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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?"
The EROI for ethanol is 1.67 to 1 while the EROI for biodiesel is 3.2 to 1. That is, both have a positive energy balance. But that still doesn't change the fact that corn and soy are crummy energy crops. It just so happens that they have huge agribusiness lobbies behind them. Of course, trading ExxonMobil and Chevron for ADM and Monsanto isn't a big improvement.
That having been said, ethanol and biodiesel don't have to come from these feedstocks. The folks at SUNY ESF have figured out how extract simple carbs from cellulose for fermentation using only heat and pressure with only water as a solvent. And then you have the enzyme approach the Iogen folks in Canada are pushing. Likewise, the algae biodiesel folks are really close to turning the corner.
My point? Just because corn and soy based biofuels aren't a magic bullet doesn't mean that liquid biofuels don't have an important place in our energy policy.
Disclaimer: I drive a 2003 VW TDI that gets 46mpg lifetime (paper log, not dash readout). By using the B20 pump near my house, I can go 57.5 miles for every gallon of petrodiesel consumed.
Very true. There are three solutions to this problem.
The first is a fuel stabilizer added to the fuel. This can be a toxic solution, but is not necessarily. One possibility is (as you say) to thin it with petrodiesel. Another is to thin it with alcohol, which as we know is already known to be run in diesel engines with only minor additive and modifications. A modern TDI diesel with high compression (One report I read featured vehicles running at 23:1 compression pre-turbocharging, which is fairly high except that some of your old school mercedes diesels are 22:1 anyway) but I'm not sure if an additional additive would be necessary to prevent the alcohol and biodiesel from interacting somehow.
The second is some sort of heating mechanism. For instance, a small, electrically-heated fuel reservoir could provide enough fuel to start the vehicle, and operating heat could be used to heat the fuel tank. This does add some weight and complexity but it could be a working solution. This could even be a subreservoir inside the fuel tank, that the driver is not necessarily even aware of.
The third solution is basically just a modification of the second, in which we have a completely separate fuel system. We fill this with petrodiesel and start up on it. Even petrodiesel requires heating at very low temperatures, of course, but we can use an additive with this fuel, and not feel too bad about it almost regardless of what that additive is, because we're only using it to come up to temperature.
I still believe that butanol has the most promise, however. To quote from butanol.com (a business, mind you):
The primary reason is that it's a direct replacement for gasoline, and even at current prices it's not dramatically more expensive than gasoline. Most butanol is currently made from petro sources, but (again, as per the front page of butanol.com) "The historical ABE fermentation technology produces a variety of fermentation products. The ABE process uses bacteria to produce Acetone Butanol and Ethanol. This fermentation process yielded a 6:3:1 ratio of Butanol, Acetone and Ethanol".
Thus the biggest problem with this process is "what do we do with the acetone"? :)
(The ABE process was first used to make chemicals for TNT.)
The best part is that the process works on any biological material, the only thing that changes (based on how tightly the constituent parts are bound to each other) is how long it takes to break down. All of our organic waste could simply be ground up into mush (whatever isn't already) and fed into reactors for this system.
Well, actually, the best part is that it's energy-dense, cleaner than gasoline, and works in gasoline vehicles without modification.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"