[Square] Recycling, Carbon Reduction, Biodegradation... Directions of Global Environmental Policies

Professor Yoo Young-sun, Department of Biotechnology, Catholic University

The issue of plastic waste disposal has come to the forefront due to the surge in plastic usage. Since the inauguration of the Biden administration, the United States has emphasized carbon reduction to combat global warming. In particular, with efforts to rejoin the UN Climate Agreement, which it withdrew from in 2019, global interest in carbon reduction is rising.

Worldwide environmental policies for carbon reduction and earth protection prioritize reduction first, recycling second, and the use of bioplastics third.

The top priority, reduction, fundamentally means minimizing the use of plastic itself, which is the most desirable approach. However, since there are limits to reducing usage, attention is focused on the possibility of simultaneously advancing reduction and recycling. Examples in use include bottle caps with reduced plastic content, PET bottles with reduced heat-sealing areas, and biobased plastics substituted with plant biomass. Recently, the industrialization of packaging materials replaced by paper and plant biomass is accelerating.

The second priority is recycling. In countries with high population density like South Korea, the use of biodegradable plastics, which are difficult to recycle, is discouraged, and the use of products that are easy to recycle is recommended. Since South Korea’s basic law is the “Act on the Promotion of Saving and Recycling of Resources,” greater efforts in reduction and recycling are required.

Recently, biobased plastics with the same molecular structure that are easy to recycle and partially replace plastic usage with plant biomass have become an alternative. In the case of paper, water-resistant (耐水性) surfaces are coated with vinyl (PE), which makes recycling difficult. Water-soluble coated paper products that solve this problem are gaining attention as substitutes. Currently, all coated paper products must be disposed of in volume-based waste bags. The industry points out that despite the difficult development and commercialization of easily recyclable water-soluble coated paper products, having to discard them in volume-based waste bags is actually hindering industrialization.

The third priority, bioplastics, includes biodegradable plastics that are difficult to recycle and therefore should only be applied in areas where recovery or recycling is challenging compared to general products. Instead, the use of easily recyclable biobased plastics, carbon-reducing plants, and natural materials should be expanded.

Biodegradable plastics have the limitation that most raw materials are imported, in addition to the difficulty of recycling. Due to the impact of COVID-19, smooth imports are currently difficult, and there is almost no domestic biodegradable raw material, predicting a supply crisis for biodegradable products such as approved biodegradable plastic bags. Urgent alternatives are needed.

Among biodegradable plastic products, PLA (eco-friendly resin) disposable plates are made of biodegradable plastic material that is difficult to recycle and must be disposed of in volume-based waste bags. However, consumers are largely unaware of this. Globally used biodegradable plastics for carbon reduction overwhelmingly consist of plastic-based synthetic polymers rather than carbon-neutral plant-based starch or cellulose raw materials. Ultimately, the use of synthetic polymers that decompose better than plant-based raw materials is being promoted. Especially in South Korea, raw materials for biodegradable plastics are limited to PBS (poly butylene succinate) and PBAT (polybutylene adipate terephthalate), synthetic polymers derived from plastics. Biodegradable plastics for carbon reduction are ironically turning into a situation that encourages the use of chemical products.

Professor Yoo Young-sun, Department of Biotechnology, Catholic University