How Is E85 Ethanol Made

Are you interested in knowing how E85 ethanol is made? If you’re someone who values control over what you put in your car’s fuel tank, then understanding the production process of E85 ethanol is essential.

E85 ethanol is a fuel blend consisting of 85% ethanol and 15% gasoline. It is an alternative fuel source that is becoming increasingly popular due to its lower environmental impact and potential for reducing dependence on crude oil.

To produce E85 ethanol, a series of complex processes are involved. It all starts with raw materials, which include corn, sugarcane, sorghum, or any other plant that contains high levels of sugar or starch. These raw materials undergo fermentation and distillation, where the sugars or starches are converted into ethanol.

Afterward, the ethanol is dehydrated and blended with gasoline, and finally, it undergoes quality control checks to ensure that it meets the regulatory standards. Understanding each step in the production process can help you appreciate the effort and expertise invested in producing E85 ethanol.

Overview of E85 Ethanol

You’re probably wondering what the heck E85 Ethanol even is, but let me tell you – it’s a game changer for the environment and your wallet.

E85 Ethanol is a type of fuel that consists of 85% ethanol and 15% gasoline. It’s primarily used in flexible fuel vehicles (FFVs) that are designed to run on either gasoline or ethanol blends. E85 contains more oxygen than gasoline, which means it burns more efficiently and produces fewer emissions. This is why it’s considered a cleaner burning fuel than gasoline.

The benefits of using E85 Ethanol are numerous. Not only does it help reduce harmful emissions, but it’s also domestically produced, which means we’re not relying on foreign oil sources. Additionally, E85 is typically cheaper than gasoline, which means you could save money at the pump.

However, there are some drawbacks to using E85 as well. For one, it has a lower energy content than gasoline, which means you may need to fill up more often. Plus, not all vehicles are designed to run on E85, so you’ll need to make sure your car is compatible before switching over to this type of fuel.

Raw Materials

Ethanol and E85 are both fuels derived from renewable sources, primarily corn and sugarcane. Understanding how ethanol is made, and consequently how E85 is made, is essential in comprehending their composition and production process. Ethanol, also known as ethyl alcohol, is made through a fermentation process. It is produced by converting sugars and starches in crops like corn or sugarcane into alcohol. The process begins with the harvest and collection of these crops, which are then crushed and mixed with water to create a mash. Enzymes are added to break down the complex starches into simpler sugars. Once the starches are converted into sugars, yeast is introduced. This yeast consumes the sugars and produces ethanol as a byproduct. The fermentation process releases carbon dioxide and heat, which are captured and used in various applications. After fermentation, the resulting liquid is distilled to remove impurities and increase ethanol concentration. On the other hand, E85, commonly referred to as “flex fuel,” is a blend of 85% ethanol and 15% gasoline. To make E85, ethanol is mixed with a small amount of gasoline. This blend allows vehicles equipped with flex-fuel engines to operate using either gasoline or E85, depending on availability and personal preference. E85’s production process involves carefully measuring and combining the ethanol and gasoline in the correct proportions. This blend ensures optimal performance and efficient combustion in flex-fuel vehicles. Notably, the ethanol used in E85 is the same ethanol produced through the fermentation process described earlier. In summary, ethanol is made by fermenting sugars and starches found in crops like corn or sugarcane, whereas E85 is a blend of 85% ethanol and 15% gasoline. Understanding the production methods and composition of these fuels is crucial for those interested in their environmental impact and potential as renewable energy sources.

To make E85, you’ll need raw materials such as corn, sugarcane, or other plant materials that are rich in sugar or starch. These raw materials undergo a process called ethanol production, in which the sugar or starch is converted into ethanol through a series of chemical reactions.

The first step in ethanol production is the milling of the raw materials to break down its structure and release the sugar or starch content. Once extracted, the sugar or starch is then subjected to enzymatic hydrolysis, a process wherein enzymes are added to break down the sugar or starch into simple sugars such as glucose and fructose.

