(171d) Effects of Supercritical and Subcritical Pressures of Water on Coke Formation during Jet-a Reformation to Hydrogen

Jet-A, a civilian aviation fuel, was reformed to hydrogen using supercritical water as a novel reacting medium that acts both as a solvent and as a reactant. Supercritical water has also been demonstrated as an effective reformation medium for a variety of hydrocarbons. This experimental system is scalable with reformation of hydrocarbon feedstocks demonstrated in a 400 mL Hanyes® Alloy 230 tubular reactor and a 1-L Inconel® 625 Grade 1 alloy tubular reactor. Due to compact reactor volumes this process can be fabricated into portable power units. The experiments discussed in this work were conducted in a 1-L Inconel 625 Grade 1 alloy reactor with temperatures ranging from approximately 923 to 983 K. Pressures for the subcritical experimental runs were investigated from 17.23 to 21.99 MPa while the supercritical studies were examined in the range of 23.49 to 32.54 MPa. Coke residues were analyzed for percent composition of carbon and hydrogen. Mass of fuel fed was compared against total coke mass and compared with normalized carbon and hydrogen composition analyses from the various cokes to examine the effects on the composition of the coke products. This paper provides a quantitative analysis of hydrogen and carbon content in coke formed during subcritical and supercritical water Jet-A reformation. The result provides evidence for the significance of the supercriticality of the input process condition on the supercritical water reformation process.