e-Fuels Breakthrough

SYNTHESIZING FUEL FROM THE AIR.

Prometheus has developed a 100% electrochemical process to transform atmospheric CO2 to long-chain hydrocarbons. 

Technology

Energy Innovation

A new way to convert electricity into fuel.

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
Hours
0 +
Highest technology
readiness rating (methanol)
TRL 0
storage cost
Capital cost < $ 0 / kWh

Capital cost
< $5 / kWh

Storage cost

How it works

Breakthrough technology e-kerosene pathway from electricity & air.

01. Extract CO2 from Air
Our DAC draws in large volumes of air through an enclosed high-pH waterfall that flows down a mesh grid, absorbing CO2.
02. Convert to Carbonate (CO3)
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.”
03. 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.
04. Net-Zero Carbon Fuel

The only outputs of the Faraday Reactor are oxygen released into the atmosphere, and our zero-net-carbon kerosene (diesel and jet fuel).

Third-party verified

Maersk commissioned independent engineering validation.
One year of pilot data. 99.99% pure methanol.

Dec 2025

MAERSK / DEEPSENSE

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.

Oct 2025

RAMBOLL

Drew methanol samples sent to external lab — 99.99% purity confirmed. Confirmed direct DC coupling to off-grid solar. No expensive power electronics required.

99.99% purity

1-year pilot data

Fully integrated system

Our Lab Certifications

Our fuels are verified by third party labs including AmSpec (Houston, TX)

Prometheus low-cost diesel made from Solar + Air.

Gas Chromatograph and FTIR Analysis

Our diesel will run in any existing diesel engine

Gas Chromatograph Analysis Prometheus Diesel vs. Fossil Diesel

GC graph shows Prometheus diesel hydrocarbon distribution (C8–C19 range) comparable to fossil diesel.

FTIR Analysis — Prometheus Kerosene vs. Fossil Alkane Standard

Prometheus paraffinic kerosene FTIR spectrum closely matches fossil alkane reference.

Prometheus low-cost methanol made from Solar + Air.

FTIR Analysis

Our methanol and diesel fuels can store energy and deliver it when needed.

FTIR Analysis Jan 2025

Prometheus methanol FTIR spectrum matches Sigma (fossil methanol) reference — identical O-H, C-H, and C-O absorption peaks.

Laboratory

AmSpec, Houston TX

Sample

Prometheus Methanol 10-2-25 (Metal Can) Submitted Sample

Test

IMPCA001II — Methanol Purity (On Dry Base): 99.99 %wt

Test

Carbon Isotope Analysis – Unique Fuel Fingerprint

FTIR Analysis Jan 2025

Prometheus methanol FTIR spectrum matches Sigma (fossil methanol) reference — identical O-H, C-H, and C-O absorption peaks.

Prometheus zero-net-carbon methanol fuel bottle — clean synthetic fuel produced directly from atmospheric CO2

FAQ

Understand the Technology

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:

  • No desorption to CO₂ gas
  • No H₂
  • No Fischer-Tropsch synthesis
  • No high temperatures or pressures
  • No methanol-to-jet upgrading for kerosene needed
  • No distillation or thermal separation required

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:

  1. Traditional e-fuels have Direct Air Capture that requires desorption to concentrated CO₂ gas
  2. Traditional e-fuels have high-temperature, high-pressure chemical reactions, which require costly equipment to withstand these conditions (e.g., Fischer-Tropsch)
  3. Traditional e-fuels have a high cost of energy from electricity grids because their reactions require 24/7 operation and therefore, baseload or grid-connected power in industrial zones


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 allow 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:

  • Prometheus “No-Desorb” DAC eliminates the costly, energy-intensive step of desorbing the captured CO₂ to a concentrated gas
  • The Faraday Reactor hydrocarbon electrolyzer produces hydrocarbons from captured CO₂ at room temperature and atmospheric pressure — this eliminates the need for costly, energy-intensive high-pressure, high-temperature reactions, as well as the expensive equipment required to withstand these conditions
  • Prometheus kerosene self-separates from the water in which it is made, thus eliminating the need for expensive, energy-intense separation methods (e.g., distillation)
  • The system is designed to run off-grid on intermittent solar so it can use the world’s cheapest electrons
  • Equipment is low-cost and modular with linear cost scaling


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:

