Recycling plastics
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Recycling
Let’s consider plastics as they are the easiest to understand. Whichever pathway is used to produce the end product, it will come to end of its useful time sooner or later. There is a wide range of ways the materials can be re-used:
If the wear and tear is not too big or the product can be refurnished with small repairs, it makes sense to resell it through a marketplace. If the product is complex and expensive, it makes sense for the vendors to offer buy-back schemes. Customer can at best case scenario use the payment to buy something else or a newer model from the vendor if the right incentive is given. In minimum they have less unnecessary things to store and a new customer can get the product at lower value.
If this is not possible, the materials can be mechanically grounded up, reheated and made into a new thermoplastic. For thermoset plastics the product might find use as a filler is some cases.
If mechanical re-use is not possible, it’s possible to break down the plastic back into monomers either in hydrolysis or pyrolysis. Hydrolysis (”to split water”) use water to breakdown polymers into monomers. It break polymer bonds and release energy. Temperature and pressure need to be controlled and sometimes acids or bases are used as catalysts. In pyrolysis the plastics are heated in high temperature in the absence of oxygen. This breaks it into smaller molecules such as gases, liquids, and solid residues.
The image below shows the high-level overview:
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