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Wednesday, April 20, 2005

Lots of large lotted plots

More questionable ethanol number-crunching from the Minnesota Department of Agriculture here. Now that I have picked up the numerical framing device the ethanol enthusiasts have used (here and here) I thought I would actually try to pop the bubble on some of the more grandiose expectations of that crowd.

The grandest expectation of all considers that we can use ethanol as a fuel in the production of ethanol. Since this would eliminate (at the extreme end) our dependence on fossil fuels completely, one could say this represents the holy grail of biologically derived fuel creation. The breaking point of this argument, albeit rarely mentioned, remains the amount of ethanol needed to overcome the bootstrapping needs of this "self-generation" approach.

Ethanola = Ethanole - x*Ethanole

where, x is the fraction of ethanol extracted (Ethanole) that is reused in the production cycle to create available ethanol (Ethanola). So rearranging the extracted Ethanol to make the overhead more apparent:

Ethanole = Ethanola/(1-x)

So for every gallon produced for sale, we need to extract quite a bit, depending on how close x gets to one. Now if we take typical values of x used by the ethanol industry for fossil fuel overhead (x = 0.74), we get this:

Ethanole = Ethanola/(1-0.74) = 3.85 * Ethanola

So nearly 4 times the amount of ethanol available for net over-the-counter sale needs "extracting" as a gross overhead. Essentially, this means 4 times the size of corn fields needed for our "home-grown" energy independent solution, than if we used fossil fuels as a production energy source.


Well, no worry. As I write this, Air America's Mike Malloy broadcast snippets of G.W. Bushco talking at the U.S. Hispanic Chamber of Commerce Legislative Conference. Malloy mentioned something about losing his Bush to English translation guide as he tried to decipher what G.W. said:
Bush: To achieve greater energy security, we have got to 'arness (chuckles)-- harness the power of clean coal. We should also open up new areas to environmentally responsible exploration for oil and natural gas, including the Arctic National Wildlife Refuge. (Applause.)
After Bush recovered from his temporary Cockney accent, he started delving into his ethanol "visions".
Bush: The energy bill should encourage greater use of ethanol. And I like the idea of people growing corn that gets converted into energy. Somebody walks into the Oval Office and says, there's a lot of corn being grown, Mr. President. Hopefully, that one day will mean we're less dependent on foreign sources of energy. The more corn there is, the more we have to eat. The more corn there is, the more energy there is.

Lots and lots and lots and lots and lots of corn for sure.




Are we truly at the tipping point for techno-speak banalities coming out of the right wing?
"Absolutely. We've got Justice Kennedy writing decisions based upon international law, not the Constitution of the United States? That's just outrageous," DeLay told Fox News Radio. "And not only that, but he said in session that he does his own research on the Internet? That is just incredibly outrageous." (via atrios)
Millions of educated people, including scientists, engineers, plus schoolkids looking up what a protozoan looks like, and relatives searching for clues to curing fatal illnesses, etc., all of them outrageous -- are Bush and Delay truly that retarded? But, of course! Acting. Specially prepared for the base element of their following.

5 Comments:

Professor Blogger JMS said...

Interesting set of formulas - On those lines I really want to find out exactly how much land is being set aside in Brazil for their suger cane ethanol production - the cynical side of me thinks, every year it expands, and every year the rain forest shrinks...

9:59 AM  
Professor Blogger @whut said...

... and less carbon gets fixed by vegetation.

10:25 AM  
Professor Blogger Big Gav said...

Good question MG.

I've vaguely enthused about sugar cane, but maybe I'm just blindly optimistic that they are using existing cane waste rather than cutting down more rainforests to grow the stuff.

If anyone sees some good data please post it up.

The place I'm consulting at is in the process of setting up some small power stations that burn cane fibre (bagasse) - there's certainly lots of it to burn (and burn it is what they did in the past, so there is no change to the carbon cycle).

As for right wing banalities, I'm more scared of methane hydrates than ethanol.

4:56 AM  
Professor Blogger JMS said...

Yeah. And I am fine with bio-diesel and ethanol on a small scale, typically in terms of being thrifty with things already produced.

Of course, this stuff is being promoted like it is the silver bullet to replace oil, and it probably ranks well below wind and solar in terms of practicality.

And wind and solar won't exactly fill the energy gap.

7:04 PM  
Professor Blogger Unknown said...

The American Lung Association of Minnesota makes no claims that ethanol is a 'miracle fuel.' We DO say, however, that the largely renewable ethanol-based gasoline alternative E85 burns cleaner than gas and reduces tailpipe emissions -- Minnesota's single largest source of outdoor air pollution. We now have 150 E85 outlets across the state, with prices 20-50 cents cheaper than regular unleaded. See www.CleanAirChoice.org for more details.

Bob Moffitt
Communications Director
American Lung Association of MN

6:19 AM  

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