10-01-2008, 04:16 PM
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#11 (permalink)
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No it doesnt because because again it is an energy analysis.
If a farm uses 1000 gal of gasoline (or energy equivalent other processes) to produce ethanol, it doesnt produce 1300 gal of ethanol, it produces 1300x1.25=1625 gal of ethanol. What we are doing is taking a concentrated energy source and turning it into a lower concentrated energy source but more of it (as well as running it through the 1.3 energy multiplier).
If you are having a hard time wrapping your head around it then think of ethanol as gasoline with 25% water added so they now have the same volume and energy content. And since water is practically free there is no cost associated.
Last edited by Duffman; 10-01-2008 at 04:39 PM..
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10-01-2008, 04:32 PM
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#12 (permalink)
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I think that a lot of empahsis has been placed on corn was to get the infrastructure off the ground. I am not a Chem Eng. but I would assume that converting a plant that makes ethanol from corn to a plant that makes ethanol from other sources is not a huge change or upgrade. I think the U.S. govt was/is trying to make conditions that when we figure out better sources for ethanol, the plants will be in place and the cars will be on the road already so the transition is a 1 year time frame instead of 10 years.
This is really why H2 cars will not take off, there is no infrastructure in place for people to buy the cars and nobody wants to build the infrastructure because there are no cars to use the fuel.
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10-01-2008, 04:51 PM
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#13 (permalink)
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So; Just because the first tax credits were for inferior technology, then it is all bad?
I don't entirely believe these studies (I'd suspect that they are funded in part by oil). I do believe that you can make ethanol from corn using only farm energy sources just like Henry Ford intended the Mode T to be run off of in the first place.
Now I need to go dig some sources . . . .
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10-01-2008, 05:07 PM
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#14 (permalink)
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10-01-2008, 05:59 PM
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#15 (permalink)
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Interesting discussion. I read lots of news about new tech issues, and one thing that is very interesting is using algae grown in vertical 'beds' (for lack of a better term). This process produces vastly more vegetable matter per acre than any other agricultural method. In addition, algae is very high in vegetable oil, and after extracting the oil, the remains can be fermented into ethanol (or other alcohols, with gene modified bacteria).
Vertigro video
One other thing- ethanol isn't the best alcohol by any means. Butanol has higher energy density and lower solubility with water.
If the processes to get alternative fuels can be made profitable, they will continue to proliferate.
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10-01-2008, 06:33 PM
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#16 (permalink)
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Quote:
Originally Posted by Duffman
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Thank you sir!
Just to clarify; I do not think that Ethanol is gods gift to man, just one of many small changes that can add up to a big change.
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10-01-2008, 10:49 PM
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#17 (permalink)
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Quote:
Originally Posted by Duffman
No it doesnt because because again it is an energy analysis.
If a farm uses 1000 gal of gasoline (or energy equivalent other processes) to produce ethanol, it doesnt produce 1300 gal of ethanol, it produces 1300x1.25=1625 gal of ethanol. What we are doing is taking a concentrated energy source and turning it into a lower concentrated energy source but more of it (as well as running it through the 1.3 energy multiplier).
If you are having a hard time wrapping your head around it then think of ethanol as gasoline with 25% water added so they now have the same volume and energy content. And since water is practically free there is no cost associated.
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Actually, the relation you show here for gasoline to ethanol is impossible. We dont make ethanol from gasoline...
What I am trying to get across here is that in the making of ethanol, from step one, we use gasoline in the tractors that are used to plant the corn, then spray the corn with a round of herbacide (more fuel used) a round of pestacide (again, more fuel used) and sometimes another round of the same if the bugs are really bad. Then harvesting costs, transportation, then the fuel and electricity costs to process the feedstock corn into ethanol. One small side benefit I hear is that the corn byproduct can be dried and ground into feed for the cattle and still be useful. Processing the sawgrass is not as fuel intensive like I mentioned before.
Oh, and the bit about algae I had forgotten about, thanks for the reminder!
