Sustainable Diesel Alternative in CRDI Engine: Performance, Emissions, Energy, and Exergy Analysis of Pyrolysis Oil Blends With Diethyl Ether and Graphene Nanoplatelets

ABSTRACT The performance of a compression ignition (CI) engine could be improved by incorporating waste materials such as waste high density plastic oil (HDPO) and diesel blends by dispersing various non‐metallic, carbon‐based additives (graphene nanoplatelets [GNPs]) and higher alcohols (di‐ethyl ether (DEE)) in recent days. In the present investigation, waste plastic oil (WPO) is prepared and blended with diesel to produce the WP20 sample. The WP20 sample is mixed with additives DEE at 10% Vol. and GNPs at concentrations of 25, 50, and 75 mg/L and tested on a four stroke, twin cylinder, common rail direct injection (CRDI), CI engine to evaluate performance, emissions and thermodynamic irreversibilities as per first and second law including energy and exergy efficiency, and sustainability index (SI). The inclusion of additives improved brake thermal efficiency (BTE) by 15.54%, and decreased brake specific fuel consumption (BSFC) by 16.5%. While emissions including carbon monoxide (CO), carbon dioxide (CO 2 ), hydrocarbon (HC), nitrogen oxide (NOx), and smoke are decreased by 9.27%, 13%, 9.89%, 9.30%, and 8.68% respectively for WP20 + DEE10 + GNP50 sample than the WP20 mix at higher BP. Furthermore, the energy and exergy efficiencies, sustainability index (SI), and (EPC) are enhanced by 7.89, 16.7%, 18.95%, and 8.77%, respectively. According to the 2nd law of thermodynamics (TD), the energy and exergy losses (exhaust gas, cooling water, and unaccounted losses) are reduced, indicating the WP20 + DEE10 + GNP50 blend is sustainable and suitable in diesel engines as an alternative fuel.