:rolleyes:
Oh jeeze. Where is Anthracite when I need her?
Let me repeat (and I’ll try to stay calm): Alcohol is not a fuel. Hydrogen is not a fuel. They are classified as energy storage media or secondary energy carriers.
Fuels are substances that, when burned, release more energy than are required to produce them. In other words, more energy must be expended to produce hydrogen & methanol than what you can get out of them. This is not true for gasoline, therefore gasoline is a fuel.
Classified by whom? Alcohol and hydrogen definitely fit the dictionary definition of fuel.
What you are describing violates the laws of thermodynamics. Unless you want to qualify your use of the word “produce.”
Even if you are only counting the energy needed to refine the substances, alcohol and hydrogen are made from plants and fossil fuels, right? I find it hard to believe that the energy needed to refine them exceeds the stored energy.
Well, Crafter_Man, it doesn’t seem to me that “releasing more energy than are required to produce them” should be a necessary condition for defining “fuel”. This would imply that, for example, if I used a horrendously inefficient means of producing gasoline from crude oil, then the gasoline so produced would NOT be “fuel”, even if it were indistinguishable from gasoline produced in the normal way.
In any case, for ethanol at least, a gallon of ethanol will produce more energy than is required to produce it. From this document (pdf file!) on Argonne’s web site (page 18-19):
So even using your definition of fuel, ethyl alcohol is a fuel.
It looks like we have a “dueling” definition of “fuel” here:
“Hydrogen is not a fuel in the sense that coal or sunlight is. Hydrogen is just an ‘energy vessel.’ It depends on how you make the hydrogen. If you burn coal to generate electricity to electrolyses water, then the only value is in shifting the source of pollution from the urban environment where the hydrogen is used to the location of the power plant.” Dr. Bob Allen, Professor of Chemistry, Arkansas Tech University
“Hydrogen is not a fuel, it is an energy carrier analogous to electricity. It is not a generating technology, it is an enabling technology.” - Dr. H.M. Hubbard, Chair, Committee on Programmatic Review of the U.S. Department of Energy’s Office of Power Technologies, National Research Council, to the Hearing Charter Subcommittee on Energy, Committee On Science, U.S. House Of Representatives, President’s National Energy Policy: Hydrogen and Nuclear Energy R&D Legislation Thursday, June 14, 2001
“Ordinarily we think of a fuel as a substance that, when burned, releases more energy than is required to produce them.” Dr. Vladislav Bevc, Hoover Institution, Stanford, Calf.
“It should be borne in mind that hydrogen is not a fuel but an energy carrier.” - Energy at the Crossroads, The Chemical Engineering Contribution to the UK Energy Debate, A response to the PIU Energy Review and the joint departmental energy policy consultation, published in May 2002, Briefing prepared by The Institution of Chemical Engineers for Mr. Brian Wilson MP, Minister of State for Energy & Industry
“A fuel is any substance that is able to produce net BTU’s of energy at an economically reasonable cost.” – Don Lancaster, P.E.
More on the viability of hydrogen vs. gasoline…
“In the U.S., 90-95% of hydrogen is produced by steam reforming. Theoretically, the energy that must be supplied to the process is the difference between the heat of combustion of the resulting hydrogen and the heat of combustion of the reformed feedstock. This difference sets the lower limit on the energy required to produce an alternative fuel. In practice the overall efficiency of the process – that is, the energy content of the hydrogen produced divided by the total energy consumed by the reforming process – is approximately 65%.” - M.J. Murphy, H.N. Ketola, P.K. Raj, Summary of Assessment of the Safety, Health, Environmental and System Risks of Alternative Fuels, rep. No. FTA-MA-90-7007-95-1, US Department of Transportation and U.S. Department of Energy, Washington DC. (1995)
“To produce an amount of hydrogen with the energy content of 1 MJ, about 1.6 MJ of energy must be expended. But only 0.167 MJ of energy must be expended to produce a quantity of gasoline with an energy content of 1 MJ.” - M.A. Delucchi, A Revised Model of Emissions of Greenhouse Gases from the Use of Transportation Fuels and Electricity, rep. No. UCD-ITS-RR-97-22, Institute of Transportation Studies, University of California, Davis (1997)
Finally, here’s a good write up you may want to take a look at:
http://63.140.207.28/glib/muse115.pdf
zut: I have read that methanol is not a fuel, but your site seems to contradict this (at least for ethanol). Perhaps efficiencies have improved to the point that it has become a fuel?? I don’t know. We should throw a party if it’s true. At any rate, I’m going to look into it further. Thanks for the link.
http://www.unisci.com/stories/20013/0813012.htm
Ethanol For Fuel Fundamentally Uneconomic, Study Says
13-Aug-2001
Neither increases in government subsidies to corn-based ethanol fuel nor hikes in the price of petroleum can overcome what one Cornell University 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,” says 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 in September in the forthcoming Encyclopedia of Physical Sciences and Technology.
