Posted on 02/12/2004 4:53:51 PM PST by wallcrawlr
Neither increases in government subsidies to corn-based ethanol fuel nor hikes in the price of petroleum can overcome what one Cornell agricultural scientist calls a fundamental input-yield problem: It takes more energy to make ethanol from grain than the combustion of ethanol produces.
At a time when ethanol-gasoline mixtures (gasohol) are touted as the American answer to fossil fuel shortages by corn producers, food processors and some lawmakers, Cornell's David Pimentel takes a longer range view.
"Abusing our precious croplands to grow corn for an energy-inefficient process that yields low-grade automobile fuel amounts to unsustainable, subsidized food burning," said the Cornell professor in the College of Agriculture and Life Sciences. Pimentel, who chaired a U.S. Department of Energy panel that investigated the energetics, economics and environmental aspects of ethanol production several years ago, subsequently conducted a detailed analysis of the corn-to-car fuel process. His findings will be published next month in the forthcoming Encyclopedia of Physical Sciences and Technology.
Among his findings:
Nickels and dimes aside, some drivers still would rather see their cars fueled by farms in the Midwest than by oil wells in the Middle East, Pimentel acknowledges, so he calculated the amount of corn needed to power an automobile:
Unless there have been some really dramatic developments in physics lately that I missed, it also takes more energy to produce electricity at the local power plant than is generated as electricity and than is recovered in it's final application.
And why does ethanol have to be produced from corn only? Seems there are other crops available, and plenty of fermentable sugars are lost to waste products in the agricultural industry overall.
The whole thing seems to be centered around the use of highly efficient fuel cells for electricity production anyway, not highly inefficient IC engines using alternatives fuels. The fuel cell does not need to be run on ethanol, or methanol, or natural gas or gasoline (all of which could power it), it only needs a hydrogen input of some kind. Gaseous hydrogen is not necessarily the best fuel source for practical use at this time. The electric car, ignoring the power source, is far superior in every way to an IC powered car and would have a much lower overall cost to operate for it's lifetime than an equivalent IC powered car. The electric car also reduces the pollution of the vehicle to almost zero (which leads to the source of the fuel/power considerations).
Batteries have been the major stumbling blocks for electric vehicles since the first Baker rolled off the assembly line in 1908: Batteries are just too heavy, expensive, low powered, and take too long to recharge: Even the most advanced batteries.
The fuel cell seems to be the most promising technology on the horizon that offers the possibility of taking full advantage of the electric motor for vehicle design, and research into hydrogen sources to power electric vehicles is, IMO, a very valid pursuit, worthy of both public and private funding. I don't understand the almost blind hatred for hydrogen fuel cell technology that some people seem to have.
I think the wording in the statement is a bit misleading. If I understand it right, the device can get hydrogen from an ethanol/water mixture and doesn't require anhydrous ethanol other processes would. The water is basically being ignored, not used. The result is a whole lot less (energy consuming) processing of the ethanol than would otherwise be required, and no problem with trying to keep it anhydrous during storage and use.
I guess I miss how this is relevant to hydrogen as a fuel. Are you equating hydrogen to electricity?
And why does ethanol have to be produced from corn only?
Because it's the cheapest.
The electric car, ignoring the power source, is far superior in every way to an IC powered car and would have a much lower overall cost to operate for it's lifetime than an equivalent IC powered car.
You can't ignore the power source since the vehicle functions as a system. I presume that you have some sort of data to back up this literally fantastic statement. I would like a link, since it goes totally against everything that's happened in the electric car industry to date. The batteries alone which have to be replaced quite frequently cost as much as most small IC cars.
, a very valid pursuit, worthy of both public and private funding. I don't understand the almost blind hatred for hydrogen fuel cell technology that some people seem to have.
They don't hate it they're just educated enough to realize that the first and second laws of thermodynamics prove it's a total waste of resources anad it will always be a total waste of resources. Second law says that it will always take more fossil fuel to run a H2 car than you would use burning the fossil fuel directly. H2 and ethanol are just boondogles for funneling taxpayer money into unworthy corporate pockets. They are in effect perpetual motion scams. ADM's greedy grasping tentacles reach into the pockets of every taxpayer in the USA and provide no benefit to anyone except the stockholders and employees of ADM. (oh and of course to corrupt politicians like Bob Dole who front for them)
Indirectly. The hydrogen involved here would be used to produce electricity at the point of use (vehicles, i.e.).
The batteries alone which have to be replaced quite frequently cost as much as most small IC cars.
I guess you missed the paragraph where I said "Batteries have been the major stumbling blocks for electric vehicles since the first Baker rolled off the assembly line in 1908: Batteries are just too heavy, expensive, low powered, and take too long to recharge: Even the most advanced batteries." ? That's why I went on to the use of fuel cells. Batteries are just no good for vehicles (submarines maybe, but not vehicles). BTW, there is also the consideration of all the total energy used to produce and operate the two types of vehicles, not just the micro scale look at the final energy use in driving the finished vehicles around town.
