As industries seek ways to reduce emissions, improve fuel efficiency, and meet growing environmental regulations, the option to retrofit diesel engines with hydrogen has emerged as a practical, cost-effective solution. This innovative approach allows fleet operators to keep their existing diesel-powered vehicles and equipment while integrating hydrogen-assisted combustion to create a cleaner, more efficient engine.

In this blog, we’ll explore how retrofitting diesel engines with hydrogen works, the benefits it offers, and why it’s gaining momentum as a crucial step toward cleaner, more sustainable operations.

What Does Retrofitting Diesel Engines with Hydrogen Involve?

Retrofitting a diesel engine with hydrogen involves modifying the existing diesel engine to allow for the injection of hydrogen into the combustion process. By introducing hydrogen alongside diesel fuel, the engine can achieve a more complete and efficient burn, leading to reduced emissions, improved fuel efficiency, and enhanced engine performance.

This process typically utilizes a Hydrogen on Demand system, which generates hydrogen through electrolysis, eliminating the need for high-pressure hydrogen storage. The hydrogen is injected into the air intake system and mixes with the diesel before combustion, allowing the engine to take advantage of hydrogen’s clean-burning properties without requiring extensive engine modifications.

How Retrofitting Diesel Engines with Hydrogen Works

Retrofitting a diesel engine with hydrogen generally follows a straightforward process that integrates a hydrogen injection system with the existing engine. Here’s how it works:

1. Hydrogen generation: Hydrogen is produced on-demand through electrolysis, a process that splits distilled water into hydrogen (H2) and oxygen (O2) using electricity from the vehicle’s alternator.
2. Hydrogen injection: The hydrogen gas is injected into the engine’s air intake manifold, where it mixes with the air and diesel fuel before entering the combustion chamber.
3. Combustion: In the combustion chamber, the hydrogen-diesel mixture ignites. Hydrogen’s faster burn rate helps the diesel fuel burn more completely, enhancing combustion efficiency.
4. Emissions reduction: The more complete combustion results in fewer harmful emissions, including carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM).
5. Improved efficiency: Since more of the diesel fuel is burned completely, the engine requires less fuel to produce the same amount of power, leading to improved fuel efficiency and reduced fuel consumption.

This approach allows fleet operators to retrofit their existing diesel engines to take advantage of hydrogen’s environmental and efficiency benefits without needing to replace their entire fleet.

Benefits of Retrofitting Diesel Engines with Hydrogen

Retrofitting diesel engines with hydrogen offers several significant benefits for industries that rely on diesel-powered vehicles and machinery. These advantages make it an attractive option for fleet operators seeking to reduce costs and environmental impact.

1. Reduced Emissions

One of the most significant advantages of hydrogen-assisted diesel engines is the reduction of harmful emissions. Diesel engines contribute heavily to air pollution, emitting CO2, NOx, and PM. By retrofitting diesel engines with hydrogen, these emissions can be drastically reduced:

• Lower CO2 emissions: Hydrogen improves the combustion process, reducing the amount of diesel fuel needed to generate power and cutting down on carbon dioxide (CO2) emissions.
• Up to 64% reduction in NOx: Hydrogen’s faster burn helps reduce peak combustion temperatures, minimizing the formation of nitrogen oxides (NOx)—a major contributor to air pollution.
• Reduced particulate matter: Hydrogen’s ability to help diesel burn more completely leads to fewer unburned hydrocarbons and reduced particulate emissions.

For industries aiming to meet stricter emissions regulations, such as those set by the EPA and CARB, retrofitting diesel engines with hydrogen provides a practical solution for achieving compliance.

2. Improved Fuel Efficiency

Fuel efficiency is crucial for fleet operators, and retrofitting diesel engines with hydrogen can significantly boost efficiency by enabling a more complete combustion process. Hydrogen helps diesel engines extract more energy from each gallon of fuel, leading to:

• Up to 10% fuel savings: Hydrogen-assisted combustion allows for more efficient fuel use, reducing the amount of diesel needed for the same power output.
• Lower fuel consumption: Fleet operators can reduce their overall fuel consumption by retrofitting engines to burn fuel more efficiently, leading to significant cost savings over time.

3. Enhanced Engine Performance

Hydrogen’s fast burn rate improves the overall combustion process, enhancing engine performance and delivering more power and torque. Retrofitting a diesel engine with hydrogen can improve vehicle performance in demanding applications:

• Increased power and torque: The cleaner, more efficient combustion process increases the engine’s power output, especially under heavy loads, making it ideal for industries that rely on high-performance diesel engines.
• Smoother operation: Hydrogen-assisted combustion also leads to smoother engine operation, improving acceleration and responsiveness, particularly in stop-and-go conditions or when hauling heavy loads.

