The Missouri and Mississippi rivers and their floodplains could help create about two-thirds of the 21 billion gallons of biofuels called for in federal goals by 2022, according to a consortium of more than 40 academic institutions and agricultural and energy companies.
America’s plans to produce 36 billion gallons of biofuel by 2022 have fallen short because of three main bottlenecks: reliable and large-scale biomass availability; economical transport of bulk plant materials; and a biorefinery infrastructure. But, the rivers and the lands near them provide a solution to all three problems, says Shibu Jose, director of the Center for Agroforestry at the University of Missouri — the lead institution in the Mississippi/Missouri River Advanced Biomass/Biofuel Consortium (MRABC).
Preliminary research shows that about 116 million acres of marginal land near these rivers are unsuitable for traditional crops because of flooding, erosion and poor soil. These lands could be planted with biofuel feedstocks, such as switchgrass, poplar trees, willows, energy cane or Miscanthus, Jose says. Moreover, many of these crops require little to no fertilizer. Most are soil-stabilizing plants and could absorb fertilizer runoff that would normally be carried down to the Gulf of Mexico. Scientists have reported that nitrogen-rich runoff starves coastal areas of oxygen, creating what has been called the “Gulf Dead Zone.”
Switchgrass and Miscanthus can be harvested every year for 15 to 20 years before needing to be replanted, Jose says. Cottonwood and willow trees can reach 20 feet high in three years. Planting biomass crops on six million acres — just five percent of the marginal land available around the rivers — would produce enough raw material to be converted into seven billion gallons of biofuel, Jose adds. This would be a dramatic increase over the less than one million gallons expected to be produced this year.
Barging toward a solution
It is economically difficult to transport huge quantities of low-energy plant material from the fields to refineries, Jose points out. This is where the rivers offer a solution. A University of Minnesota study estimated that it costs 50 cents to transport a ton of bulk material one mile by barge compared to $5 to $6 per ton by truck. Moreover, traveling with the current on the lower Mississippi, a barge can move 1,290 tons of bulk product one mile per gallon of diesel fuel burned, according to a University of Iowa study. These economics make it possible to move bulk plant materials from where they are grown to processing plants, Jose says.
A University of Nebraska-Lincoln study indicated that switchgrass grown for biofuel production produces 540 percent more energy than needed to grow, harvest and process it into cellulosic ethanol. Researchers found that switchgrass grown on marginal fields produced an average of 300 gallons of ethanol per acre compared to average ethanol yields of 350 gallons per acre for corn. UNL scientists have been studying switch grass production since 1990.
The last part of the MRABC plan would see the creation of regional biofuel processing and refining plants along the rivers. Jose imagines facilities near harvest sites will process the biomass into easier-to-ship pellets or liquid fuel. These products could then be economically shipped via truck throughout the U.S. or through the Port of New Orleans for export. The pellets would be used to replace coal in electricity generation. Other refineries would use fermentation, gasification or pyrolysis to produce a variety of liquid fuels, including jet fuel, diesel, butanol and ethanol.
Planting on marginal lands and using existing barge infrastructures are the easy parts of the plan. The MRABC consortium reports that it needs $10 million in grants per year for the next five years to construct an experimental biorefinery for demonstration and testing. MRABC says it has industrial partners capable of scaling up the model up to two million gallons of biofuel.
The preliminary research was funded by the College of Agriculture, Food and Natural Resources, Mizzou Advantage and the MU Office of Research. For more information, visit http://cafnrnews.com/2012/07/river-fuel/