BY: NATHAN WINESBURG Ethanol Process

Goals for This Project To describe from beginning to end the process of making ethanol. Talk about how ethanol plants reuse materials and don’t overuse things. To see if they are trying to help the environment in any way.

Step 1- Hammer Mill Once corn is brought to an ethanol plant, it is stored and then sent to a hammer mill. The hammer mill grinds the corn into a flour, and while doing so removes debris and corn stocks from the corn.

Step 2- Slurry Tanks/Cooker The grain from the hammer mill is mixed in with water. The pH is set to about 5.8 (pH is how acidic or basic the solution is. The pH of water is 7.) The combination in the slurry tank is acidic Enzymes are also added, I will describe what they do later on. The slurry is heated to 190F for about 45 minutes to reduce thickness and stickiness.

Step 3- Jet Cooker The jet cooker is a fast and efficient process. The ethanol is in this process for only a few minutes but is heated to around 220F. After a little bit of cooling the mixture is passed along to the next stop.

Step 4- Liquefaction Tanks To begin the liquefaction, the mixture is heated near 190F for 2 hours. The reason for this is to give the previously stated enzymes time to breakdown the starch into dextrins (type of carbohydrate). Once completed there is another enzyme added before the mixture moves on.

Step 5- Fermentation Now the new enzymes break down the dextrins into sugars. Then yeast is added to convert the sugars into ethanol and carbon dioxide. The mash is then allowed to ferment (or develop) for hours, what results is a mixture that contains 15% ethanol

Step 6- Distillation The mash is now heated to a point where the ethanol and water can be separated. Once the ethanol is ready to move on for the next step, it contains roughly 95% ethanol and only 5% water.

Step 7- Molecular Sieve/Dehydration Here the remaining water is removed, resulting in waterless ethanol.

Step 8- Denaturant The final step of the ethanol process is adding the denaturant. This simply makes the ethanol unfit for people to consume.

Final Product Through all of the steps I listed, we now have ethanol. Now it can be stored until it is ready to be shipped away from the ethanol plant.

What happens to the leftover material? What about the released carbon dioxide? How is leftover water reused? How are distiller grains made?

Carbon Dioxide The carbon dioxide is produced in the fermentation process, when the yeast and sugar create ethanol. Rather than it being released into the atmosphere, some ethanol plants will capture and purify it so it can be used for other things Hopefully this is something that all ethanol plants will catch on to and be able to do in the future.

Reusing Water and Solids Water and solids left over from the distillation process is sent back to a centrifuge. The water is sent back to the slurry tanks, reducing the amount of fresh water that the ethanol plant needs. The solids are mixed with syrup and more reused water, creating wet distiller grains. Wet distiller grains are used as feed for cattle. Wet distiller grains are sometimes dried to make dry distiller grains, which is used as a high protein ingredient for cattle.

Reflection Overall this was a good experience for me as I move forward with my life. It is also good to see things being done to improve the environment and that we are not using more than we need – and that things used in the process are being re-used.

Thank You! Thank you all for being my judges this evening and listening to what I presented.