Effects of nano-copper additive on performance, combustion and emission characteristics of Calophyllum inophyllum biodiesel in CI engine

Depletion of non-renewable energy sources are at elevated manner due to the rapid growth of industrialization and transportation sector in last few decades and leads to further energy demand. Biodiesels especially second-generation fuels from non-edible oil resources are alternate sources for replacement of diesel fuel in CI engines due to their considerable environmental benefits. In the present work, non-edible feedstock of Calophyllum inophyllum seed oil (tamanu oil) is used for biodiesel production. Transesterification method is used for preparation of biodiesel in the existence of methanol with NaOH as catalyst. The copper nanoparticles are synthesized by electrochemical method, and it is characterized by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). XRD and SEM results confirm the presence of copper nanoparticle and size of around 30 nm. This paper aims to investigate the effects of the copper additive nanoparticles with biodiesel blends on the engine performance, combustion and emission characteristics of single-cylinder direct-injection diesel engine and compared that with diesel fuel. The results showed that the addition of nano-additives enhances brake thermal efficiency and reduces specific fuel consumption compared to biodiesel blends but slightly lower than diesel. Combustion characteristics also are enhanced by improved oxidation reaction inside the combustion chamber which resulted in higher heat release rate. The emissions of HC, NO x and O 2 are significantly reduced for nano-additive blends compared to diesel but increased CO 2 emission was observed. It is noticed that higher CO 2 emission and substantial reduction of unused O 2 emissions from engine fueled with nano-additive are evident for enhanced oxidation and better combustion. Energy and exergy analysis of the diesel engine is carried out to estimate the effect of using nanoparticle additive with biodiesel.