|Quoting tdscanuck (Reply 2):|
That must be "greener" if they're only considering the airplane side of the cycle...by the time you roll in the energy and emissions to grow/feed/slaughter/process/ship the animal in the first place, I think you'll fall off an environmental cliff.
It can't possibly be more efficient to turn corn into beef into biofuel that it is to turn corn straight into biofuel, can it?
All it takes to turn corn into cattle is to dry it, crack it into coarse meal, and put it in a trough where the cows can reach it.
Turning corn into ethanol requires drying it, cracking it into coarse meal, putting it into a big boiler, adding water and yeast, heating it up, and then distilling the alcohol vapors that are produced by the yeast consuming the sugars in the corn. This requires a lot of investment, both to raise the massive additional amounts of corn needed plus to convert said corn into a usable fuel via distillation which isn't a particularly efficient process in itself, especially not with corn because of it's relatively low sugar content. Sugar cane is vastly better in this respect, but it doesn't grow well enough in most of the US to be commercially viable.
Animal fat, on the other hand, is a waste by-product of the already existing meat packing industry. While I'm sure that there would be a tipping point at which cattle would be raised both for lean table meat and
for fat, it would take a while to reach that point. Even at the aforementioned tipping point there's an easy solution available: Farmers could simply raise different breeds of cattle. Black Angus is the current preferred breed because they tend to be very lean, as in their percentage of body fat at slaughter is quite low, but other breeds such as Polled Herefords have much higher body fat percentages and are equally, if not more, hardy and easy to raise.
[Edited 2011-04-27 08:20:25]