Quote:The jatropha bush seems an unlikely prize in the hunt for alternative energy, being an ugly, fast-growing and poisonous weed. Hitherto, its use to humanity has principally been as a remedy for constipation. Very soon, however, it may be powering your car.
Almost overnight, the unloved Jatropha curcushas become an agricultural and economic celebrity, with the discovery that it may be the ideal biofuel crop, an alternative to fossil fuels for a world dangerously dependent on oil supplies and deeply alarmed by the effects of global warming.
The hardy jatropha, resilient to pests and resistant to drought, produces seeds with up to 40 per cent oil content. When the seeds are crushed, the resulting jatropha oil can be burnt in a standard diesel car, while the residue can also be processed into biomass to power electricity plants.
It might be intersting to see an analysis of combustion products for coal, petroleum, and jatropha (per BTU produced)...
...as well as the source of this blurb...
Quote:Biodiesel reduces carbon dioxide emissions by nearly 80 per cent compared with petroleum diesel, according to the US Energy Department.
Perhaps the CO2 emissions are replaced by CO & NOx emissions...?
Is it possible for a plant to absorb more CO2 than it emits when burned...? What happens to the carbon absorbed but not emitted...?
Now if we could only do the same with kudzu.
Ahriman Wrote:Now if we could only do the same with kudzu.
Indeed...!
Kudzu is edible (not poisonous), but doesn't bear berries...
...same CO2 contribution however...
Kudzu produces purplish black berries.
I've been to a few different farmer's markets where they sell kudzu jelly made out the blossoms. I've never had it myself but I'm told it has a flavor that's vaguely similar to grapes. Any here ever tried it?
Quote:Biodiesel reduces carbon dioxide emissions by nearly 80 per cent compared with petroleum diesel, according to the US Energy Department.
Isn't it wonderful that Chemistry and Physics can be changed by a mere political pronouncement. I would love to see their heat and mass balance on that one.
oldpack69 Wrote:Quote:Biodiesel reduces carbon dioxide emissions by nearly 80 per cent compared with petroleum diesel, according to the US Energy Department.
Isn't it wonderful that Chemistry and Physics can be changed by a mere political pronouncement. I would love to see their heat and mass balance on that one.
ditto
The oil is great, but the yield hasn't turned out to be as promised so far.
Turn kudzu into an alternative energy source and the South will rise again!
I went to the homebrew store last weekend, and got into a discussion about distilling moonshine and biofuel. The guy who ran the shop has a 300-gallon setup that 5 or 6 people use. They go around to Chinese restaurants and collect their used oil. It's something that only benefits you if you're committed to the labor involved.
He said once they got the used oil from a donut place, and it smelled heavenly. But most of the time collecting is a dirty, disgusting process.
BornAJacket Wrote:oldpack69 Wrote:Quote:Biodiesel reduces carbon dioxide emissions by nearly 80 per cent compared with petroleum diesel, according to the US Energy Department.
Isn't it wonderful that Chemistry and Physics can be changed by a mere political pronouncement. I would love to see their heat and mass balance on that one.
ditto
If you add in the Carbon offsets for growing them, they do.
But I agree that just the burning them should produce approximately the same amount of CO2/BTU.
GH
Carbon chemistry has not changed. The carbon life cycle hasn't changed.
It doesn't matter whether the diesel came from plant seeds, turkey guts, plant fossil liquified coal, plant fossil oil, it is still the same no matter what your politics say. Anything to the contrary is just total BS.
ColaJacket Wrote:If you add in the Carbon offsets for growing them, they do.
They do what...???
What do "carbon offsets" do...?
Until you can answer those questions, whatever else you have to say on the topic is irrelevant...
The CO2 is not replaced by CO emissions. Nitrous oxide emissions do increase with biodiesel.
I believe the carbon offsets are addressed in this link:
Quote:Burning biodiesel in a vehicle returns the carbon from the
fuel to the atmosphere as carbon dioxide. Vehicles using regular diesel and
biodiesel both emit carbon dioxide. However, the carbon from CO2 released
when burning biodiesel is recycled back into the growing plants
(at least in part), preventing accumulation in the atmosphere. Approximately 78%
of the carbon is re-cycled in this way, meaning that B100 reduces life-cycle
carbon dioxide emissions by 78% compared to petroleum diesel.
Put another way, increasing crop production the same amount for human consumption while using diesel would absorb as much CO2 as biodiesel claims to. It's an accounting trick.
oldpack69 Wrote:Carbon chemistry has not changed. The carbon life cycle hasn't changed.
It doesn't matter whether the diesel came from plant seeds, turkey guts, plant fossil liquified coal, plant fossil oil, it is still the same no matter what your politics say. Anything to the contrary is just total BS.
This is from the National Biodiesel Board
A study by the US Department of Energy has found that biodiesel production and use, in comparison to petroleum diesel, produces 78.5% less CO2 emissions. Carbon dioxide is “taken up” by the annual production of crops such as soybeans and then released when vegetable oil based biodiesel is combusted. This makes biodiesel the best technology currently available for heavy-duty diesel applications to reduce atmospheric carbon.
Link Here
Spot the Wonder Dog Wrote:oldpack69 Wrote:Carbon chemistry has not changed. The carbon life cycle hasn't changed.
It doesn't matter whether the diesel came from plant seeds, turkey guts, plant fossil liquified coal, plant fossil oil, it is still the same no matter what your politics say. Anything to the contrary is just total BS.
This is from the National Biodiesel Board
A study by the US Department of Energy has found that biodiesel production and use, in comparison to petroleum diesel, produces 78.5% less CO2 emissions. Carbon dioxide is “taken up” by the annual production of crops such as soybeans and then released when vegetable oil based biodiesel is combusted. This makes biodiesel the best technology currently available for heavy-duty diesel applications to reduce atmospheric carbon.
