Engine operational characteristics of carbon nanotube-doped algae biodiesel with higher alcohol fuel blends

This paper experimentally investigates how carbon nanotube additives affect the performance, combustion, and emission properties of a diesel engine fuelled by an oxygenated ternary blend. The base fuel mixture was the mixture of diesel (80%), biodiesel (10%), and propanol (10%), and single-walled (SW), double-walled (DW), and multi-walled carbon nanotubes (MW) were incorporated at 100 ppm. A one-cylinder diesel engine was used to test engine experiment under different load conditions. It was found that the addition of the carbon nanotubes increased the combustion behavior by increasing the rate of heat release and stabilizing the in-cylinder pressure development. On average, thermal efficiency was improved by 1.78% and 2.14% with DW and MW respectively, whereas all blends with oxygenated content had higher specific fuel consumption because of lower heating value. The nano-enhanced ternary blends showed considerable emission reductions with an average of 35.52% reduction in hydrocarbon emissions and a maximum reduction of 34.43% in the nitrogen oxides. The emissions of carbon monoxide were also minimized in most of the operating conditions. As shown by the findings, the morphology and geometry of carbon nanotubes are a key element in maintaining a balanced level of combustion, engine performance, and engine emission reduction with DW and MW having a more desirable balance than SW in oxygenated ternary blends of fuels.