Sustainability in the circular economy

By Cecelia Thirlway, freelance writer

In Back to the Future II, Dr. Emmet Brown’s iconic DeLorean time machine had been modified to run on household waste. That imagined future innovation, portrayed as happening in 2015, is already at least five years behind schedule. But while fueling vehicles with banana skins and plastic bags is not on the horizon just yet, there are ground-breaking innovations being made in the world of waste.

Without urgent action, annual global waste generation will rise to 3.4 billion tonnes by 2050, a 70 percent increase on 2018 levels, according to the World Bank. While more than one-third of waste in high-income countries is recovered through recycling and composting, only 4 percent of waste in low-income countries is recycled.

If we can tackle the recycling problem, we may also gain ground in solving the climate crisis and associated loss of precious habitats. The more virgin resources we use, the more we damage our planet. The World Economic Forum (WEF) estimates that “resource extraction and processing alone cause over 90 percent of global biodiversity loss and water stress, and about half of the effects of global climate change."

By reducing our dependence on the extraction of oil and minerals, we can avoid generating high levels of emissions and thereby help restore our planet’s ailing ecosystems. And there is an opportunity here. As noted by WEF: “Smart resource use and business models that do not rely on natural resource extraction are a huge untapped field for innovation and for a new model of growth.”

One person’s waste is another’s treasure

The key to creating fully sustainable, closed loop systems, where resources are re-used, recycled and never discarded, lies in their economic value. When we start perceiving waste as resources of equal – or even greater – value than those used to create it, we will have closed the loop and created a truly circular economy. This isn’t a new idea. For example, in the seventeenth century whisky producers started re-using oak casks that brought sherry to their ports from Spain. This was a far cheaper solution for them than buying new oak, and it made little sense to send empty casks back to Spain for refilling. The flavor benefits of this approach were only discovered later.

Similarly, legislation passed in the United States in 1935 to protect the cooperage industry made it illegal to use bourbon casks more than once. This turned used bourbon casks into a waste stream, and resulted in a huge proportion of whisky in the UK (where casks can be reused as often as the wood allows) now being aged in American oak casks.

But how do we apply these principles to materials that are more difficult to re-use? In 2016, the world generated 242 million tonnes of plastic waste, leading many to view plastic as a problem material.

Plastic waste is cluttering our oceans, and micro-plastics are entering natural ecosystems and the food chain at an alarming rate. Many countries and cities around the world have already dramatically reduced plastic bag usage either by charging customers directly to use them, or by taxing retailers who supply plastic bags to their customers. In addition, initiatives such as Sky’s Ocean Rescue in the UK and Plastic Free July in Australia are urging businesses and consumers to eliminate single-use plastic from their lives.

But is going completely plastic-free the answer? Plastic is a highly versatile material and finding suitable alternatives isn’t always easy. Furthermore, it’s important to ensure that the alternatives developed don’t create new waste or emissions problems.  One option might be to do better at dealing with the plastic we already have.

“The biggest problem we’ve got is that people now are classing plastic as the demon, as death and doom and gloom,” says Professor Martin Atkins, CEO of Green Lizard Technologies. “But actually, if you look at the benefits of plastic, they far outweigh anything else that we can package and carry our food in, for example. The only problem with plastics is that we don’t know how to treat them as waste properly.”

Green Lizard Technologies, a spin-out company of Queen’s University Belfast, focuses on finding green and sustainable solutions to industrial problems. Its solution for plastic waste is a process that converts waste PET (polyethylene terephthalate) to BHET (Bis(2-Hydroxyethyl) terepyhthalate), an organic compound that is now being commercialized through Poseidon Plastics UK.

“A lot of people are just burning plastic to get the energy back, and that's about the worst thing you can do because you generate carbon dioxide (CO₂) in that process, and you don't actually get that much energy back. We've developed a process that takes plastic all the way back to fuels, to chemicals, to solvents to give them secondary and tertiary uses and convert them into products. These are products you could make through another route, but this is much cheaper because you’re using a feedstock which is classed as waste.”

The crucial element of a process such as Green Lizard’s is that the outputs can be re-used for a purpose of the same value as before.

Professor Atkins highlights that while managing plastic waste is a challenge, replacing it in the food supply chain might result in higher transport emissions from heavier packaging (e.g. glass), or greater food waste. But if discarded plastic could be reused in an economically viable way, that would change everything.

“The minute we put a value on plastic the problem will go away, in my view, because people will see it as a resource rather than a problem.”

Recycling versus downcycling

Conway Daw of toothbrush manufacturing company Reswirl agrees: “A lot of plastic that’s returned for recycling isn’t really recycled, it’s downcycled. It’s chopped up and turned into a lower grade material, and becomes park benches or watering cans or bollards, which gives it a second use, but it’s not a continuous cycle. It’s still going to end up in landfill eventually.”

