Gasoline prices are already ticking upward now that OPEC has put out word that it will curtail production, but US motorists may have some new options in the pipeline. Earlier this week, the US Environmental Protection Agency proposed some biofuel rule changes that would, among other things, enable producers to add willow trees and poplar trees to the renewable fuel mix.
CleanTechnica has covered the tree thing previously but not recently, so now is a good time to catch up.
Biofuel From Trees
Squeezing fuel out of trees and other woody plants (or parts of plants) is a challenge, but there is a pathway to doing it economically. Trees like poplar and willow grow quickly and they are low maintenance compared to many other biofuel crops.
A sustainably managed biofuel tree farm could also do double duty as a wildlife habitat and recreation area. Bioremediation is another potential second use for a field of fast-growing trees.
Biofuel tree farms could also offer rural property owners a cash-crop alternative to leasing out their land for fossil fuel extraction.
The main obstacle stalling competitive tree-based biofuel is the need to break down lignin (that’s the woody part) as a first step in order to get to the good stuff.
News of a new breakthrough in that regard came from Washington State University just last month:
…the WSU researchers used a new type of solvent to separate the lignin from wood without altering its key properties. The researchers were able extract lignin from poplar and Douglas fir samples in high yields. The lignin products have high purity and distinct characteristics.
You can get all the details on that from the latest issue of Green Chemistry under the title, “Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization.“
Biofuel From Trees, Sooner Than You Think
The WSU research is going to take a while to get from the lab to your gas tank, but in the meantime researchers at Oak Ridge National Laboratory have been exploring some bioengineering options. They have come up with a biofuel-friendly gene for new varieties of poplar. Here’s how friendly:
The team’s research demonstrated that the gene could decrease lignin content by nearly 50% and raise the ethanol production up to 250% on biomass that was not mechanically or chemically pretreated.
The team established that plants bearing a variant of the lignin-producing gene demonstrated an increase in sugar discharge of up to 280%, which caused the 250-percent increase in ethanol yield.
EPA Hearts Willow And Poplar
As reported by Reuters, the EPA is proposing some tweaks to the Renewable Fuel Standard, which was enacted in 2007 under the Bush Administration.
As the EPA notes, biofuel production has increased significantly since 2007:
…fuel ethanol production in the U.S. more than doubled in volume from approximately 6.5 billion gallons in 2007 to about 14.8 billion gallons in 2015. 6 Growth in biodiesel and renewable diesel production in the U.S. has increased more than two and a half times, from approximately 0.5 billion gallons in 2007 7 to 1.43 billion gallons in 2015.
However, the agency sees potential for upping the pace.
The new rule would add poplar and willow trees to the list of materials approved for biofuel production.
You can get all the details on the new rule straight from the EPA, but for those of you on the go here’s a snippet:
…we are proposing to approve new pathways for the production of cellulosic fuels using short-rotation hybrid poplar and willow trees as a feedstock. These new pathways would allow for ethanol and naphtha produced from these feedstocks to qualify for cellulosic biofuel (D-code 3) RINs, and for diesel, jet fuel, and heating oil produced from these feedstocks to qualify for cellulosic biomass-based diesel (D-code 7) RINs.
The Peoples’ Tree
The folks over at Oak Ridge have also been examining willow but they have a particularly ambitious program for the poplar tree. Here’s a rather poetic introduction the lab’s poplar explainer, “The Peoples’ Tree:”
In the days of the Roman Empire, people met under trees with leaves that fluttered noisily in the slightest breeze. These trees came to be known as arbor populi, or “the people’s tree.” The poplar tree, also known as cottonwood and aspen, certainly stands up to the name.
Here’s another snippet bringing things up to current history:
Results from ORNL’s bioenergy feedstock program indicate that an annual yield of 10 tons of wood per acre of poplars is both achievable and practical. “Our goal is to get 20 tons per acre per year of biomass from trees using less water and nutrients,” says Tim Tschaplinski, an ORNL plant physiologist and biochemist. “We want these trees to be able to grow in most regions of the United States, even under drought conditions, and to be harvested in six to seven years.
Gas Prices On The Rise
Last month’s Colonial Pipeline break in Alabama gave motorists in several states across the US southeast a taste of the long lines and empty gas tanks that characterized the last OPEC muscle-flexing exercise back in the 1970’s.
The organization’s most recent action is not expected to have quite such a dramatic effect. So far, the production curtailment is in the tentative agreement stage, and some industry observers are betting that it won’t hold up.
Nevertheless, our friends over at Fuel Fix have noted that gas prices are already begin to trend up in Houston and across the state of Texas:
Local prices at the pump rose to an average of $1.96 per gallon of regular unleaded gasoline, compared with a statewide average of $1.98 and $2.22 nationwide, according to GasBuddy, which tracks fuel prices and refining activity.
Part of that increase, though, could have to do with outages and scheduled maintenance at refineries in the region.
Even so, if prices keep sliding upwards that will help the market for biofuel as well as electric vehicles, so stay tuned.
Image (screenshot, cropped + rotated): via ORNL.