FULL ARTICLE: While fuel shortages due to the Iran war made some countries double down on electrification, they also highlighted one industry that could be quite literally grounded without fossil fuels: aviation. Flying relies on fossil-based jet fuels and is extremely hard to decarbonize.
Researchers in China now report a process that could help bring down flying’s carbon emissions while also tackling the plastic waste crisis. The two-step process converts plastic waste into high-quality jet fuel more efficiently and at much less cost than other methods researchers have reported in the past to convert plastic waste to fuels.
The team’s preliminary analysis, reported in published in Nature Energy, shows that the plastic-based fuel would cut carbon dioxide emissions by 73% compared with petroleum-based jet fuel.
The plastic that the researchers break down is polystyrene. This lightweight polymer, often commonly called Styrofoam, is used to make packaging and insulation. It is notoriously expensive and challenging to recycle. Besides usually being contaminated, it is composed mostly of air, which makes sorting and transportation difficult. Nearly all waste polystyrene goes to landfill today.
The team from Nanjing Forestry University and Tsinghua University designed a new catalyst that breaks down polystyrene at high temperatures in the presence of hydrogen. Their process runs continuously in a tandem reactor.
The first reactor heats the polystyrene to 460°C in a hydrogen atmosphere step. This breaks the long polymer chains in polystyrene to shorter strands. In the second reactor, the fragments are passed over the ruthenium catalyst at 160°C. The resulting chemical reactions convert the fragments into molecules called alkanes. These are energy-dense hydrocarbon molecules that work for jet fuel.
Past work on making fuels from plastic waste include a one-step, low-temperature process as well as a method that is powered by sunlight and also utilizes carbon dioxide. This new method needs higher temperatures, but it is faster, has a much higher yield and requires lower pressures. But still, whether or not it can be cost-effectively scaled up remains to be seen.
In their study, the researchers show that the method converts 94.8% of waste polystyrene to liquid fuels. And their preliminary analysis shows that the fuel would sell for a minimum of $1–1.80 per kilogram, competitive with conventional fossil-based jet fuel.
Source: Jia Wang et al. Ambient-pressure conversion of plastic waste to jet fuel cycloalkanes by tandem hydropyrolysis and vapour-phase hydrogenation. Nature Energy, 2026.
