Ethylbenzene is an an additive that improves the functional characteristics of sustainable aviation fuels.
The study is believed to help the aviation industry overcome its near-total reliance on fossil fuels.
Hong Lu, a research scientist at the Illinois Sustainable Technology Center led the new research.
Typical fuels derived from oil or grease sources lack high levels or aromatic hydrocarbons that keep fuel systems operational. Ethylbenzene, however, is an aromatic hydrocarbon from fossil fuels.
To find a more sustainable way of producing ethylbenzene to test polystyrene because it is rich in hydrocarbons and is abundantly available in the waste stream.
To convert the polystyrene to ethylbenzene, the team used thermal pyrolysis, heating it to break the polymer down into a styrene-rich liquid. A second step, hydrogenation, converted it into a crude ethylbenzene, and distillation yielded a product that was 90% pure.
When mixed with a sustainable aviation fuel, the polystyrene-derived ethylbenzene performed “almost as well as ethylbenzene derived from fossil fuels,” Lu said.
Further purification would improve its performance.
“We did a preliminary cost analysis, and we found that the ethylbenzene produced from waste polystyrene is cheaper than that produced from crude oil. And a lifecycle analysis of our ethylbenzene found it reduced carbon emissions by 50% to 60% compared with the ethylbenzene made from crude oil," said Lu.
