Forage-based ethanol production will not solve all of the nation’s energy woes, but it’s a good place to start.
“Forage ethanol is not the only answer to our energy needs, but it is a big answer,” says Carol Jones, stored product engineer at Oklahoma State University.
Jones discussed the dual challenges of storage and transportation for forages used in ethanol production at a biofuels field day at the South Central Research Station in Chickasha.
“We have a lot of work to do and it will take a lot of money,” Jones said. She said current preference for corn and other grain-based ethanol is partly due to ease of transportation. “Grain is easy to store and the delivery process is already in place.”
Forages have a bit more gearing up to do. “We’ve found that square bales are easier to store and transport than round ones." But moving heavy bales from one processing site to the next adds to expense. “If we’re only using part of the bale, why haul all of it? We’re working on possibilities.”
Biomass farmers need a system that allows them to reduce transportation costs and time. “Moving from one processing site to another processing location and then to another is just not feasible,” she said. “We need a process where we can handle it once.”
Grinding dry forage plants and packing into a module, similar to a cotton module, may offer promise. “We’re working with Texas A&M on a closed environment module."
“We’re not certain yet what the first step in breaking down cellulose will be.” Gasification may be an option. “We’re looking at the economics.” She said enzymatic processing may be cheaper for now since the equipment is already in place. “As more gasification equipment is built, cost will come down.”
Jones said converting forages to ethanol is more efficient than converting corn.
She said sorghum looks promising for much of Oklahoma. “In this area (south Central Oklahoma) we have better success with sorghum than with switchgrass. But Oklahoma can be diverse.”
Maintaining quality is of less concern with biofuel forages than if those same bales were being held for livestock feed. “We don’t need to worry about palatability, moisture content or the nutrient value,” Jones said. “Mold is not as big a deal unless it’s bad enough to limit mass. Outside storage is economical, using tarps, and storing inside might actually increase moisture content.”
Cellulosic ethanol production is no longer a pipe dream. “A plant in Kansas will be operational in 2010, running half corn and half cellulosic ethanol,” Jones said. She said the corn by-product can be used for feed.
“Forage sorghum is the best for biomass production. We can use grain sorghum, cut the grain and use the stalks for biofuels production. But we don’t get the tonnage we do with forage sorghum.”
Sweet sorghum also shows promise for sugar-based ethanol.