Written by Jade Ruston
You may have heard the myth that us wee humans on average have access to only 10% of our brains, thus being an excuse used by many to justify their inaction. Fighting science with science and debunking that myth once and for all is an immensely intelligent brain, residing in the head of Dr Christian Sonnendecker who is a researcher at the profound university of Leipzig, Germany.
The research being carried out by Dr Sonnendecker and his team has an admirable core drive to it. Make the world more safe for all living things. The passion resonating from Christian is both contagious and inspiring as he details simple life responsibilities that get brushed under the carpet by many worldwide regarding….
Plastic.
Specifically PET. Most of our water, takeaway or store bought food, beauty products and household cleaning products arrive in our possession securely contained in PET plastic. Whilst we frolic around and justify our usage once we see the little recycle symbol on our products, it remains a heavily ignored truth that growth in production levels and our lack of energy put into recycling properly, mean that most of these items still end up in the wrong place which is devastating to our miraculous planet.
Dr Sonnendecker has been trialling a new method of biological recycling using a newly discovered enzyme ( a protein that acts as a biocatalyst, meaning that it can speed up the pace of a reaction as well as not be destroyed in the process, so the protein can be used repeatedly). In LESS.THAN.A.DAY. Dr Sonnendecker was able to break down a PET item by around 90%! In the wild (landfill), our future children’s childrens children could probably go and find the same plastic bottle that we threw away a year ago, so this achievement is one that should be met with the tallest enthusiasm from us, from animals, from mother nature, and from the big firms that have already surpassed the deadline for phasing out single use plastics.
Whack your volume up for a moment and get mesmerised in how it’s done below.
Hydrolysable – it has components capable of being broken down due to a reaction with water.
Right now, the discovery of this new enzymatic process is fantastic enough, but hold your socks….it gets even better.
The system is turning out to be suited well for small-scale decentralised action with a very minor level of energy consumption. No additional by-products or toxic compounds are released during the process apart from the additives that are already present within the plastic such as any pigmements, heavy metals, chain extenders etc. (You may have just seen in the news that Sprite has changed their noticeable green bottle to a clear one to cater for easier recycling for example.) The water only needs to reach between 60-70 degrees celsius to achieve efficient depolymerization.
It could be done at room temperature however would take a much longer time.
Dr Sonnendecker explains below in a much more professional way;
“The current dominant method is mechanical recycling. Here, the PET bottles are washed and formed into pellets or flakes and subsequently the material is melted and formed into a new shape. This is very efficient, but this cycle can only be repeated a few times as the material properties suffer from this procedure. Then, the end of life product can be incinerated to recover at least the energy that is already in the PET (but this releases CO2). Chemical recycling and biological recycling decompose the polymer into its unit blocks (which are subsequently purified and used to form virgin PET instead of using fossil fuels as feedstock). Chemical recycling is probed and further developed, but still most projects have not proven to run under economic considerations.”
Chemical recycling requires harsh conditions in order to complete the process. Whilst monomers are still released, this method is handy to have to close the loop. However, it is cost intensive and requires a large facility. Using the new enzyme with successful developments in place. It could see countries localise their waste, and allow us to witness a game changing moment for pet recycling if it manages to get within an economic range.
Christian continues to explain,
“We are working together with a huge network of European research groups and companies, e.g. within the EU projects MIPLACE and ENZYCLE, and the future looks really promising to build towards a larger reactor so we can do this on a bigger scale. It’s likely that we will soon know more about whether the process can produce money through the requisite to use it in an industrial application”
There are many things that we, as the end consumers can do, such as using reusable beverage containers or sorting of waste. In a nutshell, responsible consumption behaviour is key. We need to understand that this story is not going to end well if we just keep on going. A change in how we deal and live with plastic is urgent to prevent further damage to our ecosystems.
Most of our daily-use plastic products are hard to recycle or just absolutely non recyclable and we just can’t handle them. As people become more aware of this and change their consuming behaviour, it can give some pressure to the producing industries to focus more on sustainable solutions. The consumer has the power, he is just not aware of it.
Another problem that drives the cost high for recycling is that when the waste gets thrown in the bin sorting and cleaning it is already contributing to the high costs. The households in Japan for instance are already very efficient in sorting their plastic waste. A recycling facility in Japan could thus access a high quality feedstock without investing much in sorting and cleaning.
Thermoform PET packaging is almost at the end of its life. After the thermoform stage, the most valuable approach will be to recover the monomers. This is one example where the enzymes could help us to close the recycling loop for PET.
It’s not the efficiency of the enzyme. The enzyme is already efficient enough.
Enzymatic recycling is currently propped, but it will not be a cheap option. However, there are some tricks as to how the costs can be reduced. Energy for heating could be gained from exhaust heat from other industrial processes. If households and companies would sort and clean their PET waste, a much cheaper feedstock cost could be accessed. Small things like that could make the difference whether the process will be adapted in our industries or not.”
Science is just remarkable. There are some great lessons and learnt words of wisdom coming from Dr Sonnendeker and if this wasn’t enough and you need to know more, get around his work on Linked In or keep up to date with his team’s YouTube channel. Whilst this is exciting, please remember to take an extra few seconds to think about what you’re buying, using and throwing away.