Delicious, but More
Fresh hot corn on the cob is one of America’s favorite foods. Yet, when the last buttery morsel is eaten, the cob is thrown into the garbage can, eventually winding up in a county dump. Historically, corncobs have been viewed as a worthless waste material. Thanks to scientific research, the corncob is beginning to be considered a raw material, a valuable resource.
Corn shocks and corn cobs plowed back into the soil offer little by way of nutrient value. Does this mean corncobs should be viewed as mere waste? No! Corncobs carry a lot of potential. For instance, corncobs can be dried, chopped and ground into abrasive grit or grinding media. Activated carbon is derived from corncobs and that carbon is capable of storing natural gas. But there is more.
Corncobs are Rich in Carbohydrates
Corncobs contain hemicelluloses that, upon splitting with acid produce appreciable quantities of xylose and arabinose, with lesser quantities of glucose and galactose fermentable sugars.
This makes them suitable starting materials for manufacturing organic compounds. One valuable compound derived from corncobs contains a 5-member ring-furfural, OC4H3CHO. Furfural is formed by hydrolysis (splitting with water) through the (destructive) reflux distillation of chopped corncobs with dilute acid (often sulfuric acid plus a small quantity of sodium chloride).
Furfural may be used directly in the manufacture of resins for automotive brakes or fiberglass. It is an important solvent in the refining of lubricating oils. Resins may be made by reacting furfural with various phenolics. Furfural may also be used to generate furans and other important organic compounds.
Corncobs might help alleviate the fuel shortage problem, since ethanol can be made from them, through the process of fermentation. In its November 13, 2007 article, MS-NBC tells of a Sioux Falls based company named POET, which expressed great interest in corncobs for such a purpose. In fact, it was estimated they might pay $30 to $60 per ton for them.
That even “waste” such as the lowly corncob can be put to useful purposes ought to open the minds of entrepreneurs to the possibilities of other, hitherto discarded materials.
Biomass Magazine – Nebraska Corncob Harvesters
Conversion of waste corncob to activated carbon for use of methane storage
The Carbohydrate Composition of Corn Cob Hemicelluloses
International Furan Chemicals – Applications of Furfural