A group of scientists at the Illinois Sustainable Technology Center (ISTC) has studied a cost-effective method for producing ethylbenzene, an additive that enhances the functional characteristics of sustainable aviation fuels, from polystyrene, a common hard plastic in many consumer goods.
The success is also helpful for the efforts of switching commercial aircraft in the U.S. from reliance on fossil fuels to more sustainable aviation fuels.
To convert the polystyrene to ethylbenzene, scientists heated it to break the polymer down into a styrene-rich liquid. Then, they converted it into a crude ethylbenzene, and distillation yielded a product that was 90% pure.
According to Hong Lu, a research scientist at ISTC, polystyrene-derived ethylbenzene performed as well as ethylbenzene derived from fossil fuels when mixed with a sustainable aviation fuel. Additionally, further purification would also improve its performance.
Ethylbenzene is an aromatic hydrocarbon and can be derived from fossil fuels so finding a sustainable way to produce it would aid the aviation industry’s conversion to sustainable jet fuels.
Lu said the team chose to develop ethylbenzene because it has a lower tendency to form soot upon burning than other highly aromatic compounds. Also, they chose polystyrene because it is rich in hydrocarbons and is available in the waste stream, It is estimated that 2.5 million metric tons of polystyrene are disposed of in landfills in the U.S. every year.
Lu and his colleagues found that the ethylbenzene produced from waste polystyrene is cheaper than that produced from crude oil. In addition, it also reduced carbon emissions by 50% to 60% compared with the ethylbenzene made from crude oil.
The U.S. Department of Energy, the U.S. Department of Transportation, the U.S. Department of Agriculture, and other government agencies set goals for the production of domestic sustainable aviation fuels to 3 billion gallons per year by 2030, and 35 billion gallons per year by 2050.
The Government’s present standards require at least 8.4% aromatic hydrocarbons to be included in any blend of sustainable aviation fuels and fossil-derived fuels aiming to maintain compatibility with existing aircraft and related infrastructure.
ISTC is a part of the Prairie Research Institute at the University of Illinois Urbana-Champaign.
Image source by Ivan Bandura on Unsplash
Source by University of Illinois
