energy balance. The Argonne National Laboratory, Michigan State University, the U.S. Dept. of Agriculture among others have conducted studies which concluded ethanol yields more energy than it takes to manufacture it. this really is not a subject for debate among the scientific community anymore, although the popular press continues to entertain with disinformation to the contrary. What you do not know is the main perpetrator of this disinformation is a retired professor of entomology named Pimentel. Also, a former pertroleum engineer for Shell oil, Tad Patzek, (founder of the UC Oil consortium, supported by grants from Oil companies) is responsible for some too.
In the January 2006 issue of the journal, Science, Farrell et al published the rusults fo their study of 6 stduies of the energy balance of ethanol. They concluded that the "studies" by pimentel and patzek differed form all the other studies in that they concluded a negative energy balance for ethanol whereas the other studies showed a postive energy balance. They also stated that the Pimentel and patzek 'studies' differed from the other studies in that they contained input data which could not be evaluated as to it's quality due to poor documentation for the input data.
Argonne National Laboratory summary results by Michael Wang - postive energy balance for ethanol, negative balance for gasoline (19% loss)"As you can see, the fossil energy input per unit of ethanol is lower—0.74 million Btu fossil energy consumed for each 1 million Btu of ethanol delivered, compared to 1.23 million Btu of fossil energy consumed for each million Btu of gasoline delivered."
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From the article in Science:
http://rael.berkeley.edu/EBAMM/FarrellEthanolScience012706.pdf"To better understand the energy and environmental implications of ethanol, we surveyed the
published and gray literature and present a comparison of six studies illustrating the range
of assumptions and data found for the case of corn-based (Zea mays, or maize) ethanol
(11–16). To permit a direct and meaningful comparison of the data and assumptions across
the studies, we developed the Energy and Resources Group (ERG) Biofuel Analysis Meta-
Model (EBAMM) (10). For each study, we compared data sources and methods and parameterized
EBAMM to replicate the published net energy results to within half a percent. In
addition to net energy, we also calculated metrics for greenhouse gas (GHG) emissions
and primary energy inputs (table S1 and Fig. 1).
Two of the studies stand out from the others because they report negative net energy values
and imply relatively high GHG emissions and petroleum inputs
(11, 12). The close evaluation required to replicate the net energy results showed that these two studies also stand apart from the others by incorrectly assuming that ethanol coproducts (materials inevitably generated when ethanol is made, such as dried distiller grains with solubles, corn gluten feed, and corn oil) should not be credited with any of the input energy and by including some input data that are old and unrepresentative of current processes, or so poorly documented that their quality cannot be evaluated."
Notes:
11. T. Patzek, Crit. Rev. Plant Sci. 23, 519 (2004).
12. D. Pimentel, T. Patzek, Nat. Resour. Res. 14, 65 (2005).------------------------------------------------------------------------------------------------------------------
given that ethanol does have a postive energy balance and reduces GHGs and is available right now it doesn't make much sense to not use it even as we investigate other renewable fuels.
Iowa State files for patent on Ultra-Sound process which boosts alcohol yield by 30%
Samir Khanal, an Iowa State research assistant professor of environmental engineering, said the conventional dry-milling process that's used to make ethanol doesn't convert all the starch in corn kernels into the simple sugars that can be fermented into ethanol. A team of Iowa State researchers has demonstrated that pre-treating milled corn with ultrasonics can break the corn pieces into even finer particles. That exposes more of the corn's starch to the enzymes that convert starch to simple sugars. The research team also plans to see if ultrasonics releases some sugars from the fibrous, cellulosic material in corn.
Grewell said ultrasonic treatment in laboratory experiments has increased corn's release rates of sugars by nearly 30 percent. And that could mean each bushel of corn that goes into an ethanol plant could more efficiently produce ethanol for your car's fuel tank.
"This seems to work very well," Grewell said. "We're releasing more of the corn's stored energy in a shorter period of time with less energy consumption."
The discovery has led to a patent application and a one-year provisional patent for immediate commercialization of the technology.
Regarding Bio-diesel, I think the potential here is very good. I wish we were developing this fuel much more aggressively than we currently are. We should be developing any and all promising renewable energy sources. Dealing with Global Warming and fossil fuel dependence probably wont' be a matter of either-or but a combination of renewables fuels and technologies.
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