Performance and emission analysis of cassava peel waste pyrolysis oil-hydrogen-diesel blends in a compression ignition engine

As the world moves away from fossil fuels and embraces sustainable energy sources, the need for sustainable fuels for transportation becomes paramount. This study investigates the effects of pyrolysis oil derived from cassava peel waste (CPO), hydrogen (H), and diesel (D) blends as a partial substitute for low-displacement compression ignition engines. We tested three blends - CPO25, CPO25H5, and CPO25H10 - against neat diesel operation at engine speeds of 3400 rpm, 3600 rpm, and 3800 rpm and torques of 4 Nm, 6 Nm, and 8 Nm. Our findings reveal that while energy efficiency decreased with CPO25 compared to D100 operation, adding H2 increased energy efficiency. The highest increase was 7.8 % for CPO25H5 and 16 % for CPO25H10 compared to CPO25. Exergy efficiency also decreased with CPO25 compared to D100, but adding H2 compensated for this reduction. The highest increase was 8.0 % for CPO25H5 and 17 % for CPO25H10 compared to D100. CPO25H10 showed an increase of 8.1 % in combustion pressure and 9.9 % in heat release rate compared to CPO25. Emissions analysis also revealed that CO emissions were considerably lower with CPO and H2 than with D100, with the highest decrease of 11 % with CPO25H10. CO2 and hydrocarbon emissions followed the same trend as CO. Although NOx emissions slightly increased, the benefits of using pyrolysis oil-H2-diesel blends as a partial substitution fuel for low-displacement compression ignition engines are evident.