Environmental Engineering Reference
In-Depth Information
Table 8.
Criteria Values
1
Process is still in R&D and requires additional research before being production ready
2
Production is still in R&D phase but is ready for production evaluation
3
Process is in production evaluation process and appears ready for production
4
Process has been used in production but process is still undergoing improvements
5
Process has been used in production for several years with known results
Cost of Operation (35 points)
As in any production process for commercial-
ization, cost is an extremely important factor in
determining which production method to chose.
The production method will ultimately define
the profit margins for the company based on the
market price of the goods sold. In this case there
is already an established market for ethanol in the
northwest. That is why the production costs and
operation costs will account for 35 percent of the
decision. The production cost will be a relative
scale because each process can be tailored and
modified based on the pre-treatment and fermenta-
tion steps, which will affect the overall production
cost. This relative ranking will be based on the
general production processes based on the steps
required (Table 9).
Production Yield (25 points)
Another critical factor in determining the pro-
duction process is the ethanol yield. An Oregon
based cellulosic ethanol industry will potentially
process thousands of tons of biomass per week
and produce millions of gallons of ethanol annu-
ally. An increase in ethanol production yield will
have a significant impact on the profitability of
such an industry. As mentioned in the raw material
selection, each biomass has a different theoretical
ethanol yield based on the molecular composition
of the plant material. Each hydrolysis production
process will yield a different percentage of ethanol
based on the theoretically amount of cellulose in
the biomass. Because of the impact on the success
of the company, this criterion will consist of 25
percent of the decision (Table 10).
By-Products / Environmental Impact (10
points)
As the global focus changes and environmental
impacts become more important, it is necessary
for companies to evaluate their processes impact
on the environment. In addition to the direct
impact on the environment, the production by-
Table 9.
Cri
teria Values
1
<25% or unknown efficiency
2
25 - 49% efficiency
3
50 - 74% efficiency
4
75 - 90% efficiency
5
>90% efficiency
Table 10.
Criteria Values
1
Major environmental impact and by-products requiring severe mediation and additional processing.
2
Minor environmental impact and by-products negatively impacting ethanol production.
3
Potential environmental impact and by-products requiring mediation which effect ethanol yield.
