Heat with propane or shelled corn?

UNIVERSITY PARK, Pa. – When the price of corn is low and the price of energy high, agricultural producers may wonder if it would be cheaper to burn shelled corn rather than propane. The answer, according to an expert in Penn State’s College of Agricultural Sciences, is “it depends.”

“This winter, corn is abundant while the price of energy is going through the roof and further,” said Dennis Buffington, professor of agricultural and biological engineering. “It’s a good year to consider burning corn to dry grain or heat animal facilities.”

Buffington developed a chart to help people decide whether to burn shelled corn or propane. To use the chart, you find the intersection point of the value of shelled corn (vertical axis) and the price of propane (horizontal axis). “The territory where the intersection point falls tells you whether it’s cheaper to burn shelled corn or propane,” Buffington said.

“In late 2000, corn had a value of about $2 per bushel and propane cost about $1.30 per gallon,” he said. “In this case, the intersection falls in the ‘burn corn’ territory. On the basis of combustion values, it’s cheaper in this case to burn corn. than propane.

“Now, you need to do some homework to find out how much it will cost to make the transition. Additional expenses include burner modifications and handling and storage facilities for the corn. These expenses aren’t trivial and must be considered before any plans are finalized.”

Buffington suggests that producers consider having two different burners to switch between depending on whether prices fall in the ‘burn corn’ or ‘burn propane’ territory.

“You may want to consider burning last year’s corn, or corn of a lesser quality,” he said.

Homeowners who have their own heating system – particularly wood stoves that burn pellets – also could burn shelled corn.

“Burning corn smells really good, like baking corn muffins,” he said. “It’s also easier to handle than wood. Check with the company that manufactured your wood stove to find out what accessories are available to make the transition to pellets and/or corn.”

For consumers interested in knowing how much storage space would be needed to burn shelled corn, Buffington explains that the heating value of 63 bushels of shelled corn is equivalent to one cord of firewood.

When developing the chart, Buffington assumed the heating value of shelled corn at 381,000 BTU per bushel, the heating value of propane at 91,600 BTU per gallon, the combustion efficiency of corn at 75 percent and the combustion efficiency y of propane at 85 percent.

To obtain graphs based on other assumptions, contact Dennis Buffington by phone at 814865-2971, or by e-mail at deb2@psu.edu.