  • 100% of the carbon used to make Prometheus fuels comes from atmospheric CO₂
  • All energy inputs used to drive Prometheus fuel production are renewable
  • No fossil inputs are used at any stage of the Prometheus process

The origin of every molecule in Prometheus fuels can be verified using Prometheus' carbon isotope fingerprint method, which shows a unique ratio of ¹²C, ¹³C, and ¹⁴C 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:

  • AI data center energy storage
  • On or off-grid firming and shaping of renewable energy across seasonal time scales
  • Off-grid distributed energy storage and power generation
  • Defense
  • Aviation
  • Marine
  • Trucking
  • Industrial heat
  • Chemicals and plastics feedstocks

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:

  • Diesel
  • Jet Fuel
  • Gasoline
  • Rocket Fuel
  • Methanol
  • Other alcohols (ethanol through octanol)
  • World's first fuel made from air and off-grid renewable electricity
  • World's first DAC cost at less than $100 per ton CO₂
  • World's first non-desorption DAC
  • World's first DAC to achieve 100% carbon capture efficiency (no lost CO₂)
  • World's first hydrocarbon electrolyzer, the "Faraday Reactor"
  • Demonstrated direct coupling of solar (no expensive power conversion electronics) for e-fuels production
  • Prometheus' first vehicle powered by fuel made from air and renewable electricity (2025 Honda Grom — January 3, 2025)
  • Prometheus' first car powered by fuel made from air and renewable electricity (the "Promethean Stang," a 1968 Mustang Fastback — April 9, 2025)
  • TRL 9 status with its 50-cell commercial-scale Faraday Reactor installed in Titan Forge Alpha
  • World's first demonstration of using fuel made from air and renewable electricity to power AI
  • One full year of DAC-to-methanol production at the Titan Forge Alpha pilot plant
  • World's 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. Prometheus has developed this pathway from bench scale to demonstration in five full-size Faraday Reactor cells
  • World's first jet fuel and diesel that can cost less to make than jet fuel and diesel made from oil

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.

  • Independent techno-economic assessments and life-cycle analysis of Prometheus process and costs performed by the engineering firm Ramboll
  • Technology validation study performed by the engineering firm Ramboll on Prometheus' Titan Forge Alpha pilot system, observing methanol and kerosene production
  • Technology validation study performed by the engineering firm DeepSense, commissioned by Maersk, on Prometheus' Titan Forge Alpha pilot system, observing methanol and kerosene production
  • Carbon isotope fingerprint analysis verifying atmospheric origin of CO₂ used to make Prometheus fuels, performed by AmSpec Houston Technical Center
  • Tests showing Prometheus methanol purity of 99.99%, performed by AmSpec Houston Technical Center
  • FTIR analysis showing fuel quality
  • IP granted and pending across 10 patent families in major jurisdictions

Prometheus has two commercial-scale projects planned:

  • Project Lodestone — 100,000 tons/year methanol (estimated completion 2028)
  • Project Lodestar — 1 million tons/year methanol (estimated completion 2030)

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:

  • McGinnis' years of experience with carbonate chemistry in NH₃CO₂ forward osmosis desalination at his first startup company Oasys Water, based on research McGinnis did while earning his PhD in Engineering at Yale University
  • McGinnis' years of experience with nanoscale separations using carbon nanotube membranes at his second startup company, Mattershift
  • Prometheus' 7 years developing DAC-to-fuel technology, including extensive iteration with large-scale prototype hydrocarbon electrolyzers
  • Prometheus' innovation on intermittent operation using off-grid solar with low-voltage DC power

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:

  • No desorption of CO₂ from air capture or purification of CO₂ from a smokestack
  • No high temperatures or pressures, which cause equipment to be exorbitantly expensive
  • No Fischer-Tropsch
  • No methanol-to-jet required
  • No distillation required
  • No need to connect to a grid. The system is designed to run entirely on off-grid solar power

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:

  • Oxygen is its only byproduct
  • Operates at room temperature and atmospheric pressure
  • No toxic aromatics in our fuel
  • No toxic solvents
  • Closed-loop carbonate chemistry

Several key milestones aligned at once:

  • Foundational patents have been filed and granted
  • Titan Forge Alpha has successfully operated for a full year, reaching TRL 9 for DAC-to-e-methanol
  • Kerosene and methanol pathways have been demonstrated
  • Commercial projects are now planned and pre-sold
  • Independent technology and economic assessments have been completed

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.