Surprising Discovery

Researchers stumble upon new ethanol application
By Kris Bevill | September 12, 2011

A group of scientists at Washington State University and the U.S. DOE’s Pacific Northwest National Laboratory recently discovered that isobutene, a valuable chemical used mostly to produce rubber for automobile tires, can be created from ethanol by introducing a low-cost catalyst comprised of zinc oxide and zirconium oxide. The researchers made this unexpected discovery while attempting to extract hydrogen from ethanol. The hydrogen experiment didn’t work, but the outcome was better than expected, according to lead researcher Yong Wang, a chemical engineer who holds a joint appointment at PNNL and WSU. He says ethanol producers around the country could “absolutely” apply this new finding to their process and begin producing the biochemical to replace its fossil fuel-derived counterpart.

Isobutene’s many uses make it a good candidate for widespread production at ethanol plants, unlike zein, for example, which could be produced by only a few ethanol plants before the market becomes saturated. “It’s basically a platform molecule,” Wang says. “You can use it for making a solvent, chemicals and also fuel additives. It diversifies the application of ethanol plants. There’s no limitation.” He estimates that for every gallon of ethanol produced, about one-third of it could be used to make isobutene. The catalysts used at PNNL were produced using conventional methods and are “very cheap,” he says, which should make the process even more attractive to cash-strapped ethanol producers.

The isobutene discovery was particularly surprising for researchers because while they knew that the conversion was scientifically possible, no one had done it in a one-step reaction before, Wang says. Now that they know it is possible, researchers are working through the usual steps of scaling-up a new technology to apply it at a commercial level. The back-of-the-envelope calculations show that it is economically possible and the chemistry is proven, he says, adding that discussions are ongoing with several ethanol producers to partner with for the scale up to commercial production. 

—Kris Bevill