The effect of a novel hybrid nano-catalyst in diesel-biodiesel fuel blends on the energy balance of a diesel engine

In internal combustion engines, only about a third of the total fuel input energy is converted into useful work. If the energy rejected into the cooling system and the exhaust gases could be recovered instead and put into useful work, fuel economy would have been substantially improved. The main aim of this research paper was to evaluate the effects of the hybrid nano-catalyst containing cerium oxide and molybdenum oxide in amide-functionalized multiwall carbon nano-tubes (MWCNTs) on the thermal balance of a diesel engine using two types of diesel-biodiesel blends (B5 and B10) in three concentrations (30, 60, and 90 ppm). The research engine was a single-cylinder, four-stroke, direct-injection, and air-cooled diesel engine. The engine was run at two speeds (1,700 rpm and 2,500 rpm) in full load conditions. The thermal efficiency (useful work) resulting from the energy transferred into the cooling system, the exhaust gases, and the unaccounted losses, including the lubricating oil heat loss and the convection and radiation heat transfer, were computed using the first law of thermodynamics. The results showed that by increasing the amount of nano-catalysts (cerium oxide and molybdenum oxide) in fuel blends, the energy transferred to the cooling system and exhaust gases were decreased. The highest reduction in the energy transferred to the cooling system and the exhaust gases was 5.38% and 2.26% for B5, containing 90 ppm (B590ppm), and 5.61% and 2.62% for B10, containing 90 ppm (B1090ppm) respectively. Also, the thermal efficiency went up. Compared with the nano-catalyst-free fuel blends, the highest increase in thermal balance was observed as 6.75% and 5.41% for B590ppm and B1090ppm respectively.