Bio-based Polyethylene: A Sustainable Solution for Plastic Waste

By Taha KhanReviewed by Lexie CornerJul 18 2024

Plastic waste is a growing environmental issue, with tons of plastic ending up in oceans yearly, harming wildlife, polluting ecosystems, and threatening human health. This problem is not only immediate but will persist for many years because traditional petroleum-based plastics can take hundreds of years to decompose, leaving a lasting scar on the planet.¹

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To mitigate this challenge, researchers have identified bio-based polyethylene (Bio-PE), derived from renewable biomass sources such as sugarcane, corn starch, or wood cellulose, as a sustainable alternative. Bio-PE offers significant environmental benefits and boasts a much lower carbon footprint than traditional polyethylene.²

Understanding Bio-based Polyethylene

Bio-PE is derived from biological sources like sugarcane instead of petroleum. The manufacturing process begins with extracting ethanol from sugarcane, which is then dehydrated to produce ethylene, the monomer used to create polyethylene. The resulting Bio-PE is chemically identical to conventional polyethylene and can be used in the same applications without changing existing processing technologies.^2-4

The key difference between Bio-PE and traditional polyethylene is that traditional PE is derived from fossil fuels, whereas Bio-PE is produced from renewable resources. This distinction is crucial because it means Bio-PE can offer a lower carbon footprint and a more sustainable lifecycle. It can also be recycled in the same facilities as conventional PE, facilitating its integration into current recycling systems.

However, both types of polyethylene share similar properties, such as durability, flexibility, and resistance to moisture, making Bio-PE a viable substitute in a wide range of applications.^{2, 5}

Environmental Impact and Sustainability

A significant advantage of using Bio-PE as an alternative to traditional PE is that it reduces carbon footprint and greenhouse emissions.

For instance, a 2018 study examined the reduction of greenhouse gas emissions and carbon footprint using 100 % bio-derived polyethylene terephthalate (Bio-PET). They utilized biomass-derived monoethylene glycol and terephthalic acid produced from ethanol.

The study followed ISO 14040 and 14044 standards to calculate emissions, revealing that Bio-PET derived from 20 % sugarcane and 80 % corn reduced emissions by 24 % compared to traditional petroleum-based PET. Moreover, bio-PET using solely sugarcane-based ethanol showed a potential reduction of about 58 %, highlighting the environmental benefits of shifting to biomass-based production processes.⁵

Another study conducted a life cycle assessment to evaluate the environmental impacts of bio-based high-density polyethylene and partially Bio-PET compared to their European petrochemical counterparts. The study found that Bio-PE, derived from sugarcane ethanol, produces greenhouse gas emissions of around −0.75 kg CO₂eq/kg, which is 140 % lower than petrochemical polyethylene.

According to the study, Bio-PE offered approximately 65 % savings on non-renewable energy use. In contrast, partially, Bio-PET showed greenhouse gas emissions similar to its petrochemical equivalent but had slightly lower non-renewable energy use. The study also discusses the potential of Bio-PE to significantly reduce greenhouse gas emissions, especially when process energy is optimized.⁶

Discover More: Analyzing Recycled Polyethylene

Challenges and Limitations

Several challenges require attention from the scientific community, governments, investors, manufacturers, and policymakers. One major challenge is the current limitation in production capacity, as Bio-PE manufacturing is still in its early stages. This leads to higher costs compared to traditional PE. Scaling up production is crucial to making bio-PE a more cost-competitive alternative.

Similarly, the cost of producing one kilogram of Bio-PE is almost 30 % higher than that of traditional polyethylene, necessitating technological advancements to reduce production costs and make Bio-PE a more economically viable option.³

Another challenge is consumer awareness, as misconceptions about the biodegradability of Bio-PE exist. It is essential to communicate that Bio-PE, while derived from renewable resources, is not biodegradable and should be appropriately recycled. However, it does offer environmental benefits by reducing reliance on fossil fuels.^{3, 4}

Similarly, technical challenges, such as ensuring consistent quality and performance of Bio-PE products and developing better production processes, must also be addressed to gain consumer and industry trust.

Future Outlooks

The future of Bio-PE is tied to ongoing research and development aimed at improving its production efficiency and reducing costs. Researchers can focus on feedstock sourcing, such as using agricultural residues, which could provide more sustainable and abundant raw materials.

Advancements in biotechnology and chemical engineering may also enhance the properties and applications of Bio-PE, making it a more versatile and attractive option.

Government policies and incentives can play a significant role in promoting Bio-PE. Subsidies for bio-based materials, tax incentives for sustainable practices, and regulations limiting fossil fuel-based plastics can encourage industries to transition to Bio-PE.Public awareness campaigns highlighting the environmental benefits of Bio-PE can also drive consumer demand and support for sustainable plastic alternatives.

By addressing these current challenges and continuing to innovate, Bio-PE can contribute to reducing plastic waste and developing a healthier global environment.

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References and Further Reading

1. MacLeod, M., Arp, HPH., Tekman, MB., Jahnke, A. (2021). The global threat from plastic pollution. Science. doi.org/10.1126/science.abg5433
2. Burelo, M., Hernández-Varela, JD., Medina, DI., Treviño-Quintanilla, CD. (2023). Recent developments in bio-based polyethylene: Degradation studies, waste management and recycling. Heliyon. doi.org/10.1016%2Fj.heliyon.2023.e21374
3. Siracusa, V., Blanco, I. (2020). Bio-polyethylene (Bio-PE), Bio-polypropylene (Bio-PP), and Bio-poly (ethylene terephthalate)(Bio-PET): Recent developments in bio-based polymers analogous to petroleum-derived ones for packaging and engineering applications. Polymers. doi.org/10.3390/polym12081641
4. Barbalho, GHDA., et al. (2023). Bio-polyethylene composites based on sugar cane and Curauá fiber: an experimental study. Polymers. doi.org/10.3390/polym15061369
5. Semba, T., Sakai, Y., Sakanishi, T., Inaba, A. (2018). Greenhouse gas emissions of 100% bio-derived polyethylene terephthalate on its life cycle compared with petroleum-derived polyethylene terephthalate. Journal of cleaner production. doi.org/10.1016/j.jclepro.2018.05.069
6. Tsiropoulos, I., Faaij, AP., Lundquist, L., Schenker, U., Briois, JF., Patel, MK. (2015). Life cycle impact assessment of bio-based plastics from sugarcane ethanol. Journal of Cleaner Production. doi.org/10.1016/j.jclepro.2014.11.071

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