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Einzigartiger Planet

She turns plastic waste into a raw material

Plastic waste is everywhere — nature has practically no remedy for plastic. This is where technology comes in. Miranda Wang is developing procedures that turn plastic waste into useful raw materials. For this she received the Rolex Award for Enterprise.
Published in January 2020Time to read: 4min 7s

The tallest heights of the Earth are in the Himalayas, at 8,848 metres. However, the highest peak, Mount Everest, would easily fit into the deepest depths of the Earth: the Mariana Trench marks 11,000 metres between the water surface and the seabed. In 2012, director and Rolex Testimonee James Cameron (Titanic) dived to the bottom in his DEEPSEA CHALLENGER.

Cameron later reported that, as he continued to descend ever further, he thought to himself: “Here I am now, in the depths of the ocean, at the deepest point on Earth. What does that mean?” The Mariana Trench was “the absolute furthest and most isolated point on Earth. I feel as if I was on another planet for a day”. In the meantime, it has been shown that not even this ultimate place, this maximal depth, is safe from plastic waste. A few years after Cameron’s expedition, plastic waste was discovered on the bed of the Mariana Trench. A plastic bag.

Plastic is practical, plastic waste is a problem
Plastic waste is a worldwide problem — a very large one. Plastic waste pollutes countries and seas, plastic waste kills animals. Plastic is practical, plastic waste is a problem. Our plastic becomes waste far too quickly. A plastic bag, such as the one from the Mariana Trench, is only used for an average of 25 minutes before it is disposed of. On the seabed, it will last for at least another 20 years. A straw that is used on an evening for a drink exists as waste for 200 years after that. According to estimates, it will take 450 years for a plastic bottle to decompose.

And even then, the waste is only visibly gone: the plastic crumbles into tiny pieces, which are consumed by animals with their food. Through the food chain, micro-plastic will also be found in human food. This is not healthy.

Wang wants to acquire valuable raw materials from waste
Recycling? Difficult: most plastic waste can so far not be re-used. Miranda Wang wants to change that. The Canadian molecular biologist has developed a procedure with which valuable raw materials can be produced from previously unusable plastic waste. For this she received the Rolex Award for Enterprise.

The Swiss luxury watch manufacturer Rolex awards this prize every two years, to pay tribute to people and their projects that provide innovative solutions to preserving the world in which we live. The prize winners receive support for the continuation of their projects, as well as access to the Rolex network. The Rolex Awards for Enterprise are a part of the large-scale Rolex campaign, “Perpetual Planet”.

Rolex commits itself to long-term support
“Perpetual Planet”, established in 2019, is dedicated to projects that intend to protect our world from harm caused by human interaction with nature. Rolex is committed to the long-term support of researchers in their efforts to protect the environment. This specifically means: alongside the Rolex Awards for Enterprise, the “Mission Blue” initiative, by the American marine researcher and Rolex Testimonee Sylvia Earle also belongs to “Perpetual Planet”, as do a number of expeditions, which Rolex sponsors as a partner of the National Geographic Society.

For many years, Earle has been committed to the creation of protected marine areas, called “Hope Spots” — ocean reserves with significant amounts of endangered flora and fauna. The National Geographic Society, with Rolex's support, conducts research on how human activity affects the environment. A research group studied the effects of climate change on the glaciers in the Himalayas.

A lorry load of waste goes into the sea every minute
Miranda Wang conducts her research in the US state of California. She is 25 years old and is developing a special procedure in her own start-up, “BioCellection”, with the goal of making plastic waste a part of a closed circuit economy rather than the end stop in the production chain. Currently the process is being tested, but soon it will be used at municipal level.

There is a lot of demand. Humanity produces 300 million tonnes of plastic waste per year — this amounts to a total of roughly 8.3 billion tonnes since the 1950s. Ten million tonnes land up in the world’s oceans every year, roughly a lorry load every minute. Less than a tenth of the world's waste has been recycled so far. The reason: plastics are practically indestructible. Their chemical structure is often so complex that they cannot even be dissolved with the aid of technical tools. Let alone in a natural way.

Plastic is unfortunately stable and robust
Miranda Wang focused on plastic waste from polyethylene (PE). This plastic makes up the largest part of global plastic production, around 30 percent. Many everyday objects contain PE: cling film, milk cartons, garbage bags and plastic carrier bags. In supermarkets, these are recognisable by the recycling codes 02 or 04 displayed on the packaging.

PE plastic is especially stable and robust, as is the plastic waste that comes from it. And because PE often comes into contact with food, PE waste is contaminated and therefore not recyclable. Wang believes that something needs to happen because “there is still no economically viable technique to make high-quality products from these plastics”.

The Canadian had the initial idea for her research as a teenager. She was 15 years old when she visited a waste recycling plant on a school trip. Plastic waste became her subject, so to speak. Together with her school friend Jeanny Yao, she became increasingly serious about solving the problem. This eventually resulted in a start-up. Today, Wang and Yao are partners at BioCellection and lead a ten-person team, which is developing its own recycling process.

New chemicals are created from waste
The current position: “We have developed a cheap and sustainable procedure to produce valuable industrial chemicals from plastic waste”, Wang states. “And we have shown that these have the same quality as chemicals made of oil.” BioCellection also works with municipal waste managers, recycling companies and manufacturers who want to use recycled plastics in their production chain.

If Wang’s procedure could be used on a large scale, more plastic waste would be re-used. “Accelerated thermal-oxidative depolymerisation” is the name of the procedure by which plastic waste is decomposed into simpler substances via a series of chemical reactions. The chemicals thus obtained can be used to produce other plastics. Bonus effect: less use of fossil fuels. So far, oil, among other things, has been required for these “precursor chemicals” used to manufacture plastic.

In order to recycle plastic waste, it must first be sorted. This is often impossible, as different plastics are combined with each other in many products. For this reason, more than half of all plastic waste in Germany is burnt to produce energy. Filtration systems are used to remove poisonous gases and pollutants from the exhaust gases. In 2017, just 0.8 percent of German plastic waste was reused as a raw material, which could also be done by using Miranda Wang’s procedure. At the same time, nearly 46 percent was processed as a material by being recycled into new, cheaper plastic.

We must do something. Otherwise, by 2050, there could be more plastic than fish in the oceansMIRANDA WANG, winner of the Rolex Award for Enterprise

Of all the plastic waste that has accumulated since the 1950s, only 9 percent has been recycled to date. “This cannot continue”, said Wang, “otherwise in 2050 there could be more plastic than fish in the oceans”. Every year 135,000 marine mammals and over a million sea birds die because they mistook plastic for food. Ocean currents cause plastic particles to be gathered into giant waste carpets that make entire areas uninhabitable. The largest of these, the Great Pacific Garbage Patch, is located between California and Hawaii. It is 4.5 times the size of Germany.

Wang plans to build a commercial processing plant for PE plastics soon. By 2023, it should be used to process 45,500 tonnes of plastic waste. If the process can be further refined, many more options would become available, according to the vision of the company: then plastic waste could one day replace fossil fuels in the production of plastics. Waste instead of oil – a good thing.

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