Ethanol Analysis Report

“Ethanol is promoted as a farm product, but it is largely a product of fossil fuels�

(Wald 2006)

Michael Transue Science of Sustainability October 18, 2011

Transue 1 There is no doubt that mankind is in the midst of a worldwide energy crisis.

Several economic, political, social and scientific dilemmas stem from the eventual shortage of available oil and the environmental damage those fossil fuels inflict. This dramatic decline in the amount of remaining fossil fuels is due mainly to the incessant harvesting of natural resources to fuel factories, heavy machinery, airplanes, ships, and vehicles. Attaining a peak of possible production is the resultant of these intense extracting techniques initially practiced a century ago, during the industrial boom. This concept, termed ‘peak oil’ suggests “that the world is on the verge of, or has already passed, the maximum amount of oil that can physically be produced” (Witze 2007). A large contributor to this inevitable crisis is the transportation sector, which not only places innumerable vehicles in the roadways, waterways and skies, but also contributes to polluting the air with carbon dioxide, and other harmful, emissions from gasoline combustion. As populations rise and potentially sprawl farther away from urban centers, vehicular use and gasoline demand will also surge, resulting in greater volumes of pollutant emissions into the environment.

The Environmental Protection Agency released data stating that the “transportation [sector currently] accounts for 27% of anthropogenic emissions of carbon dioxide [in the United States]” (Holzman 2008). This single sector impact is the catalyst of the popularity boost in alternative fuel solutions for transportation systems. One of the alternative fuel sources currently assisting transportation services is ethanol. Created by the linear process of breaking down plant matter with enzymes, fermenting that plant life and then distilling the fermented solution, ethanol is essentially alcohol (Wald 2007).

Transue 2 The fabrication of ethanol is highly controversial due to the harvesting of particular resources as well as the processes those resources undergo. Utilizing crops such as corn, sugarcane, and cellulosic grasses (i.e. switchgrass) to fabricate ethanol opens debates pertaining to the feasibility of the production of these fuels as well as potential improvements to the processes involved.

The most common domestic crop harvested for ethanol production is corn. Corn ethanol has been in use as an additive in gasoline to stretch the remaining petroleum available; this admixture currently ranges form 90% gasoline and 10% ethanol to 15% gasoline and 85% ethanol, the latter dubbed E85 (Wenner 2009). Although the creation and use of corn ethanol for transportation has been an accepted practice, there are serious concerns involving the feasibility of the production. “There is only so much land in the world” (Schiermeier 2008) and harvesting existing corn crops for ethanol instead of feeding the growing population could render a potential food crisis. Moreover, corn crops require nitrogen fertilizers made with natural gas and are harvested with the help of diesel fueled farming equipment (Wald 2007). However, when the corn reaches the ethanol plants, is where “ethanol’s green label [severely] starts to brown” (Bourne 2007).

The distillation process entails vast quantities of fossil fuel emissions as natural gas or coal is burned to create the steam needed. Ironically, “producing corn ethanol consumes just about as much fossil fuel as the ethanol itself replaces,” (Bourne 2007) especially when understanding the process at a macro level.

Environmental impact is not the only concern of corn ethanol production, as the overall power and efficiency of the energy generated is also in question. Every single (1)

Transue 3 unit of fossil fuel energy used to manufacture the fuel from corn yields only 1.3 units of ethanol fuel energy (Bourne 2007). This system offers a mere 30% increase in energy.

Another study performed by the American Institute of Biological Sciences (considering a life-cycle analysis of energy required in the process) claim only 10% more energy is created (Wald 2007). In fact, Cornell University published a study stating “21 pounds of corn are needed to produce just one gallon of ethanol. And farming that corn requires half a gallon of fossil-fuels” (Wenner 2009). As it stands today, corn ethanol is simply not the answer to the transportation fuel dilemma.

“Sugarcane is the ultimate plant source, far richer… in the sugars that are distilled into ethanol,” (Wald 2007). In light of this, and unlike corn, sugarcane does not need the mass quantities of special enzymes to break down the plant matter into sugars for fermentation. This is due to the stalk of sugarcane comprising of 20% sugar and the plant’s ability to begin to ferment at harvest (Bourne 2007). The sugarcane resource itself assists in creating much higher yields of ethanol than that of corn crops. In addition to higher yields, more powerful energy is created as each unit (1) of fossil fuel energy used to make sugarcane ethanol yields approximately 8 units of energy, resulting in roughly an 800% increase (Bourne 2007). However, the American Institute of Biological Sciences claims a 370% energy yield is a more accurate estimate “when considering all the steps in the chain” (Wald 2007).

