Hydrogen ICE Is Heating Up

Internal combustion engines fueled by H2 are emerging as a key technology to eliminate carbon emissions from heavy-duty sectors.

Kohler’s new direct-injection KDH hydrogen engine (shown) is based on the KDI 2504 TCR diesel. (Kohler Engines)

In the past three months, at least four major announcements have detailed the kickstart of development programs or real-world demonstrations of hydrogen-fueled internal combustion engines (ICE). As OEMs and fleets look to accelerate the decarbonization of their product portfolios, engine makers are ramping up efforts to provide another alternative.

An “end-to-end” demonstration will trial Cummins’ X15H hydrogen engine in Terex front-discharge concrete mixer trucks. (Terex)

“Hydrogen internal combustion engines are emerging as a key technology to eliminate carbon emissions from heavy-duty sectors, while retaining the power density and operational range typical of diesel engines,” Jim Nebergall, General Manager - Hydrogen Engines at Cummins, said in an October statement detailing a collaboration with Terex Advance Mixer, end user Edge Materials and hydrogen producer PCC Hydrogen.

Caterpillar is building and demonstrating a hydrogen-hybrid powertrain built on the new Cat C13D engine platform that was revealed at the CONEXPO 2023 tradeshow. (Caterpillar)

The “end-to-end” demonstration will trial Cummins’ X15H engine in Terex front-discharge concrete mixer trucks operating on construction sites and critical infrastructure projects. “Decarbonizing concrete mixer trucks can be difficult due to the energy demands and long operational hours,” added David Grabner, General Manager at Terex Advance Mixer. Such heavy-duty applications are where engine makers believe H2 ICE can outperform other zero-carbon alternatives such as hydrogen fuel cells and battery-electric systems.

In November, Caterpillar announced a three-year demonstration project of a hydrogen-hybrid powertrain built on the new Cat C13D engine platform that was revealed at the CONEXPO 2023 tradeshow. Partially funded by the U.S. Department of Energy, the project will demonstrate how the latest control systems and electric-hybrid components can help hydrogen-fueled engines meet or exceed the power density and transient performance of traditional diesel engines.

JCB expanded the application range of its H2 engine by outfitting a Mercedes Sprinter van with the 448 ABH2. (JCB)

The C13D currently is capable of operation using renewable liquid fuels such as 100% HVO, B100 distilled biodiesel and up to B100 standard biodiesel in select applications. Starting in the first quarter of 2024, development of the hydrogen-hybrid powertrain will take place at Caterpillar facilities in Chillicothe, Illinois, and San Antonio, Texas.

“Every off-highway application has its own unique duty cycles, lifecycle demands and performance expectations, and this complexity is driving the development of a wide range of power solutions for the energy transition,” said Steve Ferguson, SVP for Caterpillar industrial power systems.

The 4-cyl. KDH variant from Kohler maintains the same envelope as the KDI diesel engine and will keep the same cooling circuit, power take-off and flywheel, engine mounting points and intake line. (Kohler Engines)

JCB revealed its clean-sheet hydrogen ICE, the 448 ABH2, at CONEXPO earlier this year. Demonstrations in hydrogen-powered construction and agricultural machines have been ongoing, but the company recently expanded the application range by outfitting a Mercedes Sprinter van with its H2 engine. The diesel-powered van reportedly was retrofitted in just two weeks.

“We retrofitted this vehicle…to demonstrate how simple it will be to convert existing vans and to show that it is not only construction and agricultural machines that can be powered by hydrogen,” said JCB Chairman Anthony Bamford. “While converting vans will not be for JCB to do, it does prove there is something else other than batteries that can work very effectively.” JCB has manufactured more than 70 hydrogen engines to date.

At the Agritechnica 2023 tradeshow in November, Kohler Engines unveiled its new direct-injection hydrogen (KDH) engine that is based on the KDI 2504 TCR diesel. The 4-cyl. KDH engine for off-highway machines is said to maintain the same in-machine installation, dimensions, PTOs and performance as conventional diesel engines. Its maximum power output is 55.4 kW (74 hp) at 2600 rpm, and max torque is 315 Nm (232 lb-ft) at 1500 rpm.

Kohler notes that hydrogen combustion is cleaner than that of a standard diesel engine, and when fitted with an aftertreatment system results in a reduction of exhaust emissions to “extremely low values, thus making the engine near zero-emission according to the most recent agencies’ definitions.”

SAE Media Group’s first editorial webinar  in the new year will focus on hydrogen’s promising role in heavy-duty vehicles. An expert from FEV will discuss H2 ICE advancements, and Nuvera will present the latest in fuel cell technology and applications. Also look out for continued coverage of hydrogen technology, including an upcoming story about the advanced modeling of H2 combustion, emissions and aftertreatment.

The hydrogen-propulsion topic is only getting hotter.