Gevo’s proprietary integrated fermentation technology platform (GIFT®), which has been designed to produce low-cost renewable isobutanol, consists of two elements:

  • A proprietary yeast biocatalyst, which converts sugars derived from multiple renewable feedstocks into isobutanol, and
  • A proprietary separation unit which is designed to bolt onto existing ethanol facilities.

This production technology is similar to ethanol production, except that Gevo replaces the ethanol-producing biocatalyst with its isobutanol-producing biocatalyst and then adds a separation unit.

Pat Gruber demonstrates how easily isobutanol separates from water.

Reduced capital requirements from retrofit design

We expect GIFT® will enable isobutanol fermentation productivity at least equal to that achieved in the current conventional production of ethanol, which should allow Gevo to fit its technology into existing ethanol plants and thereby reduce related capital expenditures compared to less efficient fermentation processes. Gevo has designed a proprietary engineering package through a strategic alliance with ICM to carry out its isobutanol fermentation and recovery process. This equipment has been successfully deployed via the retrofit of a one MGPY corn ethanol demonstration facility in St. Joseph, Missouri.

Gevo has used the tools of biotechnology to replace the metabolic pathways in a robust yeast biocatalyst so that instead of making ethanol, the biocatalyst (cell factory) would now make isobutanol. Click on the image to view a larger version.

Gevo has used the tools of biotechnology to replace the metabolic pathways in a robust yeast biocatalyst so that instead of making ethanol, the biocatalyst (cell factory) would now make isobutanol. Click on the image to view a larger version.

Our biocatalysts

Gevo’s biocatalysts are microorganisms that have been designed to metabolize sugars to produce isobutanol. Gevo’s technology team develops proprietary biocatalysts to efficiently convert fermentable sugars of all types into isobutanol by engineering the isobutanol pathways into the biocatalysts, and then minimizing the production of unwanted by-products to improve isobutanol yield and purity and reduce operating costs. Our yeast biocatalysts are built upon robust industrial varieties of yeast that are widely used in large-scale fermentation processes, such as ethanol and lactic acid production. We have carefully selected our yeast biocatalyst platforms for their tolerance to isobutanol and other conditions present during an industrial fermentation process, as well as their known utility in large-scale commercial production processes. As a result, we believe our second- and future-generation biocatalysts will be well-suited to produce isobutanol in commercial industrial settings and expect them to equal or exceed the performance of the yeast used in prevailing grain ethanol production processes.

Future-generation biocatalyst: cellulosic isobutanol

Through an exclusive license with Cargill, one of the world’s largest agricultural processors, Gevo is developing a yeast biocatalyst that is specifically designed to efficiently produce isobutanol from the sugars derived from cellulosic biomass. Cellulosic feedstocks include dedicated energy crops (e.g., switchgrass), and residues from forestry and agriculture (e.g., waste wood, pulp corn cobs and stalks and sugarcane bagasse).

Feedstock utilization

The GIFT® platform is designed to enable the economic production of isobutanol from multiple renewable feedstocks, including grains (e.g., corn, wheat, sorghum and barley), sugar cane and non-food-based or cellulosic feedstocks.

PHOTO CREDIT: Carbohydrate and energy-yielding metabolism in non-conventional yeasts, Carmen-Lisset Flores, et al. Copyright © 2000 Wiley. Reproduced with permission of Blackwell Publishing Ltd.