Thank you for the in-depth Gazette editorial, “Fueling the fire” (Dec. 15). It is obviously an important subject for Iowa and the nation. A puzzling omission, however, in this and many scholarly articles on the net carbon dioxide impact of the biofuels mandate, is that the production of ethanol from the fermentation of glucose sugar (regardless of from corn or cellulose) also generates CO2.
It has been calculated that for every gallon of fuel ethanol produced, there are 6 pounds of CO2 generated from the fermentation process. This is not an insignificant number when that is extrapolated to 15 billion gallons of ethanol produced annually in the United States. If we are to have a meaningful debate on the net impact of fuel ethanol on greenhouse gas generation, then we must include these numbers in the calculation.
Interestingly, in the 1940s, we had the technology to produce another biofuel — butanol. Butanol is a higher octane oxygenate additive for gasoline and circumvents many of the blending issues associated with ethanol. Additionally, as a bonus by-product of the butanol process, hydrogen is generated instead of CO2. Perhaps as a nation we should be reinvestigating the butanol process as an alternative to ethanol.