Variation of JP-8 Properties in the Continental United States (CONUS) and Potential Implications During Blending with Synthetic Paraffin Kerosene

摘要

Both U.S. military JP-8 and commercial Jet A/A-1 fuel specifications allow blending up to 50 vol. % Synthetic Paraffinic Kerosene (SPK) produced via the Fischer-Tropsch (FT) process with a certification petroleum-derived fuel. Understanding the impact of historical variations of neat JP-8 fuel properties on the resulting fuel blends will assist with implementation. In this effort, statistical analyses were performed using the PQIS database to investigate the variation of selected JP-8 properties as a function of year (1997-2008) and procurement region in CONUS. Properties considered were: Aromatic Content, Density, Freeze Point, Viscosity, Heat of Combustion (by mass), and Volumetric Heating Value. Consistent historical trends were observed for several properties within specific regions, allowing for future prediction. However, statistically significant historical differences exist in certain fuel properties depending on procurement region which requires that the region be considered when estimating the expected fuel properties during blending. Calculations indicated that a substantial probability exists that a 50 vol. % blend will not satisfy the minimum 8.0 vol. % aromatic content and/or 0.775 g/mL density requirements. Probability varied significantly depending upon the procurement region, indicating that solely using the average CONUS property values would result in inaccurate prediction of fuel properties. These analyses provide an initial basis of evaluation for the implementation of alternative fuel blends and the expected maximum volume percentages which can be safely employed. The methodology used during the analyses, the historic JP-8 property trends as a function of procurement region, the property correlations investigated, and analysis and implications of blending JP-8 with SPK are presented. Appendix A includes supplemental statistical analyses.