Production\nof a Sustainable Aviation Fuel Additive\nfrom Waste Polystyrene

Sustainable aviation fuels (SAFs) are an important lever\nto achieving\nnet zero CO<sub>2</sub> emissions in aviation. Fuel quality standards\nlimit the blend volume of nonpetroleum-based jet fuel such as synthetic\nparaffinic kerosene (SPK) in Jet A to 50 vol %. One reason for this\nlimit is the limited seal-swelling ability of SPK. Ethylbenzene (EB)\nas an additive can improve the swelling propensity of SPK. In this\nstudy, EB was produced through polystyrene pyrolysis, hydrogenation,\nand separation. The thermal pyrolysis of polystyrene produced a styrene-rich\npyrolyzate. The pyrolyzate was hydrogenated by using Pd/C to produce\nan EB-rich mixture that yielded a crude EB of ∼90% purity on\ndistillation. The O-ring swelling ability of crude EB of ∼90%\npurity was tested as a 12 and 16 vol % blend with SPK. Results reveal\nthat EB addition enhanced seal swelling, but a more refined EB grade\nwould be preferable. The results provide a pathway to address the\ntwin issues of plastic pollution and SPK property improvement.