In Defense of Ethanol
As recently reported by the Renewable Fuels Association, in 2008 approximately 180 biorefineries in 26 states produced 9.25 billion gallons of ethanol displacing the need for 320 million barrels of oil, which is roughly 4.4% of all petroleum consumed in the U.S. during the year. Today, another 20 facilities are under construction and three existing facilities are being expanded. This promises a total displacement of 480 million barrels of oil or 6.6% of our total annual consumption, which is equivalent to almost one quarter of the oil our nation imports annually from the Persian Gulf. Thus it is evident that ethanol has become a vital contributor to our liquid fuel needs.
On the other hand, much has been said and written recently on the negative aspects of producing ethanol from farm products, especially corn. The criticisms have been fourfold:
1. The amount of fuel ethanol obtained from the fermentation of biomass, mainly corn, is little more than the amount of fossil fuels used in its production. Hence, little is gained with respect to reducing overall oil consumption in the U.S. and the world.
2. The enormous quantity of corn and soybeans diverted from the food chain in the process of manufacturing ethanol is creating serious food shortages throughout the world.
3. The amount of greenhouse gases (GHG) emitted into the atmosphere in the production of corn ethanol exceeds the reduction of GHG achieved by using ethanol in place of gasoline.
4. The destruction of forests in various countries of the world in order to grow fuel crops such as sugar cane, soybeans and corn is removing valuable CO2 absorption sinks from the earth resulting in greater amounts of CO2 going into the atmosphere, thereby exacerbating climate change.
Before we pass judgment on any of these assertions, let’s first examine each of them closely.
Addressing Criticism #1
The argument made by some agricultural gurus, such as David Pimental of Cornell University, is that it takes more fossil fuel to produce corn ethanol than the amount of gasoline-equivalent ethanol that is actually produced Many experts disagree citing studies that show that the ratio of liquid fuel produced vs. fossil fuel consumed is anywhere from 1.2 to 1.6. Regardless, this is NOT the full story. The goal is to reduce the amount of petroleum consumption overall.. Therefore we must look at the total picture – not just the ethanol production cycle in isolation from all other factors involved.
It is true that fossil fuel is used in the manufacture of fertilizer but this fuel is almost always natural gas. Similarly it is coal or natural gas, not petroleum, that is used in most ethanol refining processes. Therefore neither of these energy inputs is germane when assessing “the amount of petroleum IN vs. the amount of ethanol OUT.” On the other hand, it is a fact that a great amount of diesel fuel is consumed by tractors used in planting and cultivating the corn. Further, much gasoline is used in the transportation of the corn from the farm to the ethanol plant. But in the total picture, this is also irrelevant and should not be counted. Let’s face it. Were the farmer not engaged in raising corn for ethanol, he would most likely be using the same land to raise the same amount of corn for livestock feed. Therefore he would be using the same amount of diesel fuel to cultivate his crops and the same amount of gasoline to ship the corn from his field to the feed lots. Thus, the amount of petroleum used in both scenarios cancel each other out and should not be considered when assessing the gain of liquid fuel realized from the process. On the other hand, the fact that it takes about 1.4 gallons of ethanol to provide the same energy as 1 gallon of gasoline must be taken into account when calculating the NET gain of liquid fuel in the process. But even considering this, plus all the other factors cited, corn ethanol unquestionably makes a very positive contribution towards the reduction of overall petroleum demand.
This said, there are other farm products that could be grown today in place of corn to produce ethanol in a much more efficient manner. One is sugarcane. This is the feedstock used most successfully in the production of ethanol in Brazil. It could be successfully grown in several southern states in the U.S., such as Florida, especially if it were given the same subsidy that is now granted to corn. And in the longer range, producing ethanol from cellulosic matter such as switchgrass, wood chips, and municipal waste is far more efficient than from corn. In addition, many cellulosic crops such as switchgrass may be grown in marginal lands unsuitable for most other crops, and will use far less fertilizer and water. While the technology to convert cellulosic matter into ethanol is not yet fully developed, it is expected to be online and in production within the next two to three years.
Addressing Criticism #2
There is some truth in the statement that corn ethanol production has impacted our food supply. But it is not nearly as bad as has been sensationalized in many recent statements and articles voiced by the media, including the cover story in Time Magazine on April 7, 2008. While admittedly land that is currently being used to produce corn for ethanol might otherwise be used to grow corn for food, the overall loss is far less than is often portrayed. An acre of land produces between 115 to150 bushels of corn. In normal farming, 85% is used as feed for livestock (cattle, milk cows, pigs, and chickens) while only 15% is used to produce human edible food. In the following discussion it is assumed that ethanol corn is only being grown in place of feed corn.
