What’s That Wednesday – ETHANOL

Analysis by Abby Gerry

Is it a food preservative, a biofuel, or both? In today’s What’s That Wednesday, we’ll explore ethanol, an organic compound with diverse applications. Ethanol is renewable and domestically produced in the U.S. It serves not only as an additive in beverages but also as a sustainable material sourced from biomass, playing an intrinsic role in the fuel industry. Let’s explore this sustainable material sourced from biomass and uncover its various uses in the fuel industry!

What is Ethanol?

Ethanol is a liquid alcohol derived from biomass. When ethanol is pure, it is a colorless, flammable liquid. Chemically, it is a simple molecule, composed of two carbon atoms, six hydrogen atoms, and one oxygen atom. As a polar molecule, ethanol dissolves readily, making it versatile for various applications. It’s primarily sourced from biomass such as corn, sugarcane, wheat, and other plants rich in sugars. Ethanol plays integral roles in both industrial and fuel sectors, serving as a solvent and an additive in automotive gasoline. When used as a biofuel, ethanol is recognized as renewable, produced through the fermentation of corn and qualifying as an alternative and sustainable fuel additive to fossil fuels. Ethanol provides less energy per gallon compared to regular gasoline, which is why it is considered a desirable source of renewable fuel.

How Ethanol is Produced

Ethanol is produced in various ways, depending on what it will be made for.  For ethanol to be utilized as a biofuel, the process includes converting biomass to ethanol through a fermentation process. In the United States, the fermented sugars from corn are the main biomass source used for ethanol. During the fermentation process, bacteria and yeast metabolize the corn sugars, and thus, ethanol is produced. What separates edible ethanol and ethanol used for biofuels are denaturants. Denaturants are substances that diminish the original properties of ethanol, making it undrinkable yet suitable as a biofuel.

Ethanol as Biofuel

When ethanol is used as a biofuel, it acts as a blending agent with gasoline. This increases octane levels and reduces carbon monoxide and other emissions. There are different approved blends of ethanol for gasoline-powered vehicles. The most commonly used blend is E10 ethanol, which consists of 10% ethanol and 90% gasoline, effectively reducing air pollution. Another popular blend is E15 or 15% ethanol and 85% gasoline. These blends are widely used and approved for most gasoline engines.

Ethanol is also available as a flexfuel  (E85) and can be used in vehicles designed for flexible fuels that can operate with any blend of gasoline and ethanol up to 83%. It plays a significant role in fuel economy, but its impact varies depending on the ethanol content in the fuel. Factors such as engine optimization for gasoline versus ethanol also influence its efficiency. Ethanol also has a higher-octane number than regular gasoline, thus providing increased performance and power.

The Role of Ethanol in Energy

The United States is the leading producer and user of ethanol as a biofuel. By the end of 2022, ethanol production capacity had increased to 17.7 billion gallons annually, up from 13.6 billion gallons in 2011. This capacity has continued to rise over the years. Ethanol is heavily relied upon in the United States, particularly for biofuel purposes. Since corn is the primary biomass source for ethanol production in the U.S., our ethanol demonstrates a positive energy balance. This means the ethanol production process does not require more energy than what is contained in the biofuel.

Ethanol’s economic benefits make it a valuable commodity in the U.S. The production of ethanol is a driving force in fueling profitability in the farm economy. For farmers, ethanol represents a profound value-added market. Despite a 74% increase in feedstock prices in 2021, ethanol biorefineries processed over 5.1 billion bushels of corn, managing to remain profitable. During the COVID-19 pandemic, when the economy was in a downturn, the ethanol industry provided critical support in the nation’s economic recovery. This aided rural communities facing economic crises. Ethanol biorefineries also contribute by providing stable, well-paying jobs, which are particularly valuable in regions where employment opportunities are scarce. In the U.S., 18% of ethanol biorefinery employees are military veterans, which is three times above the national workforce average. As the U.S. continues efforts to reduce carbon emissions, refineries have optimized their processes to harness ethanol’s properties effectively. With a consistent nationwide demand for ethanol, the industry continues to bolster the economy and reap benefits across various sectors.

As the nation transitions to renewable fuel sources, ethanol has become one of the most sought-after biofuels. As a renewable energy source, ethanol serves both as a biofuel and as a fuel additive. It reduces overall greenhouse gas emissions compared to conventional gasoline, making it a cleaner alternative in the transportation sector.