Sustainable plastics from agricultural waste
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AN IPHONE CASE PRINTED WITH THE SUSTAINABLE POLYAMIDE MATERIAL.
view moreCREDIT: LORENZ MANKER/EPFL
In our rapidly industrialized world, the quest for sustainable materials has never been more urgent. Plastics, ubiquitous in daily life, pose significant environmental challenges, primarily due to their fossil fuel origins and problematic disposal.
Now, a study led by Jeremy Luterbacher's team at EPFL unveils a pioneering approach to producing high-performance plastics from renewable resources. The research, published in Nature Sustainability, introduces a novel method for creating polyamides – a class of plastics known for their strength and durability, the most famous of which are nylons – using a sugar core derived from agricultural waste.
The new method leverages a renewable resource, and also achieves this transformation efficiently and with minimal environmental impact.
“Typical, fossil-based plastics need aromatic groups to give rigidity to their plastics – this gives them performance properties like hardness, strength and high temperature resistance,” says Luterbacher. “Here, we get similar results but use a sugar structure, which is ubiquitous in nature and generally completely non-toxic, to provide rigidity and performance properties.”
Lorenz Manker, the study’s lead-author, and his colleagues developed a catalyst-free process to convert dimethyl glyoxylate xylose, a stabilized carbohydrate made directly from biomass such as wood or corn cobs, into high-quality polyamides. The process achieves an impressive atom efficiency of 97%, meaning almost all the starting material is used in the final product, which drastically reduces waste.
The bio-based polyamides exhibit properties that can compete with their fossil counterparts, offering a promising alternative for various applications. What's more, the materials demonstrated significant resilience through multiple cycles of mechanical recycling, maintaining their integrity and performance, which is a crucial factor for managing the lifecycle of sustainable materials.
The potential applications for these innovative polyamides are vast, ranging from automotive parts to consumer goods, all with a significantly reduced carbon footprint. The team's techno-economic analysis and life-cycle assessment suggest these materials could be competitively priced against traditional polyamides including nylons (e.g. nylon 66), with a global warming potential reduction of up to 75%.
The production of these materials is now being scaled up by the EPFL spin-off, Bloom Biorenewables, in an effort to get them into the market.
Other contributors
- University of Applied Sciences and Arts Western Switzerland
- EPFL Institute of Materials
- EPFL Valais-Wallis
- The University of Manchester
Reference
Lorenz P. Manker, Maxime A. Hedou, Clement Broggi, Marie J. Jones, Kristoffer Kortsen, Kalaiyarasi Puvanenthiran, Yildiz Kupper, Holger Frauenrath, François Marechal, Veronique Michaud, Roger Marti, Michael P. Shaver, Jeremy S. Luterbacher. Performance polyamides built on a sustainable carbohydrate core. Nature Sustainability 13 March 2024. DOI: 10.1038/s41893-024-01298-7
The dyed and natural polyamide fibers after extrusion
Highly precise extrusion of 3D-printing filament
The polyamide is tough and flexible allowing it to be twisted and plied without breaking
CREDIT
Lorenz Manker/EPFL
JOURNAL
Nature Sustainability
ARTICLE TITLE
Performance polyamides built on a sustainable carbohydrate core
ARTICLE PUBLICATION DATE
13-Mar-2024
KIMM finds solution to medical waste problem, which has become a major national issue
Through business support program, KIMM develops medical waste sterilization technology that can be applied to hospitals.
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MEDICAL WASTE TREATMENT SYSTEM CAPABLE OF PROCESSING 100 KILOGRAMS OF MEDICAL WASTE PER HOUR, DEMONSTRATED AT THE CHUNGNAM NATIONAL UNIVERSITY HOSPITAL
view moreCREDIT: KOREA INSTITUTE OF MACHINERY AND MATERIALS (KIMM)
A medical waste treatment system, which is capable of 99.9999 percent sterilization by using high-temperature and high-pressure steam, has been developed for the first time in the country.
The Korea Institute of Machinery and Materials (President Seog-Hyeon Ryu, hereinafter referred to as KIMM), an institute under the jurisdiction of the Ministry of Science and ICT, has succeeded in developing an on-site-disposal type medical waste sterilization system that can help to resolve the problem caused by medical waste, which has become a national and social issue as the volume of medical waste continues to increase every year. This project was launched as a basic business support program of the KIMM and was expanded into a demonstration project of Daejeon Metropolitan City. Then, in collaboration with VITALS Co., Ltd., a technology transfer corporation, the medical waste treatment system was developed as a finished product capable of processing more than 100 kilograms of medical waste per hour, and was demonstrated at the Chungnam National University Hospital.
