Facing the Green Promise of Bioplastics: Real or More Greenwashing?

Nick Terran
By Nick Terran

Bioplastics are rising in popularity as an eco-friendly alternative to conventional plastics, which are notorious for their long-lasting environmental impact. With the cumulative plastic production surpassing nine billion tons and a mere 9 percent recycling rate, the majority of traditional plastic waste ends up either polluting our oceans or sitting in landfills for centuries. As we face this grim reality, bioplastics emerge with the promise of sustainability.

The Appeal of Bioplastics: The Sustainable Alternative or Another Green Mirage?

Unlike traditional plastics derived from petroleum, bioplastics are made from renewable resources, with many variants containing 20 percent or more renewable materials. The potential benefits of bioplastics are compelling: they require less fossil fuel to produce, boast a smaller carbon footprint, and their decomposition process is faster and less toxic. Free from harmful additives like bisphenol A (BPA), bioplastics offer a cleaner alternative that could alleviate some of the environmental burdens posed by their petroleum-based counterparts.

Columbia University’s Professor Kartik Chandran, a specialist in bioplastic research, asserts that “bioplastics are a significant improvement” over traditional plastics. This optimism stems from bioplastics’ eco-friendly production and the potential for safer disposal.

Decomposition: The Bioplastics Differentiator

The terminology around the biodegradability of plastics can be confusing, so it’s important to understand the nuances:

    • Degradable: Technically, all plastics degrade, meaning they can break down into smaller fragments. However, this doesn’t equate to a return to nature. Some plastics are engineered to degrade faster with additives that respond to light or oxygen, yet they may still leave behind microplastics and other pollutants.
    • Biodegradable: In contrast, biodegradable plastics are those that microbes can completely break down into water, carbon dioxide, and biomass within a certain timeframe, typically a few months. Yet, the rate of biodegradation can vary, and not all bioplastics are created equal. Some bioplastics are labeled “durable,” indicating a slower degradation rate, while others may be made from biomass that is resistant to microbial breakdown, categorizing them as non-biodegradable.
    • Compostable: Compostable plastics are a specific type of biodegradable plastic designed to decompose in composting facilities. They should break down at a rate comparable to other organic waste, ideally leaving no toxic residue. For plastics to earn the compostable label, they must meet stringent standards that confirm their ability to degrade adequately in a composting setting.

With these definitions in hand, it’s easier to navigate the complex landscape of bioplastics and understand their potential environmental benefits. While the shift toward bioplastics reflects a growing consciousness about sustainability, it’s crucial to recognize that they’re not all created equally, and their environmental impact can vary significantly.

Exploring the Spectrum of Bioplastics and Their Applications

Bioplastics are emerging as a key player in the quest for sustainability, finding their way into various products, from disposable packaging to medical implants. With the global market for bioplastics predicted to more than double in just a few years, it’s evident that these materials are gaining traction. However, understanding the types of bioplastics and their specific uses is crucial for assessing their role in our shift towards eco-friendly materials.

The Expanding Realm of Bioplastics

Currently, bioplastics are utilized for a myriad of items that include both single-use products, like utensils, bottles, and packaging, and more durable goods, such as automotive insulation, phone cases, and even 3D printing materials. The versatility of bioplastics means they’re increasingly found in everyday items, making the expected growth of the bioplastics market from $17 billion to nearly $44 billion by 2022 both plausible and promising.

Bioplastics can be made from almost anything.

The Main Contenders: PLA and PHA

The bioplastics universe is diverse, but two main types stand out due to their unique properties and applications:

    1. PLA (Polylactic Acid):
      • Originating from plant sugars found in resources such as cornstarch, cassava, or sugarcane, PLA is known for being biodegradable, carbon-neutral, and even edible.
      • The transformation from corn to PLA involves breaking down corn kernels into their constituent parts, extracting the oil, and then harnessing the carbon molecules from the starch. These molecules, similar to those in traditional fossil fuel plastics, are then synthesized into long-chain polymers, forming the basis for plastic production.
      • PLA can mimic the properties of several conventional plastics, making it a versatile substitute in various applications.
      • NatureWorks, a Minnesota-based company, is a leading producer of PLA, marketing it under the brand name Ingeo.
    1. PHA (Polyhydroxyalkanoate):
      • PHA is a bioplastic produced by microorganisms, which are sometimes genetically modified to optimize production. When these microbes are restricted from essential nutrients but given abundant carbon, they produce PHA as a form of carbon storage.
      • This microbial plastic is harvested and processed, yielding a material with similar characteristics to many petroleum-based plastics.
      • The biodegradable nature of PHA makes it suitable for medical uses such as sutures and tissue engineering, and for eco-friendly packaging solutions that aim to reduce plastic waste.

