That plastic bottle containing your
favorite beverage or even the plastic shopping bag holding your
latest grocery haul may one day help to power a jet airliner across
the country. In 2019, a research group, led by scientists
at the University of Washington, was able to successfully turn plastic waste products into refined jet fuel in the laboratory.
The type of plastic used in this process was low-density polyethylene, which encompasses a wide variety of plastic products, such as: water bottles, milk bottles and other beverage containers, as well as plastic wrap, and grocery bags. First, this waste plastic is ground down into granules that are around 3 mm in diameter (about the size of a grain of rice). Then, the plastic is placed on top of an activated carbon catalyst. This carbon is very porous, and thus has a large surface area for chemical reactions to take place. The carbon catalyst works to speed up the chemical reaction, helping to break down the plastic when the mixture is heated to 800 – 1,000℉ in a tube reactor. After testing a variety of temperatures and catalysts, the research team was able to produce a mixture with a maximum of 85% jet fuel and 15% diesel fuel.
While the fuel production process in the lab was only on a small scale, the process could be easily scaled up for industrial applications, according to one of the study's authors, Dr. Hanwu Lei. Furthermore, the team was able to recover almost 100% of the energy from the plastic waste products used, and they were able to even reuse the carbon catalyst for subsequent plastic conversion runs.
This new breakthrough presents one promising solution to the growing problem of plastic pollution across the globe, particularly for plastics less often recycled, like plastic bags that are particularly dangerous to animals in the ocean.