Among his findings are:
An acre of U.S. corn yields about 7,110 pounds of corn for processing into 328 gallons of ethanol. But planting, growing and harvesting that much corn requires about 1,000 gallons of fossil fuels and costs $347 per acre, according to Pimentel’s analysis. Thus, even before corn is converted to ethanol, the feedstock costs $1.05 per gallon of ethanol.
The energy economics get worse at the processing plants, where the grain is crushed and fermented. As many as three distillation steps are needed to separate the 8 percent ethanol from the 92 percent water. Additional treatment and energy are required to produce the 99.8 percent pure ethanol for mixing with gasoline.
Adding up the energy costs of corn production and its conversion to ethanol, 131,000 BTUs are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 77,000 BTU.
“Put another way,” Pimentel says, “about 70 percent more energy is required to produce ethanol than the energy that actually is in ethanol. Every time you make 1 gallon of ethanol, there is a net energy loss of 54,000 BTU.”
“That helps explain why fossil fuels – not ethanol – are used to produce ethanol,” Pimentel says. “The growers and processors can’t afford to burn ethanol to make ethanol. U.S. drivers couldn’t afford it, either, if it weren’t for government subsidies to artificially lower the price.”
“Corn production in the U.S. erodes soil about 12 times faster than the soil can be reformed, and irrigating corn mines groundwater 25 percent faster than the natural recharge rate of ground water. The environmental system in which corn is being produced is being rapidly degraded. Corn should not be considered a renewable resource for ethanol energy production, especially when human food is being converted into ethanol.”
Increasing ethanol production would further inflate corn prices, Pimentel says, noting: “In addition to paying tax dollars for ethanol subsidies, consumers would be paying significantly higher food prices in the marketplace.”
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:
The average U.S. automobile, traveling 10,000 miles a year on pure ethanol (not a gasoline-ethanol mix) would need about 852 gallons of the corn-based fuel. This would take 11 acres to grow, based on net ethanol production. This is the same amount of cropland required to feed seven Americans.
If all the automobiles in the United States were fueled with 100 percent ethanol, a total of about 97 percent of U.S. land area would be needed to grow the corn feedstock. Corn would cover nearly the total land area of the United States. - By Roger Segelken
For kicks I also sent Don Lancaster the link provided by zut. Here’s his response:
Context of statement should be “US farm corn based ethanol”. Ethanol under subsistence bagasse (sugarcane residue) conditions is theoretically positive.
I believe the pro-corn ethanol ripper-offers hired some really questionable research to state their case. Ethanol nearly bankrupted Brazil.
In the US, it remains a twelve billion dollar vote buying scam, nothing more.
See http://www.tinaja.com/glib/energfun.pdf
Their own statement clearly states that corn ethanol is ludicrous.
The thing that pissed me off was the hype surrounding it. It was supposed to be this revolutionary new device, and all we got was a self-balancing scooter, whoopie. People are still starving.
Clearly, crafter_man the people you quote are using the term in a particular way, peculiar to their specialty. Which is a common problem with groups of specialists. Fact is, they are at odds with every accepted definiition of “fuel” that I can lay my hands on (OED, Websters, Macquarie). If they, (and you) are going to use commonly used words as a term of art peculiar to a particular specialty, perhaps you would come across as rather less of a boor if you were to explain that, rather than treating your fellow posters like idiots for understanding a word to mean what it is widely accepted and defined to mean.
Sorry, Crafter_Man, I’ve been out at a large power plant in Maryland helping with their “fuel” issues.
Your definition is correct, in that you are measuring the total net energy available. However, I would, in everyday parlance, also refer to hydrogen and alcohol as “fuels”, and even my freeware program I am writing refers to them as such.
I feel you are technically correct on those issues, but I would not refer to them as “not” being fuels as is commonly known. If I tried to talk to clients, owners and operators of power plants, and biomass experts and started calling hydrogen “not a fuel”, I would be lambasted. So I refer to the “net energy” of it, when called upon.
But electricity should never be referred to as a “fuel”, as that is incorrect both from a technical parlance and an actual standpoint. I agree with that. I would say it has an “electric power source” instead.
Electricity as a fuel
Peace,
mangeorge