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.
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