For the laborers safety and convenience, the crops are usually burned before harvest, releasing harmful gasses into the atmosphere (Bourne 2007). Similar to corn ethanol production, sugarcane ethanol also requires nitrogen fertilizers and diesel

Transue 4 machinery to harvest the crops and fossil fuels to heat the fermented solutions for distillation, ultimately emitting large amounts of carbon dioxide and other harmful gasses into the environment. Also like corn ethanol, sugarcane ethanol production requires large areas of land, which could lead to deforestation if food crops cannot be sacrificed (Bourne 2007). Sugarcane ethanol is no real improvement to corn ethanol. “Switchgrass [is] the favored [cellulosic] grass for ethanol production� (Wald 2007). The immediate benefit to utilizing grasses like switchgrass, etc. to manufacture ethanol is the simple fact that it is not a food source crop. Having the ability to grow with minimal fertilizers (Holzman 2008) and requiring virtually no maintenance, cellulosic materials could be the future of ethanol production. Cellulose material has a wide range of potential energy yields depending on the methods of production. Currently, “[c]ellulosic ethanol yields roughly 80% more energy than is required to grow and convert it (Ratliff 2007). However, this number could be as high as 200% to 3,600% if produced efficiently (Bourne 2007). This large disparity of projected values is due to the lack of a proven system to break down the cellulose material with the most beneficial enzymes to better harness the potential energy. A gluey substance called lignin in cellulosic material deters efficient production as it makes plant matter difficult to break down (Bourne 2007). In light of this, scientists are turning to natural cellulose processors like termites, to understand the enzymes necessary to collect the plant energy (Ratliff 2007). This practice remains at the laboratory level but could pay high dividends in creating massive amounts of energy utilizing non-food plant life by mimicking nature.

Transue 5 Practices are currently in development to make ethanol production processes more sustainable and environmentally friendly. Experts state that ethanol production practices could be more sustainable by utilizing the waste materials in a more responsible manner.

Corn stalks themselves contain cellulosic matter and could be burned to create energy to heat the fermented solution for distillation, offsetting emissions from the current process; wastewater could also be recycled into crop fertilizers as well (Bourne 2007). Others hope to improve the procedure by incorporating a closed-loop system involving the creation of methane from cow manure to heat the boilers for distillation (Bourne 2007).

Another possible strategy to improve the negative environmental impacts as well as potentially promote higher energy yields is incorporating carbon capture and storage mechanisms into power plants (Schiermeier 2008). This process could create facilities that are carbon neutral or perhaps carbon negative, “effectively sucking carbon dioxide out of the atmosphere and storing it in the ground” (Schiermeier 2008).

“Americans burn through 140 billion gallons of gasoline a year… [and] the nation’s fuel needs are expected to increase by a fifth [of that amount] over the next 20 years” (Wenner 2009). Eventually the earth will allocate less oil than that required to sustain the energy needs of America as well as the world, perhaps finally then causing worldwide urgency for significant resolve. However our time is limited so we must first “solve the science” (Ratliff 2007) of efficient ethanol production instead of waiting to see what potential atrocities lie ahead.

Transue 6

Bibliography

Bourne, J. K. (2007) "Green Dreams," National Geographic, p. 38-59, October.

Holzman, D. C. (2008) "The Carbon Footprint of Biofuels: Can We Shrink It Down to Size in Time?" Environmental Health Perspectives, 116(6):A246-A252.

Ratliff, E. (2007) "The Plant That Will Save America," Wired, p. 158-167, October.

Schiermeier, Q. (2008) "Electricity without Carbon" Nature 454:816-823.

Wald, M. L. (2007) "Is Ethanol for the Long Haul?" Scientific American p. 42-49, January.

Wenner, M. (2009) "The Next Generation of Biofuels," Scientific American Earth 3.0, p.

46-51, April.

Witze, A. (2007) “That’s Oil, Folks” Nature 445:14-17