Was ethanol fuel an empty promise?
Bring up the subject of gasoline in the company of folks who drive vintage cars and the rumble of conversation will start low. Soon it builds into a great cacophony of voices lamenting the ethanol-laced fuels currently occupying most pumps across the U.S. The concern with ethanol in fuel typically centers around the deposits left when evaporation takes place, or how aging rubber fuel system components tend to degrade once ethanol starts chewing away at them. There’s even more to it, though, as Engineering Explained tells it. The YouTube channel’s latest deep dive into some recent studies on ethanol fuels is more than a little enlightening.
Before dashing to the comments section, I ask you to actually watch the video or at least read the rest of this article. I promise there is new information to chew on.
The core of what host Jason Fenske discusses two studies: one done by a team at University of Wisconsin Madison and a second by the Environmental Protection Agency. The EPA study originated in 2010, and the key finding from it that there is a 21 percent reduction in greenhouse gas emissions when comparing gasoline vs. ethanol in a combustion engine. That sounds significant, but the University of Wisconsin Madison study that published just last month paints a different picture. The Wisconsin study swings the opposite direction by concluding that if one considers the entire process of ethanol fuel production, such biofuels in combustion engines actually emit 24 percent more carbon into the atmosphere.
The critical factor here is that of land conversion for the growth of corn to make ethanol fuel. For example, it could be farm land that was sitting fallow or was wild before being cleared, tilled, and planted. That clearing releases carbon that the plants had stored in various manners, along with the emissions of the machinery used to perform the work.
Even the best case scenario of the 2010 EPA study had a long tail on it. For ethanol fuels to break even after the initial spike in emissions, and relatively small reduction while in use, took 14 years. For the actual 21 percent reduction in greenhouse gasses would require keeping the same pace for another 14 years. Twenty-eight years is a long time, but given that in actual implementation ethanol is only a fractional amount of what we get from the pump—just 10% in most cases—it could take even longer to break even. In the best-case scenario it could mean 2 percent better emissions in 28 years. Not nothing, but hardly a magic bullet.
Of course, just two studies are not sufficient to make firm conclusions about this complex issue.
Is ethanol so terrible? Hardly. It has strong value as an octane booster and for better oxygenating fuel, which can slightly boost efficiency. What many studies eventually point to is switching away from corn to a different crop for the production of ethanol; switchgrass, for example, can offer a break-even timeline that’s almost immediate and potentially stands to triple the reduction in greenhouse gasses in just three years.
Good science and engineering is about responding to the reality of the data—no different than how we learned that polished intake runners are actually bad for fuel mixture and flow going into an engine, changing the conventional wisdom. Ethanol is likely not going away anytime soon, but it seems there’s good cause to better scrutinize how effective our current biofuel strategy is in terms of meeting its stated goals.
