Alexandria Engineering Journal (Jun 2022)
Influence of sweet orange peel oil additive on physicochemical properties of gasoline
Abstract
The effect of a sweet orange peel oil additive on fuel blends of low-octane gasoline was investigated. The additive contains limonene, β-myrcene, eugenol, and triacetin, which have characteristics resembling gasoline but with advantages in terms of molecular structure that can increase RON and produce a homogeneous mixture. The additive changed the molecular behaviors influencing the physicochemical properties of the fuel blends. The experiments were conducted using fuel blends with additive fractions of 0%–75% (v/v). The fuel blends were mixed manually in 50-ml volumes in closed beaker glasses under STP conditions. The physicochemical properties were then measured to evaluate the chemical molecular structure compositions, viscosities, densities, heating values, and RONs of the blends, to determine the effect of the fuel additive on engines.The results show that the additive compounds were able to change the molecular behaviors of the fuel blends. The fuel blends produced 50 hydrocarbon compounds from 32 pure gasoline hydrocarbon compounds, which influenced the physical properties of the blends. The viscosities, beyond the lowest value at approximately 1.8 cSt, exhibited an increasing pattern compared to the viscosity of base gasoline fuel. The density and heating values tended to increase, even though there were fluctuating values due to intramolecular force movement and differences in molecular dipoles in the fuel blends. The RONs of the fuel blends, with additive fractions of 1%, 5%, 10%, 25%, 50%, and 75%, increased to 88.2, 91.5, 92.1, 95.7, 103.9, and 120.45, respectively. The increase in RON was also affected by the additive components among the fuel-blend molecules, which reacted to form highly stable hydrocarbon molecules, particularly aromatic and branched hydrocarbons, that inhibited combustion at low temperatures. Therefore, sweet orange peel oil as an additive can improve the physicochemical properties of gasoline, and thus can be mixed with any commercial fuel, especially those with a low octane number. It can be used for engines that require standard physical and high-octane properties.
