Ethanol Production: A Brief And Simple

Ethanol is a huge industry in the Midwest with over 40% of corn in the US made just for the production of ethanol. Ethanol is used in many aspects of our life including gasoline, laboratory testing, and even medicine.

Learning how ethanol is extracted from corn can help you learn the science and understand more about how this widely used product is used in our daily lives.

That’s why in this blog post we are going to go over the science behind how corn is extracted to turn into ethanol.

So let’s get started.

Ethanol Industry

Ethanol is a 20-year stable market where people grow out corn in the Midwest. What we would need to do is to break down dead corn (which is the most widely produced in the cornfields) and ferment them into alcohol.

Most of this goes into gasoline for your machines and most of the gasoline you use for your car typically has ethanol in it. 

Before we can turn the corn into ethanol, we need to understand that corn is made up of starch which is a pretty long carbon chain and we need to “cut it down” into small pieces in order to turn it into ethanol which is helped by the enzyme amylase.

Although most companies denature it by adding gas to it (and thus is super cheap and found in cosmetics and CBD) labs usually use pure ethanol for research and experiments.

The Steps For Processing Ethanol

We’re going to do a basic overview of how ethanol is broken down into pure ethanol to be used in the lab.

Mash-Up That Corn

If we want to extract ethanol from the corn we’re going to need to mash it up and grind it.

Machines usually do this (because it’s easier) but grinding it does help break down the corn so that it will be easier to extract ethanol in the future.

Once the corn is smashed, they usually pick them up in sterile reagent bottles so that it would be easier to transport and extract the sample from it.

Add the enzyme amylase to break it down

Amylase is the enzyme in your saliva that helps break down food. 

You would use the exact same enzyme to help break down corn into smaller chunks as well.

The goal is to make the corn as tiny and soluble as possible so that extraction would be simpler (and that you don’t clog up your instruments…)

When you break it down with amylase, there are going to be byproducts as well (which have their own uses) but to extract pure ethanol, we’re going to have to separate them so that we can create pure ethanol.

And what happens is that people add amylase every 4 hours to make sure that the corn gets broken down and the key part is to balance it (since enzymes are expensive…)

Too much enzyme and you’re wasting cash while too little enzyme and the reaction speed to break it down is too slow.

We would use filter papers throughout the whole fermentation to see how it’s going before we put it into the centrifuge to separate the materials.

Separate it with the HPLC and analyze the results

We would then use the syringe filter to extract the sample into the vial where it would go through the HPLC, the guard column, and finally, the ion exchange column which usually takes one hour to run through.

The whole process is designed to separate ethanol from the other byproducts into its purest form.

That’s why scientists run samples every 4 hours through the HPLC, a High-Performance Liquid Chromatography machine, to make sure the ratios are right. It separates into axolic acid, ethanol, and malic acid where it is all broken down to ethanol and the cool part is that the chromatogram quantifies how much of each substance there is.

You also want to pay attention to the analites which are peaks of others that are high and decrease during each session to increase ethanol peak.

Moisture Testing

Another important thing to remember is to test the moisture content of the sample as well. The reason why we want to do this is that if we have too much moisture, the sample will get moldy (and gross) whereas if there’s not enough moisture, the sample will be too dry to use.

What they use is something called the mobile phase where they use a pre-filled IV bag fiddle with a solvent that easily connects to your instrument. They typically use 0.005 normal sulfuric acids and what the mobile phase shows is separating the components based on how fast they separate via water.

We can customize that by either using polar vs nonpolar compounds in columns depending on your goals.

If your substance is polar and your column is polar, then the material is going to stay longer (because like attracts like).

The column is usually a metal tube with sand or polymer/resin where the substance goes through where it separates the compounds by attracting them at different time points which creates peaks in the graph for the computer.

Conclusion

I hope you learned something about the breakdown of ethanol from a very basic overview of what happens in the ethanol industry and how we convert the huge amount of corn in the midwest into ethanol and biomass. We also went over the basic steps in how a lab tests to make sure that ethanol is in its purest form.

If you have any questions about the ethanol industry or about how ethanol is made, you can let us know in the comments below.