Graphene-enhanced sustainable fuel from Calophyllum inophyllum for premixed charge compression ignition engines: Advancing circular economy and emission reduction

This study investigates the impact of modifying a conventional compression ignition (CI) engine by inducting pentanol in inlet manifold and injecting graphene-blended tamanu biodiesel into the cylinder. These modifications significantly enhance ignition quality and expand operational capabilities within the premixed charge compression ignition (PCCI) engine. The use of graphene-enhanced biodiesel in PCCI mode demonstrates potential for improved combustion efficiency and emission reduction. Dispersed graphene nanoparticles in tamanu biodiesel notably improve brake thermal efficiency due to their increased surface area, which enhances fuel-air mixing. Graphene-suspended biodiesel at a concentration of 100 ppm in PCCI mode results in an 11.5% peak pressure rise and an 8.4% rise in heat release rate with respect to pure biodiesel in CI mode. This nano-suspension biodiesel also shows significant thermal efficiency improvements, with an 8.20% increase and a 22.08% reduction in fuel consumption with respect to neat biodiesel in CI mode. The combination of pentanol and graphene-blended tamanu biodiesel improves combustion quality, yielding a 13% reduction in carbon monoxide emissions, a 34.67% reduction in hydrocarbon emissions, a notable 65.84% lower in nitrogen oxide, and a 33.91% reduction in smoke with respect to neat tamanu biodiesel in CI mode of operation. • Novel integration of pentanol in the intake manifold. • Pentanol and graphene-tamanu biodiesel boost CI engine performance and combustion. • Graphene improves brake thermal efficiency via better fuel-air mixing. • Increased surface area of the nanoparticles allows for superior fuel-air mixing. • Combined modifications reduce CO by 13% and HC by 34.67%.