In the ethanol process only the starch component of the corn is used to make ethanol. What is left is a mix of different forms of “Distiller’s Grains.” These distiller grains make excellent animal feed and are regularly sold to feed lots for such purpose. However it is noteworthy that a bushel of corn consumed in the ethanol process produces only about 17 pounds of distiller grains compared to the 56 pounds of corn per bushel realized when the corn is harvested directly. By weight it appears that the amount of distiller’s grains produced comes to less than 1/3 of the feed corn harvested from the same number of acres. However, this is misleading. Distiller grains with solubles (DDGS), which is by far the principal distiller’s grain that is produced, are far more nutritious than corn and provide 10-15% more energy per pound than is found in regular corn and contains 30% protein vs. 10% protein in the corn.. As a result, feeding animals DDGS can replace all or most of the protein supplement ordinarily fed to the livestock and nearly all of the corn usually fed to them as well. In the case of milk cows, the resulting diet will support as much or more milk production than the traditional corn-based diet and at lower cost.
Thus, it cannot be presumed that all or most of the corn lost to ethanol farming is a total loss to the food chain. In fact, we can safely assume that the recovered DDGS provides at least two thirds of the food value lost by not raising feed corn on the same acreage on which the fuel corn was grown. Hence, we can only say that corn ethanol production has reduced our food supply of corn from the same land by 1/3 at most.
And this isn’t the entire picture either. It was recently reported in the Chicago Tribune by energy gurus, Robert Zubrin and Gal Luft, “despite a threefold growth in the corn ethanol industry over the last five years, the U.S. corn crop grew by 35 percent, the production of distillers grain quadrupled, and the NET food and feed corn output in the U.S. increased by 26 percent.”
Addressing Criticism #3
The assertion that more greenhouse gases (GHG) are generated in the ethanol production process than are reduced in tailpipe emissions by using ethanol in place of gasoline is untrue. The argument suffers from the same flaw in reasoning as cited under Criticism #1. Once again the critics are including all the GHG that is generated in producing fertilizer, in tilling and cultivating the land with tractors, and in transporting the corn to the ethanol plant. And just as pointed out in the rational refuting Criticism #1, these GHG emissions cannot be counted since the same emissions would occur when the same land would otherwise be used to grow corn for livestock feed. Disregarding these farming and distribution GHG emissions, the overall ethanol growing/manufacturing/using process is “carbon neutral.” That is, the total amount of CHG emitted during manufacture and at the tailpipe is approximately equivalent to that which was absorbed from the atmosphere by photosynthesis during the growth of the fuel crop.
Addressing Criticism #4
The premise of the feature article in the April 7, 2008 edition of Time Magazine and other media assertions has been that the widespread destruction of forests to create open land for the planting of energy crops is detrimental to the environment. Their principal concern is for the massive amount of deforestation that is going on in the Amazon and other tropical regions. While this is true, it should be pointed out that very little forest land is being destroyed in the U.S. to make way for the planting of energy crops, or for that matter, any crops. The fact is that most U.S. forests are either protected, privately owned by logging companies, or located on land that is unsuitable for farming. In the U.S. most forest destruction is the result of lumber harvestation, forest fires and pine beetle infestation.
There is truth, however, that much CO2 is expelled into the atmosphere during the destruction of forests, particularly by the “slash and burn” techniques employed in many foreign regions. While this CO2 emission is a one time occurrence, it is of no small magnitude and adds substantially to our global warming problems. On the other hand, the argument that the absence of the destroyed forests further ads to the global warming problem fails to take into account the amount of absorption of CO2 by the substitute energy crops. Here are the facts.
As reported in a recent University of Florida study…1 acre of growing trees (trees that have not yet reached their full maturity) will absorb 5000 Kg of CO2 per year (mature trees, which are predominant in most old forests, absorb much less). This translates into 5.5 tons of CO2 per acre per year. Also, as reported by the Canadian research firm, Cemcorp Limitted, 1 hectare of corn absorbs 22 tons of CO2 per year (this presumes a single crop per year). This translates into 8.9 tons of CO2 per acre per year. Based on these figures, the replacement of forests by energy crops (corn as an example) is a plus for the environment. While this advantage will not immediately offset the amount of CO2 emitted during the initial destruction of the forest, over many years it will and eventually add to the reduction of CO2 in the atmosphere.
Summation
Long term we are looking at cellulosic ethanol to take over from corn ethanol. The recent energy bill (EISA 2007), which sets a target of 36 million gallons per year of biofuel production by 2022, caps the amount of biofuels from corn at 15 billion gallons per year while directing that 21 billion gallons per year be produced using other feedstocks “that exhibit much more positive GHG attributes than current corn-based production affords.”
All told, ethanol production from biomass is far and away a positive means of relieving our dependence on oil. According to the Energy Information Administration ethanol already represents about 9 percent of the total U.S. gasoline supply. Overall, its shortcomings are offset by its many advantages. Not only does it reduce our need for oil but it also provides many new domestic jobs, increases farmer liquidity, and lowers fuel prices (according to Merrill Lynch “without biofuel programs, the price of oil would be about $21 a barrel higher than it is now”). While ethanol is not without its faults, it is a positive contributor to our nation’s oil independence and should not be sold short.
By: Paul Natori
Read more about Cellulose Ethanol Market Potential
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Good article for Energy vs Ethanol. Question – concerning Methanol – if new technology for concentrated solar power (IAUS) were used instead of the current natural gas energy source and the chemical reaction that combines co2 with hydrogen that produces methanol were used, what would be the detrimental effects of m85 instead of e85? Both are alcohols and emitt basically the same things when burned with gas.
Ron