GTL Diesel Way Forward to Improve Properties by Separating Light Ends and Formulating the Specifications

Abstract

Gas-To-Liquid (GTL) Diesel fuel produced from synthetic crudes obtained from natural gas that is converted by the Fisher Tropsch (FT) technology is a promising key player for the mobility industry future along with conventional diesel fuels. The main distinctive properties that distinguish between GTL Diesel and conventional Diesel fuels include density, viscosity, lubricity and Cetane Index. The aim of this study was to identify the effect of the change in GTL Diesel’s composition and boiling range on its market specifications, then to develop predictive models for the GTL Diesel properties based on the fuel’s composition. The study recommends how the industry can use these data for upgrading the fuel quality based on distribution market demand. Intensive testing to analyze many characteristics for GTL Diesel was done at Texas A&M University at Qatar (TAMUQ), and ORYX GTL Company provided the GTL Diesel samples. The study was divided into two sections; the first section consisted of the experimental and modeling work where multiple GTL Diesel cuts were initially prepared. The properties of the prepared cuts were analyzed for five critical GTL Diesel fuel market specifications: Density, Viscosity (kinematic and dynamic), Flash point, Cetane index and Cold properties (Pour and Cloud points). In the second section, these properties were compared with the original market specifications in order to identify whether an improvement in fuel characteristics is obtained. In the third section, the properties of these fuel cuts are used to generate mathematical models for properties-compositions relationships. Finally, we proposed certain modifications to the existing GTL Plants that will improve the separation of specific quality of fuels and value-added chemicals cut. This study also identified the potentials for the light cuts obtained from GTL Diesel fuel to be used for the production of Linear Alkyl Benzene (LAB), which is considered as an expensive value-chemical and a feedstock to detergents manufacturing plants.