Optimization of the lubricating oil composition to reduce emissions from hydrogen engines

The decarbonization of the transport sector has become a priority for governmental authorities and industrial stakeholders alike, driving regulatory measures and innovation in powertrain technologies. Among the innovative solutions, hydrogen combustion engines have gained significant attention due to their customization to diverse applications, including heavy-duty vehicles, passenger cars, generators, and even two- and three-wheelers. Hydrogen combustion, characterized by high ignitability, rapid flame speed, soot-free operation, and water as a combustion by-product, introduces distinct challenges for engine lubrication. These unique characteristics require the development and adaptation of lubricant formulations to ensure optimal engine performance and durability. Specifically, tailored lubricants play a vital role in addressing four key challenges: pre-ignition, particulate emissions, water contamination, and wear protection. This study investigates the impact of crucial formulation parameters - such as the choice of base oils and additive packages - on oil consumption mechanisms and particulate emissions. Experimental data derived from tests on a medium-duty truck engine are analyzed, focusing on: 1. Oil Consumption: Evaluating the influence of base oil types and additive compositions on oil emission mechanisms. 2. Particulate Emissions: Results of measurements carried out with different formulas, compared with regulations PN10 targets. This study applies method oriented approaches combined with statistical evaluations to assess the significance of influencing factors. The findings provide valuable insights into lubricant optimization for hydrogen combustion engines, supporting their development as a practical solution for sustainable mobility.