Are petite poplars the future of biofuels? Studies say yes

In the quest to produce affordable biofuels, poplar trees are one of the Pacific Northwest's best bets - the trees are abundant, fast-growing, adaptable to many terrains and their wood can be transformed into substances used in biofuel and high-value chemicals that we rely on in our daily lives. 

But even as researchers test poplars' potential to morph into everything from ethanol to chemicals in cosmetics and detergents, a commercial-scale processing plant for poplars has yet to be achieved. This is mainly because production costs still are not competitive with the current price of oil.

A University of Washington team is trying to make poplar a viable competitor by testing the production of younger poplar trees that could be harvested more frequently - after only two or three years - instead of the usual 10- to 20-year cycle. These trees, essentially juveniles compared with fully grown adults, are planted closer together and cut in such a way that more branches sprout up from the stump after each harvest, using the same root systems for up to 20 years. This method is called "coppicing," and the trees are known as poplar coppice.

The team is the first to try converting the entire young tree - including leaves, bark and stems - into bio oil, a biologically derived oil product, and ethanol using two separate processes. Their results point to a promising future for using poplar coppice for biofuel.