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10-02-2008, 01:04 AM
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#18 (permalink)
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Quote:
Originally Posted by Duffman
If a farm uses 1000 gal of gasoline (or energy equivalent other processes) to produce ethanol, it doesnt produce 1300 gal of ethanol, it produces 1300x1.25=1625 gal of ethanol. What we are doing is taking a concentrated energy source and turning it into a lower concentrated energy source but more of it (as well as running it through the 1.3 energy multiplier).
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Suppose we think about that a minute. First, using current tech you put in 1000 gallons of gas, and get out the equivalent of 1300 gallons. That seems like a net gain to me. Now if you only got 999 gallons out, and had no prospect of improvement, you'd have a good argument that the whole idea is a boondoggle.
Now remember that there are two things you want out of this process: 1) To get energy out of it; and 2) To get than energy in a concentrated liquid form that can run current engines. So thinking a bit, why does the energy in all have to be from gasoline? As mentioned, some/all of the processing could be done with waste heat from power plants. Or if you have farms that use center-pivot irrigation, it'd be fairly easy to adapt that to run electric tractors, harvesters, etc, with the electricity coming either from your farm wind turbines, or your friendly local nuclear plant.
Then there are probably better sources of feedstock than corn, or even switch/sawgrass. Using mixed native prairie plants produces more net energy, and wouldn't require lots of cultivation or chemicals: Prairie grasses emerge as rich energy source : UMNews : University of Minnesota And if the bottom falls out of the biofuel market, you could always graze a few buffalo :-)
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10-02-2008, 02:11 PM
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#19 (permalink)
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Hiya,
Corn is very fertilizer intensive (it is the "SUV" of farm crops!). And rather than pay for (expensive) crop insurance, many farmers use 2X the fertilizer recommended -- so, something like 200 pounds per acre?
Fertilizer is made from natural gas.
Do the GMF corn seeds take energy to grow? Probably, and most/all corn is hybrid anyway, so the farmer has to buy the seed, and the seed represents a fair bit of energy.
The chemical insecticides also come from petroleum, IIANM.
The tractor burns diesel usually, and it has to be used to prepare the soil (plow and harrow), and then to plant the seeds, and then again to spray insecticides (a couple of times?), and then again to harvest the corn. That is (at least) six passes around the field by the tractor.
If irrigation is needed, this takes electricity or some sort of pumps.
The corn then needs to be stored, transported, and then processed into methanol -- which takes more energy. Only the kernels are used, and I guess that the stalks are used for silage, usually?
Switchgrass is a native plant, and it doesn't need very much energy investment. Jatophra lives for about 50 years, and grows in marginal land that can't be farmed, and is drought resistant.
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10-02-2008, 03:34 PM
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#20 (permalink)
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Quote:
Originally Posted by NeilBlanchard
Corn is very fertilizer intensive (it is the "SUV" of farm crops!). And rather than pay for (expensive) crop insurance, many farmers use 2X the fertilizer recommended -- so, something like 200 pounds per acre?
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That's a business decision. If the price of artificial fertilizers &c go up due to rising oil prices, the farmers will look at ways to use less. Consider recent interest in no-till farming methods, for instance.
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Fertilizer is made from natural gas.
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Not necessarily. Mine's made by the neighbors' horses :-)
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Do the GMF corn seeds take energy to grow?
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No more than any other seed. That's really the whole point of plants, you know. They grow by capturing energy from sunlight.
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The tractor burns diesel usually, and it has to be used to prepare the soil (plow and harrow)...
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Again, these are business decisions. Diesel fuel, pesticides, and artifical fertilizers have been relatively cheap, as a consequence of cheap oil, and that economic fact has shaped the way farmers do things. But those technques aren't laws of nature: change the underlying economics (expensive oil), and the methods will change.
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Switchgrass is a native plant, and it doesn't need very much energy investment.
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Corn is/was a native plant, too, before the Olmec/Maya/Aztec biotechnologists started tinkering with its genome. So what might happen with your native switchgrass or jatophra, once people start doing a bit of selective breeding? Then you have the whole spectrum of problems that arise when you try to grow monocultures of anything...
Once you actually start thinking about some of this stuff, it's nowhere near as clear-cut as some would like to think, but OTOH there are a lot more possibilities.
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