(379c) Aquathermolysis of Waste Triglycerides in a Continuous Flow Reactor for Jet Fuels Production

Authors: 
Kumar, S., Old Dominion University
Feng, M., Southwest Research Institute
Asiedu, A., Old Dominion University
The unavoidable dwindling fossil fuel and its attendant climate change in our time have given impetus to researchers in the energy sector to delve into different sustainable energy sources. One of such energy sources is the abundant waste triglycerides whose long chain hydrocarbons can be separated from their short oxygen chain via hydrodeoxygenation, decarbonylation, and decarboxylation in the presence of a heterogeneous catalyst and hydrogen. However, the use of gaseous hydrogen is limited by a diffusion process since it is not readily soluble in liquid (polar) components and requires an excess use of hydrogen. To address these challenges, a single-pot â??Formic Acid Assisted Autotheromolysis to Jet Fuel (FAT2JF)â?? process is studied. The use of aqueous phase (formic acid and water mixture) serves as an in situ source of H2 (hydrogen precursor and hydrogen transfer agent) and organic solvent where the reactions in aqueous media (aquathermolysis) helps in reducing mass transfer resistances that results in significant increase in reaction rates in this FAT2JF process. The phase diagram of water, formic acid and some typical triglycerides will be presented.

The present study on aquathermolysis is focused on developing a metal oxide-based low cost catalyst (e.g. Fe-Ni/activated carbon, Fe-Ni-Co/Al2O3) system that is stable in aqueous media. The study is conducted in a packed bed continuous flow tubular reactor in the range of 250 to 400áµ?C under hydrothermal conditions. In order to alleviate coke formation and evaluate the stability of the catalyst, the effects of reactants flowrates, feedstock composition, pressure, temperature, and formic acid concentration are studied. GC-MS and elemental analyzer are used to analyze the product compositions. Thermal gravimetric analysis (TGA), energy dispersive X-ray, SEM, BET method, FT-IR, and XRD are used to characterize both fresh and used catalyst. The proposed novel approach has certain advantages over conventional commercial hydrotreating processes including no handling of hydrogen gas, faster reaction times, and use of renewable formic acid as hydrogen source.