After the enzymatic hydrolysis process, the next step in ethanol production is the fermentation process. In this process, the simple sugars are added to yeast or bacteria to convert them into alcohol. Through this process, the simple sugars are converted to ethanol and carbon dioxide, which is then separated through a distillation process.

The resulting ethanol is then blended with gasoline to produce E85. Understanding the raw materials and the ethanol production process is crucial in producing high-quality E85 ethanol that can be used as an alternative fuel source.

Fermentation and Distillation

Once the simple sugars have been extracted through enzymatic hydrolysis, all that’s left is to add yeast strains into the mixture and let the fermentation process do its work.

Yeast strains are crucial in producing ethanol as they convert the simple sugars into alcohol. Different yeast strains work better with specific sugar sources, and that’s why it’s important to choose the right yeast strain for the job. For example, Saccharomyces cerevisiae is the most commonly used yeast strain in ethanol production, as it can ferment glucose, fructose, and sucrose, which are found in corn, sugarcane, and sugar beets.

After fermentation, the alcohol is then separated through distillation. This process involves using heat to vaporize the ethanol, which is then condensed back into a liquid form.

The distillation process results in an ethanol concentration of around 95%, which is not suitable for use in vehicles. To make e85 ethanol, the concentration must be reduced to 70-85% ethanol and 15-30% gasoline. This is done by adding gasoline to the ethanol and mixing it thoroughly.

The final product, e85 ethanol, is a renewable fuel source that burns cleaner than gasoline and is better for the environment.

Dehydration and Blending

Dehydration and blending are the next steps in the process of making E85 ethanol. The dehydration process is crucial in removing any remaining water from the ethanol. Water can cause issues with engine performance and can also be detrimental to the fuel’s shelf life.

The most common method of dehydration is azeotropic distillation, which involves the use of a solvent to remove water from the ethanol. The solvent and water are then separated from the ethanol, leaving behind an anhydrous ethanol solution.

Once the ethanol has been dehydrated, it is blended with gasoline to create the final E85 fuel product. Blending techniques are important in ensuring the proper ratio of ethanol to gasoline is achieved.

The most common blending method is splash blending, where the ethanol and gasoline are mixed together in the same tank. However, other methods such as metered blending and batch blending can also be used.

The final product must meet specific standards for ethanol content and other chemical properties to ensure optimal engine performance and emissions reduction.

Quality Control and Regulations

Ensuring the quality and compliance of E85 fuel requires strict adherence to regulations and rigorous quality control measures. The production of E85 fuel involves blending ethanol and gasoline in specific ratios, and these ratios must comply with federal regulations.

Additionally, the ethanol used in E85 fuel must meet certain standards in terms of purity, water content, and other factors. To maintain regulatory compliance, E85 producers implement quality control measures throughout the production process.

This includes testing ethanol samples for purity, water content, and other parameters. The production efficiency of E85 fuel is also an important consideration, as it affects both the cost and availability of the fuel.

E85 producers work to optimize their production processes to ensure that they can meet demand while maintaining quality and compliance with regulatory requirements. Overall, the production of E85 fuel requires careful attention to detail and a commitment to meeting strict regulatory standards.


Congratulations, you now have a better understanding of how E85 ethanol is made. The process involves the use of raw materials such as corn, sorghum, and barley which undergo fermentation and distillation to produce ethanol. This ethanol is then dehydrated and blended with gasoline to create E85.

Quality control and regulations are an essential part of the production process. To ensure the quality of the final product, strict regulations are put in place to monitor the production process and ensure that the final product meets specific standards.

Furthermore, the use of E85 ethanol has many benefits, including reduced emissions and a reduced dependence on foreign oil. Overall, the production of E85 ethanol is a complex and intricate process that involves the careful selection of raw materials, precise fermentation and distillation, and strict quality control measures.

However, the benefits of this alternative fuel source make it a worthy investment for both the environment and the economy. So, next time you fill up your car with E85, remember the science and effort that went into making it possible.