Chemical Recycling? Not so Fast

05 May 2021
0 Comments

Only 15% of plastic is recycled. That means 85% of it ends up in landfills and incinerators. Right now, we depend on mechanical recycling to overcome that huge environmental burden. But what if there was another method of recycling? One that could complement the methods we already use.

There’s been a lot of talk around how chemical recycling could be that method, but the truth is, we just don’t know enough yet to give you a straight answer. So, we’re dedicating this blog post to introducing you to the concept of chemical recycling, the potential benefits and, of course, the unknowns (spoiler alert: there are a lot of them). Before we get to those...

What’s the Difference between Mechanical and Chemical Recycling? 
During the mechanical recycling process, plastics are broken down into smaller parts that are melted and remolded to create lower-grade plastic products (think plastic crates, lumber, fencing, and textiles). The problem is, the quality of a plastic item is affected every time it’s recycled, which means that the number of times it can be recycled is limited. Ideally, we want plastic to keep its value long term.

While mechanical recycling takes good care of Polyethylene Terephthalate, or PET plastic (soda or water bottles and plastic jars) and High-Density Polyethylene, or HDPE plastic (washing detergent and shampoo bottles), it can get difficult to recycle more complex items. Which is what chemical recycling claims to do.

The chemical recycling process works by breaking up the molecular chain of a plastic item and using the (molecular) fragments to create a new product. The end result? You see no difference between a ‘virgin’ plastic product, and a recycled one. This process could also make it possible for plastic to be recycled over and over. Next up, some examples.

New Life for a Wider Range of Plastics?
Unless colorants based on soot particles are used, black plastic is notoriously difficult to recycle (when sorted using machinery, it’s passed over by scanners because it doesn’t reflect light). But, if recycled using the chemical recycling process, color is irrelevant. That goes for other difficult-to-recycle products too (any item that is made up of multiple materials and layers. Think yogurt containers).

Thin films and microplastics are also difficult to recycle using the mechanical recycling process. They get trapped in machinery (because of their size and strength), potentially causing the whole system to get stuck. Another problem chemical recycling claims to solve.

Now: The Unknowns
While there is potential, there’s still a lot of information (and evidence) we need before we can confidently say that chemical recycling is a safe supplement to mechanical recycling. Does chemical recycling perpetuate the use of hazardous chemicals? How much fuel does it take to power the process, and how much does that contribute to greenhouse gas emissions? Do the benefits outweigh that expenditure? Is the yield (the return over time) worth it? These questions will only be able to be answered over time.

Verdict: Mechanical and chemical recycling have something important in common. They both keep carbon in the loop. But, while chemical recycling holds a lot of promise, not only ecologically, but economically as well, the technology needs to get beyond ‘pilot phase’ before we really know and understand its power and impact. Watch this space.




Join ReSociety

Can't wait to hear more?

Join the movement, become a member of ReSociety!

Get Free Membership

Comments

Subscribe to our Blog