Combustion and emissions aspects of a diesel engine working with sheep fat oil biodiesel-diesel blends

In this article, biodiesel is prepared from the Egyptian sheep fat oil applying the transesterification process, which is detrimental to the ecosystem and paid for its elimination. Then its physicochemical properties are measured according to the ASTM standard. Also, the produced biodiesel is assessed utilizing Fourier-transform infrared spectroscopy (FTIR) analysis. The two blending ratios of diesel and sheep biodiesel are mixed in volume proportions of 10% and 20%, and they are denoted as B10 and B20. The combustion and emissions parameters are evaluated utilizing a CI engine fueled with pure diesel fuel, B10, and B20 combinations under variable loads. The burning findings demonstrate that the peak pressure and maximum HRR are lower for B10 in contrast with base fuel, while the B20 combination indicates an improvement in the cylinder pressure and HRR. A related tendency is remarked for pressure rise rate and mean cylinder temperature. There is a sizeable drop in the HC, CO, and smoke levels for B10 and B20 mixtures compared to base fuel, while the NOx emission is marginally enlarged. It can be inferred that the mixture of B20 gives a substantial improvement in engine performance and emissions. •The biodiesel produced from sheep fat oil using two-step transesterification.•The peak pressure and HRR are slightly lower for B10 and B20 compared to pure diesel fuel.•The bsfc reduced by 6% and 8% for B10 and B20, respectively, compared to diesel fuel.•CO, HC, and smoke reduced by 15-30%, 30-40%, and 25-50% for B10 and B20, respectively.•It can be deduced that the recommended blending ratio of sheep fat oil-diesel fuel is B10.