Link Here
Bogus Agricultural Subsidy based. If you are going to figure in the CO2 in the photosynthesis of the plants then you must also figure in the fuel and fertilizer used to the grow the crop specifically for fuel use as well as the energy used to process it into a useable form. Then you must also figure in that the biodiesel has less energy content and is therefore less effecient. That means that you burn more per mile. The net effect is that it is just as polluting as petrodiesel.
I'm normally a AGW skeptic and from what I've seen most of the biofuel plans just do not work out when looked at on a life cycle basis but I'll tip my hat to this and had not really thought about it before.
When we aquire fossil fuels deposited from plants long ago and burn them we add the carbon absorbed by those plants eons ago to the atmosphere of today. When we harvest it from plants grown this year then the yearly net atmospheric carbon gain has to approach zero. (I'm sure they get some carbon from non-atmoshperic sources)
If we can make biofuels work out so that more energy is burnt from them than it takes to make them it makes sense to go that direction in case our burning of fuels is really what is driving what little global warming has been measured. I've always said I would prefer to go towards 'green' solutions if they were economically feasible at least in the long term. If nothing else oil is going to get more and more expensive to aquire as we use up the easy to reach deposits.
Where can I buy stock in these plants that can tell where the CO2 came from...?
Link please...!!!11
:rolleyes
Quote:This is from the National Biodiesel Board
A study by the US Department of Energy has found that biodiesel production and use, in comparison to petroleum diesel, produces 78.5% less CO2 emissions. Carbon dioxide is “taken up” by the annual production of crops such as soybeans and then released when vegetable oil based biodiesel is combusted. This makes biodiesel the best technology currently available for heavy-duty diesel applications to reduce atmospheric carbon.
Come on people...!!! This is your "Big Chance" to rub your noses at "Ol' Slo"...!!!
How is 'Biodiesel" CO2 different from coal or petroleum CO2...???
---dumb guppies---
Slo,
I don't think the balances really work out in the long run but I see their point on this.
If the world currently has 10,000 units of co2 in the atmosphere and we dig up a fossile fuel and burn it generating 100 units then the atmosphere now has 10,100 units.
If instead we plant some bushes to harvest the same oil from and burn it generating 100 units of co2 those buses have to absorb about that much co2 from the atmosphere while growing. Therefore the net gain is about zero we still have 10,000 units of co2 in the atmosphere.
For that balance to work out they'll have to do some work but in theory it is an advantage. For instance the new plants have to be in addition to all the current plants in the world, it does no good to cut down rainforest to plant them. Also the energy used in the entire process for the bush, plowing field, weeding, harvesting, processing into oil, distributing the oil, etc., must be less than the energy obtained by burning or else that energy must be provded by another method that will probably involve burning fossil fuel.
WilmingtonSkip Wrote:Slo,
I don't think the balances really work out in the long run but I see their point on this.
If the world currently has 10,000 units of co2 in the atmosphere and we dig up a fossile fuel and burn it generating 100 units then the atmosphere now has 10,100 units.
...
A surprisingly thoughtful response...!
...but I think the numbers are a little off... Try this:
If the world currently has 10,000,000 units of co2 in the atmosphere and we dig up a fossile fuel and burn it generating 10 units then the atmosphere now has 10,000,010 units.
And if the original 10,000,000 units had a 0.004 deg contribution to "Greenhouse Warming" the increased warming is:
10,000,010/10,000,000 x 0.004 deg, or about 0.004 deg... *
Where is the saving...? or the benefit...? ...and how much are you willing to pay or sacrifice for it...?
* this is actually a false formula, because the more CO2 increases, the less effective it is as a "Greenhouse Warmer"...
That is, a doubling of CO2 has a MUCH less than twice the warming effect...
Like I said they got a lot of work to do if this is the best answer to the problem they're touting. I agree with you I was just tying to point out that this is about the first time I've seen anywhere close to a rational argument for biofuels.
The thing that no one has addressed is that biodiesel has less energy content.
Like about 30% less!
so you need to burn more per unit work done.
oldpack69 Wrote:The thing that no one has addressed is that biodiesel has less energy content.
Like about 30% less!
so you need to burn more per unit work done.
Biodiesel has about 2 to 3% less energy the petro diesel. 30% is not correct
Spot the Wonder Dog Wrote:oldpack69 Wrote:The thing that no one has addressed is that bio diesel has less energy content.
Like about 30% less!
so you need to burn more per unit work done.
Bio diesel has about 2 to 3% less energy the Pietro diesel. 30% is not correct
What are the relative CO2 emissions per energy unit...?
...and what is the CO2 contribution to "warming"...? (Minuscule at worst...!)
The AGW Evangelistas are essentially unarmed combatants, who just don't know when they're beat...!
If we're pushing biofuels for CO2 purposes instead of for renewability and independence from oil producing tyrannies, we've lost our collective minds and deserve what we get.
I'll repeat for the umpty-leventh time; if the church of the AGW was really as worried about the fate of the planet as they claim, instead of being worried about getting their sociopolitical agenda rammed down our throats, as has been blatantly obvious from the beginning, they'd have been pushing nuclear power and the ending of tariffs on imported ethanol for years now, and pushing it REALLY hard.
It hasn't happened, of course, and it's not going to happen, even though we could cut carbon emissions by far more than half in ten years or less if we did so, because they don't WANT their imaginary problem solved. They want to be able to blame anything and everything bad that happens in the world on AGW in every election from now to kingdom come, and actually taking positive action would take away that gravy train.