Effect of Cerium Oxide Nanoparticles and Carbon Nanotubes as fuel-borne additives in Diesterol blends on the performance, combustion and emission characteristics of a variable compression ratio engine

An experimental investigation is carried out to establish the performance, combustion and emission characteristics of a variable compression ratio engine using Cerium Oxide Nanoparticles and Carbon Nanotubes as fuel-borne nanoparticles additives in Diesterol (diesel-biodiesel-ethanol) blends. As Diesel and Ethanol are immiscible, Castor oil biodiesel is used as an additive which acts as a bridging agent to prevent the phase separation. Stability studies are carried out using Cerium Oxide Nanoparticles (CERIA) and Carbon Nanotubes (CNT) each 25, 50, 100 ppm in the Diesterol blends subjected to high speed mechanical agitation followed by ultrasonic bath stabilization. It is observed that the blends are stable which are suitable for performance test on the compression ignition engine. Studies on the performance, combustion and emission characteristics are carried out on a variable compression ratio engine using the stable Diesterol-CERIA-CNT blends under various loading conditions at an optimum compression ratio of 19:1 to estimate the emission reduction potential of CERIA and CNT as catalyst in Diesterol blends. The addition of CERIA and CNT in Diesterol blend increases the cylinder gas pressure when comparing with the neat Diesterol blends. The Carbon Nanotubes act as a catalyst to accelerate the burning rate which results in decreased ignition delay and cause for the lower heat release rate and advancement of the peak heat release rate. The Cerium Oxide Nanoparticles act as an oxygen donating catalyst which provides oxygen for the oxidation of carbon monoxide and absorbs oxygen for the reduction of nitrogen oxides. The activation energy of Cerium Oxide acts to burn off carbon deposits within the engine cylinder at the wall temperature and helps to prevent the deposition of non-polar compounds on the cylinder wall resulted in significant reduction of hydrocarbon and smoke emissions. The combined effect of CERIA and CNT as fuel-borne nanoparticles additives in the Diesterol fuel blend contributes for the cleaner combustion and significantly reduces the harmful exhaust gas emissions.