Saturday, 31 March 2018

A solution to our plastic problems > biodegradable plastic

There are alternatives out there to plastic:
Futures Forum: Creating alternatives to the plastic takeaway coffee cup >>>
Futures Forum: Bioplastics > and the circular economy
Futures Forum: The alternatives to plastic

And companies are doing their bit - following some pressure:
PG Tips ditches plastic to create completely biodegradable tea bags - Dezeen
Futures Forum: Taking the plastic out of your teabag

New technologies are emerging all the time - for example:
SPhere pushes plastic innovations using plant-based and biodegradable materials | South China Morning Post
Hemp Plastic: Why Plastic Derived From Cannabis Could Save The Planet - Herb.co
New Customised Compostable Materials for the Manufacture of Packages and Single-use Bags - Packaging Europe

Unfortunately, it's complicated - as shown in this recent piece from a packaging technology news website:
Are biodegradable plastics better for the environment? - Packaging Europe
Commentary: Are biopolymers better for the environment? - Recycling Today

One problem is that almost all biodegradable plastics are designed to biodegrade in soil, not water
Biodegradable plastic 'false solution' for ocean waste problem | Environment | The Guardian

As the plastics industry points out:
Biodegradable plastics were never designed to be a solution to marine litter – European Bioplastics e.V. 

Another technology would be the 'Oxo-biodegradable plastic' - but this is controversial too:
Oxo-degradable plastics increasingly under fire in Europe – European Bioplastics e.V.
Case Study: Compostable vs Oxo Degradable | Natur-Bag

Here again is the industry's point of view:

Another complication is that 'bioplastics' are not the same as 'biogradable plastics': 
Bioplastics and the Truth About Biodegradable Plastic | HuffPost  

Here's an excellent piece giving an overview of the issues:

How sustainable are biodegradable and plant-based plastics?

By Tom Szaky in Sustainable Packaging on May 30, 2017


Coca-Cola's PlantBottle is an example of a durable bioplastic (rather than a biodegradable bioplastic), meaning it will last like a traditional PET bottle, but that it is also recyclable.

Finding solutions for the world’s plastic problem is an uphill battle. Manufacturers and consumers alike are now accustomed to products and packaging made lighter, less costly and more convenient by plastic, the iterations of which have only grown more complex. As it stands, we are manufacturing approximately 300 million tons of plastics across the world every year, and this number continues to grow.

The scope of the world’s plastic problem goes beyond straining Earth’s finite resources; it is also a waste management issue. It is estimated that up to 129 million tons (43%) of the plastic used per year is disposed of by landfill or incineration, and approximately 10 to 20 million tons of plastic ends up in the oceans.

Rethinking all aspects of the plastics supply chain in terms of full lifecycle, from sourcing to end-of-life, is the key for manufacturers and major brands aiming to design into a more circular plastics economy. Driven by demand for more sustainability and positive environmental impacts in consumer packaged goods (CPGs), there is a growing industry for bioplastics—plastics made from plant biomass, such as corn.

One argument in support of increased use of bioplastics is mainly that the raw materials used to generate it are more sustainably sourced than petroleum-based plastic. Abundant availability of raw materials for manufacturing bioplastics place less strain on resource supply, as well as cause less strain to the earth from sourcing processes. Drilling for oil to use for petroleum-based plastic may disturb land and ocean habitats, and is a major source of emissions and airborne byproducts.

Bioplastics can be broadly broken down into two categories: durable and biodegradable. For instance, the PlantBottle is a durable bioplastic alternative to traditional PET bottles made by Coca-Cola. Made with up to 30% ethanol sourced from plant material, the PlantBottle won’t decompose, but it can be recycled with traditional PET containers and bottles. It is important to note that this is an outstanding example, as not all bioplastics are recyclable.

Of the many bioplastic varieties currently on the market or in development, no variant has attracted more attention than those dubbed “biodegradable.” Biodegradable bioplastics, like increasingly popular PLA (polylactic acid), are exactly as they sound: in theory, they break down naturally in the environment or may be composted. This is unique, as the vast majority of plastics today will never break down. Petroleum plastics may degrade into smaller and smaller pieces, but most won’t decompose or be absorbed by the surrounding environment.

Where bioplastics theoretically are an answer to our dependence on fossil fuels to manufacture the plastics the world demands, biodegradable bioplastics are meant to be a solution for the world’s plastic waste problem. However, in most cases, biodegradable bioplastics will only break down in a high-temperature industrial composting facility, not your average household compost bin. Plus, these are not recyclable.

