Closed loop manufacture of bio-based polyester fibres for a circular bioeconomy
Lead Research Organisation:
University of Leeds
Department Name: Sch of Design
Abstract
Novel synthetic biology and engineering have an essential contribution to offer to the transition towards a circular bioeconomy for the textile industry, currently the fourth most polluting industry in the world (10% of carbon emissions), and this project intends to demonstrate this. Our vision is to disrupt the current textile recycling mindset of unaffordable downcycling attempts (e.g. turning used clothing into insulation materials) and enable revolutionary circular modalities that will transcend the use of fossil-derived raw materials and allow the creation of polyester textile fibres (the most dominant man-made fibre globally) from non-edible biomass, specifically, coffee waste in the form of used coffee grounds.
Coffee waste is a non-edible biomass of emerging importance due to its valuable organic composition, the lack of efficient recycling methods, and the coffee industry expansion, with the UK ranking among the largest coffee-consuming markets in Europe.
This research will exploit these appealing attributes of coffee waste to develop new bio-based polyester fibres that can be integrated, degraded and upcycled at the end of life into new forms of functional materials (e.g. environment-friendly face masks, antimicrobial coatings and controlled drug delivery devices) to enable future, circular textile manufacture. New synergistic research on microbial biorefineries, integrated fibre spinning, and molecular upcycling will enable breakthrough synthetic biology routes for the ethical transformation of non-edible biomass (coffee waste) into functional (dyed) polyester fibres. This will enable to meet the requirements of multiple industrial sectors and disrupt the textile industry overreliance on non-recyclable synthetic fibres, facilitating the creation of a truly circular and sustainable polyester economy.
Coffee waste is a non-edible biomass of emerging importance due to its valuable organic composition, the lack of efficient recycling methods, and the coffee industry expansion, with the UK ranking among the largest coffee-consuming markets in Europe.
This research will exploit these appealing attributes of coffee waste to develop new bio-based polyester fibres that can be integrated, degraded and upcycled at the end of life into new forms of functional materials (e.g. environment-friendly face masks, antimicrobial coatings and controlled drug delivery devices) to enable future, circular textile manufacture. New synergistic research on microbial biorefineries, integrated fibre spinning, and molecular upcycling will enable breakthrough synthetic biology routes for the ethical transformation of non-edible biomass (coffee waste) into functional (dyed) polyester fibres. This will enable to meet the requirements of multiple industrial sectors and disrupt the textile industry overreliance on non-recyclable synthetic fibres, facilitating the creation of a truly circular and sustainable polyester economy.
Technical Summary
The proposed textile biotechnology research will pursue environment-friendly microbial biorefineries, integrated fibre spinning and molecular upcycling to accomplish the ethical conversion of coffee waste (as non-edible biomass) into functional (dyed) bio-based polyester fibres that can be integrated, degraded and upcycled at the end of life for future textile manufacture.
The specific objectives of this project are:
- Environment-friendly bacterial transformation of coffee waste into bespoke, high yield polyhydroxyalkanoates (PHAs).
- Creation of bio-based functional fibres with controlled elasticity and textile functionality by exploiting novel spinning technologies and the nanoscale of fibre-forming PHA chains.
- Bacteria-directed depolymerisation of manufactured fibres for end-of-life upcycling into novel valuable materials.
- To demonstrate fibre recyclability and affordability of the proposed experimental platform for future textile manufacture and circularity
These will be realised via the following research strategies and methods:
- Green extraction of coffee oil (from coffee waste) as non-edible carbon source for bacterial transformation
- Use of bacterial halophiles as environment friendly biorefineries with high transforming ability
- Integrated, green wet spinning route enabling bespoke fibre formation and dyeing
- Enzymatic hydrolysis of manufactured fibres to raw materials (monomers and dyes)
- Molecular upcycling of collected raw materials via green re-polymerisation and spinning into functional fibres with no loss in fibre performance
The specific objectives of this project are:
- Environment-friendly bacterial transformation of coffee waste into bespoke, high yield polyhydroxyalkanoates (PHAs).
- Creation of bio-based functional fibres with controlled elasticity and textile functionality by exploiting novel spinning technologies and the nanoscale of fibre-forming PHA chains.
- Bacteria-directed depolymerisation of manufactured fibres for end-of-life upcycling into novel valuable materials.
- To demonstrate fibre recyclability and affordability of the proposed experimental platform for future textile manufacture and circularity
These will be realised via the following research strategies and methods:
- Green extraction of coffee oil (from coffee waste) as non-edible carbon source for bacterial transformation
- Use of bacterial halophiles as environment friendly biorefineries with high transforming ability
- Integrated, green wet spinning route enabling bespoke fibre formation and dyeing
- Enzymatic hydrolysis of manufactured fibres to raw materials (monomers and dyes)
- Molecular upcycling of collected raw materials via green re-polymerisation and spinning into functional fibres with no loss in fibre performance
Publications
Brooker C
(2023)
A collagen-based theranostic wound dressing with visual, long-lasting infection detection capability.
