French the renewable chemicals firm, CARBIOS, is developing a technology that would allow the depolymerisation of 100% amorphous PET into its original monomers, terephthalic acid and ethylene glycol. Not only does this enable the materials to be recycled an infinite number of times, but the process requires no presorting and is not effected by contaminants in the feedstock...
When it comes to recycling polyethylene terephthalate (PET), the traditional process requires waste materials to be sorted, ideally at source, shredded and into flakes and cleaned ready to be sold as rPET. However, over a number of recycling cycles the material can become contaminated and lose its integrity. It’s a problem that French start-up CARBIOS is looking to mitigate by taking a very different biological approach – and that’s not all its doing.
“I started CARBIOS with some money in hand, but with no real idea. It’s quite different to the normal story of a young company because very often there will be an idea but no money,” Jean-Claude Lumaret, chief executive officer of Carbios tells WMW. “My first business was involved with biodegradable plastics made with starch, so when I started CARBIOS I knew that the biodegradability of plastics is very important for the environment.”
As he put his thinking cap on back in 2011 and began searching for an innovative R&D project to bring to market, a number of patents filed by the Centre national de la recherche scientifique (CNRS) and the University of Poitiers came to Lumaret’s attention. Those patents covered micro organisms which were able to degrade PLA plastic at room temperature.
But CARBIOS did not simply jump onboard with CNRS to bring that technology to market. Lumaret had also become aware of another R&D firm which was developing a technology to introduce enzymes into the extrusion stage of a polymer manufacturing process. His idea? To combine the two technologies.
In July 2011 CARBIOS began the process of building a major R&D programme, THANAPLAST™, working in a consortium with a number of industry partners, including French National Institute for Agricultural Research (INRA), the Toulouse White Biotechnology (TWB) and the Laboratoire D’Ingénierie des Systémes Biologiques et des Procédés (LISBP) from INSA Toulouse, Deinove, Limagrain Céréales Ingredients and the Groupe Barbier.
The programme was presented to Bpifrance, a bank dedicated to supporting innovation in France. In July 2012 the bank approved the project and work began. The company initially focused on its academic partnerships as it looked to get the ball rolling quickly and cost effectively.
“To secure CARBIOS I preferred at the beginning to work with the academics than to employ a lot of people and to make a large investment inside the company. Because we decided to do it that way we were able to start the business with 16 workers dedicated to the programme,” explains Lumaret. “It’s the reason why last year we were able to achieve step three. It’s a five year programme and each year we have to present a report to Bpifrance. If it is approved they give us a more money.”
In total the THANAPLAST project has a global budget of €22 million over five years, including €15 million directly raised by CARBIOS. Support from Bpifrance accounts for €9.6 million, of which €6.8 million is directly allocated to CARBIOS. To date, CARBIOS has received €5.3 million and is slated to collect € 1.5 million from Bpifrance at the completion of future development stages.
In 2013 the company raised additional funding through an Initial Public Offering (IPO), which Lumaret says meant it could ramp up its in-house technology development.
The company has three core areas of research:
Developing a new generation of biodegradable plastics with a controlled lifecycle that is adapted to its end use
Deriving polymers directly from recycling with the use of enzymes to allow the treatment of large volumes of plastic without the need for sophisticated sorting processes
A new technology to produce biopolymers through the conversion of biomass to increase the competitive value of biosourced polymer production processes.
Biodegradable Plastics
In December 2014 the company opened its pre-industrial pilot plant to develop its enzymatic depolymerisation recycling technology at its headquarters in Saint-Beauzire, Auvergne, in central France. In September last year it added the capability to produce 40kg of plastic film per hour using its biodegradation technology, enabling it to test all steps required for the manufacturing process. The process entails embedding an enzyme into the plastic at the time of production.
The additional equipment encompasses several production modules, from the extrusion of the plastic materials to their transformation into flexible film, as well as the characterisation of all properties of the materials produced.
The company says that the new platform effectively brings to completion the pre-pilot development plant for the production of enzymes, and the collaboration with the CRITT Bio-Industries (Regional Center for Innovation and Technology Transfer) in Toulouse established in 2015 for the production of enzymes at the pilot scale of 300 litres.
