[Niagara]

Aaron, I LOVE your avatar. LOL!

So I guess if lorenzo suddenly sees his router do a quick jump he should duck!

[lorenzo]

$this->bbcode_second_pass_quote('pstarr', 'L')orenzo you are a piece of work. You ripped into good reputable scientists Pimentel and Patzek, you ignore my comments and responses, and know you want to have a gentlemanly discussion. You remember that avocado you used to display on your avatar? Well you can shove it right back up there where it used to be.

[davep]

$this->bbcode_second_pass_quote('lorenzo', '')$this->bbcode_second_pass_quote('pstarr', 'L')orenzo you are a piece of work. You ripped into good reputable scientists Pimentel and Patzek, you ignore my comments and responses, and know you want to have a gentlemanly discussion. You remember that avocado you used to display on your avatar? Well you can shove it right back up there where it used to be.

[gampy]

Sorry to interject here, I am not too savvy when it comes to the biofuel debate, or what place biofuels should take in our economies going forward.

But I have a kind of dumb question. Why are people trying to convert cellulosic material into sugars, when they could just grow sugar cane?

Or corn?

Or oilseed?

It seems to me that even with less actual biomass to work with, corn, sugar cane, or oilseeds would be the most economic way to get simple carbohydrate from the sun's energy.

Are they working on ways to bioengineer plants that produce the maximum amount of carbohydrates?

[yesplease]

$this->bbcode_second_pass_quote('Heineken', 'Y')ou remind me of Hitler---confidently making all sorts of ignorant observations about a country he never visited.

[davep]

$this->bbcode_second_pass_quote('gampy', 'S')orry to interject here, I am not too savvy when it comes to the biofuel debate, or what place biofuels should take in our economies going forward.

But I have a kind of dumb question. Why are people trying to convert cellulosic material into sugars, when they could just grow sugar cane?

Or corn?

Or oilseed?

It seems to me that even with less actual biomass to work with, corn, sugar cane, or oilseeds would be the most economic way to get simple carbohydrate from the sun's energy.

Are they working on ways to bioengineer plants that produce the maximum amount of carbohydrates?

[yesplease]

$this->bbcode_second_pass_quote('gampy', 'S')orry to interject here, I am not too savvy when it comes to the biofuel debate, or what place biofuels should take in our economies going forward.

But I have a kind of dumb question. Why are people trying to convert cellulosic material into sugars, when they could just grow sugar cane?

Or corn?

Or oilseed?

[Ludi]

With greater production per acre, how will you keep from depleting the soil?

[davep]

$this->bbcode_second_pass_quote('Ludi', 'W')ith greater production per acre, how will you keep from depleting the soil?

[davep]

$this->bbcode_second_pass_quote('pstarr', '')$this->bbcode_second_pass_quote('davep', 's')ay he is the only one to properly factor in the costs of the machinery etc. Even if we accepted his highly dubious evaluation for the energy required in the machinery, it would never make up the shortfall relative to other studies. In other words, even if we added his machinery costs to other studies, they would not achieve the same energy deficit that Pimentel arrives at. This indicates that he vastly overinflates other aspects of the energy requirements as well.

[Ludi]

Do the equations take into account the cost of returning the nutrients to the soil?

[gampy]

[quote="davep"]
The yield could be far higher per acre using cellulose. Oilseed won't get you ethanol btw, and generally biodiesel yields are even lower than starch/sugar-based ethanol yields.[/quote="davep"]

Yeah, that's my question, though...could is different than can.

I understand that it requires a lot of plant to produce fruit, and that it takes up a lot of land and nitrogen to produce sugar cane or corn. The simple carbohydrate is at the top of this energy pyramid, with the sun, atmospheric CO2, and nitrogen, and phosphorus at the bottom.

Hence the idea to unlock the carbon in the cellulose. But is it feasible in the long run? Anyway to get that carbohydrate without wasting it on things like bark, roots, leaves?

I dunno, cellulosic ethanol seems to be an attempt at alchemy.

Maybe they should focus their efforts on another type of organism than yeast to get the alcohol. Kind of what the bovine stomach does.

I dunno, just thinking out loud really. Thanks for the reply.

[davep]

$this->bbcode_second_pass_quote('Ludi', 'D')o the equations take into account the cost of returning the nutrients to the soil?

[Ludi]

I'm just not so convinced of the net energy benefit. It takes a great deal of work to move materials around, even in a small space. Hence the benefit of using animals, as they move themselves around, rather than vehicles. I'm just not yet convinced of the net energy benefit even of farm-scale production of liquid fuels. And I'm less convinced of their sustainability, given how difficult it is to preserve nutrients and especially humus in soils.


Call me still sceptical.

[davep]

$this->bbcode_second_pass_quote('gampy', 'Y')eah, that's my question, though...could is different than can.

[Ludi]

Won't cattails require special harvesting equipment? Granted they are a wonderful plant, but, tend to grow in places it will be difficult to drive a tractor....

[davep]

$this->bbcode_second_pass_quote('Ludi', 'I')'m just not so convinced of the net energy benefit. It takes a great deal of work to move materials around, even in a small space. Hence the benefit of using animals, as they move themselves around, rather than vehicles. I'm just not yet convinced of the net energy benefit even of farm-scale production of liquid fuels. And I'm less convinced of their sustainability, given how difficult it is to preserve nutrients and especially humus in soils.


Call me still sceptical.