Washington State University researcher Jon Johnson, in collaboration with private industry partners, has won a $583,000 grant to assess poplar wood as a feedstock for the production of ethanol.
Johnson is partnering with GreenWood Resources, a hybrid poplar company headquartered in Portland, Ore., with plantings throughout the western U.S., Chile and China, and with ZeaChem, which has developed and patented a conversion process for ethanol production. Johnson is based at the Washington State University Puyallup Research and Extension Center.
The challenge Johnson and his collaborators face is in assessing the quality of the feedstock from the ethanol-producers perspective.
“The problem with most studies is that they investigate either the production side or the conversion side of the process. What we’re doing is bringing those two aspects together,” Johnson said. “There’s an attitude of ‘if we grow it, they will come,’ without much thought about the end-user, the ethanol producer, and if the feedstock is really optimal for ethanol production.”
Feedstock from selected hybrid poplar clones will be provided to ZeaChem to develop ethanol yield data, which will be used to determine breeding and selecting criteria of hybrid poplar with specific feedstock characteristics.
Poplar wood has many of the characteristics of a high quality bioethanol feedstock. A perennial tree, its feedstock can be “stored on the stump.” Poplar is cheap to grow, with low input costs, low tillage requirements and requiring little to no fertilization. The tree’s productivity can be maximized for a particular region and climate through breeding. Poplars are also the fastest growing temperate-region tree in the world and are widely adapted to grow in many soils and climates.
Johnson figures that a 950-acre poplar farm could yield enough biomass to produce one million gallons of ethanol every year. Americans consume about 400 million gallons of gasoline per day.
Environmentally beneficial poplars sequester carbon in soil, remove excess nutrients from soil and water, and provide food and shelter for animals. And since they grow well on marginal land, they don’t take up valuable food-producing agricultural land.
Johnson and his collaborators have over 30 years experience in breeding, selecting, deploying and commercially growing poplars for maximum biomass production in the Pacific Northwest and throughout the west.
ZeaChem’s production process involves recycling the conversion byproducts, such as hydrogen gas, back into the conversion system. As a result, all of the feedstock contributes to the final product, dramatically increasing yield while lowering the cost for cellulosic ethanol. Laboratory bench scale yields of over 130 gallons per bone dry ton have been observed, suggesting commercial costs of well under $1 per gallon should be achievable.