Professor of Agricultural and Biological Engineering
Penn State University
Reprinted with permission
LOCATING A SUPPLIER OF SHELLED CORN
Do not purchase a corn-burning stove or boiler without first identifying a reliable supplier of shelled corn. To find suppliers of shelled corn, contact the feed and seed stores in your area as well as any feed mills and grain elevators. The Extension Office in your county or the land-grant university in your state may also be able to identify suppliers of shelled corn. If you know any farmers, contact them directly to inquire if they or other farmers they know will sell shelled corn to you on a direct basis. Be sure that the moisture content of the shelled corn that you buy is no higher than 15.5 % for good combustion characteristics and for safe storage of the corn. (See the link for “Quality of Shelled Corn” on the homepage of the web site.)
Generally, it will be cheaper to buy the corn directly from a farmer than from a feed mill or elevator. Probably the most expensive place to buy shelled corn is from a fireplace/hearth shop where the corn is sold in cute little decorated bags. In many cases, it will be necessary to purchase a large amount of corn at a time to get the cheapest price for the corn. You may find it is necessary to purchase 25 bushels (1,400 pounds) to 100 bushels (5,600 pounds) to negotiate the cheapest price. Whenever discussing price, be sure to consider the cost for the delivery of the corn to your home.
The price of corn fluctuates throughout regions of the U. S. and throughout each year. It is impossible for any supplier to provide a firm price for corn over an extended period of time, unless you buy the corn on a futures contract. You may be able to negotiate a price that is a fixed number of cents higher than the price of corn on the commodity market at the time of your purchase.
QUALITY OF SHELLED CORN
For best results, the quality of shelled corn to be burned in a corn-burning stove or boiler must be specified.
Moisture Content – The moisture content of the shelled corn should be no higher than 15.5%. Higher moisture contents will result in the growth of mold and mildew in the corn, thereby leading to spoilage of the corn. The growth of fungi will likely create problems of the corn clumping together in the storage area and the corn may not feed properly through the distribution system into the combustion chamber of the stove or boiler. There is also the danger of the fungal spores causing or aggravating respiratory problems with the people exposed to the spores.
Whenever the moisture content of the corn is above 15.5%, then there will be less heat available from each pound of shelled corn. For each one percent increase in moisture content above 15.5%, there will be a corresponding reduction of about 90 BTU of heat per pound of shelled corn.
Some models of corn-burning stoves and boilers may require that the moisture content of the shelled corn be as low as 13% to get efficient combustion of the corn. Be sure to ask the dealer or manufacturer about the recommended moisture content of shelled corn for efficient combustion.
Cleanliness of Shelled Corn – The shelled corn needs to be clean, with a minimum of broken kernels and foreign materials (cob pieces, husks, stalks, stones, and other residue). Small pieces of corn kernels may interfere with proper combustion and likely cause some smoking problems. The foreign materials tend to clog the flow of the shelled corn into the stove’s combustion chamber. Specify U. S. Grade #2 to get the shelled corn with just a small amount of broken corn and foreign materials (BCFM). If there are problems associated with burning Grade #2, then it may be necessary to specify U. S. Grade #1 which will have even less BCFM. However, Grade #1 corn will be considerably more expensive than Grade #2.
STORAGE REQUIREMENTS OF CORN
Proper storage of shelled corn is important for good performance of a corn-burning stove or boiler. The corn must be stored in a clean, dry environment. It should not be stored directly in contact with a concrete or dirt floor. If the corn is in bags, the bags should be stacked on a pallet in an area free of rodents, birds, squirrels, and other varmints. If the corn is stored in bulk containers, the containers should not sealed shut because there must be some air circulation around and through the corn. Inspect the corn from time to time to ensure that there are no insect or disease infestations and that the corn does not develop a musty odor.
Shelled corn is generally sold by the bushel or by weight. One bushel of shelled corn with a moisture content of 15.5 % weighs 56 pounds and requires a storage volume of 1.25 cubic feet. One hundred pounds of shelled corn (about 1.8 bushels) requires a storage volume of 2.25 cubic feet.
DISPOSAL OF CORN ASH
A plan for proper disposal of corn ash needs to be developed before purchasing a corn-burning stove or boiler. Burning shelled corn yields less ash residue than burning firewood or cinders from burning coal. Corn ash has some modest value as a fertilizer and as a liming agent, with no evidence of heavy metals or any other contaminants. The corn ash (after cooling) can be safely applied to garden areas, flower beds, lawns, and fields.