It isn’t news that annual harvests are crucial time periods for ethanol plants. From corn quality and starch content to enzyme dosage to process changes, there are a variety of considerations plant managers must make pre-harvest. Moreover, the amount of time plants spend on preparation varies anywhere from none at all to four weeks.

To help you better prepare your plant for the upcoming fall harvest, here are five best practices to consider:

Run a trial with the new corn crop.

As the early corn crop comes in, running a small-scale pilot through your plant is often a good move. Consider segregating your new crop corn and running a sample through your cooking process to see if you can detect any required process changes. Such an experiment is a good investment of time and effort in order to make necessary process changes before the bulk of your crop starts running through a potentially non-optimized plant.

Optimize your enzyme dosage.

A major aspect to test for during your experiment is the dry starch content of the corn. Subsequently, the enzyme dosage may need to be changed to accommodate any increases in starch content.

Be aware that as corn matures in the field, it is developing the starch that you will ultimately process. It is a good idea for your plant to run tests throughout the maturing process to get a dry analysis of starch content. If you have concerns with what you are seeing, supply your enzyme provider with samples to ensure the starch can be hydrolyzed.

Research the risk of aflatoxins.

Mycotoxins are toxic metabolites produced by molds. These molds are generated by human conditions and elements like drought, stress, or rain. Mycotoxins—aflatoxins specifically—contaminate corn and are a recurring issue for ethanol producers.

Plant managers should monitor U.S. Department of Agriculture (USDA) publications for information describing the potential for aflatoxin in their corn crop. Local grain elevators will also have excellent knowledge on the presence of aflatoxins in their trade area.

While aflatoxin doesn’t accumulate in ethanol, it can be concentrated in Dried Distillers Grains. Proper testing and identification of contaminated grain can help reduce further contamination. Make sure that you order your aflatoxin test kits well ahead of harvest.

Focus more attention on storage.

Storing your harvested corn crop is tricky. Depending upon the moisture and quality of your new crop corn, you may need to segregate lower quality corn for blending at a later date to ensure consistency to your ethanol process. Be careful mixing wet loads of corn into dry bins that may not be used for a few weeks, as significant spoilage can occur.

More and more plants, especially in the United States, are beginning to utilize outside storage in ground piles with plastic covers. With such a storage method it’s imperative that plant staff controls the moisture content of corn going into the pile as well as the quality of the corn throughout its storage period.

Analyze the damage to the new corn crop.

Continuing the previous point, most damage inflicted on your crop will occur after storage: Damage negatively affects ethanol production, as it lowers ethanol yield and can reduce DDGS quality. Be careful.

Specifically, if the corn crop comes in very wet, many ethanol plants often dry the crop before running it through the plant. Consider the temperature you employ during this step of production. The higher the drying temperature, the more starch is crystallized, lowering your yield. The ideal temperature is 130-150°F (54-65°C), though drying throughput may be significantly reduced.

What about your plant?

What does your plant do to prepare for harvest? Has your plant had success employing any of the strategies listed above? Use the comment box below to ask questions or share your experience.

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Frank Moore

After spending 35 years in the processing and business development segments of the ethanol industry, I now work as a Novozymes Plant Consultant in doing my small part to help our customers reach their next level of efficiency.

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