The model took into account regional attributes such as weather, crop yield, farm size and transport distances, Shastri said. The model can optimize more than 300,000 variables, he said, including harvest schedules, equipment selection, storage sizing, transport distances and the logistics of moving the biomass from place to place.
As a test, the researchers used the model to optimize biomass production for a 13-county region in southern Illinois. (BioFeed can be adapted to analyze any region of the world, the researchers said.)
A major challenge of the emerging biofuels industry is the need for a vast and steady stream of plant biomass, the researchers said.
"If the biorefinery capacity is 50 million gallons of biofuel per year, you need to deliver roughly 1,500 to 2,000 tons of biomass per day," Ting said. "It's not a trivial task."
"Ideally, the biorefinery is expecting year-round delivery of biomass, and yet the harvesting season is a very short portion of the year and greatly dependent on weather," Hansen said. A January or February harvest, which most agronomists recommend for Miscanthus in the Midwest, means farmers must bring in their crop in some of the worst weather of the year, he said. This can cause expensive delays. BioFeed found that a November harvest would significantly reduce weather-related costs, which must be weighed against the potentially higher fertilization needed the following spring.
The model also found that storing the harvested grasses in a barn or other protected site on the farm would in most cases reduce the overall cost of the system more than if it were stored uncovered on a farm or at a centralized facility.
Each optimized solution will have its drawbacks, however, the researchers said.
"If you reduce costs in one part of the system, you may increase
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign