A global effort is underway to try and make use of the product, which is currently found everywhere from the human brain to sedimentary rock.
By converting plastic waste back into usable oil, experts believe they could create an almost-unlimited energy source to fuel boilers, burners, furnaces and turbines. Some trains, ships and lorries could also use the resource.
Pyrolysis, which involves heating materials without oxygen, is used in the process, and is currently capable of turning around 60% of plastic in tests back to so-called ‘bio-oil’. A recent study at Yale University in the US has since managed to boost this to a 66% yield.
The key to the experiment was a triple-section 3D-printed carbon column reactor. Each part of this has a different pore size: 1millimeter, 500micrometer, and 200nanometer. As chemicals pass through these they can control the reaction.
However, for the time being the method required to achieve this backwards conversion is considered to be inefficient and has yet to be proven at scale. Pyrolysis also requires a huge amount of energy, with plastic’s polymer chain breaking down at 900C. Both of which betray the huge environmental challenges that need to be overcome before this could be considered a viable solution to the plastics crisis.
With the current energy mix, higher temperatures would almost certainly mean greater carbon emissions to fuel the pyrolysis itself for a relatively small amount of plastic to be utilised at any one time. The rationale for creating the energy source also focuses on applications which will also contribute to further emissions — carbon and other — at a time when most of the world is focused on reducing greenhouse gas output.
It is also not clear how carbon emissions compare from plastic-based oil compare to traditional oil and gas. Meanwhile, it’s worth noting the label ‘bio-oil’ could be considered misleading. At a time when the public is highly aware of greenwashing, the political wrangling that could arise from this could threaten to overshadow any genuine advantages.
Image: Nick Fewings / Unsplash
More Energy: