Lignin-based jet fuel and its blending effect with conventional jet fuel

Abstract

Sustainable aviation fuels (SAFs) must demonstrate specific physical and chemical properties as well as material compatibility (i.e., seal swell) to be used as aviation turbine fuels. Several alternative jet fuels incorporated in ASTM D7566 are comprised mainly of n/iso-alkanes and can only be blended up to 50 vol% due to material compatibility and density issues. Prior work illustrated the ability of cycloalkanes to replace the swelling potential of aromatics required for material compatibility. Here, we report the first archival documentation of a feedstock and chemical process to yield a product composition that could complement 5 existing SAF ASTM D7566 annexes. A lignin-based jet fuel (LJF) blend component is generated and composed of mostly C6–C18 mono, di, and tri-cycloalkanes. The neat LJF was blended with conventional jet fuel at 10 vol% (LJF blend) to simulate a potential qualification goal. Fuel properties critical to engine operability (ATSM D4054 Tier 3 & 4) were either predicted or experimentally tested based on the volume availability. All LJF-blended operability properties fall within the experience range of conventional jet fuel, with neat o-ring swelling exceeding the typical range of conventional fuels. These results support the potential use of this LJF pathway to complement other SAF pathways and achieve 100% drop-in SAF.