Although this is not a known widely, and most people may be prone to think otherwise, alcohol’s main usage is not in beverages – it is fuel. More alcohol fuel gets burned or used every day than all the world’s population manages to drink, and this says something about this aspect of ethanol, which is not widely known or almost equally considered as alcoholic drinks.
Ethanol is most often used as a motor fuel, mainly as a biofuel additive for gasoline. To name some figures, world ethanol production for fuel tripled between 2000 and 2007, rising from 17 billion to some more than 52 billion liters. In percentage, the share of ethanol in global gasoline type fuel increase from 3.7% to 5.4% in just one year – between 2007 and 2008. In 2010, worldwide production reached 87 billion liters with the United States topping the list of producers with approximately a 50 billion liters of production, or 57.5% of the entire world production.
Alcohol as a fuel has a significant history since the the beginning of the 20th century, when Ford Motor Company used corn alcohol gasoline for fuel energy. In fact, alcohol’s use as a fuel is strongly tied to its use in alcoholic beverages, and there is evidence of fuel usage as early as the 15th century, for various purposes.
In 1940, the first U.S. fuel ethanol plant was built and operated by the U.S. Army in Omaha, Nebraska, producing mainly fuel for the army. After 1940, and particularly until 1970, the interest in ethanol fuel was minimal, mostly due to the favorably cheap price of gasoline fuel during that time.
In 1975, the U.S. began phasing out lead in gasoline and replacing it with MTBE, a chemical compound not completely dissimilar to alcohol in its trait as a solvent. MTBE was to be later banned due to groundwater contamination.
During 1980 to 2000, several U.S. Energy Acts were passed mandating the increasing use of alternative fuel sources such as ethanol, in order to reduce dependence on imported petroleum. Since 2003, almost all U.S. states have banned MTBE and replace it with ethanol, accompanied with U.S. auto manufacturers offering Flexible Fuel Vehicles (FFVs) which can run on up to 85% ethanol.
Comparison with Conventional Fossil Fuels
Compared with gasoline, consumption of ethanol in an engine is around 50% higher than that of gasonline, due to the fact that the energy per unit volume of ethanol is 34% lower than gasoline’s – effectively, ethanol contains almost a third less energy than gasoline. However, combusted in an ethanol-only engine, more power output and better fuel economy can be obtained due to higher compression ratios available due to the exclusive use of ethanol. In flexible fuel vehicles, the lower compression mandates tunings that may produce similar output to that of using gasoline or hydrated ethanol. However, for maximal use of ethanol’s benefits, one must use a high level of compression – the current levels are still 20 to 30% less fuel efficient than their gasoline-only counterparts.
When compared with conventional leadfree gasoline, ethanol produces 1.94 CO2 kg/l while gasoline produces 2.44. On the surface, then, it appears ethanol is more environmental friendly. However, since ethanol contains only 2/3 or 66% of the energy per volume as gasoline, it actually produces 19% more greenhouse gases for the same amount of energy used. One aspect neglected in comparison is alcohol’s renewablility compared to fossil’s fuel limited amount of supply.
However, how many grams of carbon dioxide are produced as per a megajoule of energy is largely dependent on the origin of ethanol, i.e. from which material it is produced. For example, bioethanol produced from sugar cane in Brazil releases only 18 grams of CO2 per a megajoule of energy, while U.S. corn produces 103 grams. Other interesting figures are for coal, 112 grams, gasoline, 85 grams as well as natural gas, 62 grams. We can conlude that the amount of pollution generated by the production and use of ethanol is largely and almost exclusively dependent on the type of material used for production and the method used.
Conflict with Food Interests
Bioethanol such as the one discussed here in this article, being a form of renewable energy produced from agricultural feedstocks, may pose considerable problems to the food industry. Ethanol needs a large amount of arable land required for crops to produce, which derives farmes of needed space to grow food, driving food prices higher. A recent research indicates that if all corn grown in the U.S. were used to make ethanol, it would replace only 12% of current U.S. gasoline consumption – not very efficient production per area rate.
Still, new technology being phased in may enable farmers and processors to keep the same output produced using less land for input. One such idea involves using so called cellulosic ethanol. This type of ethanol can be produced from any plant material, not just starch by-products. The technology is currently in its commercialization stage, and the production of this type of ethanol may be double or even up to four times more environment friendly than current use of gasoline.
In addition, as indicated before, some crops possess completely different efficiency in being a source of ethanol production. Sugar cane and popular may reach up to 1/4 greenhouse gas emissions vs. petroleum, while corn is much less efficient.
While producing ethanol or any other source of energy, we may consider the so called energy balance of the production, meaning how much energy is spent on producing more material to create energy. A 1 to 1 balance would mean we have created the same amount of energy as we used in its creation, and would not make much sense. Ethanol has commonly energy balance rates of 1:1.3 (corn, U.S.) to 1:8 (sugarcane ethanol in Brasil). Some numbers in between are those of Biodiesel in Germany, aroun 1:2.5.
Exotic or Not Widespread Uses
Ethanol fuel may actually be used not only for combusion — for example electricity. If biomass is converted directly to electricity for charging electric vehicles, it may increase savings even more on greenhouse gas emissions.
Apart from marginally being used a rocket fuel in lightweight rocket-racing aircraft, there is still some extensive use of kerosense for cooking and lightning in less developed countries.