RHEOLOGY ON A WATER IN OIL EMULSION SYSTEM

Abstract

Diesel, kerosene etc. fuels are used in transport vehicles. These fuels produce gases emissions of hydrocarbons (HC), carbon-oxides (COx), suphur-oxides (SOx) and especially the Nitrous Oxides (NOx). Water-in-diesel nano-emulsion is used as one of the possible alternative fuel for reducing the pollution in transport vehicles (diesel engines) and in industrial boilers. Nano-emulsion fuels are described as emulsions containing 5-20% of water in fuel, added with surfactants and the base fuel (e.g. kerosene or diesel). Many types of research on emulsion fuels reported that the emissions of hydrocarbons (HC), carbon-oxides (COx), suphur-oxides (SOx) and especially the Nitrous Oxides NOx and small carbon particles are less as compared to pure diesel fuel. Present study deals with the optimization of HLB value, water percentage in nano-emulsion and its effect on stability of water-in-diesel (w/o) nano-emulsions. Moreover rheology of nano-emulsions is performed to find its non-Newtonian behavior. Formation of w/o nano-emulsion is achieved by selecting two different non-ionic surfactants, span 80 (Sorbitanmonooleate) and triton X-100 (Alkylphenolhydroxy polyethylene), having different HLB values 4.3 and 13.5, respectively. These two surface-active agents are mixed to find the optimum HLB curve and used to prepare w/o nano-emulsion by low energy method with different water percentages. From the whole study it is found that increase in water percentage increases the droplet size and pseudo plastic fluid behavior in water-in-diesel nano-emulsion. Samples formed during the study were found stable for 30 days. Instability mechanism responsible for changing the droplet size with respect to time is found as Ostwald ripening.