An Overview of Development and Challenges in the Use of Hydrogen as a Fuel for a Dual-Fuel Diesel Engine

The gradual exhaustion of fossil fuel reserves, along with the adverse effects of their consumption on global climate, drives the need for research into alternative energy sources that can meet the growing demand in a sustainable and eco-friendly way. Among these, hydrogen stands out as one of the most promising options for the automotive sector, being the cleanest available fuel and capable of being produced from renewable resources. This paper reviews the existing literature on compression ignition engines operating in a dualfuel configuration, where diesel serves as the ignition source and hydrogen is used to enhance the combustion process. The reviewed studies focus on engine systems with hydrogen injection into the intake manifold. The investigations analyzed the influence of hydrogen energy fraction on combustion characteristics, engine performance, combustion stability, and exhaust emissions in diesel/hydrogen dual-fuel engines operating under full or near-full-load conditions. The paper identifies the main challenges hindering the widespread and commercial application of hydrogen in diesel/hydrogen dual-fuel engines and discusses potential methods to overcome the existing barriers in this area.