4. Extended Engine Life and Lower Maintenance Costs

Carbon buildup is a common issue in diesel engines due to incomplete combustion, leading to higher maintenance costs and shorter engine lifespans. Retrofitting diesel engines with hydrogen helps reduce these issues by promoting cleaner combustion:

• Reduced carbon buildup: Hydrogen’s more complete burn minimizes carbon deposits inside the engine, reducing wear and tear on critical components like pistons, cylinders, and exhaust systems.
• Extended engine lifespan: With less carbon buildup and wear, engines that use a hydrogen-diesel mix can operate more efficiently and for longer periods.
• Lower maintenance costs: Hydrogen-assisted combustion reduces the need for frequent repairs and maintenance, helping fleet operators save on long-term operating costs.

5. Compatibility with Existing Diesel Engines

One of the key advantages of retrofitting diesel engines with hydrogen is that it can be done with existing diesel engines. Unlike electric or fully hydrogen-powered vehicles, which require completely new systems, hydrogen retrofits can be applied to current diesel engines:

• Cost-effective solution: Retrofitting is more affordable than replacing entire fleets with new vehicles, allowing fleet operators to reduce emissions and improve efficiency without a significant upfront investment.
• Scalable technology: Hydrogen retrofits can be applied to a wide range of vehicles and machinery, from trucks and buses to construction equipment and marine vessels, making it a versatile solution for various industries.

How Retrofitting Diesel Engines with Hydrogen Compares to Other Emissions-Reduction Technologies

Retrofitting diesel engines with hydrogen offers a unique combination of fuel efficiency and emissions reduction, making it stand out from other emissions-reduction technologies like Selective Catalytic Reduction (SCR) and Diesel Particulate Filters (DPF):

• Fuel efficiency gains: Unlike SCR and DPF systems, which primarily focus on reducing specific emissions, hydrogen retrofits also improve fuel efficiency, providing fleet operators with both environmental and economic benefits.
• Lower maintenance needs: Hydrogen-assisted combustion reduces carbon buildup, leading to less frequent maintenance. In contrast, SCR and DPF systems require ongoing maintenance, such as filter cleanings or urea refills.
• Simpler installation: Hydrogen retrofits can be installed with fewer modifications than SCR or DPF systems, making the technology more accessible and easier to implement across a fleet.

Challenges of Retrofitting Diesel Engines with Hydrogen

While retrofitting diesel engines with hydrogen offers many advantages, there are a few challenges to consider:

• Hydrogen infrastructure: The availability of hydrogen fueling stations is limited, particularly in rural areas. However, Hydrogen on Demand systems that generate hydrogen on-site help address this issue by producing hydrogen as needed, without the need for storage or dedicated fueling infrastructure.
• Hydrogen production: The majority of hydrogen is currently produced from natural gas, which emits CO2. To fully realize the environmental benefits of hydrogen retrofits, cleaner methods like electrolysis powered by renewable energy will need to be more widely adopted.
• Initial cost: While retrofitting is more affordable than purchasing new hydrogen or electric vehicles, the initial cost of installing a hydrogen system can still be a barrier for some operators. However, long-term savings in fuel and maintenance costs often offset the upfront investment.

The Future of Retrofitting Diesel Engines with Hydrogen

As industries continue to seek cleaner and more efficient energy solutions, retrofitting diesel engines with hydrogen will play an increasingly important role in reducing emissions and improving fuel economy. With advancements in hydrogen production and infrastructure, more fleet operators and industries are expected to adopt this technology as a key part of their sustainability strategies.

The combination of Hydrogen on Demand systems, which generate hydrogen in real-time, and the compatibility of retrofits with existing diesel engines makes this a scalable and practical solution for reducing environmental impact without compromising performance.

Conclusion: Retrofitting Diesel Engines with Hydrogen – A Cleaner, More Efficient Future

Retrofitting diesel engines with hydrogen provides a practical, cost-effective way to reduce emissions, improve fuel efficiency, and enhance engine performance—all while extending the life of existing diesel-powered vehicles and machinery. By integrating hydrogen into diesel engines, fleet operators can achieve immediate environmental and economic benefits without needing to overhaul their entire fleet.

As hydrogen technology continues to evolve, retrofitting with hydrogen will become an essential step toward a cleaner, more sustainable future for industries that rely on diesel engines.