As recently as a year or two ago, corn ethanol seemed like a fantastic fix to America’s global warming and fuel supply problems. The yellow crop was well established, heavily subsidized, and blight-resistant, and brought commuters cheaper gas at higher octane. But the laws of thermodynamics answer to no chief executive, and careful study revealed corn ethanol to be more harm than good in several ways.

So with the promise of corn biofuels now gone the way of the dodo, biofuel experts have been pushing something called “cellulosic ethanol,” which relies on largely on agricultural plant waste, thus sidestepping a great deal of the inefficiency involved in spending energy to make energy. The problem is, cellulosic ethanol requires significant, reliable amounts of biological products from an already existing, widely grown plant.

Enter sweet sorghum. A resilient grass cultivated in warm regions all over the world, the plant tolerates drought extremely well, and, perhaps most importantly, contains a large,  lingocellulose-rich stalk that is completely irrelevant to its use a food crop. The first large-scale studies of sorghum-based cellulosic ethanol (oddly enough, done in conjunction with the Tata Motor Group, which will likely amplify world carbon emission drastically with it’s new Nano) reveal sweet sorghum could produce eight times as much energy as is expended in growing it.

"Sorghum isn't traded internationally, it's grown and consumed locally in dry areas," said Mark Winslow of the International Crops Research Institute for the Semi-Arid Tropics in a recent Reuters interview. "Since you're producing the grain on this plant, it's not a trade-off as it is with corn." 

Additionally, massive amounts of cellulosic ethanol could be produced from already existing sorghum plantations, since the new ethanol creation techniques would use only waste products. This means sorghum could be adapted to biofuel use without requiring the massive carbon-releasing deforestation inextricably linked to other crops, such as cane sugar.

Finally, sweet sorghum already grows—and grows well—in some of the poorest areas in the world. This means that the newly crowned front-running biofuel could offer historically resource poor nations a shot at energy independence and increased development, all without the massively deleterious environmental impacts modernization brought during the rise of the now industrialized world.

While wide-scale ethanol conversion remains more or less untested, it’s clear that sweet sorghum offers some of the most alluring biofuel prospects to date. An upcoming conference, organized by the United States, may yet yield further developments. 

Photo by sisudave

Related articles:
Sweet Sorghum Promoted as "Smart" Biofuel
The Age of Renewables Has Arrived
Our First Cellulosic Ethanol Plant!