Effect of Nanosilver/Water-in-Kerosene Emulsion on NOx Reduction and Enhancement of Thermal Characteristics of a Liquid Fuel Burner

This study investigated the effect of nanosilver/water-in-kerosene emulsion on thermal and radiative characteristics and pollutant emissions of a liquid burner. The results were compared with the corresponding, values resulted from neat kerosene. Light microscopic imaging was used to study microexplosion of the fuel droplets. Also, combining chemiluminescence technique and measurement of pollutant concentrations, a qualitative study was carried out to find out the effect of CO, CO2, water vapor, and intermediate soot particles on the flame emissivity coefficient. The results showed that the Brownian motion of silver nanoparticles and localized convection between nanoparticles and the adjacent fluids increased the evaporation rate of nanoemulsion droplets and the rate of their mixing with oxidizing air. Besides the nanoparticles effect, the secondary injection of nanoemulsion due to microexplosion of water droplets enhanced the mixing rate of nanoemulsion fuel and oxidizing air. Although absorption of heat by water content of nanoemulsion fuel decreased the flame temperature, the nanoemulsion fuel, compared with neat kerosene, enhanced the average radiation of flame by 23%. Further, the results indicated that although CO and CO2 did not change significantly in amount, NOx emission reduced as much as 23.7% when the nanosilver/water-in-kerosene emulsion, instead of neat kerosene, was used.