As the demand for cleaner and more efficient energy solutions continues to grow, Hydrogen on Demand systems have emerged as a key technology for reducing emissions and improving fuel efficiency, particularly in industries that rely on diesel engines. Central to the success of Hydrogen on Demand systems is the Proton Exchange Membrane (PEM) cell, a technology that safely generates hydrogen gas on-site and on-demand through electrolysis. This hydrogen is then injected into diesel engines to enhance combustion, reduce emissions, and boost overall engine performance.

In this blog, we’ll explore how PEM cells work, why they are integral to Hydrogen on Demand systems, and how they enable hydrogen-assisted combustion in diesel engines. By understanding the role of PEM cells, we can see how hydrogen technology is shaping the future of cleaner, more sustainable energy solutions.

What is a Proton Exchange Membrane (PEM) Cell?

A Proton Exchange Membrane (PEM) cell is a type of electrolyzer that splits water into hydrogen and oxygen through an electrochemical process known as electrolysis. PEM cells are central to the production of hydrogen in Hydrogen on Demand systems, where hydrogen is generated in real-time and injected directly into a diesel engine’s combustion chamber to improve combustion efficiency.

The key components of a PEM cell include:

1. Proton Exchange Membrane: The heart of the cell, the membrane only allows protons (hydrogen ions) to pass through while blocking gases such as oxygen. This selective permeability is critical to the electrolysis process.
2. Electrodes (Anode and Cathode): The electrodes are responsible for driving the electrochemical reaction. An electrical current is applied to the anode, where water is split into oxygen, protons (H+), and electrons (e-). The protons pass through the membrane to the cathode, where they combine with electrons to form hydrogen gas (H2).
3. Water Supply: The PEM cell uses steam distilled water as the feedstock for hydrogen production. The water is split into its constituent parts—hydrogen and oxygen—through electrolysis.

This process generates pure hydrogen gas, which is then used to assist the combustion of diesel fuel in engines, improving efficiency and reducing emissions.

How PEM Cells Power Hydrogen on Demand

Hydrogen on Demand systems leverage PEM cells to produce hydrogen gas in real-time, meaning hydrogen is generated only when needed and immediately injected into the engine. This eliminates the need for hydrogen storage, making the system safer and more practical for use in vehicles and other mobile applications.

Here’s a step-by-step breakdown of how PEM cells power Hydrogen on Demand systems like Diesel-Hydrogen Assist Technology (D-HAT™):

1. Electrolysis: Splitting Water into Hydrogen and Oxygen

The PEM cell generates hydrogen through the process of electrolysis, where distilled water is split into hydrogen (H2) and oxygen (O2) using electricity from the vehicle’s alternator. The PEM cell is highly efficient, using a small amount of power to produce hydrogen gas. The electrolysis reaction is as follows:

At the anode:

H2O (l)→2H+(aq)+O2(g)+2e−\text{H}_2\text{O (l)} \rightarrow 2\text{H}^+ (\text{aq}) + \text{O}_2 (\text{g}) + 2\text{e}^-H2​O (l)→2H+(aq)+O2​(g)+2e−

At the cathode:

2H+(aq)+2e−→H2(g)2\text{H}^+ (\text{aq}) + 2\text{e}^- \rightarrow \text{H}_2 (\text{g})2H+(aq)+2e−→H2​(g)

The result is hydrogen gas produced at the cathode and oxygen gas released as a byproduct at the anode.

2. On-Demand Hydrogen Generation

One of the key advantages of PEM cells is their ability to produce hydrogen on-demand. Unlike other hydrogen technologies that require hydrogen to be stored under high pressure in tanks, PEM cells generate hydrogen in real-time as the engine operates. This hydrogen is then injected directly into the engine’s air intake system, where it mixes with the diesel fuel for combustion.

This on-demand production minimizes safety risks, as there is no need to store large volumes of hydrogen, and it ensures that hydrogen is only produced when the engine is running.

3. Hydrogen Injection into the Combustion Process

Once the PEM cell has generated hydrogen, the gas is immediately injected into the engine’s air intake manifold. Hydrogen is an ideal fuel additive because it burns much faster than diesel, promoting a more complete and efficient combustion process. When hydrogen is mixed with diesel in the combustion chamber, it helps the diesel fuel burn more completely, resulting in:

• Increased combustion efficiency: Hydrogen assists in the more complete combustion of diesel fuel, raising combustion efficiency from around 70% to as high as 93%.
• Lower emissions: By burning the fuel more completely, hydrogen reduces the production of carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM), helping diesel engines meet stricter environmental standards.

