(441c) Development of Visualization Models for the Correlations Between Synthetic Jet Fuels Hydrocarbon Structure and Their Properties

Nimir Elbashir*, Jahanur Rahman

Chemical Engineering Program, Texas A&M University at Qatar, PO Box 23874, Doha, Qatar

*Corresponding author: nimir.elbashir@qatar.tamu.edu

Abstract

This study aimed at better understanding the relationship between synthetic fuels’ hydrocarbon structure and their properties to speed up the design of future fit-for-purpose fuel blends of superior performance from natural gas via the Gas-to-Liquid (GTL) technology. The novelty of our approach is that it simultaneously utilizes experimental and modeling techniques for product design.  Furthermore, the outcome of this research may further support Qatar’s leadership in the GTL market as it envisioned itself to become the “World capital of Gas Processing”. The main focus of the current study is on the synthetic GTL derived jet fuels since they have lower emissions SO_x (Sulfur oxides), NO_x (Nitrogen oxides), CO (carbon monoxide), and soot particles compared to jet fuels obtained from petroleum crude. Furthermore, they smell and smoke less than conventional jet fuels and have better eco toxicity, better fuel economy and better thermal stability coupled with less soot formation upon combustion. However, a major concern with using synthetic fuels is that lack of aromatics which would result in possible degradation of elastomers used for sealing purposes as well as affecting other properties unfavorably [1]. Due to these concerns synthetic fuels are blended with conventional Jet A-1, with Qatar Airways having used a 50/50 blend for the first commercial flight from London Gatwick airport to Doha airport [2]. Current research activities are focused on developing a suitable GTL fuel, through the use of certain additives to meet the aviation industry’s certification requirements. Currently jet fuels must have a density between 0.775 and 0.84 g/ml as well as a minimum flash point of 38°C and other limitations which are given in ASTM 1655 [3]. The experimental investigations measuring the properties of fifty-four blends represents typical are discussed elsewhere [4].  Visualization of the relationship between fuels’ hydrocarbon structure and their physical/chemical properties are essential to define the optimum region of composition that meets the aviation industry standards. We developed different phases of this visualization process that started with two-dimensional visualization (2D Visualization Models) and ended with three-dimensional visualization (3D Visualization Models) whereby optimum regions of typical synthetic jet fuel composed of GTL fuels’ hydrocarbon pillars (n-paraffin iso-paraffin, and cyclo-paraffin) plus the aromatics can be identified. The latter is major accomplishment in this field since the 3D models provide us an opportunity to do both surface analysis and depth analysis to identify the optimum composition for synthetic jet fuels of different hydrocarbon groups, carbon numbers and other additives that meet the aviation industry’s standards. 

References:

[1] – Blakey S, Rye L, Wilson C. Aviation gas turbine alternative fuels: A review. Rep. Proceedings of the Combustion Institute, 2011, pp. 2863 – 2885.

[2] – Qatar Airways Corporate Communications, Worlds first commercial passenger flight powered by fuel made from natural gas lands in Qatar. 2009. http://www.qatarairways.com/global/en/newsroom/archive/press-release-12O...

[3] – ASTM D 1655, Standard specification for aviation Turbine fuels, American Society for Testing and Materials, 2010.

[4]-                   Raza, B., Elmalik E., Al-Meer M., Ramahdan H., Al-Mohannadi D., Elbashir  N.O. (2011) “Characterization of synthetic Gas-to-Liquid jet fuel blends and properties correlation with hydrocarbon structure” Preprint Paper - American Chemical Society, Division of Fuel Chemistry, 56(2): 431-433.