One major technology in the world of chemical manufacturing that has surged in interest is a way to recycle plastics that would otherwise be left at landfill.
Traditionally, the way to recycle certain types of suitable plastic is through a process of mechanical recycling. This is where plastics are sorted, shredded, removed of impurities and then melted down into pellets which are used to make other products.
It is an effective system but limits what kinds of plastics can be made, as clear plastics often cannot be recycled into other clear plastics, and thermoset plastics cannot be melted down at all, simply burning when heated up.
Chemical recycling is the name for a range of processes which break down plastics with the help of chemical agents back to their component molecules.
These can then be turned into effectively new plastic products.
There are three main ways in which chemical recycling can be undertaken.
Purification
For purification, plastics are dissolved in a dedicated solvent, before purification methods are undertaken to remove contaminants and additives from the plastic before being turned back into the desired polymer.
Because plastics are collected as mixed polymers, more intense sorting and separation is needed than with other recycling methods.
Depolymerisation
Sometimes known as chemolysis or reverse polymerisation, it turns polyurethanes and other condensation polymers into their component monomers, which can be then reused. However, it does not currently work for PVC and other addition polymers.
Feedstock Recycling
Feedstock recycling is when plastics are transformed back into basic hydrocarbon products by intensely heating them, turning them into synthetic gases, crude oils and waxes.