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Vinod Khosla Talks Ethanol
IamTheRealMike writes "Vinod Khosla, venture capitalist and co-founder of Sun, has a new obsession these days. Ethanol is the fuel touted by many as an alternative to dwindling oil stocks, but is it all it's cracked up to be? Whilst Khosla is an avid supporter of ethanol as an alternative fuel (video link) his optimistic views have been rigourously challenged by Robert Rapier, an oil industry insider who is also engaged in a quest to discover alternatives. Recently the two debated via phone the merits of an ethanol economy, and Mr Rapier has now written up a report of the debate. What will be powering our cars 10 years from now?"
And lastly, most ethanol is produced by corn in an extremely wasteful process that requires an enormous amount of energy which cuts in on its overall efficiency.
Worldwide, most ethanol is actually produced by sugarcane. The corn thing is a US-specific thing based largely on the economics of government subsidies. Per-acre ethanol yields for sugar cane (Brazil and India) and sugar beets (France) are reportedly double that of corn in the US.
There are 0x40000000 types of people: those who understand 32-bit IEEE 754 floating point, and those who don't.
If you want to get energy independent quickly and reliably, this is the answer. If you want to create a lot of sloppy hype and get people to spend stupid amounts of money on shoddy technology that's going to be under development for decades, then micro-pile atomic reactors are a better bet than Ethanol.
Ethanol is not perfect. It's only being hyped because GM et al are selling E85 engines. They aren't selling Diesel engines because they don't know how to make small ones. VW, BMW, Peugot, Reanault, and Mercedes all have decades of experience with small block engines. E85 is being pushed because if they pushed Diesel engines what little is left of the big three would collapse over night. Personally, I prefer Diesel. It isn't going to explode.
Whenever someone pushes ethanol that hard, they're really pushing for corn subsidies. If he starts talking wood chips or sawgrass, that might be something worthwhile, but as it stands it's just another pork project.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
Actually, Brazil (which encompasses much of the Amazon basin), manages a great degree of self-sufficiency for vehicle fuel using ethanol, and they haven't had to use 97% of their land to do it. A large part of their success stems from the fact that they use sugar cane, not corn, to make ethanol, which I read is far more efficient in terms of both land use and energy required for conversion than corn.
Corn is not a great source for producing ethanol, but the reason it is the highly touted source in the US is because there is already a massive and highly subsidized infrastruture for growing corn in the US, and corn farmers have a powerful lobby. Ethanol from corn may well not be a long-term energy solution, but that doesn't mean that ethanol form other sources can't be viable, and Brazil has shown that.
Momentarily, the need for the construction of new light will no longer exist.
Now the next useless fact: Gasoline does not explode in the engine either. If it does it is called detonation or knock and will eventually wreck the engine. Although it burns much faster than Diesel (hence gasoline engines running at much higher rpm) it is flame not explosion.
Finally, (and this perhaps needs to be posted all over this thread because a lot of people do not understand it) ethanol has a higher octane rating than standard gasolines and has more charge cooling. As a result it can be made to burn more efficiently in an engine because the compression ratio can be raised. A modified Atkinson cycle (compression ratio lower than expansion ratio) ethanol engine can have quite reasonable efficiency, not as good as Diesel but better than lead free gasoline. And it should lose less power in the catalytic converter.
Although the fuel tank needs to be bigger than that for a gasoline engine, because of the lower energy density, this has little to do with cost per Joule which is the important thing. It does not matter if I need 6l/100Km versus the 5 used by my Diesel engine if the cost per Joule is comparable.
And finally finally, ethanol fires can be put out with water and reduced in intensity very quickly with water mist. It is comparable in safety to Diesel, as is recognised by the experts - marine safety agencies. The main problem with ethanol is that it doesn't really mix that well with gasoline, but this is the only way to introduce it gradually.
Pining for the fjords
Actually, it's not nothing. They are warning boaters against using ethanol, becuase it dissolves fiberglass, which boat fuel tanks are made from. The interior of the fuel tank dissolves and gums up the engine, causing really bad things to happen.
In regular engines, there is evidence (informal, no scientific studies to date) that ethanol produces a buildup on parts exposed to combustion much more rapidly than regular refined fuel, which, in your case, would cause your spark plugs to need replacement sooner (you might pull them and check, it's pretty easy, really). I don't know of the effects on engine horsepower and torque, but it shouldn't be a drastic change from gasoline.
just an analog boy living in a digital age.