Fuelling The Future One Hydrogen Molecule At A Time

Jon Lawson

Juliet Elliot shares some important news about hydrogen

Hydrogen is often touted as the fuel of the future, in particular with regard to generating electricity in fuel cells. However, research is also ongoing into its use in combustion engines.

This May, the Hydrogen Opposed Piston Engine Working Group was formed. Made up of private companies, universities and labs, its goal is to collaborate to examine how suited this engine format is to using the gas as a fuel.

Headquartered in San Diego, California, where member Achates Power is based, other members include fossil fuel giants such as Aramco Americas and Shell, as well as the Clean Combustion Research Center at the King Abdullah University of Science and Technology, from where James Turner, a professor of mechanical engineering, says, “An opposed piston engine with hydrogen combustion could well provide the best-known thermal efficiency from a reciprocating engine, with the potential to match the in-vehicle efficiency of a hydrogen fuel cell. If so, it is a valuable potential option for long-haul transit in our quest for sustainable transportation.”

Pierre Duret member of DI2S Consulting & Training, and former director of powertrain and sustainable mobility, IFP school in France, observes: “The direct-injection two-stroke engine could be a very promising and interesting option for hydrogen combustion because of its inherently much lower NOx emissions. These two-stroke advantages are even more significant with an opposed piston engine, thanks to its higher power density and efficiency.”

Achates recently published a white paper, concluding: “There are no ideal powertrains. Batteries, fuel cells and engines all require energy to build and operate, and cost money to manufacture, utilise, and service. Hydrogen opposed piston engines, however, offer many attractive features since they can operate efficiently with very low criteria emissions. Since it will have a significant cost and reliability advantage over hydrogen fuel cells for an indefinite period of time, the platform should be considered and developed as a viable option for an important transition to carbon-free and sustainable transportation.”

A Conventional Approach

Also in May, Cummins’ new 15-litre hydrogen engine made its public debut. It’s built on what the company calls its ‘fuel-agnostic platform,’ meaning everything below the head gasket is fairly generic while different heads offer a variety of injector equipment. It is under test now, with a view to mass manufacture around 2027. Cummins also intends to offer the unit with a 6.7-litre displacement.

Jim Nebergall, general manager, hydrogen engines at Cummins notes, “Our customers are responding favourably to this practical technology. These engines look like engines, they sound like engines, and fit where engines normally fit.”

Srikanth Padmanabhan, president, engine business at Cummins adds, “We’ve established significant goals as part of our PLANET 2050 sustainability strategy, including a target of zero emissions. Reducing well-to-wheel carbon emissions requires innovation of both energy sources and power solutions. While use cases for battery electric and fuel cell electric powertrains are promising, the pairing of green hydrogen in the proven technology of internal combustion engines provides an important complement to future zero emissions solutions.”

While the research seems promising, a fuelling infrastructure will need to grow at the same pace. According to a recent report published by Information Trends, the deployment of fuelling stations for these vehicles is poised to generate US$9 billion in revenue by 2036, half of which will come from Asia. The Americas will account for 16%, with Europe and the Middle East taking the remaining 34%.

Senior research analyst at Information Trends, Haani Kambrani, says, “The costs of hydrogen stations are declining while their capabilities are growing. These capabilities include higher fuelling pressures, increased fuelling capacity and expanded hydrogen storage. There is also a push to supply these stations with green hydrogen, i.e., hydrogen produced from clean energy sources such as solar panels and wind turbines. This trend is in line with a global drive for green energy completely free of carbon.”

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