Effects of employing B24 biodiesel on marine two-stroke diesel engine through comprehensive evaluations of cylinder oils

The utilization of alternative fuels, such as biodiesel, plays a crucial role in reducing greenhouse gas emissions in maritime transportation. However, employing biodiesel potentially impacts the performance of engine critical components, thereby influencing the reliability of marine diesel engines. Therefore, this study first collected cylinder residual oils from a marine two-stroke diesel engine employing B24 biodiesel. Subsequently, cylinder residual oils were subjected to comprehensive tests, including oil ferrographic and spectroscopic analysis, rheology behavior, moisture testing, thermogravimetric properties, and insoluble analysis. The results indicate that the initial utilization of B24 biodiesel led to fuel compatibility and adaptability issues, resulting in fuel dilution of oils. In specific, the cleanliness and thermal stability of cylinder oils decreased, while the concentration of iron, vanadium, moisture, and insoluble in oils, and oil viscosity significantly increased, indicating increased engine wear during this stage. With prolonged utilization of B24 biodiesel, the cleanliness of cylinder oils increased, and other performance was also restored to normal levels compared to those of employing low sulfur fuel oil. These research findings demonstrate the adaptability of B24 biodiesel in marine diesel engines, also providing data support for the utilization of biodiesel in maritime applications.