Will Carbon Fiber Grow On Trees?

Poplar Farm

Yes, according to Gerald Tuskin, of Oak Ridge National Laboratory near Nashville, Tennessee. Tuskin holds a Ph.D. in genetics and a M.A. in Forest Genetics. He has devoted his life to the study of trees, especially the common poplar, and he makes an extraordinary claim. In an interview with io9, Tuskin was quoted as saying;

One day, we’ll make and fuel our cars with trees.

How is that possible? Tuskin says trees are mostly made up of cellulose and hemicellulose, which contain sugars that can be fermented into ethanol fuel. But as much as a third of a tree’s total weight is composed of lignin, a substance that helps strengthen cell walls. Right now, the lignin produced during ethanol production is discarded. But Tuskin says lignin can be spun into carbon fiber.

We can melt it and spin it into carbon fibers. Or we could use it to make plastic. For a car, the tree could be deconstructed then reconstructed into the body, frame, interior, and things like that.

The only question is whether trees can be genetically engineered to yield lignin in the right amounts and with the right properties for various industrial applications. Once that process is understood, farmers could do things like grow a tree that’s designed to have more lignin or less, depending on what the market demands.

Depending on what your customer wants, you might vary or modify the molecular weight of the lignin. Chemical engineers and polymer scientists would work with geneticists and plant breeders to target the right combination of genes.

Tuskin envisions a whole new way of tree farming, one that supports a sustainable forest. No more than 20% of trees would be harvested in any one year and there would be no clear cutting of the timber as is done on many tree farms today. The growing trees would nourish the soil while they produce the timber for ethanol and lignin production.

You have to have a stable demand and product market to do this. It will take years to produce the right plant material, and then several years before harvest. So farmers have to predict market demand as many as eight years in advance. That’s the downside of perennial systems, though the upside is a positive impact on soil and wildlife.

Future tree farmers would enjoy economic advantages over conventional farmers. If the market for their products is down, they can continue to let their trees grow rather than being forced to harvest them at the end of the growing season. Then they can harvest their trees and reap higher profits when the market is up. As a bonus, the growing trees would continue to capture carbon dioxide from the atmosphere, a benefit to the entire eco-system.

Tuskin thinks that this new form of tree farming could be in operation within 50 years. To skeptics and critics, he points out that corn farming took that long to change from just a food crop to the source of the many commercial and industrial products derived from corn today.

It’s fair to say that Tuskin is thinking far beyond the next quarter or fiscal year. I’ll update you further on the success of his vision in 2064.

 

Steve Hanley

Closely following the transition from internal combustion to electricity. Whether it's cars, trucks, ships, or airplanes, sustainability is the key. Please follow me on Google + and Twitter.