Harold Keener
Ohio State University
Current agricultural issues, including low product prices and high energy costs, are similar to those faced thirty years ago. Research at that time documented the viability of using shelled corn as an agri-fuel based on crop and energy yields and initial studies were conducted using an atmospheric fluidized bed combustion (AFBC) system to generate heat energy from corncobs and other biomass. The AFBC system uses forced air to fluidize a bed of sand-like particles, resulting in a churning mass that absorbs and stores heat, allowing fuel to heat and ignite rapidly as it is introduced. Although the economic analysis in 1975 did not support development of the AFBC for small-scale use, evaluation based on current corn and fuel prices indicate that it is competitive with petroleum fuels. In a comparison of shelled corn to other fuels based on the cost per Btu, shelled corn provided heat for $13.45 per million Btu, using a corn price of $3.24/bu, which was less than natural gas, propane, fuel oil, electricity and ethanol. Analysis of the potential liquid fuel savings realized by burning shelled corn in place of fuel oil compared to using ethanol determined that combustion of shelled corn has the potential to save 2.4 to 3.9 more fuel oil than does the use of ethanol. Additional analyses that accounted for the dairy rations produced as a by-product from ethanol production indicated that the potential fuel oil savings was 2.7 to 3.2 times more for corn combustion than for ethanol. Based on these assessments, if half of the 2 billion bushels of shelled corn currently exported were combusted, 4.58 billion gallons of #2 fuel oil would not be needed for heat energy but could be used for transportation. Realization of the potential of the AFBC system will require additional testing to optimize the burner configuration as well as collaboration with the grain industry to develop a shelled corn delivery system and with industry to develop manufacturing capacity.
Note: The PowerPoint presentation given by Dr. Keener will be available on the OCAMM website in mid July.
Discussion:
John VanKeuren (OSU) asked who developed the coal-burning AFBC system used at Cedar Lane Farms and if it is used elsewhere. Keener noted that the prototype was developed by OARDC/OSU but the current system is the result of two phases of modifications during which Cedar Lane worked with the Ohio Coal Development Office and engineering firms. Will-Burt Company, a manufacturer in Orrville, Ohio, is interested in commercializing the system.
Larry Brown (OSU) questioned whether using shelled corn for combustion would eliminate government price supports for corn. Keener responded that no calculations have been made but an impact on price supports would be expected. World trade and European Union concerns would also be impacted as the corn exports from the U.S. would be reduced significantly or, possibly, eliminated.
A participant in Columbus asked how many ethanol plants are currently under construction in the U.S. and how much is too much. Keener responded that in Ohio there are two planned for construction in 2006 and up to five planned for the near future. According to the Renewable Fuels Association’s Ethanol Industry Outlook 2006 (http://www.ethanolrfa.org/objects/pdf/outlook/outlook_2006.pdf), 95 ethanol facilities nationwide produced 4 billion gallons of ethanol in 2005. As of January 2006, 29 new facilities were under construction and 9 facilities were expanding, adding an additional capacity of 1.5 billion gallons annually. To date, there has been no assessment of the limits of ethanol production; however, some concerns have been raised about the potential for an oversupply of distiller’s dried grain (DDGS), an ethanol by-product used for animal feeds, which would negatively impact the economics of ethanol production.
Maurice Watson (OSU) noted that combustion of shelled corn will produce an ash by-product that may have more value as a fertilizer than the DDGS does as a feed. Keener commented that distribution of shelled corn for combustion could be built on the infrastructure in place for fuel oil delivery. The cooperative could deliver the shelled corn then pick up the ash and market it.
A participant in Wooster asked if corn cobs could be combusted with the shelled corn. Keener responded that in the 1980’s, Minnesota was successful in using the cobs in different burner systems and have been used in the prototype AFBC. However, corn cobs do not have the same energy density as shelled corn and would require a reduction in particle size before combustion in an AFBC system.
Dianne Borger (OSU) asked if the potential energy in corn varies for different varieties. Keener noted that no evaluation has been completed but it would be expected to be true as the protein and oil content varies. Varieties with lower nitrogen levels would reduce nitrous oxide emissions.
Keener noted that the expected cost for manufacturing a 150,000 Btu AFBC systems is estimated at $5,000 to $8,000 with greenhouses and the rotation molding plastic industry markets being targeted initially.
Brown questioned whether the economics for the energy required to produce corn needs to be re-evaluated due to changes in farming practices. Keener responded that modifications could be made due to savings from new equipment and conservation tillage. However, the energy reduction is estimated to be less than 15 percent.
Notes by Mary Wicks
The OCAMM (Ohio Composting and Manure Management) Program is funded by OARDC/OSU.