The production processes of PLA and PHA exemplify the innovative approaches to creating materials that could reduce our reliance on fossil fuels and minimize environmental impact. The applications of bioplastics, particularly in the medical field, underscore their potential to revolutionize industries while maintaining ecological balance.

As we continue to navigate the complexities of bioplastics, understanding their diverse types and applications is essential. This knowledge allows us to critically evaluate their environmental benefits and envision a future where sustainable materials aren’t just a choice, but a standard. The next section will explore the reality of bioplastics’ environmental benefits, examining if they truly live up to their reputation as the eco-friendly choice and how they fit into the broader picture of global sustainability efforts.

The Environmental Cost of Bioplastic Production: A Closer Look

Bioplastics are often lauded for their potential to reduce our carbon footprint and offer a more sustainable alternative to conventional plastics. However, a comprehensive life cycle analysis paints a more complex picture of their environmental impact.

Uncovering the Hidden Impacts

A pivotal study by the University of Pittsburgh in 2010 scrutinized the life cycles of various plastics, including traditional, biobased, and hybrid forms. The findings revealed that bioplastics manufacturing could, paradoxically, introduce a larger quantity of pollutants compared to their petroleum-based counterparts. This increased pollution is attributed to the agricultural demands of growing crops, such as fertilizers and pesticides, and the subsequent chemical processes required to convert organic materials into plastics.

The study highlighted that bioplastics production might even exacerbate ozone layer depletion and necessitate substantial land use. In particular, B-PET, a plastic composed of both fossil fuel and renewable sources, presented the highest potential for ecosystem toxicity and carcinogenicity, performing the worst in the life cycle assessment due to the dual burdens of agricultural and chemical processing.

Bioplastic made from starch.

Greenhouse Gas Emissions: A Silver Lining

Despite these concerns, bioplastics do offer a significant advantage in terms of greenhouse gas emissions over their entire lifespan. The plants used for bioplastic production absorb carbon dioxide during growth, which is then offset when the material breaks down. A 2017 study posited that replacing conventional plastics with corn-based PLA could slash U.S. greenhouse gas emissions by 25 percent. Moreover, the study suggested that if both traditional plastics and bioplastics were produced using renewable energy, greenhouse gas emissions could plummet by 50 to 75 percent, with future bioplastics showing the greatest potential for significant reductions.

Challenges in Biodegradability and Recycling

The touted biodegradability of bioplastics comes with its own set of challenges. Many bioplastics require high-temperature industrial composting to decompose, yet such facilities are scarce. Consequently, bioplastics often end up in landfills, where they can release methane—a potent greenhouse gas—due to the lack of oxygen.

Improper disposal of bioplastics also poses a threat to recycling systems. Contamination of recycling streams, particularly with PET, by bioplastics can render entire batches unusable, relegating them to landfills. This necessitates separate collection mechanisms for effective bioplastic recycling.

The Land Use Dilemma

The cultivation of crops for bioplastics enters into direct competition with food production. Projections from the Plastic Pollution Coalition estimate that meeting the global demand for bioplastics could require over 4 million acres of land by 2024, an area exceeding the combined size of Belgium, the Netherlands, and Denmark. Moreover, the operation of farm machinery using petroleum contributes to greenhouse gas emissions, adding to the environmental toll.

Cost Implications

On the financial front, bioplastics like PLA are currently 20 to 50 percent pricier than similar conventional plastics, owing to the intricate processes involved in their production. However, as the industry evolves and innovations emerge, the costs are anticipated to decrease, making bioplastics more accessible.

Pioneering the Future of Bioplastics from Waste

At Columbia University, Professor Kartik Chandran and his students are at the forefront of pioneering an innovative method to turn wastewater and solid waste into environmentally friendly bioplastic.

This transformative research is redefining the potential of waste by converting it into valuable biodegradable materials.

Professor Kartik Chandran of Columbia University. Source: Columbia

The Process: Transforming Waste into Resource

Chandran’s approach leverages a community of mixed microbes that thrive on carbon sources, particularly volatile fatty acids akin to those found in household vinegar. “Our system is essentially feeding on wastewater,” Chandran explains. Within a specialized bioreactor, these microorganisms initiate the process by breaking down organic carbon from waste into volatile fatty acids.

The journey continues as this effluent moves to a secondary bioreactor. Here, a different set of microbes, known for their plastic-producing abilities, consume the volatile fatty acids. Subjected to alternating phases of abundance and scarcity—feast and famine—these microbes store the carbon molecules in the form of PHA, a biodegradable bioplastic.

