Amid global outcry for oceans and lands filth caused by the use of man-made plastics, scientists have device a technique to turn plastics waste into liquid fuel with less energy than previous one and produces a higher quality end product.
Polyethylene is the most abundant plastic in the world, used to make virtually everything from plastic film and food packaging, to water bottles and shopping bags. Statistics shows that around 100 million tonnes of plastics is produced every year.
A report earlier this year says that 95 percent of plastic is thrown out after being used just once, and 8 million tonnes of plastic – or one garbage truck-full every minute – ends up in our oceans each year.
Method For Converting Waste Plastics into Liquid Fuel
The combined team of researchers from the Chinese Academy of Sciences and University of California deviced the technique which involves mixing the plastics with an organometallic (chemical) catalyst normally used to produce polymers, and sets them to breaking down polymers instead.
The reaction caused the bonds holding the plastic together to weaken, allowing them to be more easily torn apart. After which the team was able to use the broken down material to create a diesel-like fuel which they claim could be used to power vehicles and other motors — they report that burning the fuel is also cleaner than burning other combustible materials.
As Fiona MacDolnard reported, “In a business-as-usual scenario, the ocean is expected to contain 1 tonne of plastic for every 3 tonnes of fish by 2025, and by 2050, more plastics than fish.”
This has plunged scientists into frantic researches to find a lasting solution which is; to turn plastic waste into a commodity that people can actually use, and given all the hydrogen and carbon that makes up polyethylene, liquid hydrocarbon fuel is the obvious choice.
Now, recycling has been the only option for reducing polyethylene accumulations, but even though they are made from fossil fuels, converting it back to its base parts has been a massive challenge, because of how stable plastic is as a chemical compound.
One of the team, Zhibin Guan, who’s a synthetic polymer chemist said, “If you leave plastic in the ocean or the environment or you bury it underground, it’s going to stay there for hundreds or thousands of years.”
“If you try to heat them at more than 400 degrees Celsius (which some methods do), they collapse into all kinds of combinations, resulting in a messy mix of gas, oil, wax and char that’s not especially useful.”
However, this new method only require heating (far less energy than similar techniques) at around 175 degrees Celsius (347 fahrenheit) – rather than 400 degrees (752 fahrenheit) – to break down the plastic, it uses. But the downsides are the process is slow – taking about four days to complete – and the catalysts are expensive to use.
Robert Service explained:
“For starters, the catalysts break down polyethylene slowly, over the course of a day or more. They are also expensive and decompose after breaking apart just a few thousand polymer chains, far less than the millions carried out by most commercial catalysts.”
The good news is, Guan and his colleagues are working to overcome those problems, in the hopes that they can one day extract new value from the millions of tons of plastic waste that we discard every year.