Carbon from thin air
Using greenhouse gases as feedstock for fuels or materials is already a reality, and could become a source of clean, carbon-neutral or even carbon-negative synthetic fibres.
It is the gas that is suffocating the planet. It is not the only one, but it is the one most talked about. Carbon dioxide is abundant, but it is also an inert gas, and breaking it down to produce chemicals or polymers is energy-intensive, as is harvesting it from air. But carbon is also the molecule that forms the backbone of the synthetic fibres used to make our everyday clothes, activewear and plastics. Long chains of carbon molecules, in polyester as well as in cellulose, are what we make fibres from. In this form, it is known as ‘embedded’ carbon, and this is why it is basically impossible to ‘decarbonise’ man-made polymers and plastics, but it is possible to ‘defossilise’ them.
The Renewable Carbon Initiative (RCI) was created in 2020 by nova-Institute, a German research centre and consultancy, to do just that. It has identified and promotes three alternative sources of carbon: it can come from recycling, from biomass or carbon capture and from utilisation (CCU). In a paper published this past March, the initiative proposes a scenario for a future supply of non-fossil carbon by 2050(1). It estimates that recycling (plastics and such) could cover around 55% of future needs, biomass could supply roughly 20%, and the remaining 25% or so could come from CCU technologies. It believes that all three of these sources are required to address growing carbon demand for chemicals and materials. But it takes care to note that carbon-capturing technologies must be powered by renewable energy, as using fossil fuels would defeat the purpose.
A raw material like any other?
In July, Première Vision hosted a panel talk on these novel materials made from carbon emissions which featured Babette Pettersen, head of LanzaTech’s European business and Benoit Illy, co-founder and CEO of Fairbrics. Both companies say their innovative processes deliver chemicals that have the same properties and performances as conventional ones.
Originally based in New Zealand, and now headquartered in Chicago, LanzaTech has developed a biotech-based method to turn carbon monoxide into ethanol. It collects the gas from flues directly on the sites where they are produced, namely steel mills. Chemical building blocks, or fuel, are obtained via fermentation. In May of this year, the company installed its first carbon-capturing system in Europe, at an Arcelor Mittal mill located in Ghent, Belgium. The new ‘Steelanol’ facility has an annual capacity to produce 80 million litres of advanced ethanol (derived from waste streams), which will be jointly marketed by ArcelorMittal and LanzaTech under the brand name Carbalyst. The pollution-capturing system is expected to help reduce the plant’s carbon emissions by 125,000 tonnes annually.
It is not the first such facility LanzaTech has established, three others are in operation at steel mills in China, with several other demo-sized plants located in India, Canada and Japan. Funding for the €200 million plant in Ghent was provided by the Flemish government, the Belgian federal government and the European Union’s Horizon 2020 research and innovation program, supplemented by a loan from the European Investment Bank.
CarbonSmart, LanzaTech’s own brand, has already been used to make products for major brands and retailers that are eager to adopt the new pollution-derived materials. Swedish fast fashion retailer H&M has chosen a CarbonSmart polyester fibre for its Move activewear range. It is present in the midsole of one of Swiss footwear brand On’s ranges, combined with a textile upper made from a polyester produced by Fairbrics. Yogawear brand Lululemon and Inditex-owned Zara have also introduced ranges composed of CarbonSmart polyester. Adidas’ tennis kits for the Australian Open at the start of this year were made from a polyester fibre whose mono-ethylene glycol (MEG) component, 30% of its composition, was supplied by LanzaTech. “Companies like H&M, Zara and On are looking for solutions for their carbon emissions,” says Ms Pettersen.
LanzaTech, she went on to say, “takes carbon from a source of emissions, which can be a factory or compost gases from agricultural waste, and uses fermentation and biology to make fuels or chemicals. These can include fibres for fashion, surfactants, and so on.” But she takes care to note that the company “focuses primarily on heavy emitters, such as steel mills, and not smaller facilities.”
Scaling up, she goes on to say, “is a huge challenge”. LanzaTech was founded in 2005, and its first large-scale facility was installed in China in 2018. “We need to build more plants, and this requires funding and government support,” she says. LanzaTech went public earlier this year, and this, she notes, “means that we now need to generate revenue.” Licensing the technology could be one avenue, such as expanding applications with manufacturers and brands in fragrances, detergents or packaging.
Based in Villebon-sur-Yvette, south of Paris, French cleantech start-up Fairbrics is currently producing MEG, one of the two components of polyester, from waste-stream carbon dioxide. “As our solution is a drop-in technology, it is fairly easy to find supply chain partners, but more difficult to find funders,” says Benoit Illy. “LanzaTech’s ground-breaking solution has been a huge help.” At the beginning of 2023, the company was the recipient of a €17 million grant from the European Union’s Horizon 2020 programme, and raised an additional €5 million from current partners. These funds will be used to build a pilot line, with a 100kg/day capacity, by 2024, and a 1 tonne/day demo plant by 2026.
Threading-CO2, the EU research programme into carbon-capturing and utilisation, in which Fairbrics is the central brick (pun intended) brings together a consortium of 13 partners from seven EU countries. Academic institutions, industry partners, and municipalities are involved, including French fabric manufacturer Les Tissages de Charlieu. It aims to scale-up and demonstrate what it says is a first-of-a-kind technology to produce commercially viable and sustainable polyester textiles from CO2 waste streams and running on renewable energy.
