Clean Diesel Power

Is No Contradiction. (Neither are the Savings).

Modern diesel internal combustion engines typically only completely burn 70% of fuel injected during the combustion process. The other 30% is left behind as partially burned hydrocarbons that clog the engine and exhaust systems, contaminate the oil, and blow out the stack, producing pollution and smog.

Why Hydrogen On Demand?

Hydrogen on Demand Technologies is the worldwide original equipment manufacturer (OEM) of Diesel Hydrogen Assist Technology (D-HAT™) generators, a certified and warrantied aftermarket device designed to work on all large diesel internal combustion engines (6 liters and larger in size) including trucks, buses, heavy equipment, marine vessels, power generation and more.

D-HAT provides a hydrogen-assisted fuel burn that enhances the combustion characteristics of diesel equipment by increasing overall efficiency to 95% or higher. The results are transformational: by an increasing torque, less fuel is spent for a given amount of work, providing better mileage, higher-performing engines, as well as far fewer pollutants.

Hydrogen on Demand Technologies

The Hydrogen On Demand Process

Each D-HAT unit produces up to 4 standard liters of 99.9% pure hydrogen per-minute using one of the most compact and highly efficient electrolysis processes available.

Hydrogen on Demand Technologies

01 Just add water

D-HAT’s water-to-hydrogen conversion process starts with distilled water (the only thing you ever have to add). The distilled water is used as feedstock and pumped to our Proton Exchange Membrane (PEM) fuel cell.

02 Patented Proton Exchange Membrane fuel cell

Our proprietary PEM cell technology reliably and continuously converts the distilled water into hydrogen through an electrolysis process.

Hydrogen on Demand Technologies
Hydrogen on Demand Technologies

03 Scalable hydrogen production

Our highly efficient electrolysis process produces more hydrogen using a smaller surface area that most other processes. It draws a fractional amount of power from the diesel engine's alternator/electrical system to produce up to 4 standard liters of hydrogen per minute, delivering only that hydrogen to the running engine.

04 Up to 99.9% pure hydrogen injection

The hydrogen gas is plumbed into the air-intake manifold using industry-standard tubing and tube fittings. No engine modifications are required.

Hydrogen on Demand Technologies
Hydrogen on Demand Technologies

05 On-time hydrogen added in optimum amount

The hydrogen-enriched air mixture is introduced into the diesel engine cylinder along with the injected diesel fuel. Since hydrogen burns 10x faster than the diesel fuel, the hydrogen-assisted combustion event is complete. Greater than 95% of the fuel is burned very efficiently, producing additional power and torque in each power stroke. 

06 More energetic fuel burn = more torque

The small concentration of hydrogen enriches the air/fuel mixture and assists the combustion of injected diesel fuel to burn more completely. The greater combustion efficiency means the piston is pushed down harder, yielding increased torque, improved fuel economy and reduced emissions.

Hydrogen on Demand Technologies
Hydrogen on Demand Technologies

07 More carbon burned inside engine = reduced harmful emissions

Almost all the fuel burns completely inside the engine before the exhaust valve is opened near the bottom of the stroke. Torque and fuel economy increase while emissions and vehicle maintenance decrease.

Put The Power Of Hydrogen On Demand To Work For You

The addition of D-HAT generators to your diesel-powered equipment can deliver a triple bottom line impact by improving your sustainability position, increasing net operating profitability, while reducing net operating expenses.

Hydrogen on Demand Technologies


Improve Engine Performance

Hydrogen on Demand Technologies

Go Further With Fuel and Maintenance Savings

What it does:

D-HAT’s hydrogen-assisted burn helps diesel fuel combust completely and burn more energetically. D-HAT increases efficiencies and helps fleet operations perform more efficiently than ever before.

How it helps:

D-HAT improves the performance, utilization, and longevity of your diesel-powered equipment by:

  • Increasing torque so you can carry payloads more profitably with less fuel consumption. Higher torque gives you more power on the highway so you don’t have to downshift as often. It also helps the engine run and idle more smoothly and quietly.
  • Boosting the productivity of your aging fleet. Fewer particulates going through your system mean fewer wasted days spent every week on the regeneration cycle when required.
  • Extending the life of your diesel engines by reducing carbon build-up so they run cleaner longer. It also cleans as your engine runs, purging existing carbon deposits and preventing new carbon deposits. Running cleaner increases engine durability and useful longevity, minimizing the risk of engine failure.


Increase operating profitability

Hydrogen on Demand Technologies

Go Further With Fuel And Maintenance Savings

What it does:

As D-HAT produces a more complete fuel burn, your diesel engines run more efficiently. By eliminating carbon build-up, it will increase fuel savings and decrease maintenance costs.

How it helps:

D-HAT improves the performance of diesel equipment, thereby reducing net operating expenses and increasing net operating profits by: 

  • Improving fuel economy by a minimum of 10%. It will reduce fuel consumption, increase the distance traveled per gallon/liter of diesel fuel, and improve the bottom line costs of fuel.
  • Reducing engine and emission system maintenance costs. Maintenance cost improvements are achieved by extending the time between required service intervals. Since there is virtually no carbon build-up, there is less engine wear and tear, leading to extended maintenance cycles and longer engine life.
  • Decreasing the frequency of oil and filter changes. D-HAT not only extends the interval between oil changes, but it also extends the periods between Exhaust Gas Recirculation (EGR) valve replacements and Diesel Particulate Filter (DPF) regenerations or rebuilds.


Reduce Environmental Footprint

Hydrogen on Demand Technologies

Go Further In Your Sustainability Initiatives

What it does:

D-HAT reduces the harmful effects of pollution from diesel engines to below existing EPA and CARB standards. Fast-burning hydrogen causes the diesel fuel to burn more completely. Less partially burned fuel means far fewer pollutants.

How it helps:

D-HAT is proven to reduce harmful diesel exhaust emissions. A 2019 benchmark test by the U.S. Department of Energy verifies D-HAT's effectiveness, including:

  • 77% reduction in nitrous oxide emissions (NOx). The higher thermal efficiency of the combustion cycle leads to lower exhaust temperatures, reducing NOx gases that cause smog.
  • 64% reduction in diesel particulate matter (black soot). Reducing unburned hydrocarbons purges the air of respiratory pollutants that create chronic illnesses and premature deaths.
  • 15% reduction in carbon dioxide emissions, a greenhouse gas that contributes to climate change. Increased fuel economy serves to decarbonize your fleet operations and reduce your CO2 footprint in line with your sustainability efforts.
Hydrogen on Demand Technologies


You will see up to a 10% increase in fuel efficiency plus reductions in maintenance costs and a significant reduction in emissions.


Because we make no modifications to the engine, engine sensors or air-fuel settings, D-HAT hydrogen on demand generators maintain all your original engine warranties.

Hydrogen On Demand Technologies stands behind the performance of our product by offering the following with every purchase:

Limited 3-Year Warranty: 3-year or 300,000 miles (or 25,000 operating hours) warranty that includes parts and labor.

Hydrogen on Demand Technologies
Benchmark Test Report

U.S. Department of Energy Benchmark Test Report

ROI Calculator

Calculate how much fuel and maintenance savings you can take to your bottom line

Solution Overview

Diesel Hydrogen Assist Technology (D-HAT) Solution Overview