Does Plastic Recycling Work?
The Benefits and Limitations of Recycling
Plastic is a miracle material. Since it was introduced nearly seven decades ago during the third industrial revolution, plastic has become ubiquitous. The challenge today is to clean up the waste from the era of throwaway culture and advance toward a more sustainable circular plastics economy.
Recycling offers the potential for sustainable plastic usage without the adverse effects of pollution. But recycling, on its own, is not enough to overcome the vast amount of plastic waste that has been created.
This article, the second in a series looking at plastic and plastic pollution, will examine both the positives and negatives which must be carefully weighed to assess how best to approach plastic recycling.
Pros of Recycling
Reduction of Plastic Waste in the Environment
Today, an estimated 300 million tonnes of plastic end up in the waste stream annually. To put this in perspective, the entire weight of all 7.75 billion people alive is approximately 321.9 million tonnes. Humanity creates its own weight in plastic every year.
It’s estimated that there will be 12 billion tonnes of plastics littering the aquatic and terrestrial environment by 2050 if we persist at the current rate of plastic pollution without recycling. Plastics in the ocean choke marine life, threaten food security, and lead to increased flooding due to clogged drainage systems. Animals and livestock on land can also mistake plastic for food resulting in serious health consequences. Added to these threats are the known and unknown long-term impacts of microplastics, including abrasion on the digestive systems of organisms that eat them and the fatal accumulation of these microplastics in their systems. Plastic recycling can reduce this impact by preventing plastic waste from ending up in the environment in the first place.
Value Recovery and Creation
There is value in used plastics, and if this value is fully harnessed there could be an abundance of materials for manufacturing new products. We currently only recycle about 9 percent of the plastics we produce. This seems like a tragic underutilization of resources, especially when you consider the types of products and the amount of energy that can be recovered.
Recycling offers the possibility of an effective post-consumer plastics economy. Advancement in recycled polyethylene terephthalate (rPET) means PET bottles can now be recycled back into the same food-grade PET bottles with little or no loss in value. Promising results have also been seen in the pilot-scale study for food-grade recycled polypropylene.
Recycling also creates value in the form of jobs, income, and revenue. For example, the UNFCCC reports how plastic waste collection has empowered women in Ghana. Across the world, various companies of all sizes have been formed around recycling, all of which potentially create jobs and income for more people.
China had been importing waste plastics from other countries for recycling since the 1990s and was among those countries that recognized the value of plastic waste and could harness at least a portion of it. However, in 2017, it began to ban imports as managing domestic waste became more challenging and as data revealed that over 70 percent of the imported waste was eventually discarded.
Augments Other Plastic Waste Management Strategies
On its own, recycling won’t solve the global plastic pollution challenge. It will require multiple approaches and efforts from all stakeholders to move toward a more sustainable and fully circular plastic economy. The World Economic Forum presents a roadmap for integrating multiple measures, including imposing bans on plastics, designing more sustainable products, and developing more effective alternatives.
The elimination of unnecessary plastic use reduces the volume of plastic that can end up as waste. This reduces pressure on recycling infrastructure so that recyclable plastics can remain in the cycle for as long as possible.
Cons of Recycling
Requires Energy and Releases Carbon Emissions
Energy is consumed at all stages of the recycling process. Even before it gets to the recycling facility, energy is consumed to collect, source, and transport the materials to the factory. Automated sorting requires machinery and labor resources, and plastics must be cleaned, shredded, and broken down into smaller particles.
Heat and mechanical shearing then melt and reform the plastic into smaller pellets that can be sold to plastic manufacturers or processed in-house. More energy is then required to form these pellets into new products.
In 2015, the combined emission from landfilling, recycling, and incineration was estimated to be 1.8 billion metric tonnes of carbon dioxide. Plastics are on course to contribute 17 percent of global emissions by 2050.
Some of this can be addressed through renewable energy sources. Some studies have also explored the possibility of powering mechanical plastic recycling with energy sourced from the chemical recycling of plastic, but at the current level of technology, this has been prohibitive for large-scale commercial applications. Powering recycling with 100% renewable energy can bring down the emission by 51 percent.
Not All Plastics Can Be Safely and Efficiently Recycled
There are many different types of plastics, each with its own properties and attributes. The resin identification number 1 to 6, which are indicated in between the chasing arrows recycle sign, are assigned to the most common ones which are most polluting. These are PET (polyethylene terephthalate), HDPE (high-density polyethylene), PVC (polyvinyl chloride), LDPE (low-density polyethylene), PP (polypropylene), and PS (polystyrene).
The number 7 refers to all other plastics such as nylons, ABS, polycarbonates, and many more. Plastic shopping bags for example are mostly made using LDPE, plastic drink bottles are usually made using PET, and takeaway bowls are made from PP. Not all these types of plastic are equally well suited to recycling.
Mechanical recycling of plastics can degrade it to the point that many plastics lose their physical properties after it’s recycled the first time. Virgin plastics must often be added to recycled plastics to retain some of these properties.
Additionally, stains, glues, labels, printed inks, and other impurities all contribute to less efficient recycling. A green plastic bottle is more difficult to recycle than a clear one, for example. Recent technologies have been introduced to remove ink from plastic packaging. However, this has yet to be scaled up for commercial use.
Further, plastics such as polystyrene and PVC can release toxic compounds during recycling which can result in serious health hazards. Manufacturers must therefore consider the end of life of the product or packaging during the design and production stages.
Collecting and Sorting Plastic for Recycling
Although often overlooked as technically uncomplicated, the process of collecting and sorting plastic poses a major challenge to large-scale recycling.
Once a piece of plastic is out in the environment it is very difficult to get back. It could be washed up on a beach, drifting across an ocean, clogging drainage infrastructure, inside the bellies of whales, or blown around a city street.
As the pressure increases on companies to use more recycled plastic, the surge in demand has increased the price. Recent reports show that the price for rPET has risen to $1 per pound compared to the fraction of a dollar that virgin PET costs. This emerging scarcity is not due to the lack of used PET, there’s plenty in the ocean or landfills, but instead due to the resource input that is required to collect and sort them to get them to food-grade quality.
Redefining the Age of Plastics
Plastic is not inherently harmful to the environment. It is the misuse and mismanagement of plastic that poses the biggest risk. On the flip side, if we could optimally harness the benefits of what was, and still is, a miracle material, we can redefine the age of plastics as one of abundance, sustainability, and endless possibilities.
The ideal plastic cycle is one where the material is produced sustainably, used repeatedly, and, at the end of life, converted back into raw materials to repeat the cycle perpetually.
Whether or not this is possible depends on the technology available. Optimal utilization of the tools of the fourth industrial revolution can greatly assist in creating a more circular plastic economy. Tools such as near-infrared spectroscopy can assist automated sorting and improve the purity of recycled materials.
UNEP estimates that the cost of cleaning up plastic pollution in the future far exceeds what it would cost to implement strategies to stop plastics from littering the environment today. Considering the advantages and disadvantages, at the very least, plastic recycling becomes necessary to keep the plastic in the supply loop for as long as possible.
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