Recycling is kind of this cool mystical topic – where plastic leaves our homes to one day appear as a new product. We understand that plastic should be rinsed, sorted, and collected from our homes or businesses to be separated at a Material Recovery Facility (MRF) or a Plastic Recovery Facility (PRF), which sorts plastic by type – but what happens after that can also be a mystery.
Right now, there are three types of recycling: mechanical, chemical, and energy. Understanding the basic processes behind breaking down plastics via these three processes will, however, help bring some much-needed clarity to an otherwise unclear topic.
Three types of recycling processes
Most people already know about mechanical recycling. If you don’t know the terminology, you still have an idea of what it tackles…the standard recycling of plastics, paper, and glass. Mechanical recycling involves the reprocessing and modification of plastic waste without changing the polymer structure. It includes grinding, washing, separating, drying, re-granulating, and compounding processes which create plastic pellets that can perform at close to the same standard as its previous form. Mechanical recycling doesn’t change the molecular structure of the material, so the plastic pellet is still the same type of plastic that it was before it was recycled. However, since the properties of plastic deteriorate during every cycle, there are only a limited number of reprocessing cycles that are possible.
Then there’s chemical recycling, where the polymer structures of plastic are broken down into more basic building blocks, for example via chemical or enzymatic processes. While there are many layers to chemical recycling, it’s important to note that this is done so the product’s performance is never compromised for both the brand and consumer. In chemical recycling, the original materials can be remade into high-quality resins which can be used for new packaging. Though, it’s safe to say that chemical recycling can be more costly and have more negative environmental impacts than mechanical recycling if guidelines aren’t in place. Currently, due to the cost and impact, the process is better suited to complement mechanical recycling when necessary.
Lastly, energy recycling happens when plastics are incinerated in a boiler or in other industrial equipment so the high energy value can be used in the form of fuel. In some countries with no space for landfills, energy recycling is very popular. However, its use must also be balanced with the fact that it requires heavy investments and requires clear rules when it comes to incineration equipment, so emissions don’t harm the environment.
Which recycling process makes the most difference?
At this point, you’re probably wondering, “Which process is the most effective!?” or “How do I know if one process is better than the other!?”
Given the nature of each process and their use, the answer can vary. However, if we are looking for the process that keeps “waste” as a resource to manufacture new products, a key component of a circular economy, then the answer is more straightforward. For plastic specifically, the aim of the circular economy is to have the material remain in a closed loop system. So, when thinking about recycling plastic, mechanical recycling has proven to be most effective. Recycling that is used for energy recovery, or to generate fuel, doesn’t necessarily follow this framework. This means that not all chemical recycling, and none of energy recycling, supports the circular economy. Though, it’s always important to note that each method brings something unique to the table that may prove beneficial in the future. If the goal is to have a complimentary solution after several loops of mechanical recycling, then chemical recycling may be worth considering. Energy recycling, while not widely used in the US, has been shown to be an environmentally friendly, although costly alternative.
So, what’s the way forward?
Momentum is rising toward an expansion of our mechanical recycling infrastructure here in the US. As more legislation is passed to ensure that producers provide the funds to develop our recycling programs, more people will be able to recycle and divert waste from our landfills while also decreasing greenhouse gas emissions.
If you’re thinking about why all this matters beyond the basics of “reducing waste” …having different methods of recycling means that we have options that may be worth developing in the future! For other things in life, options add difficulty, just think about the last time you swiped through Hinge! Pretty sure, your dating life got more dramatic. But with recycling, more options could lead to less impact.
So, the next time you hear about recycling, be sure to recall the different recycling processes available! Ultimately, this knowledge will allow you to join in the conversation on how best to reduce plastic waste!