USPTO Rejects Gevo GIFT® Claims as Unpatentable and Grants New Butamax Patent for Efficient Recovery of Alcohol Produced During

USPTO Rejects Gevo GIFT® Claims as Unpatentable and Grants New Butamax Patent
        for Efficient Recovery of Alcohol Produced During Fermentation

PR Newswire

WILMINGTON, Del., April 11, 2013

WILMINGTON, Del., April 11, 2013 /PRNewswire/ -- Today Butamax™ Advanced
Biofuels, LLC, the leading biobutanol technology company, announced new
biobutanol patent and technology developments.

On April 10, 2013, the United States Patent and Trademark Office ("USPTO")
issued an Action Closing Prosecution ("ACP"), rejecting all claims of Gevo
Inc.'s U.S. Patent No. 8,101,808 ("'808 patent"), in the inter partes
reexamination filed by Butamax on May 7, 2012. The '808 patent was described
by Gevo as "a landmark patent... on its GIFT® separation unit, a central
element in the Company's unique fermentation technology". The significance of
this ACP is that the Patent Reexamination Specialist responsible has now heard
both sides of the argument with respect to this patent, and has concluded that
all of the original, amended and added claims are unpatentable.

In making this decision, the USPTO adopted all prior art grounds for
unpatentability cited by Butamax against both the originally issued claims and
the claims Gevo amended and added during the proceedings. These included the
claims for both Gevo's GIFT® system, as well as all claims purported to cover
Butamax's technology. The USPTO also rejected Gevo's claims related to
retrofit of an ethanol plant, which was already known due to prior disclosures
from BP and DuPont.

In related news, on April 2, Butamax's fifth new patent this year was granted.
U.S. Patent No. 8,409,834 covers a highly efficient system for in-situ
recovery of alcohols produced during fermentation. This patent teaches an
advanced system that utilizes biomass components to benefit efficient
recovery. With this technology, Butamax is positioned to offer the industry a
unique low cost system for efficient recovery of biobutanol during
fermentation as part of its technology package.

"Butamax is very excited by the significant progress of our commercially
relevant technology and the recognition by the USPTO of these innovations,"
said Paul Beckwith, Butamax CEO. "We are also pleased with the USPTO's
decision to close prosecution on Gevo's GIFT® patent, rejecting all claims. We
have never been able to see what this patent taught beyond what was very well
known in the art and so, in our view, this decision is entirely appropriate."

The '808 patent is the first of the seven Gevo patents subject to
reexamination at the USPTO to receive an ACP. Butamax also recently petitioned
for inter partes review of two other patents related to the '808 patent.
Butamax is confident that, given the significant overlap in claimed
technology, the USPTO will issue an unpatentability decision for these patents
as well.

About Butamax

Butamax™ Advanced Biofuels, LLC was formed to develop and commercialize
biobutanol as a next generation renewable biofuel for the transport market.
The company benefits from the synergy of DuPont's proven industrial
biotechnology experience and BP's global fuels market knowledge. Butamax's
proprietary technology offers a cost-advantaged manufacturing process for
isobutanol with value from field to pump. For more information about Butamax's
biobutanol technology and patent portfolio, visit www.butamaxpatents.com.

Butamax™ is a trademark of Butamax™ Advanced Biofuels, LLC.

Media Contact:
Mark Buse, 202-679-5576
Mark.Buse@butamax.com

SOURCE Butamax Advanced Biofuels, LLC

Website: http://www.butamaxpatents.com