Chang Dou/University of Washington

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.

“Our research proved that poplar coppice can be a good option to meet the cheap, high-volume criteria of biofuel feedstock,” said lead author Chang Dou on both papers, a doctoral student in the UW’s Bioresource Science and Engineering program. “Our findings are significant for the future biofuel industry, and the ultimate goal is to make poplar coppice biofuel a step closer to the pump.”