As a versatile, durable and inexpensive material, plastic has become an integral part of the global economy. Yet the current plastics economy has its drawbacks: The sector represents 6% of global oil consumption and by 2050 could account for 15% of the global annual carbon budget, if current rates of growth continue. As momentum around the circular economy grows, bio-based plastics, commonly referred to as bioplastics — plastics made from renewable biomass sources — have emerged as a promising solution to the mounting plastics problem.
“Bio,” however, doesn’t necessarily mean “sustainable.” This then raises the question: Is environmental performance the only relevant factor? Life Cycle Assessment (LCA) offers businesses a powerful tool to evaluate the environmental impacts and economic viability of replacing fossil-based plastics with bio-based polymers.
In cases where bio-based plastics aren’t inherently advantageous, combining impact valuation methodologies with Life Cycle Thinking can provide organizations with a more holistic understanding of their potential societal, environmental and economic value.
Bio-based Plastics: What’s in a name?
Bio-based plastics are polymers derived from plants, such as corn or other biological sources. Depending on their composition, they can be biodegradable or compostable. “Bio,” however, doesn’t automatically qualify a bio-based plastic as being environmentally benign — all bio-based plastics rely on fossil resources to a certain extent. Many are made using a combination of biomass and petroleum-based inputs, others require fossil fuels to drive their sourcing, processing, transportation and distribution. The European bio-based plastics industry association, European Bioplastics, categorizes bio-based plastic feedstocks into three main categories:
- 1st Generation Feedstock (Food Crops): First generation bio-based plastics are derived from carbohydrate-rich plants such as corn, wheat and sugarcane, which are also used for food or animal feed. Braskem is one example of a company using sugarcane-based ethanol to produce bio-based plastics. The company worked with Quantis to address its carbon emissions in an effort to reduce its overall corporate footprint. The results from the collaboration were ultimately used to inform Quantis’ Natural Climate Solutions Guidance.
- 2nd Generation Feedstock (Non-Food Crops): Unlike 1st generation feedstocks, 2nd generation feedstocks come from sources that are not suitable as food or animal feed. They can be either non-food crops (e.g. cellulose) or waste materials from 1st generation feedstocks, such as waste vegetable oil. As part of its research for the BioCatPolymers H2020 project, Quantis is analyzing the technical, economic and environmental benefits of converting low-cost and residual lignocellulosic biomass to high added-value bio-based plastics. Quantis also worked with UBQ, an Israeli bio-based plastics producer, to evaluate the environmental impact of using municipal solid waste in a country where recycling rates are low.
- 3rd Generation Feedstock (Algae and Waste): A 3rd generation of feedstocks is derived from algae, which has a higher growth yield than either 1st and 2nd generation feedstock.
Using Metrics to Make the Business Case for Bio-based Plastics
Each type of biomass material has its own unique environmental impacts and challenges. LCA allows businesses to evaluate the life cycle performance of different types of bio-based plastic feedstocks, identify the pros and cons of each, and determine if bio-based plastics make sense for their organization. If bio-based polymers require more resources to produce than conventional options or cause product failure or reduced performance, they can hardly be considered viable in economic or environmental terms.
Beyond the sourcing and production stages, metrics can also provide valuable insight into another critical phase of a bio-based plastic’s life cycle: disposal. Even if the sourcing and production stages pass the sustainability test, end-of-life processing could render it unsustainable. For example, the end product could end up requiring special or energy intensive infrastructure to be sorted, cleaned and processed — infrastructure that may not yet be widely available. Confusion surrounding the proper disposal of “biodegradable” and “compostable” plastics could also mean bio-based plastics mistakenly end up in regular recycling, landfill or the ocean. As part of the STAR-ProBio project, Quantis is developing a comprehensive sustainability assessment framework that covers these steps, with the aim to support future EU policies and encourage consumer acceptance.
Would it then be better to simply produce durable bio-based plastics that can be processed by existing recycling streams?
Leveraging the value chain approach at the core of LCA, Quantis worked with Nespresso (to assess bio-based coffee capsules) and BASF (to analyze partially bio-based produce bags using 100% compostable ecovio® material) to answer that question and more to build a better business case for bio-based plastics by comparing the environmental performance of plant-based materials in their respective products. The respective LCAs revealed that while neither of the materials demonstrated optimal performance simply by virtue of being bio-sourced or biodegradable, the diversion of associated green waste from landfill can generate a number of interesting advantages, such as the production of new valuable materials (such as compost), thus in line with circular economy principles. (Contact us to learn more about these studies.)
Strong metrics also allowed UBQ to analyze whether the use of waste streams to produce bio-based plastics is advantageous in terms of sustainability and finances and where improvements could be made. Because of their relative abundance and accessibility, waste streams were identified as offering both cost savings and the opportunity to reduce reliance on virgin materials. Former UBQ Chief Sustainability Office Christopher Sveen noted:
“Working with Quantis to assess the environmental performance of UBQ secondary raw materials enabled us to put sound metrics on the benefits of producing bio-based plastics from municipal solid waste. This further emphasizes the business case for competitively reusing finite resources infinitely rather than rely on fossil-based alternatives, and we hope to inspire other stakeholders to take meaningful action in this sector as well.”
Chief Sustainability Office, UBQ
Seeing the Big Picture: The Benefits of Bio-based Plastics
In LCA, materials sourcing, product use and end-of-life processing all enter into consideration, which explains why certain bio-based options turn out not to be particularly advantageous. Despite this somewhat counterintuitive reality, bio-based plastics shouldn’t be discredited just yet.
In The New Plastics Economy: Rethinking the Future of Plastics, the Ellen MacArthur Foundation states: “An economy in which the value of products and materials is maximized through multiple loops could be considered inherently more attractive than an economy with one-way linear material flows where 95 percent of material value is lost after one use cycle.”
In essence, even with their flaws, bio-based plastics offer a more attractive option than plastics sourced from finite, CO2-emitting fossil feedstocks, as well as a “target state for the plastic packaging value chain to innovate towards.”
Connect with Gregory Simonnin to learn more about how to combine Life Cycle Thinking and impact valuation, or get in touch with Laura Peano to discuss how Quantis can help you choose the bio-based plastic best suited to your business needs.