Hardwood biofuels researched using poplar trees

Fossil fuels could soon be replaced as the blood of the world’s economy and infrastructure.

A regional consortium for sustainable biofuels is teaming up with multiple companies and universities like Washington State to convert poplar trees into ethanol.

Advanced Hardwood Biofuels Northwest (AHB) invests time, money and research to help create an industry based in biologically-derived fuels instead of relying on the burning of fossil fuels.

Patricia Townsend, AHB regional extension specialist and educator at WSU, said ethanol has been produced since cars were first being made.

She said the push toward raising crops like corn for ethanol production started in the 1970s, due to the implementation of the Renewable Fuel Standard, part of the Energy Independence and Security Act passed into law by Congress in 2007.

However, the production of corn for converting ethanol has some downsides.

WSU Regional Extension Forestry Specialist Kevin Zobrist said corn takes a lot of fertilizer to grow and leaves more of an impact on the landscape than something like poplar.

In addition, Zobrist said the net greenhouse gas emissions in corn ethanol are higher than poplar in certain conditions.

He said the decision to use poplar trees as the crop was mainly because poplar trees have a very high growth rate, making them a valid renewable source of biomass. Poplar crops also provide more wildlife habitat and would be a lot easier on the soil than corn.

Zobrist said this is because, unlike corn, they can be harvested every two years for about four cycles, cutting down on the need for replanting and fertilizing.

Townsend said there are some areas where poplar trees are growing that haven’t required any fertilizer.

“Poplar can grow on marginal sites that wouldn’t be able to yield other crops,” Zobrist said.

Jeff Kallestad, research intern in the department of entomology at the WSU Puyallup Research and Extension Center, said converting poplar biomass to ethanol is different than converting corn to ethanol because the ethanol from corn is starch-based, whereas the ethanol from poplar trees is gained from breaking down cellulose through bacterial fermentation.

“Breaking down cellulose is tough because it takes specific microorganisms,” Kallestad said.

The original focus of the project was to create jet fuel from ethanol conversion of poplar trees, Townsend said, but the focus now is on producing acetic acid.

The project shifted focus because acetic acid is easy and cheap to produce, Townsend said. Acetic acid is in high demand because it is used in shoes, paints and plastics.

She said the main market for acetic acid is produced through fossil fuels, but using bio-based acetic acid is more environmentally friendly. She added that the facility in Boardman still makes ethanol, gasoline, diesel and jet fuel, but on a demonstrative level.

Townsend said the future of the project will depend to a certain extent on oil prices because lower fossil fuel prices make it more difficult for biofuel to compete due to higher production costs.

“Fossil fuel prices fluctuating is definitely an impact,” Townsend said.

The USDA National Institute of Food and Agriculture is funding the project, Townsend said, and WSU’s main role is education and outreach; sending teams to teach potential growers about the benefits and risks.