I have been interested in cellulose-based ethanol for a long time. Plenty of experiments are also in play on this side of the 49th.

I do have some concerns about the assumption that "agricultural waste" is a massive resource, freely available to be tapped, and of no other value. It is not waste that's trucked to a landfill and buried. Most "waste" is the stalks and leaves of the producing plant, chopped up and spread during harvest. Or, as straw, used as bedding for animals and then tilled back into the land. The point is, soil is a cyclical system: if you feed it, it will feed you. And if you take away a disproportionate amount of the biomass it produces, you have to supplement with fertilizer -- which currently comes from fossil fuels. A similar principle applies to "forestry waste." There is no free lunch in nature; the only free lunch we've found so far is in fossil fuels.

But back to the point: the whole concept of cellulose-derived ethanol is fascinating in a number of ways. Including, if we can make it work, the possible end of world hunger? Pure speculation; but the stuff yeast can eat is the stuff people can eat. (Just wondering.)

Has anyone worked out the math regarding cellulose-derived ethanol? That is, at projected best production, how much bio-based fuel can be produced in N.America, and how much of our arable land mass would that require. (Yeah, I know, there are big fat politics entwined in this, meaning that the numbers from any one source need to be taken with a large grain of ... ethanol.)

Enough of my rambling. What do you think?