4. Increased Fuel Efficiency and Reduced Emissions

The more efficient combustion process enabled by hydrogen injection has two main benefits:

1. Improved fuel efficiency: By burning more of the diesel fuel, engines equipped with PEM-powered Hydrogen on Demand systems use less fuel to generate the same amount of power, resulting in fuel savings of up to 10%.
2. Reduced emissions: Hydrogen-assisted combustion reduces harmful emissions across the board, including CO2, NOx, and PM, making it easier for diesel engines to comply with environmental regulations such as those set by the EPA and CARB.

Why PEM Cells are Ideal for Hydrogen on Demand Systems

The use of Proton Exchange Membrane (PEM) cells in Hydrogen on Demand systems offers several advantages that make them the ideal choice for applications where safety, efficiency, and practicality are paramount:

1. Compact and Lightweight Design

PEM cells are compact and lightweight, making them well-suited for mobile applications such as vehicles, trucks, buses, and even marine vessels. This compact design allows the hydrogen generation system to be easily integrated into existing diesel engines without requiring major modifications or taking up significant space.

2. High Efficiency and Fast Response

PEM cells are highly efficient at producing hydrogen, requiring only a small amount of electrical power to generate significant amounts of hydrogen gas. Additionally, because hydrogen is produced on-demand, the system can respond quickly to the engine’s needs, providing hydrogen exactly when it’s needed for combustion.

3. Safe Hydrogen Production

Unlike other hydrogen systems that rely on high-pressure storage tanks, PEM cells generate hydrogen in real-time and immediately inject it into the engine. This eliminates the need for hydrogen storage and reduces the risk of leaks or explosions, making PEM-powered Hydrogen on Demand systems much safer for everyday use.

4. Minimal Environmental Impact

PEM cells produce hydrogen using only distilled water and electricity from the engine’s alternator, making them an environmentally friendly solution. The oxygen produced during electrolysis is released into the atmosphere, and the hydrogen is consumed during combustion, leaving no harmful byproducts.

Applications of PEM-Powered Hydrogen on Demand

PEM-powered Hydrogen on Demand systems have wide-ranging applications across industries that rely on diesel engines, offering benefits such as improved fuel efficiency, reduced emissions, and enhanced engine performance. Some key applications include:

• Trucks and buses: Hydrogen on Demand systems can be installed in diesel trucks and buses to reduce fuel consumption and emissions while maintaining performance.
• Marine vessels: The maritime industry, which faces growing pressure to reduce emissions, can benefit from PEM-powered systems to cut NOx, SOx, and CO2 emissions from diesel-powered ships.
• Construction and mining equipment: Heavy-duty machinery can also use Hydrogen on Demand technology to improve efficiency and comply with stricter environmental regulations.

The Future of Clean Diesel with PEM Cells

As industries continue to search for cleaner, more efficient energy solutions, Proton Exchange Membrane (PEM) cells will play a central role in the adoption of Hydrogen on Demand technology. By enabling the real-time generation of hydrogen, PEM cells offer a safe, scalable, and efficient way to improve diesel engine performance while reducing fuel consumption and emissions.

With the growing emphasis on sustainability and stricter emissions regulations worldwide, PEM-powered Hydrogen on Demand systems represent a powerful solution for fleet operators, maritime companies, and industries that depend on diesel engines to meet their environmental and operational goals.

PEM Cells Powering the Future of Clean Combustion

Proton Exchange Membrane (PEM) cells are at the heart of Hydrogen on Demand technology, providing a safe, efficient, and environmentally friendly way to generate hydrogen for diesel engines. By improving combustion efficiency and reducing emissions, PEM-powered systems like D-HAT™ are helping industries transition to cleaner, more sustainable energy solutions without sacrificing performance or reliability.

As more companies adopt hydrogen-assisted technology, PEM cells will play a critical role in shaping the future of diesel engines, offering a path to reduced emissions, improved fuel efficiency, and cleaner air.