Diesel engines power much of the world’s transportation and heavy-duty equipment, making them an essential part of the global economy. However, they are also one of the largest sources of harmful emissions, contributing significantly to air pollution and climate change. As environmental regulations become stricter and the demand for cleaner energy solutions grows, reducing the emissions produced by diesel engines is a critical challenge.

One promising solution is hydrogen-assisted combustion, a cutting-edge technology that infuses hydrogen into the diesel combustion process to create a cleaner, more efficient burn. Diesel-Hydrogen Assist Technology (D-HAT™) offers a practical and effective way to reduce diesel emissions while maintaining the power and performance diesel engines are known for. In this blog post, we explore how hydrogen-assisted combustion works and how it reduces the harmful pollutants produced by diesel engines.

The Environmental Challenge of Diesel Emissions

Diesel engines are renowned for their durability and fuel efficiency, particularly in heavy-duty applications like freight transport, mining, and construction. However, they are also major contributors to environmental pollution, emitting a variety of harmful substances, including:

• Carbon dioxide (CO2): A leading greenhouse gas that contributes to global warming.
• Nitrogen oxides (NOx): Pollutants that contribute to the formation of smog and acid rain, as well as respiratory health problems.
• Particulate matter (PM): Tiny particles of soot and unburned hydrocarbons that can penetrate deep into the lungs, leading to serious health issues.
• Carbon monoxide (CO): A poisonous gas that reduces air quality and is harmful to human health.

Diesel engines often operate at only about 70% combustion efficiency, meaning a significant portion of the fuel does not burn completely. The result is wasted energy and an increase in partially burned hydrocarbons, which contribute to emissions of soot, carbon deposits, and other pollutants. This incomplete combustion is the root cause of many of the harmful emissions associated with diesel engines.

How Hydrogen-Assisted Combustion Works

Hydrogen-assisted combustion addresses the inefficiency of diesel engines by improving the combustion process. By adding a small amount of hydrogen into the engine’s air intake, D-HAT™ helps diesel fuel burn more completely and cleanly. Hydrogen is an ideal catalyst for this process due to its unique combustion properties.

Here’s a breakdown of how hydrogen-assisted combustion works:

1. On-Demand Hydrogen Production: Using an onboard Proton Exchange Membrane (PEM) cell, the D-HAT™ system generates pure hydrogen gas from distilled water through an electrolysis process. The hydrogen is produced only when the engine is running, ensuring that no hydrogen is stored onboard and minimizing safety concerns.
2. Hydrogen Injection into the Combustion Chamber: The hydrogen gas is injected into the engine’s air intake manifold, where it mixes with the diesel fuel and air. Hydrogen burns much faster than diesel, creating a more efficient and thorough combustion process inside the engine.
3. Increased Combustion Efficiency: Hydrogen assists in igniting the diesel fuel earlier and more completely in the combustion cycle. This increases the combustion efficiency from around 70% to as much as 93%, ensuring that more of the diesel fuel is burned during each power stroke.
4. Cleaner Exhaust: With more complete combustion, there are fewer partially burned hydrocarbons left behind. This reduces the formation of soot, carbon monoxide, and other harmful pollutants in the exhaust.

The Emissions Benefits of Hydrogen-Assisted Combustion

By enhancing the combustion process, hydrogen-assisted combustion delivers significant reductions in the key pollutants that diesel engines produce. Here’s how D-HAT™ helps reduce each type of harmful emission:

1. Reduction of Carbon Dioxide (CO2) Emissions

Carbon dioxide (CO2) is a byproduct of burning fossil fuels, including diesel. It is the primary greenhouse gas responsible for global warming and climate change. While diesel engines are already more fuel-efficient than gasoline engines, the incomplete combustion of diesel fuel means that more fuel is consumed—and thus more CO2 is produced—than necessary.

