There’s probably no need to remind you that plastic is extremely harmful to our environment, and that the current methods of recycling might be doing more harm than good. So when breakthroughs in the latter are made it’s always good news. This has now been achieved by a team of scientists from the University of California, Irvine (UCI), and the Shanghai Institute of Organic Chemistry (SIOC) in China. They have discovered a way to turn plastic into a usable liquid fuel. That’s kind of like killing two birds with one stone.
Since plastics do not react to most chemical compounds, they are also not readily or easily broken down by substances used to recycle other materials, and this is where the problem lies. To recycle plastic right now, the process either employs caustic chemicals or requires heating to more than 700° F (370° C) which produces harmful byproducts such as hydrocarbon gas, oil, wax, and char. The new method found by the scientists successfully breaks down the polyethylene yet creates few and manageable toxic by-products.
In the process, the by-products of petrochemical production known as alkanes are used to separate and reconstitute the polymer molecules of plastic into other useful compounds. This process is known as cross-alkane metathesis, and it’s basically a double-dissolution chemical reaction in which two parts of two substances form two new substances. As such, the new method selectively degrades a variety of PE plastics into fuels and waxes. This is done in a more controlled manner and using lower temperatures than the processes currently in use. According to the scientists, this new method can be used to completely degrade plastics into oils and waxes in just one day at only 347° F (175° C).
They will continue working on the method, first addressing efficiencies, such as increasing catalyst activity and lifetime, as well as reducing running costs, and evolving the processes so they can be expanded to all types of plastic waste.