Alcohol Fuels and Chemistry
Alcohol in gasoline continues as a timely topic in the United States. Agriculture-based alcohol is blended into gasoline in many states. The economics of alcohol vs. hydrocarbon fuels still shows an advantage for petroleum-based fuels but alcohol use is supported by a series of tax advantages.
But the most critical issue is one of the thermochemistry of the entire process for the synthesis and the conversion of ethanol to a fuel component. It seems likely that it requires more energy, often from the same hydrocarbon fuel we are attempting to save, to produce a gallon of ethanol than we obtain by burning it.
A true scientific controversy exists in which proponents for and against ethanol use thermochemical calculations for every step in the process to support their position. This controversy is a true decision making nightmare in which political and scientific issues are blended until the best result remains obscured!
In the 1920's the growing demand for gasoline and the potential shortage of oil was one reason alcohol fuel was seen as a possible replacement. General Motors then predicted that petroleum supplies might run out by 1940 or 1950! Another important reason cited was that alcohol would keep cars on the road if there were an emergency interruption of petroleum supply (which made Detroit happy) and that it would create a new market for agricultural products (which made farmers happy).
Repeal of the Internal revenue tax on alcohol was the first step in making alcohol fuel competitive. The $2.08 federal tax on alcohol during the Civil War was meant to apply to beverage alcohol, not industrial uses such as fuel. The automobile industry was centered in Detroit and representatives of the Detroit Board of Commerce attended legislative hearings to support removing the tax. Auto manufacturers told a Senate hearing that car manufacturers worried “not so much [about] cost as ... supply.” [i]
James S. Capen, who represented the Detroit Board of Commerce, said: “Alcohol can be produced from any old thing that has sugar or starch in it, and once given our American inventor a chance at a market as great as this, in a very short time he will have processes that will do away with any fear of scarcity of fuel.” Capin said alcohol was “preferable to gasoline” because it was easier to make and harder to control than gasoline, and thus artificial shortages could not raise the price in the future. And alcohol was much safer than gasoline, as well as being “absolutely clean and sanitary.”
The Free Alcohol hearings in 1906 were the efforts made by American farm movements that would propose wider alcohol fuels use again in the 1930s and 1970s, with much the same arguments made by Capen.
In the 1930s, the“Farm Chemurgy” movement promoted industrial uses of all kinds of farm products. The movement was backed by Henry Ford and other conservative industry leaders from the Midwest, but was not embraced as part of the New Deal. Although the alcohol blended “Agrol” brand failed economically, the research behind it proved crucial to production of synthetic rubber and other vital industries during World War II.
In the 1970s, Midwestern farmers again began advocating alcohol blends in gasoline, this time to fight pollution from leaded gasoline and to stretch oil supplies in the wake of the Middle Eastern oil crisis.
The broad ranging competition between gasoline and alcohol fuels in the early and mid 20th century is not today as well known today as a similar competition between steam and electric automobiles with gasoline powered automobiles.[ii]Nevertheless, hundreds of magazine articles, reports, books and technical papers reflect that fact that alcohol fuel was widely acknowledged as technically feasible fuel and economically competitive if oil supplies should run short.[iii] By 1920, the consensus, Scientific American said, was “a universal assumption that [ethyl] alcohol in some form will be a constituent of the motor fuel of the future.” Alcohol met all possible technical objections, and although it was more expensive than gasoline, it was not prohibitively expensive in blends with gasoline. “Every chemist knows [alcohol and gasoline] will mix, and every engineer knows [they] will drive an internal combustion engine.”[iv]
- [i] Free Alcohol Hearings, US Senate Finance Committee, 1906, Statement of James S. Capen, Detroit Board of Commerce, p. 59. Capen also said: “Alcohol can be produced from any old thing that has sugar or starch in it, and once given our American inventor a chance at a market as great as this, in a very short time he will have processes that will do away with any fear of scarcity of fuel.” Capin said alcohol was “preferable to gasoline” because it was easier to make and harder to control than gasoline, and thus artificial shortages could not raise the price in the future. Capen also said alcohol was much safer than gasoline, as well as being “absolutely clean and sanitary.”
- [ii] George Basalla, The Evolution of Technology, (Cambridge University Press, 1988) p. 197.
- [iii] Some 152 popular and scholarly articles under the heading "Alcohol as a Fuel" can be found the the Readers Guide to Periodical Literature between 1900 and 1921; about 20 references to papers and books written before 1925 are found in the Library of Congress database catalog; a 1933 Chemical Foundation report lists 52 references before 1925 on alcohol fuels; a 1944 Senate report lists 24 USDA publications on alcohol fuels before 1920; and several technical books from the period document hundreds of references from the 1900 - 1925 period.
- [iv] Scientific American, Dec. 11, 1920 p. 593.