Biodiesel for HCCI engine: Prospects and challenges of sustainability biodiesel for energy transition

Biodiesel use in homogeneous charge compression ignition (HCCI) engines has the potential to improve engine performance and combustion characteristics, while at the same time reducing harmful emissions. Diesel engines have the dilemma of PM and NOx trade-off. HCCI engine emerges as a new combustion mode to reduce such trade-off, while at the same time maintaining the superiority of diesel over gasoline engine with better fuel economy and engine performance. HCCI engine is a promising technology employing the premixed combustion to ensure the homogeneous and lean mixture under autoignition event. However, controlling its combustion phasing remains a major challenge. Also, HCCI engine suffers from high HC and CO emissions. To control its combustion timing and reduce high emissions from HCCI engine, fuel is one of the important parameters. The use of biodiesel fuel can achieve that goal. This study aims to review the effect of biodiesel addition in HCCI engine. The scope includes the progress and development of biodiesel in HCCI engines, encompassing results from both experimental and numerical studies. Insights into the prospect of biodiesel for HCCI engine were provided. Also, the challenges of fuel and engine aspect were discussed with potential solutions for future improvement. By playing around with several parametric variables such as inlet air temperature, exhaust gas ratio and injection pressure, HCCI engine fuelled with biodiesel fuel could improve the engine performance and combustion characteristics, while at the same time reducing harmful pollutants such as CO, HC, NOx and smoke emissions.