Advantages And Disadvantages Of Ethanol As A Fuel

The energy demands are rising moderately in most of the developed countries in the modern era. While, in China and India which are underdeveloped countries and where economy is rocketing, energy needs increasing rapidly specifically for automobiles (PennState college of Earth and Mineral Sciences, 2018). Non-renewable Biofuels like diesel and gasoline, natural gas and coal cannot meet the all energy needs, so countries for example Brazil and United States have started using ethanol as an alternative source of energy. 85% of world’s total ethanol is produced by Brazil and United States, jointly. United States produces ethanol from corn, whereas sugar is used for ethanol production mostly in Brazil (US Department of Energy, 2018). According to The Renewable Fuels Association (RFA) there is a growth of 3700% in the use of ethanol since 1982 as an alternative source of energy. Ethanol has environmental, economic and societal benefits, but it also has drawbacks in term of health, ecology and corrosive properties which cannot be neglected. This essay will explore the advantages and disadvantages of ethanol and suggest another substitute source of energy.

First, we need to know about the chemical composition of ethanol and the methods of ethanol production from corn. Ethanol is a liquid alcohol, and carbon, hydrogen and oxygen are three main components of ethanol (Government of Canada, 2016). Ethanol is produced through fermentation of glucose by using wheat, corn and sugarcane as agri-forest feedstocks. Fermentation is followed by distillation, and dehydration to make water-free alcohol. The chemical reaction of making ethanol from glucose is as below:

C6H12O6→2C2H5OH+2CO2

Ethanol fuel is used as gasohol which is the mixture of ethanol and gasoline. Ethanol fuel is used as E10 and E85 in cars. E10 is a blend which contains 10% ethanol and 90% gasoline and E85 contains 85% of ethanol and 15% gasoline (U. S. Department of Energy, 2018). Corn is primarily used for ethanol production in Canada and United states. There are two methods of making ethanol from corn. First one is dry milling process and wet milling process. Wet milling process is a difficult process than dry milling process. The main products of wet milling process are ethanol, feed, corn oil, gluten meal and gluten feed, while dry milling process generally produces ethanol, CO2 and dried distiller grain with solubles (DDGS). The five key steps of dry milling process are grinding, cooking and liquefaction, saccharification, fermentation, and distillation. The diagrams below illustrate the different stages of ethanol production from dry milling process and wet milling process.

There are environmental, economic and societal benefits of using ethanol as an energy source in cars. The most important advantage of ethanol is lower emissions of greenhouse gas. Fossil fuels such as gasoline contain huge portion of carbon and hydrogen in their formula. Hydrogen part is used by engines in combustion, but carbon is remained and makes carbon monoxide. Vehicle emissions system transforms carbon monoxide into carbon dioxide. Carbon dioxide is a greenhouse gas and when it enters in environment, it causes global warming. However, ethanol holds much lower amount of hydrogen in its formula. It emits less carbon dioxide when it burns. According to Government of Canada “low-blend ethanol from corn produces about 3 to 4 percent fewer greenhouse gas emissions than gasoline. Low-blend made from wood or agricultural cellulosic materials would produce 6 to 8 percent fewer emissions compared with gasoline”. The second benefit of ethanol is that it is a renewable source of energy as it is produced from biomass such as sugarcane, corn and waste material like grasses and wood pulp. Biomass use sunlight to make energy during fermentation, so it changes sunlight into energy indirectly for ethanol production (Winnipeg Free Press, 2008). In addition to this, ethanol has societal and economic values too. Ethanol production creates more employment opportunities, especially in rural networks and adds to economic growth. Ethanol production plants provide construction and business jobs in countries like Canada which has rich forest resources and farmland. Canadian agriculturists are becoming progressively mindful about new market of ethanol. They grow crops as a feedstock particularly for ethanol production. According to the Renewable Fuels Association “ethanol production in 2017 accounted for more than 71,900 direct jobs across the United States, $45 billion to the gross domestic product, and $24 billion in household income”.

On the other hand, ethanol has drawbacks in the terms of health, ecology and corrosive properties. Firstly, ethanol has negative effects on health. According to Dr. Jacobson ethanol releases two carcinogens, acetaldehyde and formaldehyde when it burns. These carcinogens have distinct toxicities. These carcinogens increase the ground level ozone as they enter in the environment. This ground level ozone has destructive properties. It causes asthma, lung diseases and cancer, and serious illnesses lead to high mortality rate. Additionally, ethanol affects our ecosystem as well. Pimentel stated that ethanol production through corn results in soil erosion in United States. The degree of soil erosion is around 18 times higher than the degree of soil formation in the United States. Another side effect of ethanol is loss of biodiversity. Most of the land is used for cropping of corn as feedstock in United States, therefore native habitat does not have enough space to flourish. Many species of fauna and flora are on the verge of extinction. Giampietro et al indicated that “large-scale production of energy crops will undoubtedly result in an expansion of energy crop monocultures, which could ultimately reduce yields because of increased pest problems, diseases, and soil degradation”. Another drawback of ethanol is that it has corrosive properties. During winter, ethanol cannot start engine as it cannot evaporate swiftly at low temperature (Winnipeg Free Press, 2008). “Fuel systems need different rubber seals and stainless fuel lines or tanks for durability and it increases manufacturing costs slightly”.

In conclusion, it is wise to say that ethanol has positive aspects such as less greenhouse gas emissions, renewable source of energy and development of rural areas as well as negative aspects like more health complications, ecological effects and harsh characteristics. We need another alternative source of energy rather than ethanol due to serious drawbacks of it. According to Dr. Jacobson we should use electricity which can be produced from wind, wave, tidal power and solar, and hydrogen fuel-cell for energy instead of ethanol because battery-electric vehicles and hydrogen fuel-cell vehicles emit no pollutants and 98% of total carbon can be removed from environment through these sources too.

References

• Government of Canada. (2016). Natural resources of Canada. Retrieved from https://www.nrcan.gc.ca/energy/alternative-fuels/fuel-facts/ethanol/3493#a2
• Marcelo E Dias, d. O., Vaughan, B. E., & Rykiel, Edward J., Jr. (2005). Ethanol as fuel: Energy, carbon dioxide balances, and ecological footprint. Bioscience, 55(7), 593-602. Retrieved from https://search-proquest-com.library.sheridanc.on.ca/docview/216475329?accountid=3455
• PennState College of Earth and Mineral Sciences. (2018). Alternative Fuels from Biomass Resources. Retrieved from https://www.e-education.psu.edu/egee439/node/673
• Talk of Nation: Friday Science. (2007). Health Issues Raised Around Ethanol Use. Retrieved from http://www.npr.org/templates/story/story.php?storyId=9716353
• U.S. Department of Energy. (2018). Alternative Fuels Data Center. Retrieved from https://afdc.energy.gov/fuels/ethanol_benefits.html
• Western Farm Press. (2013). 40 interesting facts about ethanol. Retrieved from https://www.westernfarmpress.com/management/40-interesting-facts-about-ethanol
• Winnipeg Free Press. (2008). Advantages and disadvantages of ethanol. Retrieved from https://explore-proquest-com.library.sheridanc.on.ca/document/752249074?searchid=1542337596&accountid=3455