The global plastic waste crisis has reached a point where simply reducing usage is no longer enough. While biodegradable plastics have long been proposed as a solution, they are often criticized as an expensive alternative that fails to disappear quickly in nature. However, a groundbreaking review published in the journal Engineering suggests we have been looking at these materials all wrong.
A research team led by Professors Dongyeop X. Oh (Korea University), Jeyoung Park (Sogang University), and Hyeonyeol Jeon (KRICT) proposes a fundamental paradigm shift: redefining biodegradable plastics as high-value, energy-efficient resources for a circular economy. To date, these materials have been largely viewed as “disposable waste” intended only for reduction. This study demonstrates that their true potential lies in their superior chemical recyclability and economic value.
The Science of “Easier” Recycling
The core issue with current plastic management is the linear “produce–use–dispose” model. While traditional plastics like polyethylene (PE) or polypropylene (PP) are durable, they are held together by robust carbon–carbon bonds that require immense energy—typically between 150 and 250 kJ/mol of activation energy—to break down during recycling. In simple terms, recycling them is an energy-intensive and costly struggle.
In contrast, biodegradable plastics like polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT), and polybutylene succinate (PBS) are built with polyester-based structures. The study reveals that these materials require significantly less energy—specifically, less than 100 kJ/mol of activation energy—to be disassembled back into their original building blocks. This fundamental difference means biodegradable plastics can be chemically recycled with far less power and higher efficiency than traditional petroleum-based plastics. They are not just “temporary trash” but are effectively high-efficiency “circular assets” that make the recycling process more economically viable.
Beyond Composting: A Multi-tool for Energy
The research also challenges the assumption that composting is the only end-of-life solution for these materials. Through detailed life cycle assessment (LCA) insights, the authors prove that chemical recycling offers much better environmental and economic outcomes. For instance, composting 1 kg of PLA requires nearly 11 times more fossil energy than mechanical recycling and releases fixed carbon back into the atmosphere without any material recovery.
Conversely, when treated as a resource, biodegradable waste becomes a multi-tool for the 21st century. It can be chemically upcycled into virgin-quality materials or converted into methane gas for heating, biochar for carbon storage, and even nutrient-rich fertilizers for agriculture. By shifting the focus from simple disposal to energy and resource extraction, we transform a waste problem into a profitable solution.
An Environmental Fail-safe
Importantly, the study addresses the role of these plastics if they accidentally leak into the environment. Unlike traditional plastics that persist for centuries, biodegradable materials are designed to break down naturally if they escape waste systems. The researchers argue we should view this biodegradability as an “environmental insurance policy”—a safety net that protects ecosystems while the primary goal remains high-value recovery.
In conclusion, the research provides a strategic roadmap for a sustainable society. By elevating biodegradable plastics from simple waste management to the center of energy and material recovery, we can achieve true carbon neutrality without sacrificing economic growth. As major economies like China, the European Union, and the Republic of Korea pivot toward these sustainable strategies, it is time to stop seeing biodegradable plastic as a problem to be buried and start seeing it as a valuable resource to be recovered.
The review article, titled “Reframing Biodegradable Plastic as an Effective, Chemically Recyclable Resource for a Circular Economy,” was authored by Sungbin Ju, Seonghyun Chung, Sung Bae Park, Jun Mo Koo, Giyoung Shin, Hyeonyeol Jeon, Jeyoung Park, Dongyeop X. Oh. It was published in the journal Engineering. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.12.040. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.