In the bioeconomy, as innovations come thick and fast, it’s
very easy to focus all of our coverage on these developments, ranging from new
biobased products, to novel processes in the development and production of
those products. However, sometimes this coverage of the products themselves can
distract from what makes them so significant: the problems they solve. We are
entering an era where we will face many big challenges, some of which the
bioeconomy will be able to help us overcome. In this series of articles, we
will look at six of these big challenges, and the solutions that the bioeconomy
provides us with.
Around the world, countries are starting to publish their
bioeconomy strategies, and these are just some of the issues that such policy
directives will be aiming to tackle.
Problem: Plastic Waste
In recent years, as countries have begun to reduce their
greenhouse gas emissions, plastic has taken over as the “poster boy” of
environmental issues. Efforts are still being made to quantify the scale of the
problem, but recent estimates put the amount of plastic waste produced thus far
at over 6 billion metric tons. At the current rate of production, this is
unsustainable, and the negative environmental effects of releasing plastic into
the environment are long-documented.
Solution: Biobased Plastics (and Policy Change)
One of the most talked about innovations in the bioeconomy
has been the development of compostable plastics. These buck the stereotype of
plastics being “non-degradable”, as these plastics will biodegrade when subject
to the right conditions. These plastics have seen use in “disposable” items,
particularly ones associated with food waste. Compostable coffee pods, cups,
and food waste bags have all been developed, with the intention being that they
can be disposed of alongside food waste.
However, this is not without its downsides: by
“compostable”, manufacturers of these plastics are usually referring to
industrial composting, but this may not be clear to the consumers, resulting in
the plastics not being disposed of in the correct way, thus nullifying the
solution to the problem entirely.
While compostable plastics are an excellent innovation and
able to act as a solution to the problem at small scales, the infrastructure
isn’t there for composting on the scale needed to dispose of all the world’s
potential plastic waste. This isn’t to mention that not all plastics are likely
to be compostable, meaning some applications will not allow for this
end-of-life treatment. This restricts the compostable plastic solution to a
narrow range of sectors - mostly ones involving food – where composting is a
viable method of waste disposal in the first place. So, what of the other
sources of plastic waste?
For other plastic solutions, we can look to durable biobased
plastics. There are now biobased drop-in alternatives for many widely used
packaging plastics such as polyethylene and polyethylene terephthalate. If
these plastics are subsequently recycled and fed back into packaging
production, it creates a sustainable circular economy, fed by renewable
feedstocks and with waste minimised. The potential is already there for this to
become a viable solution, but the landscape needs to change.
As such, the real solution for successful implementation of
this lies in policy change. A good example would be the recently published
European Plastics Strategy, which aims to put recycling at the forefront of
plastic waste management in Europe. This has been welcomed by members of the
plastics industry, and by environmentalists, but to ensure it works as a
strategy every aspect of the value chain needs to be geared towards recycling,
right from material and product design, which will require a substantial
commitment on the part of the industry itself.
This is an offshoot of the previous problem of plastic
waste, but is a significant enough problem in its own right to merit its own
entry. Eventually, plastic waste ends up in the world’s oceans, where it is
slowly broken down into microscopic particles. These have been found to be
harmful to marine life, and are prevalent on a scale far greater than
previously imagined. However, this is the smaller facet of the problem: recent
studies have found that the majority of microplastics do not come from
breakdown of waste, but come directly from product use. Such microplastics can
be released into the environment purely through use of a product: one of the
biggest culprits is tyres: due to abrasion of the tyre rubber, microplastics
slough off and are washed into water courses by rain.
Microplastics are also intentionally included in some
products: notable examples include many cosmetic products, wherein “microbeads”
are used to improve texture of cosmetics, or as exfoliation agents in skincare
products. The major problem here is that these products are disposed of
directly into the water system when they are washed off, thus guaranteeing the
presence of microplastics therein.
Solution: Degradable Microbeads
Initially, the public response to the findings about
microplastics was very strong, which led to several governments announcing an
outright ban on the use of microplastics in consumer products. This indeed is
one viable solution, but the bioeconomy offers a more nuanced solution.
Compostable plastics were mentioned above, but these would
not be suitable as microplastics, as products containing them aren’t disposed
of by composting, but the bioeconomy has also managed to develop plastics that
will biodegrade in more natural conditions. Several companies have developed microbeads
from PHAs, biodegradable polymers produced by microorganisms, making them both
degradable and biobased, demonstrating the desirable characteristics that
biobased plastics can have at both ends of their life.
The important trait is the ability to degrade in marine
conditions, which is actually an easier approach to the problem than trying to
prevent microplastics from entering the oceans at all, simply reducing the harm
they cause once there. Of course, for such a solution to be successful, it will
require widespread adoption of these degradable microbeads, to prevent a shift
in attitude back to acceptance of water-disposal of non-degradable microbeads,
as consumers come to incorrectly believe all microbeads are safe.
Another similar possible solution was developed by the
University of Bath: to make the microbeads from cellulose instead. This has
broadly the same effect as the PHA microbeads, by allowing the microbeads to be
degradable in marine conditions. However, these microbeads use plant biomass as
their feedstock, rather than being produced by microbes. This distinction is
important for wider production of these biodegradable microbeads, as this means
they can be produced from different sources, and thus with different
technology, meaning this solution will be easier to roll out, depending on what
technology is available in what area.
In terms of the problem of microplastics produced by
breakdown of larger plastics, this cannot be as easily solved, as not all
plastics are degradable in marine conditions, and not all applications are
suitable for plastics that are. To this end, currently the best solutions are
to minimise plastic waste in its own right, to prevent this breakdown and
deposition of microplastics. This all comes under the umbrella of solutions
described in the first part of this article.
Plastics are without doubt one of the most successful
innovations of recent memory, and simultaneously becoming one of our biggest
challenges, but with the help of the bioeconomy, we may be able to solve that
problem, and have plastics that work for us without issue.