U.S. Patent Awarded for Isobutanol Production Process

(USPTO.gov)

The U.S. Patent and Trademark Office has granted Gevo Inc. in Englewood, Colorado, a maker of biofuels from renewable feedstocks, a patent for its process of producing isobutanol with reduced accumulation of by-products. Patent no. 8,133,715, “Reduced By-Product Accumulation for Improved Production of Isobutanol,” was awarded today to 12 inventors and assigned to Gevo.

Isobutanol is an alcohol that acts like a hydrocarbon, but unlike ethanol, can be shipped through existing pipelines and blended in any ratios with current fossil fuels. Isobutanol also has an energy density, octane value, and volatility closer to gasoline. Ethanol, in contrast, corrodes pipelines and requires modified car engines, when used in higher percentage blends.

Gevo’s technology uses a biocatalyst made from yeast that converts sugars derived from renewable feedstocks into isobutanol, and a unit that separates isobutanol from water. The production process is similar to making ethanol, but replaces the ethanol catalysts with the yeast catalyst and adds on the separation unit. The company aims to convert existing ethanol plants into isobutanol facilities.

The patent covers the process for preventing unwanted byproducts that divert the production pathway from interrupting the fermentation process needed to make isobutanol. This accumulation of byproducts disrupts the process and lowers isobutanol yields. Brett Lund, executive vice-president of Gevo says “The patent issued today covers the technology to eliminate one of the hijacking pathways, and improves yield of isobutanol by 20 percent. Without this technology, it is doubtful that an isobutanol producing yeast would be commercially viable.”

Lund says Gevo plans to start an isobutanol production operation this year, in what he says is the world’s first such facility.

Read More: Improved Cellulose Processing Developed for Biofuels

*     *     *