Biodegradable materials and bioproducts: the same or distinct?

The Common Misconception

If you are puzzled by the title thinking, “Wait a minute, aren’t biodegradable materials and bioproducts materials synonymous?”. In short, not always. Additionally, these words are not to be confused with biomaterials1 which have a completely different meaning (materials engineered to interact with biological systems).

Biodegradable products

Biodegradability refers to the material characteristics at the end of its usage. If a material can be broken down by bacteria, fungi, or enzymes (produced by bacteria to accelerate the process) into its elements or other compounds, then it is biodegradable. The time it takes an item to biodegrade depends on several factors including temperature, type of microorganism, and humidity. Are all biodegradable products biobased? No. For example, polybutylene succinate and polyglycolic acid2 are petroleum-derived products that are biodegradable. So, for reference, what are the typical degradation times for common items? Read the infographic below for more info.

Infographic from Be Green Packaging

Bioproducts

As shown above, biodegradability refers to the end of the life of the material. On the other hand, bioproducts describes the origin. Materials derived from biological or renewable resources like wood, plants, and waste3, are classified as bioproducts. The National Renewable Energy Lab (NREL) has research dedicated to using waste streams to create bioproducts.

Are all bioproducts biodegradable? No. In fact, bioplastics are known for this ambiguity. Depending on the type of plastic, it might still be sent to the landfill, recycled, or composted4. An article from the National Geographic mentions that if a specific location does not have a composting facility to accelerate the breakdown of these plastics, then that plastic will end up in the landfills. The term bioproduct is misleading because it implies a totally ecofriendly product. Bioderived is a more suitable term and should be used instead.  Some excited research that is being at the National Bioenergy Lab at NREL has been using algae for the production of fuels, food, and other products. Take a preview of the 360˚ algae lab!

Biodegradable bio-derived products

There are some bioproducts that are also biodegradable. For example, polylactic acid (PLA) is a bioplastic made from plant sugars recognized for its biodegradability. The solution to all right?! Not quite. As previously mentioned, biodegradation depends on several factors like temperature, microorganisms, and environment. For PLA, temperatures above 136˚F5 are required for the degradation process. This means that if a PLA straw ends up in the ocean, it will likely stay in the ocean without biodegrading for unknown time periods. Take a look at the types of plastics based on biodegradability and source below.

The Benefits of Bioproducts

Although bio-derived products are not necessarily biodegradable, they still provide several benefits. They are not derived from petroleum and depending on the type of source, give net-zero carbon emissions as a result of the carbon dioxide consumed during photosynthesis. Nicholas Rorrer, a polymer engineering researcher at the National Bioenergy Center, shares the value of bio-derived materials, “The power in bioproducts is they have functionality (or stuff) that has enhanced properties … [b]ut I think the real potential is that the handles/functionality it [bioproducts] has can enable reversible materials easier than current petrochemical pathways, and that is where I see the best promise.” The future for bioproducts is exciting, and I am enthusiastic about what technology and research has in store for the.

To answer the question in my title, biodegradable materials and bioproducts are distinct. There are some cases where they are the same but not always. Make sure to keep your eye out on these products!

Important takeaways

  1. Biodegradable products ≠ bioproducts
  2. Biodegradability depends on several conditions
  3. Not all biodegradable products can biodegrade in ambient environment
  4. Bioproducts are derived from biomass
  5. Bioproducts do not use petroleum, give net-zero carbon emissions, enhanced properties, and reversibility
  6. Bioproducts can be made from waste streams, enabling a circular economy

Thanks for reading!

References

  1. Biomaterials. (n.d.). Retrieved from https://www.nature.com/subjects/biomaterials
  2. Biodegradable plastic. (2020, March 24). Retrieved from https://en.wikipedia.org/wiki/Biodegradable_plastic
  3. Biomass explained. (n.d.). Retrieved from https://www.eia.gov/energyexplained/biomass/
  4. Gibbens, S. (2018, November 21). What you need to know about plant-based plastics. Retrieved from https://www.nationalgeographic.com/environment/2018/11/are-bioplastics-made-from-plants-better-for-environment-ocean-plastic/
  5. Krieger, A. (2019, July). Are bioplastics better for the environment than conventional plastics? Retrieved from https://ensia.com/features/bioplastics-bio-based-biodegradable-environment/
  6. Cover image from https://plantd.co/why-we-support-plastic-free-july-join-us%EF%BB%BF/