In 2018, global demand for these polymers is 360,000 metric tons, but total consumption of biodegradable polymers is expected to increase to almost 550,000 metric tons by 2023. That will represent an average annual growth rate of 9% for the 5-year period, which is equivalent to a volume increase of more than 50% from 2018 to 2023.
Hackett also noted that biodegradable polymer use has grown more slowly or stagnated in places that lack mandates. “Growing consumer awareness and activism regarding environmental issues could certainly increase the market for biodegradable plastics,” she said. “To truly capture the benefits of these biodegradable polymers, however, you need to have the collection and composting infrastructure to support their use. Very few major cities or municipalities currently have the necessary infrastructure in place.”
An important distinction needs to be made between the potential for biodegradable polymers and their actual decomposition. Biodegradable polymers are compostable only in special industrial composting facilities, which operate at higher temperatures than home compost piles.
“Only a subset of biodegradable polymers is compostable in backyard compost bins; an even smaller subset is compostable in the soil or in marine environments,” Hackett illuminated. Indeed, composting of plastics waste was negligible as recently as 2014. Landfill was the primary method of disposal, responsible for 75% of plastics waste in the US. Combustion with energy recovery was 15%, and recycling accounted for 9% of the remainder. “Biodegradable or compostable polymers can play a role in diverting waste from landfills. For example, biodegradable pods for single-serve coffee makers simplify disposal of used capsules; compostable trashbags can control odors, minimize mess, discourage pests, and otherwise reduce the ‘yuck’ factor associated with residential composting programs,” Hackett said. “Diverting organic waste from landfill reduces emissions of methane—which is a potent greenhouse gas.” The key to mass advancement and adoption of biodegradable or compostable plastics is a combination of legislation, consumer attitudes, and behavior.