Performance and emission analysis of CRDI diesel engine using methyl ester derived from Spirulina platensis as a third-generation biofuel

In recent advancements, alternative fuel strategies have emerged as promising complements to conventional diesel, offering both enhanced engine efficiency and reduced environmental impact. This research looks at how a ternary mix of Spirulina platensis-derived biodiesel, regular diesel, and n-heptane performs and how much it emits. The blend also enhanced with graphene nanoplatelets (GNPs) at levels of 50, 75, 100 mg/L. We tested the nano-additive mixes on twin-cylinder CRDI compression ignition engine. FTIR, FESEM, EDX, and XRD tests showed that nano fuel dispersion stability and structural integrity were both good. The TF + GNP75 mix had the best thermal and combustion properties of all studied formulations. At full load, it had a 16.4 % higher brake thermal efficiency and a 12.5 % lower brake specific fuel consumption. Emission testing showed that CO, HC, and smoke emissions were down by 7.8 %, 10.28 %, and 5.26 %, respectively. CO 2 emissions went up by 13 %, while NO x emissions went down by 9.09 % compared to B20. TF + GNP75 also had a better combustion reaction, with cylinder pressure and heat release rate increasing by 8.83 % and 6.36 %, respectively, compared to clean diesel. These results show that TF + GNP75 is a very promising third-generation biofuel that can be used in CI engines without any hardware changes.