Gevo Succeeds in Co-production of Renewable Isobutanol & Ethanol at its Luverne Facility

ENGLEWOOD, Colo. -- Gevo, Inc. has reported an update on the progress of the implementation of the Side-by-Side operational mode (SBS) of its plant in Luverne, MN. In the beginning of June, Gevo commenced the co-production of isobutanol and ethanol, with one fermenter dedicated to isobutanol production and three fermenters dedicated to ethanol production. This follows the companys announcement in May that it had begun production of ethanol. The benefits of simultaneously producing isobutanol and ethanol using the SBS are:

1. it facilitates the process optimization of commercial-scale isobutanol production;
2. it maximizes the utilization of the plant to generate cash by utilizing all the fermentation assets; and
3. it demonstrates the simultaneous production of isobutanol and ethanol, for the benefit of potential licensee partners who are interested in augmenting the fermentation capacities of their ethanol plants to co-produce isobutanol.

"The implementation of the SBS is tracking to our plan and validating the underlying premises for switching to this mode of production. Operating all the assets of the plant has aided us greatly in solving issues that were impeding the ramp-up of isobutanol using one fermenter in isolation, specifically the consistent management of infections and the handling of recycle streams and solids," said Dr. Patrick Gruber, Gevos CEO.

The following are some of the key results achieved thus far:

Isobutanol

• uccessfully produced isobutanol at initial run rates of tens of thousands of gallons per month in a commercial-scale one million liter fermenter (in line with previous guidance)
• Isobutanol yields have reached >90% of target based on starch content, up from approximately 70% prior to running SBS;
• Reduced isobutanol batch cash costs by >25% since beginning SBS, with a clear path towards targeted economic rates;
• Produced and sold IDGs (animal feed from isobutanol production)
• Achieved 100% recycle streams (up from 90%) while consistently producing sterile mash, controlling infections and growing isobutanol producing yeast;
• GIFT continues to work as designed (controlling the concentration of isobutanol to desired levels in the fermentation broth, by removing and collecting the isobutanol for further downstream processing) and
• No yeast cross-contamination from the ethanol system.

Ethanol

• Produced ethanol at a run rate of approximately 1.5 million gallons per month (above previous guidance of 1.25 million gallons per month)
• Generating revenue of more than USD3 million per month at Luverne; and
• No yeast cross-contamination from the i