Ethanol is commonly produced from crops like corn, switchgrass, sugar cane and sweet sorghum. But the next big ethanol crop might the ultimate summer fruit: Watermelon. A 20-pound watermelon can yield 1.4 pounds of sugar, which can in turn produce seven-tenths of a pound of ethanol. Even more ethanol could be extracted by fully degrading the rind with chemical and enzyme treatments.
Skeptics may point out that diverting land suitable for food crops makes no sense. But in 2007, around 800 million pounds of blemished and deformed watermelons were left in fields to rot. That's 20% of all watermelons produced during the year. Why not give them a second chance as fuel and give farmers the chance to make some cash on their damaged crops?
Chemist Wayne Fish has also shown that ethanol can be extracted from glucose, fructose, and sucrose found in the waste streams of watermelons that have been stripped of nutraceutical compounds like lycopene and citrulline for commercial purposes. Producing ethanol from the waste streams cuts sewage treatment costs and allows farmers to make some extra cash on their crops.
Watermelons aren't the only unexpected crop getting the ethanol treatment lately. Researchers at the Warwick Innovative Manufacturing Center used chocolate-derived biofuels earlier this month to power a race car with a steering wheel made of carrots and a body constructed from potatoes.