Bioplastics and Circular Economy: A Pathway to Sustainability Goals

TAGS:  Sustainability and Bioplastics    

The world is grappling with a critical problem of waste management and the alarming depletion of finite resources. Unsustainable practices have led to a staggering accumulation of waste and a detrimental impact on our environment. As a response, the concept of the circular economy has gained traction. It is a way to reduce waste and create a sustainable system of resource management.

Additionally, we need to consider "beginning-of-life" options to minimize environmental impact. Educating consumers and companies about "life cycle thinking" can encourage a holistic view of plastic products beyond their use and disposal. Sustainable harvesting and catalytic conversion of local, non-food, renewable resources and biological wastes into bio-based plastics can provide greater sustainability than established fossil fuel extraction and refining practices.

Bioplastics are one of the solutions explored to make this a reality. They can be involved in various stages (product design, production, usage, collection, and recycling) of the circular economy to create a more sustainable and efficient system of resource management.

Sustainability Path #1 — Use Materials of Bio-based Origin

➤ Bioplastics and Circular Economy Bioplastics 101: Making the Right Biopolymer Choice Determining Bio-based Content Biodegradability of Plastics Ensuring Supply Chain Security in Bioplastics

Let’s find out how plastic material suppliers can claim circularity & sustainability using bioplastics.

1. Unlocking 100% Sustainability in the Circular Economy
2. Making Bioplastic Raw Material Sourcing More Sustainable
3. A Sustainable Alternative to Fossil-based Plastics
4. Life Cycle Assessment – Evaluating the Environmental Impact of Bioplastics
5. End-of-life Scenarios – Busting Myths Around Bioplastics

Unlocking 100% Sustainability in the Circular Economy

Using bioplastics in your process is a start in the right direction, but it is not enough to claim 100% sustainability or circularity. While bioplastics are manufactured from renewable resources and have the potential to be less harmful to the environment than standard plastics made from fossil fuels, there are several other variables to consider:

1. Raw material sourcing: The long-term viability of bioplastics is dependent on the raw materials utilized to make them. It is critical that bioplastic feedstocks come from sustainable and appropriately managed sources. For example, obtaining feedstock for bioplastics through deforestation or monoculture methods may have detrimental environmental and societal consequences.


2. Production process: The energy and water consumption, as well as the emissions produced during the bioplastics manufacturing process, should be examined. To ensure a lesser environmental impact, the manufacturing process should aim for energy efficiency, decrease water usage, and reduce greenhouse gas emissions.


3. Options for end-of-life management: The circularity of bioplastics is determined by how they are treated at the end of their life. Bioplastics should be designed for recyclability or compostability to achieve true circularity. The environmental benefits of bioplastics are not completely realized if they wind up in landfills or are burnt.


4. Waste management infrastructure: A strong waste management infrastructure is required to achieve circularity. If appropriate recycling or composting facilities are not available, bioplastics may end up in improper waste streams, resulting in contamination or ineffective disposal.


5. Life cycle assessment: A full life cycle assessment (LCA) of the entire product life cycle, including raw material production, manufacture, distribution, consumption, and end-of-life, should be performed. This evaluation will aid in identifying potential areas for improvement and will drive decision-making toward more sustainable practices.

(Click on Image to Enlarge)

The sustainability of bio-based products compared to petroleum-based products is not always guaranteed. While bio-based products have the potential to be more sustainable due to their renewable nature, factors such as life cycle assessment, raw material sourcing, production processes, end-of-life management, and social and economic considerations must be considered. A comprehensive evaluation is necessary to determine the sustainability of a specific bio-based product. By considering these factors, we can ensure that bio-based products truly contribute to a more sustainable future.

Related Read: How Material Suppliers Work Towards Circular Supply Chain?

Making Bioplastic Raw Material Sourcing More Sustainable

Bioplastics are made of monomers extracted or synthesized from biomass compounds or non-synthetic natural polymers. Some types of bioplastics are:

1. Polysaccharide-based bioplastics – Made from starch, cellulose, chitosan, and alginate
2. Protein-based bioplastics – Made from wheat gluten, casein, and soy
3. Aliphatic polyesters – For example polylactic acid (PLA), polyhydroxyalkanoates (PHAs), poly-3-hydroxybutyrate (PHB), etc.
4. Other bioplastics – For example Polyamide 11, Polyamide 4-10, Bio-Polyethylene, Polyurethanes, Epoxy resins, etc.