Innovation in Waste Stream Utilization

Chandran’s experimentation isn’t limited to ordinary wastewater; it also encompasses denser waste streams like food scraps and human solid waste. The goal is to enhance the efficiency of volatile fatty acid production, thus boosting the overall output of PHA. “We want to squeeze as much as we can [out of both systems],” Chandran says, signifying a drive to maximize the yield from the process and make waste a pivotal part of the production cycle.

Economic and Environmental Benefits Converge

The economic advantages of Chandran’s integrated system could be a game-changer for bioplastic production. Traditional methods typically involve purchasing sugars to create PHA, but by using waste as a starting point, costs could be significantly reduced. “If you integrate wastewater treatment or address food waste challenges with bioplastic production, then this is quite favorable [economically],” Chandran points out. His vision extends beyond mere production efficiency; he anticipates a model where the processing facility would be compensated for waste removal and simultaneously generate revenue from bioplastic production.

Closing the Loop on Waste

Chandran’s ultimate aim is to create a closed-loop system, transforming what was once considered mere waste into a precious commodity. “One day, waste products will routinely serve as a resource that can be converted into useful products like bioplastic,” he envisions. This circular economy approach could significantly reduce the environmental impact of waste and provide a sustainable source for bioplastic production, marking a substantial leap towards a greener, waste-free future.

Pioneering the Path to Greener Bioplastics and Beyond

Black soldier flies have recently been used to create bioplastics.

The journey to sustainable alternatives to traditional plastics is flourishing with innovative approaches and promising technologies. Several entities are making significant strides in producing bioplastics from organic and waste materials, which could redefine the landscape of plastic production and disposal.

Innovative Approaches in Bioplastic Production

Full Cycle Bioplastics in California is spearheading the conversion of organic waste streams into PHA. Utilizing food scraps, agricultural residues, and even paper products, they create a versatile bioplastic that isn’t only compostable but also marine degradable, offering a potential food source for aquatic life should it end up in the ocean. Their process allows for the PHA to be recycled back into pristine plastic, showcasing a sustainable lifecycle.

Renmatix in Pennsylvania is pioneering the use of non-food biomass, such as wood and grasses, as raw materials for bioplastic production. Their proprietary technology leverages water and heat to extract sugars, bypassing the need for harsh chemicals. This process yields both sugars and lignin, which serve as foundational elements for bioplastics and a spectrum of bioproducts.

At Michigan State University, scientists are tapping into the power of cyanobacteria. By genetically modifying these microorganisms to secrete sugars, they provide a continuous feedstock for plastic-producing bacteria. This method leverages natural photosynthesis, reducing the dependency on agricultural sugars and pointing toward a more cost-effective production model.

Mango Materials, in collaboration with Stanford University researchers, has taken a novel approach by harnessing methane, a potent greenhouse gas, and converting it into bioplastic through microbial action. This bioplastic is then utilized to manufacture a range of products, from shampoo bottles to textile fibers, with the assurance of natural biodegradation back into methane.

The University of Bath’s Carbon-Conscious Innovation

The University of Bath’s Centre for Sustainable Technologies is breaking new ground by developing polycarbonates from sugars and carbon dioxide, circumventing the use of harmful chemicals like BPA and phosgene. Their method involves a low-temperature process that enables soil bacteria to decompose the resulting bioplastic, closing the environmental loop.

Rethinking Packaging and Preservation

The quest for plastic alternatives has led to some groundbreaking developments. AMAM, a Japanese design firm, is creating packaging materials derived from marine algae, while the U.S. Department of Agriculture is experimenting with casein-based films to improve food preservation vastly. Ecovative, based in New York, is utilizing fungal mycelium to craft a range of biodegradable products, from packaging materials to home goods.

Evaluating the Environmental Footprint

Despite the progress, the current environmental footprint of bioplastics is a subject of ongoing debate, considering factors such as land use, agricultural inputs, water consumption, and energy requirements. Although the promise of bioplastics as a solution to plastic pollution is compelling, it’s crucial to scrutinize the entire lifecycle from production to disposal.

The global effort to refine bioplastic production is aimed at minimizing environmental impacts while maximizing the benefits. 

As this field evolves, we can anticipate bioplastics playing an integral role in mitigating plastic pollution and aiding in the reduction of our overall carbon footprint. The continued research and development in this area suggest a hopeful trajectory towards a future where bioplastics not only match but exceed the environmental friendliness of their petroleum-based predecessors.

While bioplastics represent a forward step in our pursuit of environmental sustainability, they’re accompanied by significant challenges that must be addressed. Balancing the benefits of lower greenhouse emissions with the complexities of production, disposal, and land use is essential to realizing the full potential of bioplastics as an eco-friendly alternative.

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