What Do Bioplastics Mean For Us & How Do They Work?

What Are Bioplastics?

Bioplastics are alternatives to conventional, petroleum-based plastics that replicate their structure by manufacture of biomass, such as vegetable oils and food waste.

Plastics are pliable, light, and extremely durable materials found in likely thousands of objects with which you’ve interacted. However, it’s a huge problem that plastics are so durable, that they can stick around for hundreds of years. And we love them so much that we’re filling the Earth with toxic plastics far, far more quickly than they can break down. Humans produce 300 million tons of plastic waste every single year, weighing almost as much as all people on earth combined. All of this waste ends up in every ecosystem on Earth, including in our own bodies.

Using biomass materials to construct bioplastic alternatives is an attempt to replace plastic production with materials that can biodegrade and/or use more sustainable (and less toxic) materials. There are a range of bioplastics, each with different characteristics attributable to different manufacturing processes and source materials. The market for bioplastics is very small in relation to that of conventional plastics, estimated at only 2.44 million tons globally in 2020, but it is growing and exposed to undergoing advancements in research and technology.

How Are Bioplastics Made?

Plastics are made up of long, durable carbon polymer chains. These types of molecules are readily found in petroleum beneath the Earth’s surface, which is why we traditionally use that material for plastic production. These petroleum-based carbon polymers are why plastics are so strong, but also why they take so long to decompose.

Bioplastics are manufactured to replicate the same carbon polymer structure using more sustainable materials and processes. Two common bioplastics, PLA and PHA, replicate these structures through different methods.

Do Bioplastics Matter?

Permanent bioplastics … can provide a near-perfect substitute for oil-based equivalents in products where durability and robustness is vital. Plastics made from biological materials generally need far smaller amounts of energy to manufacture but are equally recyclable. … Per tonne of finished products, the global warming impact of the manufacture of bioplastics is less, and often very substantially less, than conventional plastics

- Carbon Commentary

The use of bioplastics could be enormously significant in place of conventional plastics due to the behemoth amount of plastic produced and consumed by contemporary economies — over 30 million tons of plastic every year in the United States alone (only 10% of which gets recycled).

The ability of bioplastics to achieve sustainable viability likely rests on the following, among other factors: 1) availability of renewable source materials; 2) efficiency of manufacture, in materials and energy; 3) means of disposal and reuse; and 4) efficacy and variety of bioplastics in comparison to conventional plastics.

While different bioplastics have different properties (and consequently stack up differently when compared to petroleum-based plastics), many of these properties can be leveraged for significant environmental impact, especially in the pre-use section of their lifecycle (i.e., materials sourcing and manufacture).

However, we rarely are prepared to handle the post-use (and re-use) of bioplastics in a sustainable way, so many bioplastic-based products still end up in part in landfills, oceans, and in our bodies. While bioplastics may emit less carbon after disposal, they nevertheless add to a growingly outsized amount of plastic waste lingering on Earth (9 billion tons of plastic produced since the 1950s, and growing).

Since bioplastics are all a little different, from what goes into them to how they’re made, they often share harmful side effects of petroleum-based plastics. While many bioplastics are not only defined as bio-based, but often also intended to be biodegradable, many types may take decades or centuries to biodegrade, if at all, unless routed to specific industrial processes (only then if there are proper facilities and capacities for those processes). For example, PHA may only degrade in water and PLA needs to be industrially processed to be broken down under very specific conditions. Further, virtually no bioplastic in a landfill will biodegrade, since those conditions deprive the material of any oxygen — if anything, those conditions cause bioplastics to degrade into methane, one of the most harmful greenhouse gases.

So while the benefits of bioplastics — that largely define what they are and why they are produced — are contributing, and are important, their presence alone isn’t enough to create the impact that people may imagine they have. The plastics themselves aren’t enough to generate these impacts and a critical definition of their potential lies in the infrastructure around them.

References

  1. “BIOPLASTICS MARKET — GROWTH, TRENDS, COVID-19 IMPACT, AND FORECASTS (2021–2026),” Mordor Intelligence, https://www.mordorintelligence.com/industry-reports/bioplastics-market
  2. Cho, Renee, “The Truth About Bioplastics,” Columbia Climate School, December 13, 2017, https://news.climate.columbia.edu/2017/12/13/the-truth-about-bioplastics/
  3. “The Pros and Cons of Bioplastics,” Green Home, July 7, 2008, https://greenhome.co.za/blog/the-pros-and-cons-of-bioplastics/
  4. “Polylactic Acid (PLA): The Environment-friendly Plastic,” The 3D Insider, November 9, 2017, https://3dinsider.com/what-is-pla/
  5. “The Basics of Bioplastics,” UrthPact, Mar 29, 2018, https://www.urthpact.com/bioplastics-basics/
  6. Goodall, Chris “Bioplastics: an important component of global sustainability,” Carbon Commentary, September 2, 2011, https://www.carboncommentary.com/blog/2011/09/02/bioplastics-an-important-component-of-global-sustainability
  7. Thombre, Aditi, “Can Bacteria Degrade Plastic?,” Science ABC, April 12, 2021, https://www.scienceabc.com/eyeopeners/can-bacteria-degrade-plastic.html
  8. Morales, Raul, “Why Bioplastics Are Not (Yet) the Solution to Plastic Pollution,” HAY! Straws, April 27, 2021, https://www.haystraws.com/blogs/hay-straws/bioplastics

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