The plastic industry can be broken down into various different components — one of them being the type of polymer. Globally, Polypropylene (PP) is the most produced type of virgin plastic and is used for things like laboratory equipment, automotive parts, medical devices, and food containers, yet it is not the most recycled type of plastic. In fact, only around 1–3% of the PP produced is recycled but the demand for Polypropylene, which amounts to 720 million pounds of high-quality recycled PP a year and makes up 19.3% of total plastic demand, is greatly underserved. On the other hand, demand for HDPE and PET, the most commonly recycled plastics amounts to 12.3% and 6.7% of total plastic demand respectively. The automotive industry uses the most PP and is leading the way in incorporating recycled polypropylene into the manufacturing process. Automobiles are actually the most recycled product globally, particularly in the US where cars tend to be larger and use more plastic. However, in the US despite it being the 16th largest industry, most auto recyclers are small businesses employing no more than 10 people and end up including plastic car parts as “auto shredder residue” and sending it to landfills.
The main challenge to increase the rate of PP recycling seems to be a lack of technology to properly recycle post-consumer PP. However, there have been numerous advancements that are making it possible, suggesting that the bigger obstacle is a lack of investment from businesses using PP to make the sustainable switch. Two companies, in particular, led the way in PP recycling innovation. NexTek Inc., based in the UK, developed a technology to decontaminate food-grade polypropylene for reuse. Another start-up, PureCycle joined with P&G and scientist John Layman to develop technology for an efficient process to clean Polypropylene by purifying it at the molecular level in order to produce clear, odorless, non-toxic pellets. Therefore, the technology exists but is it worth it? For the environment — yes. For companies choosing between investing in virgin PP or recycled PP — not quite.
Unfortunately, the technology is not widespread enough for it to be economically feasible for recyclers to adopt the right machinery and processes without a considerable financial expense. The timing with COVID-19 impacts now makes it even more difficult as virgin plastic is currently much less expensive, thus product manufacturers that are not sustainably-minded are more likely to continue choosing virgin Polypropylene instead, adding to the plastic pollution we are already facing. However, it should be taken into account that the process implemented by PureCycle only uses 1/7th the amount of energy that is required to produce virgin Polypropylene and the output is virgin quality recycled plastic. When comparing the energy consumed for the recycling process and transportation between virgin PP and recycled PP, the cut-off results show that recycled PP uses 35% of the energy used for virgin plastic. Open-loop results find that recycled PP requires 68% of the energy that virgin plastic requires. When comparing water consumption, similar results are found. Recycled PP resin pellets consume 54% as much water as virgin resin using the cut-off recycling method and 77% as much water when implementing the open-loop recycling method. This translates to 471 gallons of water saved per 1000 lbs. of recycled resin produced.
Overall, recycled resins beat their virgin counterparts when it comes to being more environmentally friendly in terms of energy use, water consumption, and global warming potential. What is missing are more companies making the effort and including recyclability in the design process. For example, Toyota has made recycled plastics 20% of the total plastic content in their vehicles, the Fiat Chrysler Group reported that all vehicles sold in Europe were 95% recoverable and 85% recyclable, and Volvo announced its target that 25% of all plastics in vehicles produced from 2025 onwards were recycled plastics. More brands must join in making the commitment and investing to minimize their environmental footprint any way they can, and the only way to make that happen is for consumers to hold these companies accountable. Once this starts becoming the norm, most companies will be forced to follow. To make that happen, consumers must also put pressure on their local governments to implement policy and legislation that mandates sustainable manufacturing and waste management processes in order to encourage companies to make the financial investment and provide the recycling industry with a market rather than continuing to produce virgin plastic that ends up in our environment.
Sources:
https://www.weforum.org/agenda/2016/10/how-car-manufacturers-can-reduce-waste/
Automotive Recycling Devalued is now Revalued Report by SPI: The Plastics Industry Trade Association
https://www.plasticexpert.co.uk/which-car-manufacturers-use-the-most-recycled-plastic/
Bataineh, Khaled M. “Life-Cycle Assessment of Recycling Postconsumer High-Density Polyethylene and Polyethylene Terephthalate.” Advances in Civil Engineering 2020 (2020).
Gallone, Toni, and Agathe Zeni-Guido. “Closed-loop polypropylene, an opportunity for the automotive sector.” Field Actions Science Reports. The journal of field actions Special Issue 19 (2019): 48–53.
