Alcohol fuels such as ethanol have recently been touted as cutting-edge, future fuels, clean alternatives to gasoline or diesel. Alcohol is a completely renewable resource, as it can be fermented or chemically extracted from practically any substance containing carbohydrates (most commonly starches or sugars). The use of alcohol as a vehicle fuel could greatly contribute to oil independence in the very near future, but just how ‘green’ is it, as an alternative to petroleum based fuels?
Henry Ford’s first vehicle used an alcohol-powered motor, and Ford envisioned alcohol as the primary vehicle fuel as early as 1925, telling the New York Times that, “The fuel of the future is going to come from fruit … or from apples, weeds, sawdust – almost anything,” he said. “There is fuel in every bit of vegetable matter that can be fermented. There is enough alcohol in one year’s yield of an acre of potatoes to drive the machinery necessary to cultivate the fields for a hundred years.” Although frequently discredited for his private viewpoints and political associations, no one can honestly claim that Ford was anything less than a visionary when it comes to automobile technology. A farmer himself, and champion of the American farm industry, Ford made his first car out of hemp plastics and fueled it with plant-based alcohol. He envisioned the growth of the automobile industry going hand-in-hand with that of the farming industry. So if we’ve known about this alternative fuel for over a century, why have we not been using it?
This sustainable vision of the future was largely suppressed by heavy lobbying from the petroleum industry, which included a smear campaign against Ford, claiming that his plan would make farmers rich at the expense of the common consumer. Some historians and theorists even credit Rockefeller, the billionaire oil tycoon, with heavily funding the prohibition movement in order to eliminate the potential competition from alcohol fuels. Until recently the falsely low prices of gasoline outweighed the environmental effects for most consumers, but as we are faced with the staggering effects of global warming our collective conscience urges us to seek alternatives. The earliest internal combustion engines, such as the Model A, were designed to run on either alcohol or gas, and small, inexpensive modifications can be made to allow modern vehicles to run on alcohol. In fact, over two million cars in Brazil have been modified to run on alcohol, which is no coincidence as Brazil has a huge industry in place that distills ethanol from sugar cane. The United States has also launched a massive ethanol production industry, using corn as its feedstock. Growing crops specifically for ethanol production, however, has sparked much debate about the practicality of this practice. The main arguments are: vast tracts of land are deforested, or the natural habitat destroyed, to make room for corn or sugar cane farms, thereby negating any possible benefits concerning global warming; and world food shortages may be exacerbated by dedicating fertile land to fuel production. Both of these issues can be addressed by using alternative ‘feed stocks’ for ethanol creation and many alternatives have been proposed. As Henry Ford said, “almost anything” can be used for ethanol fermentation, including agricultural wastes or food byproducts. Some of the most interesting alternatives are rice straw, which is typically burned in the fields (releasing vast quantities of greenhouse gasses) and human waste, which we currently spend billions of dollars and fossil fuel generated electricity to process. Let us imagine, then, that we can create a completely carbon-neutral process for generating alcohol fuels. How clean burning is the fuel, and what are its advantages and disadvantages in comparison with gasoline or diesel?
The famous Indianapolis 500 has used methanol as its official required fuel since the 1960s, because it is not a variable mix of chemicals like gasoline, delivers more power in correctly adjusted engines, and burns cooler than gasoline. Using currently common engine technology, alcohol has less power per volume, thereby delivering fewer miles per gallon. So, alcohol fuel tanks might need to be larger to deliver the same kind of travel distance as gasoline or diesel. One of the greatest advantages conferred by the use of alcohol is the elimination of extremely harmful compounds like tetraethyl lead, benzene, toluene, sulfur and many others. The high “octane” rating of alcohol, rather its resistance to premature detonation, eliminates the problem of engine “knocking” (which was the original reason for creating leaded gasoline). Alcohol is also safer than gasoline because of its lower volatility, meaning that it is less likely to ignite from heat or sparks. Sounds great, right? But at the moment of combustion, when used in a vehicle engine, how do the emissions of this fuel alternative stack up? Alcohol is actually a remarkably cleaner-burning fuel, emits up to 95% less carbon monoxide and delivers great reductions in or complete elimination of volatile chemicals and poisons. The total reduction of greenhouse gas emissions can be as high as 75% when using high-proof alcohols.