There are many misconceptions when it comes to the materials used to create bioplastics. Lack of knowledge on different types of bioplastics have been hurting the perception of the industry for years. Some believe that bioplastics are the same as biodegradable plastics. Years ago, starch-based bioplastics may have had biodegradable properties. Henry Ford was a firm believer that the agriculture and bioplastic industries should work together. Ford built a soybean lab in the 1930s that led to the development of soy-based oils and plastics. These plastics were incorporated into Ford Motor Vo. Vehicles until research efforts were halted by World War II. The abundance of petroleum following the war killed any profits from oil-based plastics.
Bio vs. bio-based
Bioplastics are substances created from organic sources, unlike conventional plastics which are made from petroleum. Biodegradable fossil-based plastics do exist. Therefore, biodegradability is just one of many properties that plastics can have. However, it is not the only factor that determines if something is a bioplastic. The term “bio-based” is used today to distinguish these materials from petroleum-based plastics.
Natural vs manmade
Many bio-based polymers can be extracted and modified to become bio-based plastics, while retaining the natural polymer chain. Some bio-based polymers created from renewable biomass sources qualify as synthetic. These polymers are generated from bio-based monomers that become bio-based polymers through subsequent chemical reactions.
Feedstock debate
One argument against bio-based plastics deals with land usage. The two main crops grown for engineering bio-based plastics are corn and sugarcane. According to calculations by European Bioplastics, the amount of land required at the end of 2017 for this purpose equaled 0.016% of the global agricultural area.
“Even with the predicted high growth rates of the bioplastics industry over the next years, the land-use share would only slightly increase to up to 0.021% of the agricultural area by 2022,” says the association.
Manufacturers are exploring sewerage, methane, nonfood crops, agricultural byproducts, food crop waste, and more as possible biomass sources. Leading brands, including Coca-Cola Co,. Danone, Ford Motor Co., H.J. Heinz Co., Nestle, Nike Inc., Procter & Gamble Co. and Unilever, have set up the Bioplastic Feedstock Alliance, which supports the development of plastics made from plant materials and to help build a sustainable future for the industry.
“Consumers across the world increasing are looking for more sustainable products, including those made from plant-based plastics. With increasing market demand for food and fiber in the coming decades, responsible sourcing of these materials is key to enabling sustainable growth,” the Alliance states on its website.
Some are not as easily convinced and argue that 2nd and 3rd-generation feedstocks require more energy and resources to process and are more costly than food crops.
What’s the point?
Should there be such a strong push to develop bio-based plastics if they are not even biodegradable? Michigan State University professor Ramani Narayan explains that bio-based plastics reduce the carbon footprint of plastic materials. He also highlighted that plant biomass is a renewable resource that grows everywhere. Therefore, bioplastics created from biomass will have a smaller carbon footprint at the end of life. Also, the amount of carbon dioxide that is released into that atmosphere will never be greater than the original amount absorbed by the plant that created it. Conventional petroleum-based plastics are created from depletable resources and they release new carbon into the atmosphere from fossil sources when used.
What’s the solution?
Surprisingly, most bio-based biodegradable plastics only degrade under very specific conditions, such as an industrial composting facility. Biodegradable bio-based plastics may not be the overall solution to plastic waste and litter, but the industry is quickly finding functional uses and application opportunities. The ideal option would be to recycle. When recycling is not possible, the next best solution is incineration or anaerobic digestion. Until there is a circular fossil economy, replacing conventional petroleum-based plastics with bio-based plastics will not immediately result in a circular economy.
References
http://bioplasticfeedstockalliance.org/bioplastics/
https://www.corbion.com/media/255503/13-07_food_or_non-food_nova-paper2.pdf
https://www.cedelft.eu/publicatie/biobased_plastics_in_a_circular_economy/2022