Environmental Engineering Reference
In-Depth Information
Figure 1. Raw Material Data
produce somewhere between 700 to 1,000 gallons
of ethanol. The higher estimate is based on research
at Purdue University to alter the lignin content pres-
ent in hybrid poplars (Steeves, 2006). According
to Jon Johnson, a researcher at Washington State
University, “a 950-acre poplar farm could yield
enough biomass to produce one million gallons
of ethanol every year.” (Washington State Uni-
versity College of Agriculture, n.d.). According
to Purdue University researchers, “planting 110
million acres … could replace 80 percent of the
transportation fossil fuel consumed in the United
States each year.” (Steeves, 2006).
Oregon currently has more than 34,000 acres
dedicated to growing hybrid poplar. The majority
of these hybrid poplar plantations are grown as
raw material for the paper industry, which uses
70 to 80 percent of the harvested biomass. The
remaining residue, 7 to 15 dry tons per acre, is
available for conversion into cellulosic ethanol
(Oregon.gov, 2007).
Although the paper industry creates compet-
ing demand for hybrid poplar, further planting
would likely exceed the economic demand from
this industry. Further plantings might allow for
100 percent utilization of the excess harvest by
an emerging Oregon cellulosic ethanol industry.
Evaluation of Raw Materials
Using the methodology and selection criteria
defined above, six potential raw materials are
evaluated for use as the raw material component
of an Oregon based cellulosic ethanol supply
chain. These include wheat straw, grass straw,
corn stover, forestry thinning, urban greenwaste,
and hybrid poplar. Figure 1 shows the data used
to evaluate each of these raw material options.
Applying the criteria values defined above,
Figure 2 is generated.
The formula applied for calculation of the
Total
for each raw material is as follows.
Total = 10×Yield + 40×Availability + 10×Feedrate
+ 10×Collection + 30×Compensation
Figure 2. Raw Material Evaluation
