fossil methanol) reference — identical O-H, C-H, and C-O absorption peaks.
FAQs on how direct air capture and e-fuel synthesis actually works
Prometheus uses a new patented integrated Direct Air Capture (DAC) and hydrocarbon electrolyzer system that converts atmospheric CO2, captured as carbonate and bicarbonate ions in water, directly into finished kerosene fuels (jet and diesel) using off-grid solar electricity.
Unlike conventional approaches, Prometheus jet and diesel fuels do not require the following:
In the Prometheus process, CO2 is captured from the air into water as carbonate and bicarbonate ions and is not desorbed back to gas. Prometheus kerosene is made directly from the carbonate and bicarbonate using electricity at atmospheric pressure and room temperature. The kerosene self-separates from water inside the hydrocarbon electrolyzer, called a Faraday Reactor, because oil and water naturally separate. The energy that drives the Prometheus process comes from low-cost off-grid solar. These advances radically reduce both capital and energy costs, producing jet and diesel fuels that cost less to make than those made from oil.
Because Prometheus’ fuel production process was engineered to remove the major cost drivers of traditional e-fuels:
Prometheus’ DAC technology lowers the cost of capturing CO2 by more than 80% to less than $50/ton CO2 compared to conventional DAC, because it eliminates the costly, energy-intensive step of desorbing CO2. Prometheus DAC uses water to capture CO2 as carbonate / bicarbonate, which is then converted electrochemically into kerosene in a hydrocarbon electrolyzer. The electrolyzer, called a Faraday Reactor hydrocarbon electrolyzer, operates at room temperature and atmospheric pressure, which allows it to be made from inexpensive materials. Lastly, Prometheus purpose-built its process to run off of intermittent renewable electricity. This means Prometheus can power its entire fuel production process using off-grid solar, which enables very low electricity costs. These advances are what allows Prometheus to achieve fuel costs that are lower than fossil fuel commodity prices.
Yes. Every major component of the Prometheus system was designed for low-cost production:
Independent techno-economic assessments (Ramboll, 2021, 2024) validate Prometheus’ commercial pathways and its low costs.
Prometheus captures CO2 from air as carbonate and bicarbonate ions in water, which are converted electrochemically directly into fuel. This eliminates the most expensive step of conventional DAC systems: desorbing captured CO2 to a concentrated gas. Because the formation and regeneration of carbonate / bicarbonate ions happen inside the closed loop of Prometheus’ novel, integrated DAC-electrolysis system and are driven only by electricity and pH, Prometheus’ DAC costs are below $50/ton.
The system was explicitly designed to operate in regions where electricity is cheapest: remote, high-insolation off-grid solar. Because it runs on room-temperature electrochemistry without thermal loads, the Prometheus system can operate directly on intermittent solar and wind at very low cost. Electricity does not need to be baseload or grid-connected. Over 80% of the costs of solar farms today are grid-related costs. Using off-grid low-voltage DC power allows Prometheus to access the lowest cost electricity in the world today, and these costs will continue to drop over time. For electricity cost of $0.05 / kWh or less, a gallon of Prometheus diesel costs less than $5 / gallon.
Prometheus optimizes for the lowest cost of the fuel it produces. While overall electrical energy efficiencies of over 70% are achievable, a lower conversion rate can result in lower overall fuel costs when electricity is inexpensive. At very low electricity pricing, it is best to optimize for cost of equipment (CAPEX cost). In many cases the optimal energy efficiency for the lowest cost fuel is approximately 45-50%.
Prometheus fuels are 100% carbon-neutral, meaning they have a carbon intensity of zero:
The origin of every molecule in Prometheus fuels can be verified using Prometheus’ carbon isotope fingerprint method, which shows a unique ratio of C12, C13, and C14 isotopes that identifies the fuel as being made from atmospheric CO2 captured by Prometheus DAC.
Prometheus fuels are cheaper to make than oil-based fuels at average pre-war prices for a barrel of oil. As the company acquires “learning by doing” savings with deployment, the cost of its fuels will further decrease. If one considers the OECD countries only and sets the TAM (total addressable market) to 60% of the liquid fuels used by these countries, the TAM is $1.4 Trillion dollars annually. This includes fuels for:
Because Prometheus fuels can be produced anywhere that has access to cheap renewables (e.g., land with good sun), Prometheus systems are globally scalable. The only inputs to Prometheus systems are air and electricity, so there is no limit to their scale of production.