Moreover, the installation and use of this product have been approved by the Geumgang Basin Environmental Office of the Ministry of Environment. All certification-related work for the installation and operation of this product at the Chungnam National University Hospital has been completed, including the passage of an installation test for efficiency and stability conducted by the Korea Testing Laboratory.
Through collaboration with VITALS Co., Ltd., a corporation specializing in inhalation toxicity systems, the research team led by Principal Researcher Bangwoo Han of the Department of Urban Environment Research of the KIMM’s Eco-Friendly Energy Research Division developed a high-temperature, high-pressure steam sterilization-type medical waste treatment system by using a high-temperature antimicrobial technology capable of processing biologically hazardous substances such as virus and bacteria with high efficiency. After pulverizing medical waste into small pieces so that high-temperature steam can penetrate deep into the interior of the medical waste, steam was then compressed in order to raise the boiling point of the saturated steam to over 100 degrees Celsius, thereby further improving the sterilization effect of the steam.
Meanwhile, in the case of the high-pressure steam sterilization method, it is vitally important to allow the airtight, high-temperature and high-pressure steam to penetrate deep into the medical waste. Therefore, the research team aimed to improve the sterilization effect of medical waste by increasing the contact efficiency between the pulverized medical waste and the aerosolized steam.
By using this technology, the research team succeeded in processing medical waste at a temperature of 138 degrees Celsius for 10 minutes or at 145 degrees Celsius for more than five (5) minutes, which is the world’s highest level. By doing so, the research team achieved a sterilization performance of 99.9999 percent targeting biological indicator bacteria at five (5) different locations within the sterilization chamber. This technology received certification as an NET (New Excellent Technology) in 2023.
Until now, medical waste has been sterilized by heating the exposed moisture using microwaves. However, this method requires caution because workers are likely to be exposed to electromagnetic waves and the entrance of foreign substances such as metals may lead to accidents.
In Korea, medical waste is mostly processed at exclusive medical waste incinerators and must be discharged in strict isolation from general waste. Hence, professional efforts are required to prevent the risk of infection during the transportation and incineration of medical waste, which requires a loss of cost and manpower.
If medical waste is processed directly at hospitals and converted into general waste by applying the newly developed technology, this can help to eliminate the risk of infection during the loading and transportation processes and significantly reduce waste disposal costs. By processing 30 percent of medical waste generated annually, hospitals can save costs worth KRW 71.8 billion. Moreover, it can significantly contribute to the ESG (environmental, social, and governance) management of hospitals by reducing the amount of incinerated waste and shortening the transportation distance of medical waste.
[*Allbaro System (statistical data from 2021): Unit cost of treatment for each type of waste for the calculation of performance guarantee insurance money for abandoned wastes (Ministry of Environment Public Notification No. 2021-259, amended on December 3, 2021). Amount of medical waste generated on an annual basis: 217,915 tons; Medical waste: KRW 1,397 per ton; General waste from business sites subject to incineration: KRW 299 per ton]
As the size and structure of the installation space varies for each hospital, installing a standardized commercial equipment can be a challenge. However, during the demonstration process at the Chungnam National University Hospital, the new system was developed in a way that allows the size and arrangement thereof to be easily adjusted depending on the installation site. Therefore, it can be highly advantageous in terms of on-site applicability.
Principal Researcher Bangwoo Han of the KIMM was quoted as saying, “The high-temperature, high-pressure steam sterilization technology for medical waste involves the eradication of almost all infectious bacteria in a completely sealed environment. Therefore, close cooperation with participating companies that have the capacity to develop airtight chamber technology is very important in materializing this technology.” He added, “We will make all-out efforts to expand this technology to the sterilization treatment of infected animal carcasses in the future.”
President Seog-Hyeon Ryu of the KIMM was quoted as saying, “The latest research outcome is significantly meaningful in that it shows the important role played by government-contributed research institutes in resolving national challenges. The latest technology, which has been developed through the KIMM’s business support program, has been expanded to a demonstration project through cooperation among the industry, academia, research institutes, and the government of Daejeon Metropolitan City.” President Ryu added, “We will continue to proactively support these regional projects and strive to develop technologies that contribute to the health and safety of the public.”
