Environmental Engineering Reference
In-Depth Information
Total = 45×Availability + 35×Cost + 10×Effi-
ciency + 10×Emissions
After selecting the raw material, the production
method was analyzed and it was determined that
the enzyme hydrolysis process was the optimal
production method. While the acid methods, both
dilute and concentrated, have been proven and
have many years of production history, the enzyme
hydrolysis method has the highest efficiency and
produces fewer negative by-products. There is also
much more scientific work to be done, and pro-
duction breakthroughs in the enzyme production
method will continue to increase the production
yields and reduce the production costs. Both acid
methods have reached a plateau in production
processing and costs.
Once the ethanol has been produced, it is
important to pick a distribution method that is
in keeping with the changing global factors.
Although the analysis above indicated that using
barges is the optimal distribution method, this is
not practical for all locations in Oregon. Barging
supplemented by the rail systems would make the
best combination given the current distribution
options in the Northwest.
With the combination of the above supply
chain elements, an Oregon based cellulosic ethanol
industry would be a successful and sustainable
part of our Northwest economy.
Results
Examining the results of this evaluation, the use
of barges appears to be the preferable distribution
method component for an Oregon based cel-
lulosic ethanol supply chain. Even though it has
limited availability, its cost, efficiency, and low
environmental impact make it attractive to those
producers able to take advantage of it.
A close second option appears to be rail. This
distribution method has a good balance of avail-
ability and relatively low cost, has fairly high
efficiency and low environmental impact. For
shipments of cellulosic ethanol throughout the
Pacific Northwest and where barging is not an
option, rail shipments make the most sense.
Pipelines, once they become available, will
be the clear choice of distribution method. It is
perhaps a little surprising given its availability
that it nudged trucking out of third place, but the
low fuel efficiency and relatively high environ-
mental impact of trucking weighed against it in
this analysis.
Overall Supply-Chain Selection
Recommendations
CASE STUDY OF PACIFIC ETHANOL
For a cellulosic ethanol industry in Oregon, there
are several raw material selections available, but
through the analysis and criteria evaluation it was
determined that wheat straw agricultural residue
is the optimal raw material. This was due to the
abundant supply and minimal competition for
this feedstock. As mentioned above, the main
downside to this biomass is its seasonal feedrate
which would require collection and storage to
level ethanol production throughout the year. As
a secondary alternative, forestry thinnings are
also a logical selection for an Oregon cellulosic
ethanol industry.
In order to validate the elements of this supply
chain model, we evaluated an Oregon-based cel-
lulosic ethanol startup company, Pacific Ethanol.
Company
Pacific Ethanol Inc. produces, commercializes
and sells ethanol and its byproducts in the Western
US; it also provides transportation, storage and
delivery services through third-party providers.
The company is based in Sacramento, CA, and
has production facilities in California, Colorado,
Idaho and Oregon (Pacific Ethanol Inc., n.d.).
