Performance, emissions, and lubricant oil analysis of a marine diesel engine powered by raw Schizochytrium sp. and its blends

Microalgae oil (MAO), a third‐generation biofuel, can support global transportation fuel demand as a fossil fuel substitute. Schizochytrium sp. MAO is particularly promising for direct use in compression ignition (CI) engines, especially in the marine sector, due to its adaptability and high oil yield. This study investigated the performance, emissions, and optimization of a single‐cylinder marine diesel engine operating on MAO and MAO/diesel oil (DO) blends. The results show that MAO significantly reduced nitrogen oxide (NOx) and carbon monoxide (CO) emissions by up to 59%, despite its higher viscosity and density and its lower heating value compared with DO. Brake‐specific fuel consumption (BSFC) increased by 46%, but brake power and brake thermal efficiency (BTE) decreased by up to 40% and 26%, respectively. After 30 h of operation, the lubricant oil (LO) in MAO‐fueled engines contained 15% less Zn, 19% less P, and 16% less Ca than that in DO‐fueled engines.