Modification of Canola Oil Physicochemical Properties by Hexane and Ethanol with Regards of Its Application in Diesel Engine

Abstract

A mixture of canola oil (Co), n-hexane (Hex), and ethyl alcohol (Et) was proposed as a new energy material for powering diesel engines. For this purpose, surface tension, density, and viscosity measurements, as well as engine tests, were performed for 88%Co10%Hex2%Et and 83%Co15%Hex2%Et mixtures at 20 °C. The adsorption and volumetric properties of these mixtures were compared to those of individual mixture components, as well as diesel fuel (Df) and oleic, linoleic, α-linolenic, palmitic, and stearic acids. It was revealed that the values of surface tension, viscosity, and density of Co were higher than those of the Co components. The addition of 10% Hex and 2% Et to Co caused a more than twofold decrease in its viscosity, while the addition of 15% Hex and 2% Et caused a more than fourfold reduction of Co viscosity. In addition, a mixture of Co with 2% Et and 10% Hex had a density similar to that of Df. In turn, theoretical calculations showed that the addition of n-hexane and ethanol to canola oil only slightly changed its heat of combustion. Engine tests were carried out at fixed engine rotational speeds, with a direct gearbox ratio (4th gear). The quick-changing parameters of the combustion process were registered using an AVL Indimicro system. In these tests it was found that the addition of Et to the mixture of Co and Hex did not significantly shorten the auto-ignition delay, but the kinetic phase during combustion disappeared, which had an impact on the combustion start angle.