Using the same tech platform and pathway variants, we can make:
Yes, Prometheus’ technology and cost models have undergone rigorous independent engineering review, its fuels have been analyzed by external labs, and the strength of its IP position has been verified by its patent counsel at Wilson Sonsini Goodrich and Rosatti.
Prometheus has two commercial-scale projects planned:
Both projects are pre-sold for 10 years. On-site kerosene production systems for data centers, defense, and industrial partners are also in development.
Prometheus has pre-sold 11 million tons of fuel across 10 years totaling over $8B in value at current commodity market prices.
Yes. Prometheus fuels are designed to meet ASTM and OEM requirements. For diesel, Prometheus fuels will meet ASTM D975. For jet fuel, we will apply for a new pathway annex for ASTM D7566. Methanol will meet the IMPCA international standard for purity.
Yes. Prometheus fuels can be used to power data centers by firming and shaping renewables across long time frames of 1500+ hours, storing these renewables as fuels. This includes Prometheus methanol, which can be used in natural gas turbines, and Prometheus diesel, which can be used in aeroderivative turbines and diesel generators already installed in data center backup systems.The Prometheus ultra long duration energy storage (ULDES) systems are closed loop, recovering both carbon and water from fuel use.
Prometheus’ technology was created by its founder Rob McGinnis and his team. Several aspects of McGinnis’ prior work, as well as contributions from the Prometheus team inspired the development of the tech, including:
Prometheus protected the specifics of its technology while key patents were being filed. The company has always been transparent about what its technology will achieve, but could not fully describe how it works without risks to its IP position. Now that Prometheus’ IP moat has been built to sufficient size and scale, the company can talk more freely about how its integrated no-desorb DAC and hydrocarbon electrolyzer system works.
Virtually all commercial e-fuel systems today rely on Fischer-Tropsch or methanol-to-jet technology to make jet or diesel fuels. These technologies use high temperatures and pressures that make their equipment very expensive. In addition, these processes must run 24/7, meaning they have to use expensive grid power. They cannot compete on price with fuels made from oil at any scale. Only Prometheus has a new technology to make jet and diesel fuels at the low costs needed to compete with oil. Additionally, e-fuel makers other than Prometheus currently use CO2 from smokestacks (point source) or biogenic sources as their feedstock. These CO2 sources severely limit where e-fuel makers can site their production. Only Prometheus has DAC that costs less than point-source or biogenic CO2. And because our CO2 feedstock is literally everywhere (air), we can site our fuel production anywhere. Our low-cost DAC and hydrocarbon electrolyzer tech stack allows us to make fuel anywhere, any time, at a cost that is less than making fuels from oil.
It is the first 100% electrochemical pathway for producing synthetic paraffinic kerosene directly from the air. This marks the first time in a century that a technology has been invented to make synthetic kerosene-range fuels (e.g., jet fuel and diesel) from atmospheric CO2 and electricity in a single process step. It is also a breakthrough in cost that makes fuels from solar electricity cheaper to produce than fuels made from oil. In Prometheus’ process, CO2 is captured from the air as carbonate / bicarbonate ions in water. These ions are then converted directly into long-chain hydrocarbons that automatically separate from water at room temperature and atmospheric pressure. This enables:
The physics of “oil and water don’t mix” becomes the separation step. The process’ simplicity is what enables off-grid operation, ultra-low energy use, and production costs at or below fossil fuel prices. No other company has a pathway like this.
Yes, Prometheus was the first to file patents for direct air capture of CO2 to carbonate and bicarbonate and their conversion into fuels made from electricity. In addition, it was first to file on a number of key innovations including DAC and electrochemical pH control methodologies, electrochemical oligomerization, nanotech for fuel separation, the use of novel separators in hydrocarbon electrolyzers, and other critical technologies that establish a robust IP moat for Prometheus. In addition to its patents, Prometheus also has numerous trade secrets accumulated over 7 years of development.
Yes. The Prometheus process is designed to be safe, simple and environmentally-friendly at all scales. It offers the following advantages:
Several key milestones aligned at once:
With its IP protected, its technology validated, and commercial deployment in progress, Prometheus can finally share a fuller picture of how its system works and why it is such a huge leap forward for energy and fuels.