Amaizeingly Green Facilities - The Process
The corn wet milling process starts with commercial grade corn, which has much less moisture than grocery store corn and is grown for commercial applications.
The corn wet milling process separates corn into its four basic components: starch, germ, fiber and protein. There are five basic steps to accomplish this process. First the incoming corn is inspected and cleaned. Then it is steeped in a solution to begin breaking apart the starch and protein bonds. The next step in the process involves a coarse grind to separate the germ from the rest of the kernel. The remaining slurry consisting of fiber, starch and protein is finely ground and screened to separate the fiber from the starch and protein. The starch is then separated from the remaining slurry in hydrocyclones and can then be converted into sugars and fermented.
INSPECTION AND CLEANING
Production associates at the facility inspect arriving corn shipments and clean them to remove cob, dust, chaff and foreign materials before steeping, the first processing step, begins.
STEEPING
The corn is steeped in a bath of warm water and chemicals which causes it to swell. The swollen corn is then milled and the corn germ is removed and dried for human consumption in the form of corn oil.
The kernels absorb water during steeping, which increases their moisture levels and doubles the kernel in size. The addition of sulfur dioxide to the water prevents excessive bacterial growth in the warm environment. As the corn swells and softens, the mild acidity of the steepwater begins to loosen the gluten bonds within the corn and release the starch. After steeping, the corn is coarsely ground to break the germ loose from other components. Steepwater is condensed to capture nutrients in the water for use in animal feeds and for a nutrient for later fermentation processes. The ground corn, in a water slurry, flows to the germ separators.
GERM SEPARATION
Cyclone separators spin the low density corn germ out of the slurry. Corn germ is pumped onto screens and washed to remove any starch left in the mixture. A combination of processes extracts the oil from the germ. The oil is then refined and filtered into finished corn oil. The germ residue is saved as another useful component of animal feeds.
FINE GRINDING AND SCREENING
The corn and water slurry leaves the germ separator for a second, more thorough grinding to release the starch and gluten from the fiber in the kernel. The suspension of starch, gluten and fiber flows over screens which catch fiber but allow starch and gluten to pass through. The fiber is collected, slurried and screened again to reclaim any residual starch or protein, then piped to the feed house as a major ingredient of animal feeds.
The starch-protein suspension, called mill starch, is piped to the starch separators.
STARCH SEPARATION
Protein (gluten meal) has a low density compared to starch. By passing mill starch through a centrifuge, the gluten is readily spun out. The gluten meal can be sold as a key ingredient for dog and cat food or in Amaizeingly Green’s case is sent for further refinement into fertilizer.
The starch, with just one or two percent protein remaining, is diluted, washed, rediluted and washed again in hydroclones to remove the last trace of protein. The remaining high quality starch is typically more than 99.5 percent pure.
LIQUIFACTION, FERMENTATION & DISTALATION
To make alcohol the corn starch is mixed with water to produce a liquid starch solution and enzymes are added. This is the liquefaction process that converts long molecular starch chains to short chains.
This starch is then cooked and sent to the fermenter where enzymes are added to start sacrification (conversion to sugar). Yeast is added to consume sugar and produce alcohol.
Once the yeast has done its job and consumed all the sugar, it needs to be removed in a process called yeast stripping. This removed yeast is called yeast cream. The yeast cream can either be sold to the swine industry as a high value liquid feed item or dried and sold as a high value feed item to the pet food and aquaculture industries, as Amaizeingly Green does.
This leaves us with beer. The alcohol content of this solution is approximately 14%. The beer distilled resulting in 190 proof alcohol.
To remove all remaining water resulting in a 200 proof (100%) liquid alcohol, the 190 proof alcohol is further evaporated to remove all remaining water. This pure alcohol is then combined with 2% gasoline in a process called denaturing, the result is fuel ethanol.
