It’s no secret that we need more sustainable materials if we want to help the planet. Large companies have already removed single-use plastics from their products to reduce the impact and threat of contaminating every corner of the Earth, especially the seas, which is usually the final destination of many of them. Bioderived materials are one of the potential options, but they must have an economic cost that does not significantly increase the final price.
There are rare metals on Earth, even in our mobiles, and also types of biomass that we probably haven’t heard of. This is the case of lignocellulosic biomass (LCB) , the most abundant form of biomass on Earth. “Its recovery has been extensively studied to produce sustainable fuels, chemicals and materials.” It is composed of approximately 40 to 60% cellulose, 10 to 40% hemicellulose, and 15 to 30% lignin, the specific percentages depending on the type of biomass. A team of researchers at the University of Delaware , led by Professor Thomas H. Epps, III, and collaborators at CanmetENERGY have this kind of economy from sustainable materials in mind as they look for ways to recycle biomass into new products.
So is lignin
Lignin is a component of plants and trees that provides strength and stiffness. However, in the paper industry lignin is a waste left over from the manufacture of paper products . This type of lignin is known as technical lignin and is not considered for use beyond perhaps burning or adding to tires as filler.
Researchers at the University of Delaware say it is a widely available resource on Earth . We are talking about 100 million tons of technical lignin waste generated annually in paper mills around the world that could be more valuable than we think.
The team has shown that it is possible to efficiently convert industrially processed lignin into high-performance plastics , such as bio-based 3D printing resins and valuable chemicals. This same approach could also be competitive with similar petroleum-based products.
An article published in Science Advanced and supported by funding from the National Science Foundation’s Growing Convergence Research (NSF GCR) program, which aims to solve problems through multi-pronged, interdisciplinary collaboration.
“The ability to take something like technical lignin and not only break it down and turn it into a useful product, but to do it at a lower cost and with less environmental impact than petroleum-derived materials is something that no one has been able to achieve and show before. said Epps, who leads NSF GCR efforts at UD and is the Allan and Myra Ferguson Distinguished Professor of Chemical and Biomolecular Engineering.
Overcome the high pressure hurdle
One of the main problems with lignin is that most of the processes to make it operate at very high pressures, which includes high cost and safety concerns . To overcome this adversity, the team of researchers replaced methanol, a traditional solvent used in the deconstruction of lignin, with glycerin so that the process could be carried out at normal atmospheric (room) pressure.
“Glycerin helps break down lignin into chemical building blocks that can be used to make a wide range of bio-based products, from 3D printing resins to different types of plastics, flavor and fragrance compounds, antioxidants, and more.” This change allowed the researchers to perform the reaction and separation steps simultaneously, resulting in a more cost-effective system.
Luo also conducted a life cycle assessment to understand the amount of greenhouse gas emissions (eg carbon dioxide) resulting from the production of materials. “We were trying to capture the big picture, not just the costs of the process, but also the environmental impacts throughout the operation,” he said.
The potential of the method developed by the University of Delaware together with the collaboration of students and professors to convert waste into valuable materials is as follows: “It shows that there is great potential in the use of renewable resources to manufacture different types of plastics. You don’t have to use fossil fuels, plastics from renewable resources can also be economically viable,” said Pranda, a co-author of the article and an active part of the research.