Ethical Corporation is now Reuters Events - LEARN MORE
With increasing attention drawn to their packaging washing up on pristine beaches, brands such as Unilever, Nestle and Procter & Gamble are setting stretch targets to adopt more circular approaches. We look at innovation in use of recycled plastics and the barriers to taking them to scale
Recovering the value of plastic when it’s been used means we must get better at sorting waste. The purer each recycling stream, the better the quality (and value) of the recovered plastic.
Materials-recovery centres use near infrared optical sorting systems to identify different polymers, but they can’t distinguish plastics suitable for food storage, identify what’s under a shrink-wrap sleeve or recognise black plastics, so they all end up in landfill. The pigment used in black plastics is carbon black. Its value is in the protection it offers from sunlight. But if that isn’t required, using an alternative organic pigment would allow 70,000 tonnes of black plastic to be reclaimed annually in the UK – and some 500,000 tonnes across Europe – according to Edward Kosior, managing director of recycling consultants Nextek.
“Marker technologies are a cornerstone project for achieving a plastics circular economy,” he says. His firm is leading a UK-funded project, Plastic Packaging Recycling using Intelligent Separation Technologies for Materials (PRISM), to develop novel fluorescent markers using various materials such as waste powder from fluorescent lights and tubes, and metal oxide nanoparticles. The markers can be invisibly applied to labels, and removed and recovered before recycling. Kosior says they’re able to separate out various categories of food grade and non-food grade plastics with 98% accuracy. A fluorescent marker system could allow 165,000 tonnes of polypropylene (used in meat trays and bottles) to be recycled to food-grade standards in the UK; across Europe, as much as 1 million tonnes could be recycled.
Ioniqa’s process produces just 30% of the CO2 of PET made from the usual petrochemical feedstocks
Kosior is confident that the economics of labelling stack up. Costs are currently €1 (89p) per tonne of packaging, but that will come down. What’s required is to retrofit existing sorting equipment with the necessary illumination and software, allowing consumer brands to potentially develop closed-loop recycling for their packaging. Sustainability commitments by the likes of Unilever and Proctor & Gamble “mean they want their materials back”, Kosior says.
Another important influence on the value of reprocessed plastics is how often they’ve been recycled, as this impacts on polymer properties. Nextek is awaiting patent approval for another marker technology that will allow recyclers to determine how many processing cycles a polymer has gone through.
Another task is to strip contaminants and odours from plastic waste. An EU consortium, CLIPP+, found it was almost impossible to remove inks from printed plastic film because ink manufacturers make particles so small that they can’t be filtered out. But they did find that the solvent they used, CO2 as a liquid (so-called supercritical CO2), was extremely efficient at stripping out odours, and could remove some colours. So whereas a lorry-load of reclaimed printed films (being used for despatch bags for eBay or Amazon, for example) has “quite a smell”, the film could be used for more valuable products if the odour can be removed , explains Alan Heappey, project manager at UK packaging manufacturer Skymark. Reprocessed polyolefin films could, for example, replace virgin film as wrapping for pallets of toilet roll destined for supermarkets.
Ioniqa Technologies, a spin-out from the Eindhoven University of Technology, has had more success removing contaminants from PET (polyethylene terephthalate) which is mainly used for textile fibres, and drinks bottles. But, significantly, when PET is added to the magnetic smart liquid that Ioniqa has developed, and then heated, the PET depolymerises. The colourants and other contaminants are removed in a magnetic field, to leave the original building blocks of the polymer.
Those building blocks can be used to create new PET, over and over again. That’s a big advantage, because at the moment PET can only be recycled up to six times.
Ioniqua’s founder, Tonnis Hooghoudt, describes it as a “game-changing technology that enable[s] a profitable, circular process for almost a quarter of all plastic waste in the world”. Some initial testing has also found that the process could potentially be applied to other plastics, as well as cotton and paper.
There’s a lot of inertia in the system. People prefer to be fast followers rather than innovators
Ioniqa’s process produces just 30% of the CO2 that would otherwise be the case if 1kg of PET were made from its usual petrochemical feedstocks. That’s ignoring the further carbon cost if the PET is incinerated, which happens on a large scale around the globe.
But PET producers, and consumer brands took some convincing, so Ioniqa invited some big brands to bring them their waste and then test out the resulting product in the brands’ own labs. The ambition now is to scale up, with a 10,000-tonne production plant anticipated by the end of 2018 – if Ioniqua can convince potential customers.
Even if it’s technically difficult to separate certain types of plastics (such as those from electronic gadgets) or just not economical, they still might be recycled. Dow Chemicals (amongst others) has developed what are called combatibilsers, which allow two types of resins which wouldn’t otherwise mix evenly to be recycled together. That way, the properties of the plastics (eg mechanical strength) can be maintained.
It’s evolved its RETAIN technology to help tackle one of the biggest recycling headaches: multi-layer food pouches with an inner barrier film.
