A new resin could keep fiberglass wind turbines in place for years , and later be used to make valuable products that make green energy more sustainable.
The blades of wind turbines are usually constructed to be replaced each 20-year period. That means that as the use of wind power becomes well-known increasing numbers of these massive steel structures made from fiberglass are likely to be demolished and many may end up in the soil. To encourage the recycling of the blades, one research team has created an ingredient called a binding resin that connects their fibrous material–that can be converted into more useful materials.
“We’ve created a system that was designed with the ending of our lives in the forefront,” declares John Dorgan who is a professor of materials and chemical engineering of Michigan State University, who developed the latest resin. After being used for a long time to build up turbine blades and different structures, it could be reused into a new turbine blade or turned into an elastomer that can be used to create plastic products. It is also transformed to create higher-value chemicals. These recycled options include shatter-resistant acrylic plexiglass superabsorbent polymer that is used in diapers, and potassium lactate, a food preservative that Dorgan made into Gummy bears, which he later consumed.
The blades of wind turbines are usually 170 feet long, which is roughly the size of an Olympic swimming pool. Because larger turbines can absorb more energy and produce more energy, offshore wind farms have been investing in higher turbines that have blades more than twice the length. If these huge blades become damaged or are at reaching the limit of their life they will have to be removed and removed from service. In 2050, experts predict that over two millions tons of blade materials will be removed from service every year.
There are two major hurdles for recycle these constructions. “To first, there’s their size. They’re massive, and are designed to be extremely durable, able to endure in the elements for at least 20 years. They’re also a difficult object to remove and move about,” explains Aubryn Cooperman an analyst for wind energy for the National Renewable Energy Laboratory, who was not part of the creation of the new resin. Another issue “is the fact that they’re constructed from materials that cost as little as they can be [that] nevertheless provide the performance you require.” To achieve the highest efficiency, the blades of wind turbines should be light and durable, which is why engineers usually design them using fiberglass, which is then bonded to polymer resin. In theory, the material could be reused but research suggests that the product that results isn’t much of a value. “The principal issue is that it’s economically unwise to recycle it,” Dorgan says. “It’s cheaper to just put this in the earth than to recycle it into useful products.”
To address this issue recycling blades from wind turbines will be less costly in order to make it more profit. Numerous companies in the renewable energy sector, including Siemens Gamesa, General Electric and Vestas — are engaged in this endeavor, Cooperman says. “Anything which makes it easier to recycle, which reduces the cost to recycle, improves the chance of more recycling taking place,” she notes.
Dorgan and his team came up with a novel polymer resin that would be used to bind a large fiberglass structure securely when it is in use , and it could be used to create various products once the time arrives to remove the blade. The team created the syrupy resin through dissolving polylactide (a plant-based polymer in a synthetic monomer known as the methyl methacrylate (MMA). The researchers then employed vacuum pressure to pull it through the glass fibres. Once the fibers were coated with the liquid, the resin set, creating the solid panels of fiberglass. This process can also be employed to create larger structures, such as turbine blades, boats and wind turbine hulls. The team presented their findings this week at the annual meeting held by the American Chemical Society.
When it was time to reuse their fiberglass panels, the scientists had several choices. In onecase, they could crush the panels and then add another polymer, creating an elastomer that could be made into various objects by injection molding. This composite made of short fibers could become the foundation of computer housings and other objects , but it wouldn’t be of much value, Dorgan says. Another option was to construct sturdy new panels using leftovers from the old ones. The team soaked the panels with MMA monomer which dissolving the hardened resin, and then the researchers took out the fibers of glass. The resulting “syrup” was then used to make new fiberglass panels that had similar physical properties to the original ones.
However, the resin that remains can be utilized for other purposes. “What will really stimulate recycling wind turbines when you can turn them into something worth more or even make high-value products out the resin,” Dorgan says. For instance, running the resin that was recovered through various chemical reactions enabled the group to make new substances. One of the compounds produced was polymethyl methacrylate, a polymer that is also called plexiglass. This clear, shatter-proof, transparent material is a popular replacement for glass on a wide array of items that range from windows to headlights for cars. The process of cooking the resin at the highest temperature results in poly(methacrylic acid) which is a superabsorbent substance utilized in diapers as well as other products. Further processing led to potassium lactate, that is added into a range of foods as a preservation agent. Even though Dorgan used it to create himself a gummy bear version Dorgan doesn’t necessarily view making homemade candy as the only method to increase the recycling of turbine blades. Dorgan’s goal is to encourage recycling by changing mindsets.
“I’m trying to challenge the limits of what people are thinking of recycling” the author explains. “It’s about generating new possibilities and encouraging people to think about the limits of recycling?’ As it is known there’s been no attempts to reprocess an extremely durable composite material to produce something that could be consumed.”