Bioplastics that are 100% bio-based are currently produced on a small scale of approximately 2 million tons per year.

• They are an essential component of future circular economies as they reduce the use of fossil fuels, introduce new recycling or degradation pathways, and use fewer toxic reagents and solvents during production processes.
• They offer improved circularity by using renewable resources, having a lower carbon footprint, and providing biodegradability as an alternative end-of-life (EOL) option.

However, their benefits are highly dependent on factors like chemical structure, manufacturing process, and end-of-life scenario, and must be evaluated using a life cycle assessment (LCA) that considers metrics like climate impact, ecotoxicity, and recyclability.

View Course Agenda: Identify Game-changing Innovations & Trends with Bioplastics

A Sustainable Alternative to Fossil-based Plastics

The traditional plastics industry follows a linear life cycle. Here, crude oil is cracked and refined into monomers and polymer products using fossil energy. These products, after their use, are either disposed of, incinerated, or in rare cases, mechanically recycled into lower-grade products. This approach has resulted in around 80% of plastic waste ending up in landfills or polluting the environment, making it a significant environmental concern. A circular plastic economy that minimizes waste production and utilizes materials like bioplastics made from renewable resources or recycled resources can help address this issue.

Are bioplastics good or bad for the environment?

Bioplastics have environmentally friendly attributes. For instance, the production of polylactic acid (PLA) saves a significant amount of energy compared to traditional plastics. Moreover, the biodegradation of PLA does not result in a net increase in carbon dioxide emissions because the plants used to produce it absorb the same amount of carbon dioxide during cultivation as is released during biodegradation.

PLA also emits fewer greenhouse gases when it degrades in landfills. Various studies have demonstrated that substituting traditional plastics with corn-based PLA bioplastics can significantly reduce greenhouse gas emissions. These examples provide hope that future bioplastic production can be achieved using renewable energy sources while substantially mitigating greenhouse gas emissions.

Limitations of bioplastics

Bioplastics have become a subject of intense debate regarding their environmental impact. While they are often seen as promising alternatives to conventional plastics, they also come with certain limitations.

1. Take, for instance, biodegradable bioplastics. These materials can break down into natural substances through microbial processes, integrating harmlessly into the soil. The decomposition is facilitated by water and/or oxygen. When a bioplastic derived from cornstarch is composted, the cornstarch molecules absorb water and gradually break apart into smaller fragments that can be easily digested by bacteria. However, some bioplastics degrade slowly or not at all unless subjected to high temperatures or specific conditions in composting facilities or landfills. Additionally, the decomposition process during composting releases methane gas, a potent greenhouse gas that contributes to global warming.


2. Another concern is the land usage for producing bioplastics from crops like corn and maize, which diverts agricultural land from food production. A significant portion of grain-producing agricultural land is already allocated to biofuel and bioplastic production, potentially leading to higher food prices and affecting vulnerable populations.


3. Furthermore, studies have shown that the production of bioplastics can result in increased pollution due to the use of fertilizers and pesticides during crop cultivation and the chemical processing required to convert organic material into plastic. Some bioplastics have also been found to contribute more to ozone depletion and pose toxic effects on ecosystems.

Life Cycle Assessment – Evaluating the Environmental Impact of Bioplastics

To evaluate the environmental impact of bioplastics compared to conventional plastics, life cycle assessment (LCA) is crucial. Not only should you compare, but you should also consider LCA when aiming for 100% sustainability. LCA considers the entire life cycle of a product, from raw material extraction to manufacturing, distribution, use, and disposal. It assesses factors such as:

• global warming,
• human toxicity,
• abiotic depletion,
• eutrophication, and
• acidification.