With the new production platform, CARBIOS has the ability to demonstrate the performance of its biodegradation technology for the first applications, such as plastic films, mulching films for agriculture, and plastic bags, at the pre-industrial stage.
“We have been able to prove that this film is able to be 100% degraded at room temperature – and that is very important, especially in France with the new rules for bags in France,” says Lumaret.
In June last year the company applied its biodegradation technology to polylactic acid (PLA). It previously proved the complete biodegradation of its first polymer, polycaprolactone (PCL), in less than three months. In proving the complete biodegradation of a second polymer, PLA, to its technology portfolio, CARBIOS says that it has significantly expanded the breadth of industrial applications that it is able to offer its future partners and clients, and the markets that they address.
Given the broad range of potential applications and uses of PLA, CARBIOS and its partners in the Thanaplast project prioritised this polymer. The company says that using existing technologies PLA is currently only compostable under industrial conditions, in confined environments that require temperatures above 50°C and high levels of humidity. Consequently, the use of PLA for applications that require complete biodegradation under uncontrolled conditions and that are considered to be environmental sound, faces significant constraints.
According to Lumaret CARBOIS’ enzyme allows for the successful biodegradation of PLA at ambient temperatures and constitutes a technological break-through for which many applications may be envisaged.
The specific enzyme used in the degradation of PLA is a result of biodiversity screening work carried out by the Thanaplast™ project. Having been identified and isolated the enzyme is currently produced by the CRITT and CARBIOS in 300 litre reactors.
Enzymatic Recycling
Lumaret explains that the production of biodegradable plastics is just one part of the programme supported by CARBIOS. The second part is plastic recycling, specifically PET. He says that unlike film products used to package perishable products like salads, with packaging made out of PET such as bottles the required lifespan is indeterminate, meaning that adding enzymes to the material to aid degradation is not an option. Instead the company is developing a process to use enzymes to break down the polymer into its original monomers.
“We are able to recover 100% of the terephthalic acid and 100% of the ethylene glycol. These monomers are the same as the monomers produced by the chemical companies. It’s possible to have 100% recycling,” continues Lumaret.
He adds that one of the big advantages of the process is it’s ability to cope with contaminated feedstock without effecting the quality of the recovered materials. Untreated feedstock is simply loaded into a tank in which the enzymes live. After a certain retention period the PET has been completely broken down, while any contaminants such as HDPE or other polymers can be removed. It is also not sensitive to colour.
Another advantage of the process is that because it yields the same mix of chemicals that formed the original polymer, plastics can be recycled ad infinitum without any loss in value.
“The classical process used today is more focused on processing which requires sophisticated sorting because you cannot mix the colours. With the enzyme process we have no problems with sorting because the enzyme targets only the plastic of the polymers,” continues Lumaret.
Next steps
The key objectives of CARBIOS for this year are to prove the economics of its processes at a larger scale demonstration facility.
“We need to be competitive,” says Lumaret. “If you’re not competitive then no one is interested in the process. So it’s something very important and something that we had in mind from the beginning. We hope to be able to have commercialisation of the technology with our partners in two years.”
He also sees potential for the company’s enzymatic process to be applied to other waste polymers.
“Of course we started with PET because it is the most important polyester used today in the industry, but in the CARBIOS project we are targeting the 10 major polymers used in plastics,” he says.
Conclusions
With COP21 and the EU Circular Economy Package focusing so much attention on the environment, both big business and national governments are looking for ways to reduce their carbon footprint. Technologies such as CARBIOS’s, which allows materials made from fossil fuels to be infinitely recycled will surely be needed. If the much debated carbon tax is ever introduced, with its low energy demands it will make even more sense.
According to Pierre Monsan, founding director of Toulouse White Biotechnology, the results so far reflect the success of a public-private partnership dedicated to the development of competitive ecological innovations optimising the life-cycle of plastics.
“We’ll soon be able to bring this disruptive innovation to an industrial stage,” he concludes.
