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Interestingly, if an engine is specifically designed to run only on ethanol, it will actually extract a much higher percentage of energy per unit of volume (BTU/gal) than is possible with gasoline. Ethanol burns cooler and is less susceptible to detonation, so the engine can be run at a much higher compression ratio (15:1 instead of 8:1) and with more ignition advance (20+ degrees). With less heat to expel, cooling systems become lighter and simpler. Such an engine obviously wouldn't run long on gasoline without self-destructing.
Excerpts from http://robertrapier.wordpress.com/category/compression-ratio/
Gasoline contains about 115,000 BTUs/gallon with a typical engine efficiency of 25%, yielding 28,750 BTUs/gallon of power and the remainder expelled as heat. Ethanol contains about 75,000 BTUs/gallon. If an engine was designed with an efficiency of 38%, that would result in the same 28,750 usable BTUs/gallon.
The Saab Biopower engine was designed with a higher compression ratio, so that on E-85 it showed a 12.5% drop in fuel efficiency instead of the typical 20-30% drop. Saab reported 20% extra power and 15% extra torque from this engine. Swedish automaker Scania has produced an ultra-high compression ratio engine designed for ethanol usage, and they reach engine efficiencies as high as 43%, yielding 32,250 usable BTUs/gallon.
Now if they could just figure out the problems of water absorption, cold starting, corrosion, inefficient fuel production, and a few other minor issues, we might have a viable replacement for 100LL. And at the end of the day, you can sump your tank, and (as long as it's ethanol and not denatured) add a little cola for mixer, and let the party begin. Hey, let a guy dream a bit, alright?
Patrick
Al Gietzen wrote:
Sugar cane is grown here.
Basically only grows well in the tropics.
You can make ethanol out of what ever you want. It will never make sense. Your gas mileage will drop by what ever percent ethanol you use because there is less energy in ethanol than gas.
That would suggest using 100% ethanol your mileage would be zero; when actually it would drop by about 15%. Last years race, the Indy cars ran on 100% ethanol – worked rather well.
The big difference is by using the entire cane stalk you can get better than 4 : 1 energy back for energy in. Brazil produces large quantities of ethanol; and does it efficiently.
Al
Bill B
------------------------------------------------------------------------
*From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *On Behalf Of *Al Gietzen
*Sent:* Saturday, February 12, 2011 7:04 PM
*To:* Rotary motors in aircraft
*Subject:* [FlyRotary] Re: Ethanol
So I guess we are starting this all over again? Perhaps we could all just point out to Mr Westenhaus that it is not a question of whether ethanol works as a fuel - of course it does. What is absurd is to produce ethanol from corn kernels where the overall energy used (in the form of petroleum fuel) to produce the corn and the ethanol is only about 4% less than the energy obtained from the ethanol produced.
As Lynn said at the beginning – without taxpayer subsidy it would die in a hurry.
Now if we could produce the ethanol from sugar cane, as they do in Brazil; it would make sense.
Al
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Finn Lassen
Sent: Saturday, February 12, 2011 11:02 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Ethanol
Now if we could just get a 6th option: 87 unleaded E-0:
http://oilprice.com/Alternative-Energy/Biofuels/Ethanol-Works-and-is-Here-to-Stay.html
Finn
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Patrick
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