Waste that has been pulverized and sterilized
Medical waste treatment system capable of processing 100 kilograms of medical waste per hour, demonstrated at the Chungnam National University Hospital
CREDIT
Korea Institute of Machinery and Materials (KIMM)
Meanwhile, this research was conducted with the support of the project for the “development of ultra-high performance infectious waste treatment system capable of eliminating 99.9999 percent of viruses in response to the post-coronavirus era,” one of the basic business support programs of the KIMM, as well as the project for the “demonstration and development of a safety design convergence-type high-pressure steam sterilization system for on-site treatment of medical waste,” part of Daejeon Metropolitan City’s “Daejeon-type New Convergence Industry Creation Special Zone Technology Demonstration Project.”
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The Korea Institute of Machinery and Materials (KIMM) is a non-profit government-funded research institute under the Ministry of Science and ICT. Since its foundation in 1976, KIMM is contributing to economic growth of the nation by performing R&D on key technologies in machinery and materials, conducting reliability test evaluation, and commercializing the developed products and technologies.
This research was conducted with the support of the project for the “development of ultra-high performance infectious waste treatment system capable of eliminating 99.9999 percent of viruses in response to the post-coronavirus era,” one of the basic business support programs of the KIMM, as well as the project for the “demonstration and development of a safety design convergence-type high-pressure steam sterilization system for on-site treatment of medical waste,” part of Daejeon Metropolitan City’s “Daejeon-type New Convergence Industry Creation Special Zone Technology Demonstration Project.”
“Find pearls in the soil” unveiling the magic of hydrogen production from municipal sewage
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SCHEMATIC DEPICTING THE CATALYTIC REACTION DEVISED BY THE TEAM, CATALYZING THE UREA OXIDATION REACTION
view moreCREDIT: POSTECH
Professor Kangwoo Cho and PhD candidate Jiseon Kim from the Division of Environmental Science & Engineering at Pohang University of Science and Technology (POSTECH) collaborated with the Korea Institute of Science and Technology (KIST) to devise a novel catalyst aimed at enhancing the efficiency of reactions using contaminated municipal sewage to produce hydrogen—a green energy source. Their research recently featured in the international journal Advanced Functional Materials.
With the growing environmental concerns of pollution associated with fossil fuel, hydrogen has garnered increased interest. Water electrolysis technology is a sustainable process that leverages Earth's abundant water to produce hydrogen. However, the concurrent oxygen evolution reaction during hydrogen production is notably slow, resulting in a considerably low energy conversion efficiency.
Lately, the academic community has been tackling this issue by integrating the urea oxidation reaction with the hydrogen generation reaction. Urea, a pollutant found in urine, releases a significant amount of energy during its oxidation process, offering a potential means to enhance both the efficiency of hydrogen generation and the purification of toilet wastewater. Ultimately, it is necessary to find a catalyst that can effectively drive the urea oxidation reaction, thereby amplifying the efficiency of both hydrogen generation and wastewater treatment.
In pursuit of increased efficiency in the urea oxidation reaction, the team created a catalyst known as nickel-iron-oxalate (O-NFF). This catalyst combines iron (Fe) and oxalate on nickel (Ni) metal, resulting in an expansive surface area characterized by nanometer-sized particles in fragment form. This unique property enables the catalyst to adsorb more reactants, facilitating an accelerated urea oxidation reaction.
In experiments, the O-NFF catalyst devised by the team successfully lowered the voltage required for hydrogen generation to 1.47 V RHE (at 0.5 A/cm2) and exhibited a high reaction rate even when tested in a mixed solution of potassium hydroxide (1 M) and urea (0.33 M) with a Tafel slope of 12.1 mV/dec. The researchers further validated the catalyst's efficacy by confirming its promotion of the urea oxidation reaction through photoelectron/X-ray absorption spectroscopy using a radiation photo accelerator.
Professor Kangwoo Cho who led the research stated, "We have developed a catalyst capable of purifying municipal sewage while simultaneously enhancing the efficiency of hydrogen production, a green energy source.” He added, “We anticipate that O-NFF catalysts, synthesized from metals and organics, will contribute to the improved efficiency of industrial electrolysis hydrogen production."
The research was sponsored by the Mid-Career Researcher Program and the Hydrogen Source Technology Development Program of the National Research Foundation of Korea, and the National Supercomputing Center.
JOURNAL
Advanced Functional Materials
ARTICLE TITLE
Accessible Ni-Fe-Oxalate Framework for Electrochemical Urea Oxidation with Radically Enhanced Kinetics
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