Dow has built the modifier into a pouch, which can be recycled. To demonstrate its potential, Dow worked with flexible packaging manufacturer Bemis, and converter Polykar, to recycle multi-layer film scraps into plastic bags, which were used during Ocean Conservancy’s coastal clean-up last month. It’s now working on expanding the technology to enable different pouch mixtures to be recycled.
A Greenpeace plastics audit on a Philippines beach found Nestlé, Unilever and Procter & Gamble were amongst the biggest polluters
Jeff Wooster, global sustainability director for Dow Packaging and Specialty Plastics, is optimistic the technology will soon be commercialised. But he adds: “There’s a lot of inertia in the system .... people prefer to be fast followers rather than innovators.”
Such solutions to enable recycling of multi-layer packaging are urgently needed, because while they may take less energy to manufacture and transport, they usually end up in landfill, or floating in the oceans.
Last month, Greenpeace released the results of a plastics audit along a stretch of beach in the Philippines: Nestlé, Unilever and Procter & Gamble were amongst the biggest polluters. Much of their waste turned out to be sachets, made of plastic film and aluminium foil. Billions of them are sold each year in developing countries, where they allow poorer people to buy small quantities of otherwise unaffordable products.
Unilever’s own analysis has found that more than 60% of plastic flexible packaging in landfills in Indonesia (a country that produces 64 million tonnes of waste every year) is made of polyethylene (PE), so that’s what it has decided to focus on in that country. Unilever has a worldwide commitment to ensure all its plastics are reusable, recyclable or compostable by 2025.
Landfill is still very cheap, and without policies to divert waste from landfill, the investment won’t come
It has worked with Germany’s Fraunhofer Institute for Process Engineering and Packaging to adapt a solvent technology to recover the PE, which Unilever claims is functionally equivalent to virgin polymer. The remaining layers – PET and aluminium – can also be recovered. According to the Fraunhofer Institute, the CreaSolv process can produce 6kg of recovered plastic using the same amount of energy as it takes to make just 1kg of virgin polymer.
To establish the commercial viability of the process, Unilever says it will build a pilot plant in Indonesia and, once proven, will make the technology available to its competitors. The commitment to tackle sachet waste echoes a similar pledge Unilever made back in 2012, to build pilot plants in India to turn the waste into fuel, and so recover some of its embedded energy. At that time Unilever said: “As part of the Unilever Sustainable Living Plan we have committed to developing and implementing a sustainable business model for handling our waste sachets by 2015.”
Asked about the pyrolysis technology, a Unilever spokesperson said: “This is not an established technology and has several limitations, making it difficult to develop and scale up a sustainable business model.” The CreaSolv technology would, she said, counter this.
Cambridge university spin out Enval has come up with a process to recycle plastic/aluminium laminate waste, of which 160,000 tonnes is produced each year in the UK alone, most of it going to landfill. This is especially wasteful because making aluminium requires vast amounts of energy. Enval uses a microwave pyrolysis process that enables it to recover the aluminium at a very high purity, and save 75% of the energy that would otherwise be required to produce it.
The plastic melts to produce gas and oil; the gas can be used to generate electricity to run the process, and the oil sold for fuel or feedstock for speciality chemicals. Thanks to financial backing from brands including Nestlé and Mondelez, Enval has one plant at commercial scale, handling 2,000 tonnes of pre-consumer waste a year.
What is missing is the solid business case for change that will create a waste processing infrastructure
Chief executive Carlos Palafax-Ludlow says the UK generates enough to feed three such plants. But he despairs of the difficulties of getting the waste industry interested in post-consumer waste. “Landfill is still very cheap, and without policies to divert it [waste] from landfill, the investment won’t come.”
Few local authorities collect such waste, which completes the vicious circle. But while the waste processors don’t care whose name is on the packet, Palafox-Ludlow believes the brands “have a vested interest in us being successful.”
While Enval has only one plant, it has plans for more, and could have one in every European country if it licensed the technology.
So how can the inertia be overcome? Dow used some of what it learned as part of an Innovate UK project, which aimed to provide guidance on designing for recycling. The project now has a larger ambition as Ceflex, whose goal is to see a collection, sorting and reprocessing infrastructure for post-consumer flexible packaging across Europe. It involves all players in the value chain: material producers like Dow, together with packaging converters, brand owners and retailers (like M&S); and recyclers. “What is missing is the solid business case for change [that will] create a waste processing infrastructure,” says Dana Mosora, a member of the project management team. Ceflex, she says, will “come up with technical solutions and pilot projects that will provide the data” to make the case. Then it will be up to industry to advocate.
Achieving the big eye-catching commitments that brands are making on sustainability may very well depend on their success.
This is one of a series of articles on how brands are innovating to reduce the environmental impact of plastic packaging. See also:
Unilever Nestlé PRISM CLIPP+ CreaSolv Ceflex Dow Chemicals Ioniqa Nextek Procter & Gamble plastics recycling ocean plastics