Identifying and producing the right plant material for energy production is only part of a complex system that must be efficient if it aspires to play an integral role in the country’s biofuel industry.
Harvest, storage and transportation also play crucial roles, says Steve Searcy, professor and associate department head, biological and agricultural engineering at Texas A&M.
“Our approach is that every operation has to increase energy efficiency,” Searcy said during a bioenergy field day last summer at the College Station research farm. “We are studying the logistics from the field to the processing plant.”
Harvest, storage and transportation also play crucial roles.
He said solutions to some of the most pressing biofuels challenges will require new technology and that existing equipment for forage and silage may not be adequate. The ultimate machinery may be adaptations of what’s currently available or something scientists haven’t yet devised. He quoted Arthur C. Clarke to put the process into perspective. “Any sufficiently advanced technology is indistinguishable from magic.”
He hopes he and other engineers can work a bit of magic using hybrids of current equipment along with new technology to find better ways of moving bioenergy crops from the field to processing facilities.
“We need to develop a system to optimize the process,” he said. “Currently, we’re trying to take the most desirable aspects of cotton harvest equipment and the best aspects of forage equipment and produce a hybrid of the two and design machinery that does not exist yet.”
“We’re looking at harvest equipment – self-propelled forage harvesters and balers – to evaluate designs. We’re looking at mowers and conditioners to see if we can minimize harvest losses.”
He said one challenge is that forage harvesters can blow out a lot of dry material, making harvest losses greater.
“We do a combination of field research and lab activity. We analyze the quality and chemical constituency of forages. We want to know what happens to biofuel crops from standing to delivery.”
He’s working with a modified cotton module builder to produce a large unit of biomass. “We need a large package to enhance handling and reduce the cost of transportation.”
He’s using baled material as a control since currently a lot of material is being delivered in bales. “We want to see if modules are equal to or better than bales,” he said.
Moisture is an issue. “With modules, we want to bag the material in plastic to exclude moisture. We’re in our second year with module building and we’re getting better at it.”
He said early efforts resulted in torn covers as they tried to move bagged modules from the ground into trucks, the same kind used to haul cotton.
“We’re developing a better approach. In the long run, I think another machine, other than a cotton module builder, will be better. We need to build a module that will hold high moisture biomass crops and that we can pick up and move. Then we’ll move on to improving efficiency.”
Searcy said researchers are eliminating some of the moisture concern by field drying crops. “We get as much moisture out as possible in the field. Less moisture and more dry matter may require an expensive fleet of equipment and producers can’t afford to have that investment just sit idle.”
He said dry matter transports more efficiently. Still, processing plants need to be relatively close to production sites. “That’s one reason (crop scientists) have been emphasizing sorghum. They get higher yields.”
Bob Avant, Texas AgriLife Research Bioenergy Program director, says high yield will be critical. “Corn stover will produce about 2 dry tons per acre and we don’t think that is a viable, sustainable solution. Our new bioenergy sorghums can produce about 15 dry tons per acre.”
Also, adaptability of sorghum improves potential for reducing the radius from field production to plants. “That means less distance to haul, which can make a significant impact on the average cost of delivery,” Searcy said.
He said facilities at the A&M farm give him and other researchers adequate acreage and support to do large scale research.
“Grain-based ethanol was generation one,” Searcy said. “We’re working on necessary technologies for the next generation of biofuels.”
And that’s where the magic may begin.
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