Assessment of Conversion Technologies for Bioalcohol Fuel ...

with Deere and Company, Diversa Corporation, Michigan State University, DuPont
subsidiary Pioneer Hi-Bred International, and U.S. DOE’s National Renewable Energy
Laboratory (Figure 19). The process incorporates a specially-developed organism,
known as zymomonas mobilis, said to convert higher volumes of both the (cellulose
and hemicellulose) or simple and complex sugars to ethanol than other biochemical
systems, and at a faster rate. The technology was designed to be incorporated into an
“integrated corn-based biorefinery”, combining al steps from miling and pretreatment
of corn stover through fermentation and ethanol production. This biorefinery concept is
also intended to cut natural gas use by 85 percent compared with typical ethanol
plants by putting a portion of the stover waste through a gasifier and using the gas for
on-site fuel.
Development Status–Bench-scale testing of the DuPont biomass-to-ethanol
technology has been conducted at the company’s Wilmington, Delaware laboratories.
This work confirmed the performance of the enzymatic process in three years of
testing, leading to the joint venture with Broin/POET, which was already pursuing
plans for an integrated biorefinery under DOE sponsorship. Broin/POET, a recognized
innovator in the ethanol production technology field, brings a number of its own
technology advancements to the partnership, including its advanced corn fractionation
and raw starch hydrolysis processes. Plans for carrying out a pilot-scale phase of the
project have been described.
Future Development Plans–Expansion of the existing dry-mill ethanol plant at
Emmettsburg is planned to begin upon finalizing terms of the grant agreement with
DOE, and will take 30 months to complete. This facility, with a current ethanol
production capacity of 50 million gallons per year, will be capable of producing 125
million gallons per year of ethanol from both corn and corn stover once the $200
million expansion and integration of the cellulosic process is complete. The overall
intended result is a biorefinery producing 11 percent more ethanol from a bushel of
corn and 27 percent more ethanol from an acre of corn, while consuming 24 percent
less water and using 83 percent fewer fossil fuels than what is needed to operate a
conventional corn to ethanol plant. Stated goals of the DuPont/POET collaboration are
to bring cellulosic ethanol to commercial viability by the end of the decade and to have
it match the cost of conventional ethanol production within about 7 years.
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