ShareMar. 22: With debates over ethanol heating up on the Hill again, the National Corn Growers Association launches a series of articles comparing the environmental impacts of ethanol and petroleum as transportation fuels. Scientifically examining a wide array of environmental factors, this side-by-side comparison offers insight into …">
(Posted Fri. Mar 22nd, 2013)
Mar. 22: With debates over ethanol heating up on the Hill again, the National Corn Growers Association launches a series of articles comparing the environmental impacts of ethanol and petroleum as transportation fuels. Scientifically examining a wide array of environmental factors, this side-by-side comparison offers insight into the important differences between these fuels.
Which fuel is renewable and why is that important?
- Today, ethanol is primarily made from corn, which is produced annually and thereby renewable. When corn grows, it takes carbon dioxide from the air and converts it into glucose and then starch, from which ethanol is produced. Corn production returns nutrients to the soil through its roots and decomposing stalks, thus giving back to the land used in its production.
- Petroleum and natural gas were made over millions of years ago from decayed plants and animals. The amount present in the earth is limited, and it cannot be replenished. As it takes tens of thousands of years for the planet to create more petroleum, it simply runs out once the current supply is exhausted. Once removed, the molecules containing carbon and other substances, like sulfur, are released into the environment. Unlike ethanol, petroleum is simply a product extracted from the planet and not one that gives back a valuable resource.
From a scientific standpoint, what actually makes up these fuels? What affect do they have on life prior to being used as fuel?
- Ethanol is a tiny single substance that is non-toxic. It can be enjoyed by adults in alcoholic beverages or as a transportation fuel.
- Petroleum is a mixture of hundreds of different molecules. It is toxic to biological organisms.
How does production of the fuel’s feedstock impact the environment and the global population?
- Corn used for ethanol in the United States is grown on approximately five percent of our nation’s cropland. For perspective, ethanol production uses less than three percent of all grain crops grown over the entire world.
- Petroleum is mined across the entire globe and must be extracted from deep underground. In order to collect petroleum, landscape fragmentation and the generation of toxic, hazardous and potentially radioactive waste streams often occurs.
Understanding that the distance the feedstock must travel from production to where it will be made into a useable fuel requires fuel use, how does the environmental impact of ethanol and petroleum production compare? What does it really take to make the fuel?
- Most corn-to-ethanol production facilities are located within 15 miles of the farms where the crop was produced. Yeast, similar to that used to make bread, converts the corn starch into ethanol. In addition, two co-products, corn oil and distillers grains, are produced. These co-products are used in multiple places, including biodiesel production and animal feed.
- Since petroleum extraction happens across the globe wherever deposits can be found, it must be shipped to a facility where it can be refined. Once there, the energy intensive refining process separates these various molecules into fractions; each fraction can be used for many purposes.
Looking at how the production of these fuels compares side-by-side, it becomes evident that ethanol is truly renewable and produced in a greener manner than its fossil fuel counterparts. Where petroleum is extracted from the earth and releases hazardous waste, corn grows year-after-year and returns vital nutrients to the soil.
Next week, this series will continue with an examination of how the environmental impact of the use of these fuels compares.