Electrics are far simpler, have only a fraction of the parts, weigh significantly less (making them more energy efficient and tearing up roads less) and last substantially longer without repair or maintenance (how often do you need to change the oil in your car, or lawnmower, and have it maintained vs how often do you even bother to think about that motor in your furnace blower as a practical example). Since fuel cells aren't being used currently, the overall evaluation of the energy used in it's production and lifespan is not avaialble to discuss.
Second law says that it will always take more fossil fuel to run a H2 car than you would use burning the fossil fuel directly.
I don't consider corn, waste straw, other agricultural and farm waste to be fossil fuels. Fossil fuels are only being considered in my statement in their possible use in fuel cells (natural gas, gasoline) where they would be used about three or four times as efficiently as in IC engines. And I'm no scientist, but I've never heard of fossil fuels being mentioned in the second law. I was under impression that the second law was the one about everything moving to a lower, not higher, state. Are fossil fuels somehow not subject to the same laws, depending on how they are being used, as everything else and therefore specifically mentioned? Do you also oppose the conversion of fossil fuels into electricity for the same reasons?
I have a feeling you are right. I also have a feeling the he thinks that farmers are so stupid, and American industry so regressive, that farm vehicles and equipment would continue running on fossil fuels long after everything else was converted to some form of ethanol use.
No wonder our Nation is starting to fall behind the rest of the world with people like this teaching our young, and supposedly educated people not seeing through him.
Nope I read it. I guess you missed where I said You can't ignore the power source since the vehicle functions as a system.
Electrics ... weigh significantly less (making them more energy efficient and tearing up roads less)
Absolutely false. Electric motors are much heavier per hp produced than IC motors. I have a 7.5 hp electric motor 3ph that I had to replace a bearing on. The motor was nearly 200 lb. I helped a friend take his lawn tractor motor out (8hp I think) and I could lift it without much trouble, but I had to have help with the electric motor.
I don't consider corn, waste straw, other agricultural and farm waste to be fossil fuels.
These things require fossil fuel to produce so they are just another unnecessary step on the way from fossil fuel to work done (transportation)
And I'm no scientist, but I've never heard of fossil fuels being mentioned in the second law.
2nd law applies to everything. It boils down that every time you convert from one form of energy to another you lose some energy to entropy. 1000 kcal of diesel converts to less than 1000 kcal of ethanol even with the sunlight adding energy to the system. Say 800 kcal. The 800 will necessarily convert to less than 800 of H2 say 80% efficient so you're down to 640 kcal. The fuel cell will convert it to electricity at say at 80% efficiency. Now you're down to 512 kcal. Your electricity won't go 100% into work done by the motor, let's us 80% again even though I'm fairly certain that the efficiency isn't this high. now you're down to 410 kcal of useful work. It's nothing new. This concept was explored in the '70s and even published in Science magazine. It's just that political hog feeding has totally distorted the reality on this one. Sort of like global warming. junk science, but lots of plundered taxpayer money for the hogs.
How much would such a unit cost? It seems to me that having a ready fuel supply would be worth it's weight in gold.
I think your idea is ultimate times more worthy than just trashing the plant.
Teasing aside, it isn't the abundance that's the issue but the availability. Aluminum is the most abundant metal in the Earth's crust; but, it's always found as bauxite. Until a process was developed to efficiently extract aluminum from bauxite, aluminum was thought of as a precious metal.
Just as aluminum nuggets were a rarity, so to is pure hydrogen. Until now, pure hydrogen was usually obtained by dumping energy into water. Thus the hydrogen wasn't so much an energy source as an inefficient energy storage device and all the talk of hydrogen fueled cars was pie-in-the-sky. An efficient, catalytic process changes the game.
I've been fascinated by the idea of hydrogen powered vehicles for a while, though not for the same reasons the Greenies are. In fact, they'd scream in horror at my reasoning. I hunt. Because of that, I need a dreaded SUV. (There's something about getting stuck out in the boonies that really ruins a weekend!) A hydrogen powered SUV would be a very interesting thing.
Hydrogen is most efficiently used to drive fuel cells to produce electricity. A hydrogen fueled SUV would thus have electric motors on all four wheels. Why would this interest me? Because such a vehicle would be stealthy. It wouldn't produce stinky exhaust. It would be quiet. In other words, I could sneak into hunting areas without alerting every animal for ten miles. On top of that, if I ran out of fuel, solar cells and a battery could drive the vehicle in a pinch.
And to top it all off, such a "green SUV" already exists! The DoD has been experimenting with just such a "stealth" vehicle. Just imagine the horrified looks the tree and bunny huggers (though not psycho bunny huggers, of course) would have at a hydrogen powered SUV developed partly by the Bush military as it hauled Bambi's dressed carcass out of the woods. It brings a tear to my eye just thinking about it.
Dumb dumb dumb. Ethanol comes from corn grown with huge petroleum inputs for machinery (ie tractors) and fertilizer.
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