Alexandrian laurel for biodiesel production and its biodiesel blends on performance, emission and combustion characteristics in common-rail diesel engine

Abstract

A two-step transesterification process was employed in the biodiesel production from non-edible Alexandrian Laurel. The key physicochemical properties of the Alexandrian Laurel biodiesel (ALB), diesel and blends of both fuels were compared and analyzed. The effects of blending biodiesel (ALB) and petroleum diesel on engine performance, combustion and exhaust emissions were investigated in a turbocharged, high-pressure common-rail diesel engine under six diffierent speed operations and at full load conditions. The test fuels comprised a conventional diesel fuel and four diffierent fuel blends of ALB. The results showed relatively close physicochemical properties of ALB and its blends when compared with petroleum diesel. However, the use of ALB-blended fuel resulted in penalties engine brake power, brake specific fuel consumption (BSFC) despite slightly improved brake thermal efficiency (BTE). Brake specific nitrogen oxide (BSNOx) was found worsened with higher ALB content in the blends. Nonetheless, consistent improvements in brake specific carbon monoxide (BSCO), brake specific carbon dioxide (BSCO2), and smoke were noticed when ALB blends were used. Additionally, ALB blends contributed to reduction in peak combustion pressure, peak heat release rate (HRR) and combustion duration. In general, the findings suggest satisfactory operation with ALB biodiesel-diesel blends in an unmodified diesel engine.