Spinning plant waste into carbon fiber for cars, planes

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Using plants and trees to make products such as paper or ethanol leaves behind a residue called lignin, a component of plant cell walls. That leftover lignin isn’t good for much and often gets burned or tossed into landfills. Now, researchers report transforming lignin into carbon fiber to produce a lower-cost material strong enough to build car or aircraft parts.

The researchers will present their work today at the 254th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features nearly 9,400 presentations on a wide range of science topics.

Using plants and trees to make products such as paper or ethanol leaves behind a residue called lignin, a component of plant cell walls. That leftover lignin isn’t good for much and often gets burned or tossed into landfills. Now, researchers report transforming lignin into carbon fiber to produce a lower-cost material strong enough to build car or aircraft parts.

The researchers will present their work today at the 254th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features nearly 9,400 presentations on a wide range of science topics.

“Lignin is a complex aromatic molecule that is mainly burned to make steam in a biorefinery plant, a relatively inefficient process that doesn’t create a lot of value,” says Birgitte Ahring, Ph.D., the principal investigator on the project. “Finding better ways to use leftover lignin is really the driver here. We want to use biorefinery waste to create value. We want to use a low-value product to create a high-value product, which will make biorefineries sustainable.”

In addition, there are potential benefits on the carbon fiber side of the equation. Carbon fiber made with lignin would be more sustainable and less expensive than fibers currently being produced. The carbon fiber found in modern cars and aircraft are typically made from polyarylonitrile (PAN), which is a pricey, non-renewable polymer. “PAN can contribute about half of the total cost of making carbon fiber,” Jinxue Jiang, Ph.D., says. He is a postdoctoral fellow in the Ahring laboratory at Washington State University. "Our idea is to reduce the cost for making carbon fiber by using renewable materials, like biorefinery lignin." Other researchers have tried to make carbon fibers from 100 percent lignin, Jiang says, but ended up with a fiber too weak for the automotive industry. "We wanted to combine the high strength of PAN with the low cost of the lignin to produce an automobile-grade carbon fiber."

Note: This research will be presented at a meeting of the American Chemical Society.

Read more at American Chemical Society

Image: A 2015 McLaren 650S Spider with the full Carbon Fiber appearance pack, in Tarocco Orange.

Credit: Mr.choppers via Wikimedia Commons