Forbes in a recent piece titled, “Beyond Ethanol,” touted butanol and Isobutanol as “second-generation” biofuels with many advantages over ethanol. Pat Gruber, Chief Executive of the Pasadena, California-based start-up, Gevo Inc, in an interview with Forbes said “If we want to get off petroleum, we're going to have to accept that bio-based liquid fuels are the only way to do it,” and argued butanol and isobutanol offer many advantages over ethanol.

The arguments for isobutanol are strong. For example, it takes less energy to produce a gallon of isobutanol than it takes to produce a gallon of ethanol, and also, isobutanol produces 50% more energy than ethanol. Both sides of this equation makes for a relatively economical biofuel source. Since isobutanol does not mix with water, existing storage, transportation, and distribution infrastructure can be utilized for it’s dissemination-drastically reducing up-front capital cost needed for commercial use. Isobutanol and butanol can be used in their pure forms in unmodified engines, thus eliminating the need for fuel-blends and engine modifications. In addition, current ethanol plants can be retrofitted for the production of isobutanol. Most importantly, Gevo has the support of venture capitalist gurus: Vinod Khosla of Khosla Ventures and Richard Branson of Virgin Green Ventures.

A number of concerns remain though, Isobutanol produced by Gevo, as articulated in the Forbes piece, will rely on food sources such as corn and sorghum for feedstock which means technically, the term “second-generation” should not be used to describe Gevo's fuel as this term refers to biofuels generated from non-food feedstocks. Maybe we can loosely use third-generation as defined by Tera Buckley of the Energy and Environmental Research Center (EERC). Buckley defined third-generation biofuel as “biofuels …. made from nonfood feedstocks, but the resulting fuel is indistinguishable from its petroleum counterparts.” Gevo must make sure their third generation biofuel is not hindered by the problems of first generation ethanol fuel-the food versus fuel conundrum.

For isobutanol to be competitive with gasoline, crude will have to be about $70 per barrel which indicates the cost of isobutanol production is still a bit high. Gevo, in its website, did proclaim their process for butanol and isobutanol was modeled to cost less than 60 cents per gallon, though the feedstock for this estimation was not given. Not much information was also given on the amount of water utilized in the isobutanol production process.

Isobutanol as described by Gruber sounds very promising but pertinent questions must be answered about what feedstocks will be utilized for production? and Gevo's process water demands? This is of vital importance for this third generation fuel to avoid the battles of first generation ethanol.