Reswirl is developing a manual toothbrush and replaceable heads for electric toothbrushes that, once worn out can be returned to the company for remolding into new brushes. The material and recycling process they use ensure that their outputs can be used again and again. And even if the toothbrushes do end up in normal waste channels, the handles will biodegrade safely because they are made from a biodegradable material called PHA (Polyhyeroxyalkanoate).

Reswirl has applied for a patent for its recycling process and material, but as an experienced designer, Conway Daw thinks that the patenting process could place greater emphasis on a product’s end of life.

I firmly believe in the responsibility to consider not just how something is made, but how it is un-made at the end of its life. For patent applications for things, processes, or compounds that facilitate easy re-use or recycling, perhaps there could be additional criteria for examination.

Base metals

“One material that has been successfully recycled for over a century is lead – as an expensive metal with a number of different uses, its value means it’s worth the effort to recover as much of it as possible. But this brings its own problems,” says Dr. Athan Fox of recycling company Aurelius Environmental.

“A lot of people don't realize this, but the lead acid battery is actually the world’s most successfully recycled commodity product. The battery is contained in a plastic casing, which is recycled, and this plastic makes money, its value is preserved all the way to the new plastic. Then there is an electrolyte: an acid that is usually neutralized and converted into a value-added salt that can be used in various industrial applications. And then there is the lead metal, and that lead metal has been in use in batteries since the 1850s.”

The minute we put a value on plastic the problem will go away, in my view, because people will see it as a resource rather than a problem.

Martin Atkins, CEO, Green Lizard Technologies

While this might sound like a perfect example of the circular economy in practice, the industry that recycles the lead from batteries is highly polluting, in part, because the process is expensive and highly energy-intensive, emitting large quantities of CO₂.

Aurelius Environmental has pioneered a process that can recover the active material in batteries, the so-called “leady oxide”, while reducing carbon emissions by more than 85 percent. This zero-waste process takes place in cold water rather than a furnace and thereby substantially reduces energy use.

“In our process, the old active material is converted into a new active material directly, without having to go through the refinement process and downstream conversion of materials,” continues Dr. Fox. “But the icing on the cake is that the active material that we produce through the recycling process has a higher porosity and lends itself to superior batteries; they are more energy dense than batteries produced from mined lead metal.”

This provides a powerful economic driver for the industry to adopt this new process and helps explain why Aurelius Environmental is currently negotiating licenses in all key markets across the world.

Scarcity and plenty

Waste is in part driven by plenty: when resources are plentiful, they become cheap, so we don’t value them sufficiently and allow them to fall out of use. The approaching scarcity of some of the resources we rely on – such as oil – coupled with a growing understanding of the problems caused by waste in landfill, are starting to drive innovation in how we use and re-use natural resources. However, whether this scarcity is driving innovation sufficiently fast, particularly in the context of climate change, is another question.

Sometimes the drivers for innovation around waste are not related to scarcity, but the opposite. Eoin Sharkey’s company, The BioFactory, is working on a solution to the health problems caused by unsanitary toilet facilities in developing countries.

“Basic pit latrines provide the ideal environment for pathogens to grow, they’re really difficult to clean, and they’re often neglected and overflow into groundwater sources, which causes all sorts of problems,” says Mr. Sharkey. “But one of the things we found is that the cost of building and maintaining toilets is a massive issue.”

To solve this problem, Mr. Sharkey has spent the last year designing a toilet system that uses a form of bio digestion to convert human waste into fuel – biogas. The process of doing this isn’t new but making it economically viable has always been tricky.

The problem with sanitation is often a business problem, not a technology problem. A lot of other sanitation companies collect the waste and transport it to a waste processing plant, create their by-products and then sell them back to the users. So, we built a community toilet and waste processing system that does everything in one place.

By replacing some of the charcoal used as fuel by 80 percent of people in Africa with biogas, The BioFactory’s system is helping to eliminate some of the health problems caused by charcoal smoke, such as pneumonia and lung cancer. Also, by offering a sustainable alternative fuel source, the system is helping to prevent the deforestation threatening many African countries.

We’re launching a pilot project in Mozambique to provide toilets for 150 to 250 people who don’t currently have access to basic facilities, and through that project we will be able to provide biogas at the same price for the same amount of energy as charcoal. We will initially trial this in schools.

Whether it’s reducing emissions from the recycling process, creating value from a previously valueless material, or finding economically viable ways of diverting waste from landfill, it’s clear that innovation around waste is happening all over the world. But the most recent report from the Intergovernmental Panel on Climate Change (IPCC) has demonstrated that we simply don’t have time to waste on waste. We need to change our global attitude; we need to view every piece of waste as a missed opportunity to re-use a resource. 

As Dame Ellen MacArthur, global sailor and founder of the Ellen MacArthur Foundation, has said: "We’ve paddled hard in the past, but we need to paddle a lot harder in the future because that circular economy opportunity is sitting there, waiting to happen, and it's up to us to make it happen."