PERFORMANCE AND EMISSION CHARACTERISTICS OF LEMON PEEL OIL BIODIESEL WITH DIETHYL ETHER AND ETHANOL IN A CI ENGINE: AN EXPERIMENTAL INVESTIGATIONS

The rising global energy demand and the adverse environmental impacts of fossil fuel consumption have intensified the search for sustainable alternative fuels. Among the various biodiesel sources, lemon peel oil (LPO) offers promising potential due to its biodegradability, availability from waste resources, and favorable combustion characteristics. This study investigates the performance and emission characteristics of LPO biodiesel blended with diethyl ether (DEE) and ethanol in a compression ignition (CI) engine. Three blends B5, B10, and B15 were prepared by varying the proportions of LPO, DEE, and ethanol with conventional diesel. The physicochemical properties of the blends were evaluated as per ASTM standards and found to be compatible with CI engine requirements. Experiments were conducted on a variable compression ratio (VCR) CI engine under different load conditions. Results showed that the B10 blend exhibited superior brake thermal efficiency (BTE), achieving an improvement of 0.6%–2% compared to diesel, along with significant reductions in carbon monoxide (CO), hydrocarbon (HC), and smoke emissions. However, a slight increase in nitrogen oxides (NOₓ) was observed due to the enhanced oxygen content in the blend. These findings support the viability of LPO-based blends as alternative fuels for diesel engines, contributing to cleaner and more sustainable combustion.