There is no lack of innovation in bio-based polymers, from those that store CO2 to bio-based PET. We look at the companies and brands that are trying to bring them to market
Plastics are made from non-renewable hydrocarbons like oil and gas, and expanding demand means the industry has a significant and growing carbon footprint.
There has been a huge research and development drive around the world to try to decouple production of plastics from fossil fuels. A lot of effort has gone into making plastics from biomass sources, and some of the new plastics being developed have properties that mean we will be able to use less of them in packaging.
One thorny issue is that just because a plastic is bio-based doesn’t mean that it will be biodegradable. Additives used in the final product may make it impossible for a plastic to biodegrade safely. In any case, it would still be better to recycle and reuse the bioplastic.
Another big challenge is that biopolymers can be anywhere between two and four times as expensive as fossil fuel-based polymers. “The main reason is small production volumes,” explains Rob Elias, director of the biocomposites centre at Bangor University. So there’s a big research effort to make biocomposites with increased functionality, such as those that improve food shelf life, for example.
IKEA said it would buy Newlight’s AirCarbon and ultimately produce the thermoplastic under licence for its plastic household furnishing products
Even with efficiencies from scale, Shane Kenny of Irish biopolymer producer Bioplastech doesn’t think biopolymers can compete on price with conventional plastics unless governments step in and regulate. “Without the regulatory push, the cost will always be the major driver,” he suggests.
What if you could use plastics to store harmful greenhouse gas emissions, such as methane? That’s what California based Newlight Technologies is working on, and it claims its AirCarbon product is able to out-compete conventional plastics on price. Initially its plants are designed to run on biogas from landfill, but Newlight eventually wants to use CO2 as a raw material. Newlight’s biocatalyst takes the carbon, hydrogen and oxygen from air and landfill gas and rearranges it to form the long hydrocarbon chains of a plastic called PHA (polyhydroxyalkanoate).
The company has a string of technology agreements, but two are particularly eye-catching: IKEA Group and the The Body Shop. Last year, IKEA said it would buy Newlight’s AirCarbon, and ultimately produce the thermoplastic under licence for its range of plastic household furnishing products. The Body shop has been testing AirCarbon, latterly through the laboratories of its former owner L’Oréal. Ethical Corporation understands the challenge is to ensure the plastic can form an impermeable barrier, which is crucial for cosmetics products. The Body Shop’s research is part of a commitment in its Enrich Not Exploit strategy to make sure that by 2020 70% of its product packaging is not derived from fossil fuels.
Minnesota-based NatureWorks is trying to commercialise its process to convert methane into lactic acid, which is the building block for a polylactic acid (PLA) polymer, Ingeo. At the moment, Ingeo is made from agricultural feedstocks.
Another way to make PHA is to harness bacteria. Bioplastech, a spin-out from University College Dublin, is converting PET waste into a new polymer by recruiting the services of micro-organisms. The Irish company is pyrolising PET waste at 450C. This process delivers one of the building blocks of PET, terephthalic acid, in solid form, alongside liquid and gas fractions (the gas being used for energy recovery). Since PET can’t be continuously recycled, conversion to PHA could be an attractive end-of-life scenario: it is totally biodegradable.
Traditional polymer makers are very resistant to taking in new polymers, even if they have very repeatable and defined characteristics
One particular strain of bacteria discovered in contaminated soil at a PET waste processing plant has proved very effective at using terephthalic acid to produce PHA. “It’s a bit like humans accumulating fat as an energy store,” explains Shane Kenny, director of bio-processing. He claims Bioplastech’s PHA is more flexible than other PHA on the market.
Bioplastech is part of an EU consortium, P4SB, which ultimately aims to build a pilot plant producing PHA. Ideally it would find alternatives to pyrolysis to break down the PET. Its partners at the University of Leipzig are exploring enzyme degradation of PET that would potentially deliver a purer feedstock. They’re also experimenting with an enzymatic approach to degrading polyurethane, which currently has very low recycling rates.
Others in the consortium are working to engineer more productive strains of bacteria, while Bioplastech tries to improve the fermentation process, which affects both the quality and the amount of polymer that is produced. At the moment Bioplastech’s process can convert about half the carbon in terephthalic acid to novel polymer.