in International journal of biological macromolecules
Phillips M
(2024)
Nonwoven Reinforced Photocurable Poly(glycerol seba-cate)-Based Hydrogels
in Polymers
| Description | Polyester fibres are the predominant raw material in the textile industry, including medical textiles, and contribute significantly to global carbon emissions. The global production of polyester fibres is estimated at more than 60 million metric tons, equating to over 570 kg of carbon emissions. These sustainability challenges are further compounded by the fact that over 80% of global textile waste is currently disposed of through incineration or landfill. To address these challenges, our efforts have concentrated on the manufacture of bio-based polyester fibres from polyhydroxyalkanoates (PHAs), a group of linear fossil-free polyesters that are synthesised by bacteria (for carbon and energy storage) and that present a chemical composition comparable to the one of fossil-derived plastics. To align with manufacturing processes currently used in the textile industry and to minimise environmental impact, we have successfully developed a green, scalable and industry-compliant wet spinning process that generates individual textile fibres made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). This process relies on green solvents, e.g. 2-methyltetrahydrofuran and water, throughout the entire fibre manufacture, rather than fossil-derived chemicals typically used in current industrial practice. Having selected PHBV as a promising PHA with enhanced elasticity, we have demonstrated that the above wet spinning process is flexible, scalable and that it can be integrated with dyeing, leading to bio-based, functional and homogeneous PHBV-based fibres with a length of over 1 m. The development of the aforementioned green textile fibre manufacturing platform has been complemented by our efforts to foster textile fibre circularity in the bioeconomy. To achieve this, we have pursued the use of coffee waste, an undervalorised inedible agricultural waste, as a feedstock for microbial polyester synthesis. Furthermore, we have expanded the potential for effective microbial degradation and upcycling of end-of-life polyester fibres, aiming at a closed-loop textile fibre manufacturing system. By exploiting the attributes of coffee waste, we have pursued novel microbial biorefineries for the green conversion of coffee waste into PHBV, as the fibre-forming raw material. Our groundwork to develop a closed-loop textile fibre manufacturing system has initially focused on the green extraction of coffee oil (from coffee waste) as the carbon source for the microbial synthesis of PHBV. To ensure circularity and minimal environmental impact, we have successfully demonstrated comparable yield and chemical composition of coffee oil extracted with green solvents with respect to coffee oil extracted with fossil-derived organic solvents. We have subsequently taken steps to employ this carbon source for the development of a halophilic (H. mediterranei) fermentation line, in addition to the use of conventional PHA control producers, e.g. C. necator, aiming at a streamlined production, separation and purification of PHBV. The halophilic nature of H. mediterranei employed for microbial PHA synthesis enables the extraction of PHBV in non-salty water, which is appealing aiming at bio-based polyester fibres with enhanced purity and cellular tolerability for potential biomedical use. Our ultimate vision is to integrate the aforementioned biobased polyester fibres into advanced medical textiles, such as antimicrobial fabrics for infection control and advanced chronic wound dressings, promoting circularity in the bioeconomy. By securing funding from Leeds Institute of Textiles and Colour, we have leveraged the expertise developed in this grant to explore the modification of biodegradable fibres with photosensitiser dyes, and demonstrated the antibiotic-free antimicrobial effect via fibre exposure to localised visible light, while ensuring dye confinement in the fibre and no dye-induced staining to surrounding surfaces in both dry and wet states. Given its potential for patient-centred home care, this prototype is being further investigated as the antimicrobial component in advanced dressing for chronic wound management. Leveraging the expertise developed in this grant has enabled us to develop advanced capabilities to guide the translation of medical device prototypes from the bench to the bedside, through prototype alignment with industrial sustainability constraints and medical device regulations, aiming to de-risk future technology uptake by the industry. Most notable evidence of these activities is the recent formation of HYFACOL Limited, a University of Leeds spin out company that is developing a patented collagen manufacturing technology (originated from PI's research) for wound dressing and dentistry applications. Like the biobased polyester fibres under development in this grant, the animal origin of biopolymers, i.e. collagen, does not only provide an eco-friendly alternative to classic fossil-derived polymers, but also offers key bio-functionalities for medical device development, e.g. enzymatic degradability, cellular tolerability and tissue biomimetics. The development activities within HYFACOL therefore provide a unique opportunity to accomplish the regulatory prototype compliance that is required to secure approval from the Medicines and Healthcare products Regulatory Agency (MHRA) and execute a safety clinical trial in patients affected by chronic wounds, specifically scleroderma associated digital ulcers, to demonstrate safety in humans. |
| First Year Of Impact | 2023 |
| Sector | Healthcare,Manufacturing, including Industrial Biotechology |
| Impact Types | Cultural Societal Economic |
| Description | IEC\NSFC\223289 - International Exchanges 2022 Cost Share (NSFC) |
| Amount | £11,850 (GBP) |
| Funding ID | IEC\NSFC\223289 |
| Organisation | The Royal Society |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 03/2023 |
| End | 02/2025 |
| Title | Advanced collagen-based wound dressing prototype |
| Description | An advanced collagen-based wound dressing prototype has been realised through the research conducted by the PI at the University of Leeds. The underpinning technology generating this prototype has been patented by the University of Leeds (in the US and Europe). Following successful pre-clinical testing in vitro and in vivo, a new University of Leeds spin-out company has been formed in 2023 with a £0.5m first raise, aiming to progress the clinical development of this product, with the medium term aim (2 years) looking at securing regulatory compliance and human safety data. A first-in-human clinical trial is planned following regulatory compliance /approval by the MHRA. |
| Type | Therapeutic Intervention - Medical Devices |
| Current Stage Of Development | Refinement. Non-clinical |
| Year Development Stage Completed | 2023 |
| Development Status | Under active development/distribution |
| Impact | a new University of Leeds spin-out company has been formed in 2023 with a £0.5m first raise, aiming to progress the clinical development of this product. |
| Company Name | Hyfacol Limited |
| Description | |
| Year Established | 2023 |
| Impact | HYFACOL's underpinning technology has been successfully patented in the US and Europe, with the latter covering highly profitable territories, such as France, Germany, Ireland, Italy, and the UK. |