An important co-product of the ethanol production process is distillers grains. Our ethanol production segment has the capacity to produce approximately 740 mmgy of ethanol and as a result, we produce co-products such as wet, modified wet or dried distillers grains. Processing at full capacity, our plants will produce approximately 2.1 million tons of distillers grains annually. Our plants use a dry mill process to produce ethanol and co-products. The spent grain mash from the ethanol production process is pumped into one of several decanter type centrifuges for dewatering. The water, or thin stillage, is pumped from the centrifuges and then to an evaporator where it is dried into a thick syrup. The solids, or wet cake, that exit the centrifuge are conveyed to the dryer system. The wet cake is dried at varying degrees, resulting in the production of distillers grains. Syrup might be reapplied to the wet cake prior to drying, providing nutrients if the distillers grains are to be used as animal feed. Distillers grains, a major co-product of the ethanol production process, are principally used as high-protein, high-energy animal fodder and feed supplements marketed to the dairy, beef, swine and poultry industries. Distillers grains have alternative uses as burning fuel, fertilizer and weed inhibitors.
Dry mill ethanol processing potentially creates three forms of distillers grains, depending on the number of times the solids are passed through the dryer system: wet, modified wet and dried distillers grains. Wet distillers grains are processed wet cake that contains approximately 65% to 70% moisture. Wet distillers grains have a shelf life of approximately three days and can be sold only to dairies or feedlots within the immediate vicinity of an ethanol plant. Modified wet distillers grains, which have been dried further to approximately 50% to 55% moisture, have a slightly longer shelf life of approximately three weeks and are marketed to regional dairies and feedlots. Dried distillers grains, which have been dried more extensively to approximately 10% to 12% moisture, have an almost indefinite shelf life and may be stored, sold and shipped to any market regardless of its proximity to an ethanol plant.