Exploration of combustion behavior in a compression ignition engine fuelled with low-viscous Pimpinella anisum and waste cooking oil biodiesel blends

Abstract

In today's world due to a greater demand for fossil fuels, many alternative solutions such as extracting energy from waste and also from green biofuels have been offered. Among various studies, a new approach on the usage of low viscous Pimpinella anisum as a green biofuel with waste cooking oil biodiesel blend in the diesel engine efficiently has shed new light in the field of alternative renewable sources of energy. The aim of this work is to eliminate the usage of conventional fuel in a diesel engine by incorporating binary green fuel (Waste Cooking Oil biodiesel blended with Pimpinella anisum as low viscous oil) effectively. The enhancement of Waste Cooking Oil (WCO) biodiesel production was done by employing the transesterification process. Calcium oxide heterogeneous catalyst was prepared using eggshell and it was doped with barium of 4–8 %wt. to improve the catalytic efficiency. Pimpinella anisum oil with its promising properties such as low viscosity, high O2 content, and high boiling point is better suited to the diesel engine and was prepared by steam distillation method. Binary fuels were prepared by blending Pimpinella anisum oil (A) with WCO biodiesel (B) in 90%, 80%, and 70% of volume. The engine was tested with pure diesel and WCO biodiesel for comparative study. The addition of Pimpinella anisum elongated the period of ignition delay. Among the tested fuels, B20A80 has shown better heat release rate (HRR) and cylinder pressure, bringing brake thermal efficiency (BTE) near to that of diesel since the biodiesel operation decreases BTE in diesel engines. It also has shown the reduced formation of soot, Carbon monoxide (CO), and hydrocarbon (HC) emissions by 81.43%, 43.8%, and 18.6% respectively. A slight increase of 2.49% in Oxide of nitrogen (NOx) emissions in compared with the operation of diesel was observed.