Study on Physicochemical Properties of Tailor-Made Green Jet Fuel Blend from Waste Cooking Oil

Abstract

The International Air Transport Association (IATA) intended to reduce the greenhouse gases (GHG) emissions from the aviation industry by 50 % in 2050 compared to the year 2005. Waste cooking oil (WCO) contains accumulated free fatty acids that make it a technically viable feedstock for conversion to biofuel. Its potential application in jet fuel received huge interest in recent years due to its low price and widely available. The use of waste cooking oil could avoid the inter-competition between the oil resources and edible oil-based food crops, reducing reliance on fossil fuels while also lowering harmful emissions, especially carbon dioxide (CO2). The main objective of this study is to study the physico-chemical properties of the formulation of jet fuel blend with waste cooking oil. The computer-aided approach was utilised to find the optimum jet fuel blends. The reliability of the computational design approach is dependent on the accuracy of the property prediction models. The critical jet fuel target properties are density, kinematic viscosity, heating value flash point and freezing point. The mixture properties can be predicted using Kay’s mixing rule and the Arrhenius mixing rule (for kinematic viscosity only) with high accuracy. The flash point and freezing point prediction models suitable for the prediction of jet fuel properties were identified and verified in this study. This study found that model 1 (freezing point) and model 2 (flash point) have the lowest average percentage error (APE), which are 2.10 % and 0.32 %. These models were used to find the optimal blends of jet fuel. Blend 1 (hydrotreated waste cooking oil C – 92 %, jet fuel C – 8 % by volume) was identified as the optimum green jet fuel blend that satisfied all the target properties of jet fuel. The verified models for flash point and freezing point serve as convenient models for solving the green jet fuel blend design problem.