“What sets our technology apart is that it goes directly from CO2 to chemicals,” says Mr Illy. “We mix a catalyst with carbon dioxide and a solvent, heat it for a few hours, and obtain the chemicals we want.” As opposed to LanzaTech, Fairbrics does not capture carbon emissions, but buys the gas from companies that do. The start-up’s process is powered by renewable energy and operates at a low temperature, he says, insisting that “it potentially has a very low carbon footprint, and could be carbon negative”. The next step for the four-year old start-up is to expand its technology to obtain terephthalic acid (PTA), the other ingredient in polyester.
“The fashion industry is desperate to find a solution to reduce its carbon emissions,” says Mr Illy. Though promoted as drop-in solutions, these non-fossil polyesters are currently twice as expensive as conventional petrochemical-derived ones. “The price corresponds to the value we bring to the market,” said Ms Pettersen at the Première Vision conference. As economies of scale are achieved over the next five-to-ten years, its cost will align with those of the market, she believes.
Not only polyester
Mango Materials, based in San Francisco and founded in 2010, siphons methane from wastewater treatment plants and uses it to produce a biopolymer, poly-hydroxyalkanoate (PHA), which it markets as an alternative polyester for textiles. “Historically our methane was from Silicon Valley Clean Water in Redwood City, California. We are in the process of scaling up at the Easterly Wastewater Treatment Plant in Vacaville, California,” Molly Morse, the start-up’s CEO and one of its three founders tells WSA. The methane is transformed into PHA using a biotech bacteria-based process. Footwear brand Allbirds chose the methane-made bioplastic for one of the components of its M0.0nshot sneaker.
Founded in 2020, and also based in San Francisco, Rubi Labs is developing what it says is a carbon-negative manmade cellulosic yarn (lyocell or viscose) made from carbon waste streams. It has recently received backing from Walmart and announced a pilot project to explore how carbon emissions from manufacturers and facilities in the retailer’s supply chain could be captured and converted to make apparel. The patent-pending technology developed by twin sisters and founders Neeka and Leila Mashouf is based on a special enzyme and a biocatalytic process to convert carbon dioxide into cellulose. The start-up says that this method allows it to achieve a yield of 100% of CO2 inputted with no waste. In its latest funding round, it raised $8.7 million from new investors including Patagonia’s Tin Shed Ventures, H&M Group and the Stella McCartney-backed Collaborative Fund. Nicolaj Reffstrup, co-founder of fashion label Ganni, was an angel investor. Another sign that the apparel industry is keen to support these new technologies.
Newlight, based in Huntington Beach, California, was founded in 2003 and has developed a biotech process to convert greenhouse gas emissions into a biopolymer it is marketing as AirCarbon. The material is a polyhydroxybutyrate (PHB), also a member of the polyester family, and is said to be made from approximately 40% oxygen derived from air and 60% carbon derived from greenhouse gas. The company is focusing on plastics and a leather alternative, but plans to conduct research into textiles for biomedical and personal care applications. Nike, Target and H&M are listed as customers and an unnamed global luxury goods manufacturer contributed to its latest equity round which brought in $125 million. AirCarbon is currently produced at scale in California and a second facility is being built in Hannibal, Ohio. It is expected to draw methane from anaerobic digestion of food and agricultural waste, as well as carbon dioxide from energy facilities and direct air capture.
Other similar initiatives are under way. In the Netherlands, TNO, an independent Dutch research agency, has commissioned a demonstration plant to convert CO2 waste streams into chemical building blocks for plastics by 2030. Japanese chemicals company Asahi Kasei has announced plans to produce ethylene from carbon dioxide. Both have said their technology is based on an electrochemical process and is powered by renewable energy.
Three different pathways
As seen, three main methods are being harnessed to convert captured carbon monoxide or carbon dioxide into building blocks for chemicals and polymers. In the biotech processes that LanzaTech and Mango Materials have chosen, microorganisms feed on the gases and produce the chemicals or polymers, as Pauline Ruiz, sustainability and technology expert at the nova-Institute tells WSA. A second pathway, called chemical conversion, combines energy with a synthetic catalyst to speed up the chemical reaction. “Chemical processes converting CO2 can produce many different types of products, from polymers to specific chemicals, including methanol,” she says. Electrochemistry, the third method, uses direct electrical energy to convert CO2 into different types of chemicals. “This technology will grow in the next decade,” she adds.
To optimise and scale up any of these technologies, the captured gases, be it CO, CO2 or methane (CH4), can ideally be collected from concentrated sources such as factory flue, steel mills, biogas plants or chemical plants. “Collecting concentrated CO2 currently lowers the cost of capturing it,” says Ms Ruiz. However, capturing CO2 directly from the air via Direct Air Capture (DAC) is also possible, and the technology is being scaled up and DAC projects are multiplying.
Some technologies make use of reactive flue gases from steel manufacturing (rich in CO) or biogas plant (rich in methane) to convert these directly. Otherwise, most of the technologies focus on CO2 conversion. CO2 is a stable gas and energy is required to activate it and convert it. All in all, the energy used to capture and transform any of these gases should come from renewable sources.
For the Renewable Carbon Initiative, all of these carbon-capturing technologies are needed to accelerate the transition away from fossil fuels, along with the just as necessary sources of renewable energy. In essence, more research and more infrastructure, are the colossal challenges this nascent sector faces if it wants to make a dent in the decarbonisation of energy and the defossilisation of materials.
In its tennis range for the Australian Open, German sports brand adidas chose to use a polyester yarn made from carbon dioxide fermented into ethanol by LanzaTech. It is said to constitute 30% by weight of a polyester yarn, and a minimum of 15% by weight of the garments.
Credit: Adidas
