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?

Big Business and government can't even get corn-based ethanol processed in a common-sense way, and they're already doing that!



That attitude is certifiably insane. I don't know anything about cellulose-derived alcohol, but the waste from crop-type plants is just as valuable as the sugar/starch-based alcohol that comes from it.

In a common-sense society, a crop like fodder beets could be grown on decent soil. The crop could be taken to a nearby distillery and the sugars and starch removed to make alcohol. The sugars and starches in the plants come from sunlight/photosynthesis, which is free. The 'waste product' left behind is all the protein, calcium, phosphorus, potassium, magnesium, silica, sulfur, sodium, micro-nutrients and trace minerals that were absorbed from the soil during growth.

This 'waste' can either be fed to pastured livestock and returned to the soil as manure, or returned directly to the soil and spread as fertilizer. Sending it to the landfill is just plain stupid and wasteful.

Sue

[rant ON]

My concerns are specific to the cellulostic ethanol gambit.

Most specifically, to the casual labelling (marketing?) of agricultural biomass as "waste." Waste, to the urban ear equals garbage, trash, the smelly and gross stuff that magically disappears when you put it in the bins. Gracious heavens, if you can turn "waste" into fuel for your car, to maintain your existing lifestyle, that's obviously wise; why would you hesitate?

Well, it doesn't work that way. The "waste" produced on farmers' fields needs to be incorporated back into the soil to maintain any semblance of a sustainable soil ecosystem. And even then, it's hardly enough. There is no free lunch: outputs require inputs. Otherwise, you are mining the soil.

Though I confess I haven't looked at it closely, I find it extremely hard to believe that the miracle biomass plants such as switchgrass can be harvested en masse without consequences -- or external chemical inputs. The laws of physics, and the laws of soil, altogether inconvenient, continue to apply.

-Doug, who grew up on a mixed farm and knows a little about the maintenance of soil fertility

[rant OFF]

Of course! They always have and they always will. Only within the last 60-70 years have farmers fallen for the bill of goods sold to them of being able to take without suitable return.

The soil web is life, literally. Those who think they can get around that fact are doomed to find out the hard way, and will take a lot of other people with them. TANSTAAFL applies here, as to all else.

From what I understand from the people who know this, using things like switchgrass is a way to use less desirable land for fuel so the prime land can be used for food production. You still have to feed the land and return sufficient nutrients, or even that isn't going to work.

But there seem to be a lot of people who have to learn the hard way, and the learning of it is slow in coming.

Sue

True, but you can say that about almost any resource. We exist in the billions because of fossil fuels, and those are running out. When they are rare, we will switch whole scale to 'renewable' and without petro-based fertilizers, we will deplete the soils quickly. Biomass energy only slows the process.

The root cause is simple: too many people. The solution is a bit more complex, and likely draconian.

And in a related news flash, biofuels have just been officially approved for use in civillian commercial aircraft. I'm no expert, but aviation biofuel uses different organic inputs from the various ethanol technologies, so it is a different technology track from ethanol. The inputs are also not typically food for people, unlike the current main inputs for ethanol, like corn or sugar cane.

I know that the Dept of Defense has been looking into biofuel for its military planes, but I don't know if that is still just in the experimental phase. One day, we may be sending our aircraft carriers and soldiers to novel new destinations to protect our supply of plants or algae that go into making aviation biofuel. Who knows.

However, as Byrd_Hunter points out, this promising news still doesn't get around the issue of fossil fuel-derived fertilizer to keep crops growing, but as natural gas gets permanently expensive someday, we may find a viable alternative as we are just beginning to do for transportation fuels.