This wouldn’t be as much of a concern if we had a great composting infrastructure, but we don’t. With only about 200 industrial composting facilities in the United States and 50 million tons of organic waste still ending up in landfills across the country each year, we are ill-equipped to adequately compost any meaningful volumes of biodegradable plastic. In fact, many operational industrial composting facilities today won’t even accept PLA and other biodegradable plastics—they are seen as contamination risks.

A better solution might be to place the focus on durable bioplastics that are made from plant materials, but can still be recycled. This way, the valuable energy and material inputs can be kept in the production cycle longer. It also makes far more sense to build a bio-based plastic that fits into our existing infrastructure, rather than building an entirely new biodegradable plastic composting infrastructure from scratch.

If we hope to truly make durable bioplastics as viable as they could be, we will need to start curbing the demand for plastics overall. With less demand, the market will be in a far better place to meet demand with more contained impacts to the environment. How do we reduce the demand for plastic? When manufacturers and major brands commit to packaging designs that are more durable and made to last, consumers have the opportunity to make more sustainable purchasing decisions.

Author Tom Szaky, founder and CEO of TerraCycle, has won more than 50 awards for entrepreneurship, writes blogs for Treehugger and Triple Pundit, published a book called "Make Garbage Great" and is the star of the television show "Human Resources.” 

How sustainable are biodegradable and plant-based plastics? | Packaging Digest

With a final comment here from Futurenergia: 

Biodegradable plastics: are they better for the environment?

Litter is a problem with a very negative social and environmental impact. Some people believe that one way to tackle this problem is to use biodegradable plastics as an environmentally-friendly solution for things such as plastic bags. This might seem sensible at first glance, but is it really better for the environment?

Littering is fundamentally a problem of irresponsible behaviour, which should be tackled by changing people’s attitudes rather than by changing the products they are throwing away. Making products biodegradable may actually make the problem of littering worse, by making people think that it is OK to throw away valuable resources like plastics. For example, a biodegradable plastic bag that’s thrown into a hedge will still take years to disappear, rather than days as some people believe. Even a banana skin - when thrown away - needs 1-3 years before it is biodegraded!

What’s more, biodegradable plastics require specific conditions to biodegrade properly (micro-organisms, temperature, and humidity), and if not managed properly they may be worse for the environment than conventional plastics. When biodegradable plastics are put into landfill (which should always be avoided in any case) they produce harmful greenhouse gases when breaking down.

What are biodegradable plastics? Biodegradable plastics are plastics that can be broken down by microorganisms (bacteria or fungi) into water, carbon dioxide (CO2) and some bio-material. It is important to note that biodegradable plastics are not necessarily made from bio-material (i.e. plants). Several biodegradable plastics are made from oil in the same way as conventional plastics.

So what are biodegradable plastics good for? In principle plastics are valued for their ability to make strong, durable products (for example in food storage, transport, building and construction). Biodegradability should therefore be regarded as an additional functionality when the application demands a cheap way to dispose of the item after it has fulfilled its job (e.g. for packaging, protect food and keep it fresh). Examples of useful biodegradable products are:

> Food packaging – packaging that can be composted together with its contents when the product is past its sell-by date or spoiled
> Agriculture – plastic sheeting that can be ploughed-into biodegradable mulch and seed films
> Medical – absorbable sutures; micro-devices containing medicine, which break down inside the body

Biodegradability is a material property that depends much on the circumstances of the biological environment (human body differs from soil). Given that this is the case, it could be said that making a product such as a plastic bag compostable does not make much sense because this biodegradability performance will not resolve the litter issue (different conditions in the compost and on soil).

To conclude, it is a mistake to focus on finding ways to make products easier to throw away in the name of helping the environment. Biodegradable plastics are exciting and useful materials, but they should only be used when they have a concrete benefit for a specific product. The best way to help save the planet is to save energy and improve ways of recycling and recovering all plastics.

Related link:
Chat 6: “Future energy sources” or “The plastic bag war”

Biodegradable plastics: are they better for the environment? - Futurenergia

Of course, the plastics industry would prefer business as usual - and for the effort to come from individual consumers:
Plastic associations fault recycling and consumer behaviour for pollution - The National

See also:
Futures Forum: A plastic bottle deposit scheme for England >>> >>> "Welcome as it is, such a scheme farms out responsibility to individual consumers rather than bringing into line corporations with far greater power to pioneer change"
Futures Forum: Plastic pollution and the invention of 'litter' > or, how the packaging industry avoided responsibility for creating the problem in the first place
Futures Forum: The plastics industry is "incredibly supportive of recycling legislation over a more long-term… reduction of disposable culture."

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