Chemists in China reported a new method of breaking down polyethylene into usable fuel in a new study published in Science Advances, a report by the Tech Times says. Zheng Huang from the Chinese Academy of Sciences, along with his colleagues, ran the study.
Polyethylene, a plastic commonly used to make water bottles, food packaging, plastic film and shopping bags, does not easily degrade in the environment, according to the report. In the study, the scientists added an organometallic catalyst that contains iridium that would degrade the plastic at temperatures as low as 302 degrees Fahrenheit (150 degrees Celsius).
The catalyst weakens the bond that creates the stiff structure of polyethylene and speeds up the process of breaking down the plastic into a liquid product that can be used as fuel, the report says.
"With the use of widely available, low-value, short alkanes (for example, petroleum ethers) as cross metathesis partners, different types of polyethylenes with various molecular weights undergo complete conversion into useful liquid fuels and waxes," The Tech Times says the researchers reported.
"Common plastic wastes, such as postconsumer polyethylene bottles, bags, and films could be converted into valuable chemical feedstocks without any pretreatment."
While the method uses less energy because of its low temperature process, it is slow—taking about four days to complete. The catalysts are also expensive, according to the report, but the scientists say they can hopefully scale up the process from gram scale in the lab to kilogram and even ton scales soon.