Nearly everyone touches plastics every day. Plastic film, for example, is used to make the thin bags for bread, produce, dry cleaning, newspapers and takeout food boxes. Cases of water bottles and multi-packs of paper towels are shrink-wrapped with plastic film. The plastic air pillows that are used as cushioning in packages are made from plastic film. Plastic film also has a ton of commercial applications, including its use as pallet wrap.
But despite it being such a common and abundant material, there’s still a lot of confusion about how to recycle plastic film packaging. The topic of plastics recycling in general remains a confusing topic for many people, understandably. We know that some types are more easily recycled than others, but it’s easy to get mixed up about what kinds of plastic can go in a bin of mixed recyclables and what kinds belong in the trash. MIT recently shared some promising new research that could make plastics recycling easier and more productive.
Plastic Film Recycling
Plastic film packaging, commonly made from polyethylene (PE), can be recycled into new materials. It can be made into composite lumber or turned into small pellets that are then used to create new plastic bags or other items.
That said, the major barrier to recycling plastic film packaging is its tendency to get tangled in recycling equipment. That’s why municipal recycling programs typically tell residents not to put any kinds of plastic bags or plastic wrap in their curbside bins. Commercial businesses that generate large amounts of plastic film waste, however, have other disposal options. Including your recycling service which should be able to collect plastic film along with your other recyclable waste and may even pay you for this material.
New MIT Research Turns Recycled Plastic Into Propane
MIT researchers have had promising success with a new system for recycling some of the most common plastic types including PE products like plastic film and polypropylene (PP) products like plastic toys and utensils. A team from MIT’s department of chemical engineering did the research and published the findings in October 2022.
Speaking to MIT News, the lead author of the research (Yuriy Román-Leshkov) explained that plastics are difficult to recycle because their molecules are held together by chains of “very stable” carbon bonds. Those bonds are hard to break in a controlled way. (Picture breaking a sheet of glass by dropping it on the ground; you’re not going to have much control over the shape and number of broken pieces.) So, existing recycling methods break plastic down into a mix of molecules that have to be further refined before they can be used. That obviously adds to the expense and difficulty of recycling plastic.
The MIT team treated mixed recycled plastic with a microporous material that included cobalt, a chemical element that’s commonly extracted as a by-product of copper mining. They discovered that the cobalt catalyst reacted with the plastic polymer in a way that broke the carbon chains in a consistent way, producing molecules of propane. The researchers were able to convert 80 percent of the plastic polymers into propane.
Converting abundant materials like plastic film and food containers into propane, which can then be used as fuel or to make new plastics, is an exciting possibility for the recycling industry. The MIT team also noted that they used materials that are cheap and widely available.
However, there are a few challenges ahead. Researchers have to do a lot more testing to determine how well the cobalt catalyst works on plastics that have been contaminated with ink, glue or other materials. There’s also the matter of sourcing large amounts of cobalt. Most of the world’s cobalt supply comes from the Democratic Republic of Congo, where human rights and environmental issues plague cobalt mining.
Cobalt is also a vital component for building electric vehicle batteries, so auto manufacturers are going to need more and more of it as the global “EV boom” goes on. Because of the increasing demand for Congo’s cobalt supply and attention on its mining practices, it’s unclear whether cobalt will remain a readily available and relatively cheap resource.
Miller Recycling is your source for recycling industry news, as well as any recycling services your business might need. If you have questions about getting rid of plastic film and other plastics—or any of the other waste that your business generates—contact me today.