On Feb 29, 8:04*pm, James Arthur wrote:
On Feb 28, 6:17 pm, Bill Bowden wrote:
On Feb 28, 6:15 pm, Bill Bowden wrote:
On Feb 28, 3:22 pm, James Arthur wrote:
On Feb 28, 1:48 pm, Bill Bowden wrote:
On Feb 27, 3:25 pm, James Arthur wrote:
[...]
The problem not previously considered is that any food not grown here
has to be replaced. *That means it has to be grown somewhere else,
generally under more primitive conditions (e.g. slash & burn (shudder)
or just otherwise less efficiently).
Since the planting-for-biofuel barely yields more than it consumes in
tractor fuel, etc., to start with, any overall loss in efficiency
results in net increased emissions. *So say the paper's authors,
anyhow.
Cheers,
James Arthur
What about using kelp (seaweed) for bio-fuel? The ocean is cheap real
estate and you don't have irrigation problems, mostly just transport
problems. All you have to do is harvest the kelp and turn it into
methane gas.
-Bill
Hi Bill !
1. Trashes marine habitat
2. Seaweed *is* food. *Good, too.
3. Can't speak to the energy content or growth rate, but it's
underwater, gets a lot less sun, so I'd not expect these to be
attractive.
4. Is it easily fermented to methane? *Most things aren't.
Hey, here's an idea--why not just get *smaller* cars, and drive them
*less!* *That works with zero technical risk, current technology,
saves money and saves the planet. *;-)
Cheers,
James- Hide quoted text -
- Show quoted text -
The Japaneese are working on the problem. Apparently, they can get
about 20 milliliters of gas from a ton of seeweed.
Here's a link:
http://web-japan.org/trends/science/sci060824.html
As for smaller cars, we could just ride motorcycles that get 100 MPG.
But I was thinking the other day, it would be nice if the busses ran
every 10 minutes along all the major roads. Probably reduce the
traffic 80 percent, and we can always use a car if there's a lot to
carry, or in a hurry, or afraid of motorcycles.
-Bill- Hide quoted text -
- Show quoted text -
Opps, that should have been Kiloliters.
-Bill
Thanks for the link. *I'm skeptical, for the reasons mentioned. *This
quote also raises my eyebrows:
* "In the tests to date, one ton of seaweed has been processed per
day, allowing the collection
* *of 20 kiloliters of methane gas. In order to boost efficiency, this
is blended with natural gas
* *and converted into 10 kilowatts of electricity per hour."
How much natural gas is added? *What's the blend?
If we take the entire 10kWhr as due to the seaweed, that's $1.40 worth
of electricity per ton. *Seems like a pretty low yield, and one
wonders whether more than that was spent processing the stuff.
Grinding up, pumping, collecting...
Alas, there are no easy answers.
Cheers,
James- Hide quoted text -
- Show quoted text -
Not sure if these numbers are right, but from this website it looks
like giant kelp is worth 5K to 8K BTU per pound, or maybe 2KwH which
would be 28 cents. So, a ton of seeweed would be worth 2000 * 0.28 =
$560 ???
http://www.osti.gov/energycitations/...sti_id=6868993
"Examples of biomass that may prove to be optimum crops include land
crops of Sudangrass, napiergrass, sorghum, sugarcane, and the
unicellular algae Chlorella and Scenedesmus, and seawater crops of
Macrocystis pyrifera (giant kelp).^Several of these crops could yield
20 to 30 tons of dry organic matter/acre/y, some others up to 60 tons/
acre/y.^These crops are estimated to range in fuel value from 5000 to
8000 Btu/dry lb "
-Bill