The impact of CuO nanoparticles as fuel additives in biodiesel-blend fuelled diesel engine: A review

The utilization of fossil fuels like diesel has contributed immensely to ecological challenges such as the emission of greenhouse gasses. Hence, the motivation for sourcing another energy that is renewable as well as easily accessible from relatively cheap materials. Biodiesel is a perfect replacement for petro-diesel because it is biodegradable, economically viable, and has lower toxicity. However, there are challenges associated (poor engine efficiency) with its utilization in engines. It also raises NOx emissions which necessitates frequent engine component replacement owing to clogging, and it is ineffective in cold weather. To boost efficiency, nanoparticles can be combined with biodiesel blends. Moreover, the utilization of nanoparticle additives improves the performance of engines, rate of heat transfer, fuel mixture balance, thermo-physical characteristics, as well as the reduction in exhaust emissions. Copper oxide which is a transition metal oxide aids in the heat transfer from the engine down to the exhaust thus lowering the emissions of NOx. As a result, CuO nanoparticles are thought to have a lot of potential as a diesel engine additive and therefore, this review study was conducted to deduce the various techniques for generating CuO nano-fuels, the preparation methods, as well as their physicochemical features. Furthermore, the combustion behaviour, performance, and emission characteristics of diesel engines powered by CuO nanoparticle-containing biodiesel and blends were carefully investigated.