LCA also considers land use change (LUC) emissions and the costs and benefits of bioplastic disposal. LCA studies have shown reductions in greenhouse gases by substituting petroleum-based plastics with bioplastics like PLA and thermoplastic starch. Incineration and landfilling are not ideal for bioplastic waste management, and efforts should aim for zero LUC emissions. Future studies should conduct individual LCAs for a wide range of bioplastics.

How to measure the carbon footprint of bioplastics?

When compared to fossil-based plastics, bioplastics have the potential to have a lower carbon footprint. The total greenhouse gas emissions associated with a product or process across its entire life cycle, including raw material extraction, production, usage, and disposal, are referred to as its carbon footprint.

Measuring the carbon footprint of bioplastics entails performing a life cycle assessment (LCA), which is a detailed investigation of the product's environmental implications. The LCA considers a number of elements, including raw material manufacturing, energy use, transportation, waste management, and end-of-life scenarios.

The LCA typically estimates greenhouse gas emissions using established procedures, such as those described by the International Organization for Standardization (ISO), to calculate the carbon footprint. Carbon dioxide equivalent (CO₂e) emissions are assessed, which combine the influence of different greenhouse gases, such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), based on their global warming potential.

The LCA compares the carbon footprint of bioplastics to that of fossil-based plastics by evaluating the emissions associated with both types of materials' complete life cycles. This provides a complete picture of the environmental impact and insights into the possible carbon emissions savings afforded by bioplastics.

It is vital to remember that the carbon footprint of bioplastics varies based on aspects including the feedstock utilized, the manufacturing process, energy sources, and waste management procedures. As a result, separate studies for different types of bioplastics must be carried out to appropriately quantify their carbon footprint in comparison to fossil-based plastics.

One methodology to determine bio-based carbon content has an accuracy of ±3% and has been codified into an ASTM standard, 7 D6866 titled “Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis.”


Plastic futures and their CO₂ emissions
Source: Nature
From this graphic, we can see that a circular economy approach without an additional bioeconomy push reduces resource consumption by 30% and achieves 10% greater emission reductions before 2050 while reducing the potential of negative emissions in the long term. However, a circular bioeconomy approach combining recycling with higher biomass use could ultimately turn the sector into a net carbon sink, while at the same time phasing out landfilling and reducing resource consumption.

End-of-life Scenarios – Busting Myths Around Bioplastics

Biodegradable and compostable plastics

Firstly, bio-based polymers are not always compostable or biodegradable. Similarly, biodegradable-compostable plastics are not always made from biological materials. Unfortunately, these terms are frequently used interchangeably, therefore it is important to understand how the different value propositions and criteria differ.

Are all bioplastics biodegradable?

No! Bioplastics encompass a wide range of materials, including those that are biobased, biodegradable, or both. Biobased, non-biodegradable materials make up less than 36 percent of bioplastics, while the majority (over 64 percent) of bioplastics currently available are biodegradable materials. Biodegradability is an inherent characteristic of certain polymers, which can be advantageous for specific applications like biowaste bags.


Bio-degradable vs Non-biodegradable PlasticsSource: Wiley
When it comes to biodegradable or compostable products, it is important to provide clear recommendations regarding their appropriate end-of-life options and proper disposal methods. European Bioplastics suggests obtaining certification and labeling for biodegradable plastic products intended for industrial composting in accordance with EN 13432 standards. This helps ensure that these products are correctly disposed of and managed in an appropriate manner.


End of Life of Biodegradable Plastics: Composting versus Re/Upcycling
Source: Wiley
The recycling of biodegradable plastics presents a relatively new challenge in terms of effectively utilizing discarded materials and transitioning to an innovative circular lifecycle approach. One promising avenue is bioplastic upcycling, which involves:

• breaking down polymers into chemicals or molecular intermediates and
• transforming them into valuable products.

This presents an intriguing opportunity to derive high-value outputs from bioplastics. However, the feasibility of post-consumer recycling requires reevaluating the collection processes for compostable plastics and/or developing sorting strategies to ensure proper separation and treatment.

Complete Range of Bio-based Polymers

Make use of the new sustainability facet that is live now on our website! Filter products based on origin, end-of-life, manufacturing practices, performance, regulations & labels, and more.