Agri News staff writer
ST. PAUL -- A challenge for the emerging biomass-for-energy market could become a new business opportunity.
Once farmers begin growing biomass other than grain for renewable energy production, someone will need to get it in a form suitable for transportation and haul it to a facility that can use it for energy.
This could create a new type of business, said Vance Morey, a University of Minnesota professor of bioproducts and biosystems engineering.
ADVERTISEMENT
Morey spoke recently during a conference on the St. Paul campus titled "Growing the Bioeconomy: Solutions for Sustainability."
He presented a logistics model of supplying corn stover to an ethanol plant for electricity and process heat.
The model showed farmers could receive an estimated $7 per ton profit. It accounts for costs of collecting, storing and transporting the stover as well as replacing soil nutrients.
It would take 400 to 600 tons of corn stover each day to satisfy the needs of a plant that makes 50 million gallons of ethanol annually, Morey said. That's possible, but it's a daunting task for the facility to receive so much biomass on top of the corn already coming in for ethanol production.
It's also a challenge to match supply from fields to the ethanol plant. Industrial facilities need supply year-round. Additionally, the plant may have no room to store biomass.
A possible solution, Morey said, is to keep stover on farms so the biomass supply and hauling costs are spread out during the year. Corn stover could be shredded, raked, baled, wrapped and stored on the farm's field. Then, a grinding and compacting business could come and densify the material on site and take it to the plant.
The goal will be to get biomass into easy truckloads, Morey said. There are different methods to compact biomass, but Morey said compacting corn stover into pellets gave the best overall quality, even though that requires the most grinding, which made them more costly.
The pellets were most desirable in terms of bulk density, durability, consistency and size.
ADVERTISEMENT
The model, which used an average round-trip hauling distance of 52 miles from the farm to the plant, also analyzed how much energy from fossil fuels would be used to supply corn stover to the plant. Almost half, 44 percent, is used for fertilizer replacement.
Morey's team also found some greenhouse gas emissions would occur, mostly during the combustion process. The model noted corn stover created only about 7 percent the amount of emissions that would be created if coal was used. However, biomass contains nitrogen, sulfur and chlorine, which can contribute to potential emissions that need to be addressed, he said.
ADVERTISEMENT
