NPS Driven makes significant progress with hydrogen engine

This initiative, launched in 2020 with government subsidies, aims to modify a traditional diesel engine for hydrogen combustion. NPS Driven leads the initiative, part of the Green Transport Delta Hydrogen (GTD-H) project. The company, based in Ravenstein, works closely with TNO. “The hydrogen engine has been running on TNO’s test bench for a while,” says Hes. “We are currently taking the next step. We will be testing the engine in the field with a customer as a generator engine, carefully measuring all aspects. The following step will be its application in inland shipping.” NPS Driven’s hydrogen engine was showcased for the first time at the Maritime Industry fair in Gorinchem and runs entirely on hydrogen. During the intake stroke, hydrogen is injected into the intake manifold. At the end of the compression stroke, the air-hydrogen mixture is ignited with a spark. Because hydrogen is injected in gaseous form, it occupies a relatively large volume, requiring long injection times.

Computer technology
Computer technology is essential to inject the correct amount of hydrogen and to ensure proper timing of both the injection and ignition. This requires knowledge of the combustion characteristics of the air/hydrogen mixture in the cylinder. The hydrogen engine, based on a six-cylinder diesel engine, has a larger combustion chamber with lower compression (Otto cycle) compared to the diesel version. Additionally, the piston shape is optimized for hydrogen combustion. Coils have been added for ignition, and a fuel rail for hydrogen gas injection. Hes expects it will take just over a year before the first hydrogen engines are available for commercial applications. “It is important that sufficient hydrogen is available by then. That may be the biggest challenge. There are still many uncertainties about supply, storage, and regulations. We do see a lot of interest in the hydrogen engine. It’s a familiar technology, and the combustion engine is more forgiving regarding the purity of the hydrogen used. Fuel cells, on the other hand, require very pure hydrogen and are much more expensive.”

John Deere Stage V
NPS Driven has completed the Stage V certification for the 13.5-liter John Deere 6135 engine. This engine, equipped with an after-treatment system from subsidiary Xeamos, is now marketed as the NPS 6135 in the Stage V version, available in power ranges from 272 to 559 kW. These and other John Deere marine engines are sold through Dolpower, based in Zwijndrecht. “Dolpower orders the engines from us and turns them into generators, bow thruster engines, and propulsion engines for its customers,” says Hes. “Dolpower supplies various shipyards and builders, including Dolderman. The John Deere engines can also run on HVO.”

DAF Euro 6
NPS Driven has also obtained Lloyd’s certification for the 11- and 13-liter DAF-Paccar Euro 6 engines for inland shipping, meaning they can be used on tankers and other ADN ships. Hes does not expect DAF to release a successor to the popular Euro 6 engines in the short term. “There has been some discussion about a Euro 7 standard for diesel engines, but it is still not concrete. So, it’s unclear if and when such an emission standard will impact inland shipping. The current Euro 6 engines are already five times cleaner in terms of nitrogen oxide (NOx) emissions than the legal IWW Stage V standard. Additionally, these engines have very low fuel consumption, making them 20% more efficient than a CCR2 engine. The 20% CO2 reduction is also a step forward in sustainability.”

NPS Driven is part of the Lumipol Group.