The effect of oxygen content in soapnut biodiesel-diesel blends on performance of a diesel engine

Abstract

In this study, 18 soapnut biodiesel-diesel blends along with soapnut oil as an additive in some blends were prepared and used in a diesel engine to investigate the effect of oxygen content in the fuel blends on engine performance and emission characteristics. Considering the large variations in the oxygen content of these fuel blends, the obtained results were demonstrated based on varying fuel oxygen content. Findings showed that the best engine performance was achieved with a fuel oxygen content in the range of 1.8%–3.0%, whereas the best engine emissions were obtained with a fuel oxygen content in the range of 0.71%–2.37%. Hence, considering both engine performance and emissions, the optimal zone of fuel oxygen content wasfound to be in the range of 1.80%– 2.37%. Thus, it can be concluded that biodiesel blended fuels having an oxygen content in the aforesaid range can be successfully used in diesel engines with comparable engine performance and emissions to those using diesel fuel. Nevertheless, further research is required to reduce the fuel oxygen content to this optimal range if the blends consist of higher biofuel components. Besides that, the use of suitable additives in the biodiesel blended fuels may be a viable option to achieve the said purpose, which needs further research.