With D-HAT™:

• The increased combustion efficiency means that more energy is extracted from each gallon of diesel fuel.
• Up to 10% fuel savings result in a direct reduction in CO2 emissions, as less fuel is burned to perform the same amount of work.
• By burning the fuel more completely, D-HAT™ ensures that less CO2 is emitted per mile traveled, helping fleet operators lower their carbon footprint.

2. Lower Nitrogen Oxides (NOx) Emissions

Nitrogen oxides (NOx) are a group of gases that form when fuel is burned at high temperatures, particularly in diesel engines. NOx emissions contribute to the formation of ground-level ozone and smog, both of which have harmful effects on human health and the environment. NOx is also a precursor to acid rain and can lead to the degradation of ecosystems.

Hydrogen-assisted combustion helps reduce NOx emissions in two ways:

• Lower exhaust temperatures: Because hydrogen burns faster and more completely than diesel, the combustion process finishes earlier in the power stroke, which reduces the temperature of the exhaust gases. Lower combustion temperatures directly lead to reduced NOx formation, as NOx is primarily created at high temperatures.
• Faster combustion: The faster burn enabled by hydrogen reduces the time during which NOx can form, further cutting down emissions.

D-HAT™ has been shown to reduce NOx emissions by up to 64%, making it an effective tool for fleet operators aiming to comply with increasingly stringent emissions standards set by regulatory bodies like the EPA and CARB.

3. Reduction of Particulate Matter (PM) Emissions

Particulate matter (PM), often referred to as soot, is made up of tiny particles of unburned hydrocarbons that are released into the atmosphere during incomplete combustion. PM is particularly harmful to human health, as these microscopic particles can be inhaled and cause respiratory diseases, heart problems, and other serious health issues.

D-HAT™ significantly reduces PM emissions by ensuring that the diesel fuel is burned more completely:

• With up to 93% combustion efficiency, there is less unburned fuel to form soot.
• The introduction of hydrogen prevents the formation of large carbon particles, which are a major component of PM.

By reducing the amount of unburned hydrocarbons in the exhaust, D-HAT™ helps keep diesel engines compliant with PM emissions standards, ensuring cleaner air and healthier communities.

4. Cutting Carbon Monoxide (CO) Emissions

Carbon monoxide (CO) is a colorless, odorless gas that forms when fuel is not completely burned. It is toxic to humans and animals, as it reduces the blood’s ability to carry oxygen. Diesel engines are a major source of CO emissions, especially when they operate at less-than-optimal efficiency.

Hydrogen-assisted combustion addresses this problem by:

• Promoting a more complete burn of the diesel fuel, leaving little room for CO to form.
• By improving the air-fuel mixture and increasing combustion efficiency, D-HAT™ reduces the output of CO, making the exhaust cleaner and safer.

Hydrogen-Assisted Combustion: Supporting Sustainability Goals

As fleet operators and industries look for ways to reduce their environmental impact, hydrogen-assisted combustion offers a practical and scalable solution for diesel engines. D-HAT™ helps diesel fleets achieve:

• Lower fuel consumption, which reduces reliance on fossil fuels and lowers greenhouse gas emissions.
• Compliance with environmental regulations, helping companies meet or exceed the emissions standards set by governments and regulatory bodies.
• A reduced carbon footprint, contributing to broader corporate sustainability goals and demonstrating a commitment to environmental responsibility.

Conclusion: A Cleaner Future for Diesel with Hydrogen-Assisted Combustion

The need for cleaner diesel solutions is clear, and D-HAT™ offers an innovative, cost-effective way to reduce emissions without sacrificing performance. By improving the combustion process with hydrogen, D-HAT™ helps fleet operators lower their CO2, NOx, PM, and CO emissions, while also improving fuel efficiency and reducing maintenance costs.

For companies that rely on diesel engines, hydrogen-assisted combustion represents a powerful step forward in achieving sustainability goals, reducing environmental impact, and staying compliant with evolving emissions regulations. With D-HAT™, diesel fleets can run cleaner, longer, and more efficiently, paving the way for a greener future.