Environmental Engineering Reference
In-Depth Information
Table 20. Comparison of Model to Pacific Ethanol's Supply Chain
Component
Worst Case
Pacific Ethanol
Best Case
Raw Materials
260 - Urban Greenwaste
345 - Wheat Straw / Corn Stover 410 - Wheat Straw
270 - Direct Microbial Conver-
sion
Production Process
400 - Enzyme Hydrolysis
400 - Enzyme Hydrolysis
Distribution
280 - Truck
400 - Barge
400 - Barge
Dr. Davis was in charge of the evaluation of
the commercial readiness of cellulosic ethanol
technologies. Pacific Ethanol was looking for an
end to end solution and for that reason they chose
a close-to-self-sustainable process with minimum
energy requirements and minimum impact to the
environment (Davis, 2008b). This process was
developed by Denmark's BioGasols ApS and had
been implemented in a small scale in the Maxi-
Fuels demo plant at the Technical University of
Denmark. According to Prof, Birgitte K. Ahring
co-founder of BioGasol ApS and professor at
the Technical University of Denmark, “the code
word for MaxiFuels is maximum utilization.
Think of the process as a carbon slaughterhouse.
Every carbon atom present in the raw material is
utilized, resulting not only in bioethanol but also
in other valuable energy products like methane
gas and hydrogen. The residual product at the
end of the process can be used as a solid fuel.
Maximum utilization is a major contributor to the
exceptionally competitive production process”
(BioGasol ApS Press Release, 2006). Addition-
ally the process creates an excess of fuel gases,
mainly methane, which will be used by Pacific
Ethanol to power the pilot plant and help to meet
the energy requirements of the neighboring corn
ethanol plant.
DOE's Joint Bioenergy Institute will be one of
the research partners to perform experiments on
the pilot cellulosic ethanol plant, these experiments
will be focused on cellulosic enzyme production
and development and research on recycling by-
products (Joint Bioenergy Institute, n.d.).
As for the final product transportation and
logistics, the new plant will use the robust dis-
tribution channels already in place by Kinergy
Marketing, which sells directly to oil companies
in the region. Kinergy Marketing transports the
ethanol in ships from the production site in Board-
man to the Portland Metro Area (Davis, 2008b).
Model Comparison
Using the framework described above, Pacific
Ethanol's supply chain implementation is com-
pared against the worst and best case results for
our supply chain components (Table 20). It should
be noted that Pacific Ethanol is implementing a
combined raw material base of 50% wheat straw
and 50% corn stover. For this reason the score
for their raw materials is calculated with the fol-
lowing formula:
RawMaterials = (RawMaterialScore) x (% of
material use)
According to these results, Pacific Ethanol's
supply chain very closely matches our proposed
supply chain model. The only discrepancy is
Pacific Ethanol's combined use of wheat straw
and corn stover, versus using only wheat straw.
There is a rational explanation for this discrep-
ancy however. Since Pacific Ethanol is already
operating a corn-based ethanol production facil-
ity, it has large quantities of corn stover left over
and readily available from this process. This cre-
ates an economic advantage for the use of corn
stover that is unique to Pacific Ethanol's situation.
