Two companies, Gevo and Butamax Advanced Biofuels, are leaders in developing the new technology, which aims to convert existing corn-based ethanol plants to butanol. This four carbon (versus two carbon) alcohol has more energy content per gallon than ethanol, is easier to handle, and more of it can be blended into gasoline. The butanol technology can use corn as a feedstock, facilitating the conversion of existing ethanol plants. But the goal is to switch to less expensive, environmentally more benign feestocks as the technology matures. Conversion of existing corn-based plants to make butanol will add 20 to 30 percent to the plant’s original cost.
Other developers of enzyme-based technologies aim to produce ethanol (not butanol) from low cost cellulosic feedstocks in new plants. Thus, DSM, a giant Dutch chemical company, has partnered with Poet, a major corn ethanol producer, to build a $ 250 million cellulosic ethanol plant in Iowa adjacent to its corn-based ethanol plant. (Chem. and Eng. News Oct. 8, 2012 P.22-25). It plans to license other producers with the technology. Novozymes is another very active firm in this area. In Europe, cellulosic ethanol plants are under construction.
The following graphic is generic, indicating a variety of possible feedstocks and products that can be produced with different technologies under development by a large number of companies here, in Europe and in other parts of the world. Unquestionably, corn will sooner or later be replaced by waste materials capable of being conversed to sugars and other intermediates not part of the global food supply.