They won’t be able to achieve 100% conversion, because some of the carbon is used by the bacteria themselves. Since the bacteria are killed to extract the polymer, Kenny suggests they would provide valuable animal feedstock or, at worst, fertiliser.
The main hurdles the company faces involve driving down costs. Kenny also has to contend with the fact that “traditional polymer makers are very resistant to taking in new polymers, even if [they have] very repeatable and defined characteristics.”
While the bulk of Bioplastech’s work is on developing a cost-effective plastic, it’s also looking at a range of other applications, from adhesives for packing tapes, to reusable labels.
While the R&D will focus initially on cardboard, sawdust and wood chips, rice hulls, straw and agricultural residue could be explored
A biodegradable label and adhesive would allow certain food packaging to be composted. This is important, because just 5% of a non-biodegradable product creates a big problem for industrial composters.
Earlier this year, French food group Danone and the bottled water division of Nestlé announced a partnership with California start-up Origin Materials to develop 100% bio-based PET (polyethylene terephthalate) bottles within five years.
Origin Materials began life with the aim of making biodegradable plastics, but has since developed a process to turn non-food (lignocellulosic) feedstocks like wood chips and sawdust into p-xylene, a key ingredient to make PET. Founder John Bissell has the backing of the two multinationals to build a plant that will make around 10,000 tonnes a year of p-xylene.
Origin has already made 80% bio-based bottles at its pilot plant, but the initial commercial goal is less: 60% bio-based by the end of 2018. That’s down to being able to find a commercial biomass source of another key raw ingredient. So for now, some of the PET will be produced from petro-based feedstocks. However, the ultimate aim is to have at least 95% bio-based PET bottles within five years. Bissell expects carbon emissions from the Origin process to be “substantially lower” than producing it from fossil fuel sources. The PET bottles produced are functionally and visibly indistinguishable from those that are being made today and will be recyclable. While the R&D will focus initially on cardboard, sawdust and wood chips, other materials, such as rice hulls, straw and agricultural residue, could also be explored.
Dutch-based Avantium believes it can commercially produce a stronger bio-based plastic with better barrier properties than PET. This is bio-based polyethylene furanoate (PEF). It’s made from first-generation sugars, but the expectation is that in the longer term Avantium will make the building blocks for PEF from lignocellulosic feedstocks, such as wood and agricultural residue. The polymer can be recycled with other PET waste, but the company anticipates recycling of PEF alone will become commercially viable.
Avantium says making PEF cuts CO2 emissions by up to 70% compared with manufacturing PET
Chemical differences between the two polymers mean that PEF has better barrier properties for gases such as CO2 and oxygen, which could deliver a longer shelf life for food. On top of that advantage, a higher mechanical strength means thinner packaging will be required. Avantium says making PEF cuts CO2 emissions by up to 70%, compared with manufacturing PET.
To exploit the technology, Avantium and BASF have set up a joint venture company, Synvina, which intends to build a 50,000 tonne pilot plant to make the monomer for PEF. A consortium of 11 companies led by Synvina recently got EU funding to develop a value chain for materials and chemicals based on PEF. It includes companies such as Nestlé, Lego and Austrian plastics manufacturer Alpla.
With so many promising technologies coming down the pipeline, have we reached a tipping point? “There’s been a weeding out of industrial technologies that were unrealistic - a lot of wishful thinking – it feels to me that most of the stuff that’s being worked on is more complete,” suggests Bissell. But until the first plant gets built, and works as it is supposed to, we won’t know for sure.
PHAs: polyhydroxyalkanoates. Naturally occurring family of polymers, which are usually made by micro-organisms. They are biodegradable, and can substitute for many other types of plastic.
PLA: polylactic acid. Biodegradable plastic made from corn starch and sugar cane, used to make plastic films and biodegradable medical devices.
PET: polyethylene terephthalate. Commonly used to make fibres for clothing, and in this context is known as polyester. Its other major use is for drinks bottles.
PEF: polyethylene furanoate. Has a similar chemical structure to PET, but made from plant based sugars. Can be recycled.
PE (polyethylene) the most commonly used plastic in the world. It is made from a hydrocarbon, ethylene, which is derived from natural gas or petroleum.
This is one of a series of articles on how brands are innovating to reduce the environmental impact of plastic packaging. See also
plastics carbon footprint polymers PET IKEA Group The Body Shop AirCarbon Bioplastech Origin Materials Danone Nestlé Avantium