Performance and Emission Characteristics of Diesel Engines Using Biodiesel Blends

Abstract

Biodiesel-diesel blends provide a practical pathway for reducing dependence on petroleum diesel while retaining compatibility with conventional compression-ignition engines. This methodology paper proposes a controlled experimental framework for evaluating engine performance and regulated exhaust emissions with B0, B10, B20, and B30 fuels. The design combines fuel-property characterization, a constant-speed single-cylinder diesel-engine test, staged loading, exhaust-gas measurement, and calculation of brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC). The principal emissions considered are carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity. The methodology is grounded in published work available up to 2019 and therefore treats the numerical outcomes presented in the Results section as literature-supported benchmark expectations rather than original measured data. Prior studies consistently indicate that low-to-moderate biodiesel fractions can reduce CO, HC, and smoke because of the oxygenated nature of biodiesel, although BSFC may rise because biodiesel generally has a lower heating value and NOx may increase under some operating conditions. The proposed protocol is intended to enable reproducible comparison of blend ratio and engine load and to identify a practical compromise between efficiency, fuel consumption, and emissions, with B20 serving as a particularly important reference blend.