Second-Generation Biofuel: Isobutanol Producing Biocatalyst
Gevo, Inc.
345 Inverness Drive South
Building C, Suite 310
Englewood, CO 80112
Telephone: (303) 858-8358
http://www.gevo.com
Environmental Problem
Because of the current political instability in oil-pro-
ducing nations, concerns about global warming, and
a call for domestic energy resources, development of
an economically viable and environmentally friendly
fuel alternative is needed. The EPA has established
the requirement for reformulated gasoline (the Clean
Air Act) and the Renewable Fuel Standard (Energy In-
dependence and Security Act of 2007). Ethanol,
which is readily produced by yeast, can be used for
reformulated gasoline and to meet the Renewable
Fuel standard. FHowever, the amount of ethanol that
can be blended in gasoline is limited by the EPA, at
the moment to 10%. Unless there is a considerable
increase in the share of flexible fuel vehicles and/or a
substantial increase in gasoline consumption, the op-
portunity for ethanol blending has reached its maxi-
mum limit (the "blend wall").
An intriguing alternative to ethanol is isobutanol,
which has wide uses in the solvents and plastics mar-
kets and is a second generation biofuel that can be
easily blended into gasoline and currently is ap-
proved to 16%. Isobutanol also can be converted
into hydrocarbons to make "green gasoline," diesel,
and jet fuel. It has similar physical and chemical
properties to gasoline; it has a high octane number,
low reid vapor pressure (RVP) and 25% greater en-
SBIR Success Stories
ergy density than ethanol. Products made from
isobutanol have a reduced carbon footprint and
other environmental performance features compared
to materials derived from crude oil; however, pro-
ducing isobutanol involves a more complex chemical
process than ethanol production.
SBIR Technology Solution
With support from EPA's Small Business Innovation
Research (SBIR) Program, Gevo launched a project
to identify rate-limiting steps in the isobutanol path-
way in yeast. This effort resulted in the development
of genetic and biochemical assays to characterize
each of the enzymes involved in the production of
isobutanol in yeast. The development of a yeast-
based biocatalyst provides an advantage because of
its higher tolerance to isobutanol and long history of
accepted industrial use. Gevo used synthetic biology
and metabolic engineering to develop its biocatalyst
to make isobutanol at high concentrations and yield.
Gevo's current generation biocatalyst operates on
fermentable sugars. Future generation biocatalysts
are in development for mixed sugars
from biomass, so that when the con-
version technology is commercially
available, Gevo could be able to pro-
duce cellulosic butanol.
Although isobutanol is a naturally oc-
curring alcohol, high concentrations
inhibit the growth of microorganisms.
To operate its fermentation at opti-
mum conditions for the biocatalyst,
and within the process conditions
found in ethanol plants, Gevo devel-
oped a unique separation technology.
The solution uses a process innovation
for continuous separation of the
isobutanol as it is produced. In addition, Gevo has
developed and demonstrated the technology to
convert isobutanol into hydrocarbons using known
chemistry. The hydrocarbons then are blended in
proportions that should be able to meet all ASTM
standards for fuels.
The development of a yeast biocatalyst is an integral
part of Gevo's "retro-fit" model for the commercial
production of isobutanol. Ethanol is produced using
yeast in a well designed, energy-efficient, fermenta-
tion-based process that has steadily evolved during
the past 30 years. Gevo intends to retrofit existing
ethanol plants to produce isobutanol by replacing the
biocatalyst and adding Gevo's Integrated Fermenta-
tion Technology™(GIFT™). To accomplish this,
Gevo's isobutanol biocatalyst must be able to per-
form under the same conditions and match the yield
and productivity metrics for ethanol fermentation.
Commercialization Information
In alliance with ICM, Inc., Gevo successfully retrofit-
ted a 1-million-gallon per year commercial demon-
•fr *y*
t
aw	nvmitni)	.	mm"
\- Vr1 I
nix	Am	II	Distillation
sour
T,
MILLING FERMENTATION
L
it-wi
it
PLASTICS
t
Gevo's Isobutanol Feedstock to Products Flow Sheet

-------
stration facility in St. Joseph, Missouri, the first suc-
cessful retrofit of an ethanol plant to produce
isobutanol. Cevo also launched Cevo Develop-
ment, LLC to finance and develop a group of biore-
fineries based on retrofitting existing ethanol plants.
These plants can be retrofit using GIFT™ to pro-
duce isobutanol for sale to refinery and chemical
customers. Cevo is the first company to demon-
strate an ethanol plant retrofit to commercial scale
production of isobutanol.
Cevo has purchased an ethanol production facility
in Luverne, Minnesota. This plant is expected to
provide 18 million gallons per year of production
capacity for chemicals and fuels customers. Engi-
neering for the mechanical retrofitting of the plant
has begun and isobutanol production is expected
to begin early in 2012. Commercial scale produc-
tion is projected to ramp up to a projected 400 mil-
lion gallons of capacity by 2014. Cevo is focusing
on traditional ethanol plants, but its technology also
could convert cellulosic sugars. Once cellulosic
conversion technology is available, Cevo could pro-
duce cellulosic isobutanol from biomass.
Company History and Awards
Cevo, Inc. was founded in 2005 by three California
Institute of Technology researchers to develop an
advanced biofuel that could sustainably and effec-
tively replace petrochemical products. In addition
to its EPA SBIR award, Cevo also received a Na-
tional Science Foundation SBIR award to produce
renewable isobutanol for both the transportation
fuel market and the chemical market. Cevo's in-
vestors include Khosla Ventures, Virgin Creen Fund,
Burrill & Company, Malaysian Life Sciences Capital
Fund, the French oil and gas company Total, Osage
University Partners, and Lanxess. Cevo's partners
include: Cargill, for collaboration in the develop-
ment of its biocatalyst for cellulosic conversion;
ICM, Inc., which will serve as the exclusive North
American engineering, procurement, and construc-
tion contractor for the retrofit of ethanol plants
utilizing GIFT™; and UCLA, which has granted
Cevo an exclusive license for use of UCLA's method
for modifying microorganisms for use in biofuel
development.
SBIR Impact
Isobutanol is a renewable "drop in" biofuel with a 25% greater energy
density than ethanol.
Gevo is developing a yeast biocatalyst to make isobutanol at high concentra-
tions and yield. Existing ethanol plants can be retrofit to produce isobutanol,
which significantly reduces the initial capital investment compared to capital
costs for a new site.
| Gevo began operations at a 1-million-gallon per year commercial demonstra-
tion facility in St. Joseph, Missouri. Commercial scale production should com-
mence in 2012, with a projected 400 million gallons of capacity by 2014.
¦ Gevo's technology also could be capable of converting cellulosic sugars.
When cellulosic conversion technology is available, Gevo plans to
produce cellulosic isobutanol from biomass.
SBIR Success Stories

-------