Posted on 01/25/2002 12:12:08 PM PST by John Jamieson
John R Jamieson MIT67, NASA67-94 retired
It seems like a great idea at first glance. Hydrogen is one of the most abundant elements on earth and burns very cleanly. It contains more energy per pound than any other fuel.
At second glance, things are a little less encouraging. Most of the hydrogen on earth is already burned! The oceans are the ashes of billions of years of hydrogen fires. The hydrogen is tightly bound to oxygen atoms and must be separated from those atoms before it can be used again. Using electrolysis, the hydrogen can be separated from the oxygen by putting in exactly the same amount of energy that will later be retrieved when the hydrogen is burned. Hydrogen, made from water, is thus an energy storage media like a battery, not an energy source. Neither the separation nor the recombination of this reversible process can happen at 100% efficiency. Waste heat is generated during each process. Because most of our electricity is generated by hydrocarbons, we would still be using hydrocarbons to run our cars. The inherent efficiency of the electrical energy generation process (about 40%) times the expected efficiency of the electrolysis process (about 50%) would indicate a hydrogen fuel price of about 5 times the price of fossil fuels.
The second major source of hydrogen is directly from hydrocarbons. Hydrocarbons contain both hydrogen and carbon; about twice as many hydrogen atoms than carbon atoms, but since a carbon atom weights 14 times more than a hydrogen atom, much more carbon by weight. When we drive our cars today, we burn about 5.3 pounds of carbon and .7 pound of hydrogen per gallon of gasoline. Hydrogen plus oxygen equals water, good; carbon plus oxygen equals carbon dioxide, bad (the same stuff we exhale!). If we could breakdown natural gas, methane, gasoline, or fuel oil to separate the hydrogen from the nasty carbon (on which all life is based) and sell the huge piles of carbon for enough to pay for the separation, about 3 gallons of liquid or an equivalent weight of gas (about 18 pounds) would yield about 2 pounds of hydrogen, which is the energy equivalent of 1 gallon of gasoline or 6 pounds of natural gas. Remember that burning the carbon would not be allowed. We could make diamonds with it. The net result is that hydrogen fuel cannot, ever, be made for less than 3 times the price of fossil fuels.
OK, what if we just ignore that fact that we can’t make hydrogen economically. What do we do with it in an automobile? The logical answer is we burn it, in the same cars we’re driving today. Internal combustion engines basically don’t care what provides the heat. There are a few minor problems: How do you seal up the leakiest substance known to man? How do you store enough in the car to go 300 miles? What happens in a freeway crash? Etc. But, these little issues can all be solved. IC engines will need water injection to lower peak cylinder temps so we don’t make nasty NOX, but that technology is pretty well understood. Oh, but wait a minute, IC engines are nasty and unacceptable! Enter the miracle solution: FUEL CELLS!
FUEL CELLS work! There is about a $100,000,000 worth of them on each Space Shuttle generating the equivalent of almost 36 horsepower. Coleman just announced a real commercial home power generator that puts out 1.2 kilowatts for only $7,995 (Plus $100 per hydrogen canister that lasts for a few hours). GM just drove its latest fuel cell vehicle “Hydrogen1” on an “endurance test”, 230 miles from LA to Los Vegas. They only had to stop 7 times for more hydrogen. Many other companies built fuel cell cars and tried to go along, but didn’t make it. Zero to 50 was only 18 seconds.
The US department of energy recently set a goal of only $400 per kilowatt (about a horsepower, figuring electrical controller and motor efficiencies) for STATIONARY APPLICATIONS BY 2015. Won’t they be surprised that Detroit is planning affordable family fuel cell automobiles by 2010! If Detroit gets to magic $400 per horsepower five years early, and makes it small enough and light enough to go in a family car, you too, could be driving a 200 horsepower family car for a little over $100,000 that “burns” hydrogen costing you $5 a “gallon”. What a deal! You’ll drive it with pride knowing that your leaving no bad stuff in the air of your immediate area, while increasing the pollution of the poor people that live next to the power plant outside of town by a factor of 3 and increasing the importation (and probably the price) of Arab oil by a factor of three.
All this negativity aside, there is one and only one way to cheap automotive fuel, clean air and energy independence for this country. The answer is a massive, nuclear energy economy, probably fusion (hydrogen) powered. Hydrogen used for fusion generates power thousands of times more effectively than burning it with oxygen. A national effort equal to the Manhattan project or the Apollo program could develop fusion-powered electricity (and cheap hydrogen for automotive fuel) within 25 years. Then, we can truly say, we’re driving clean, fusion-powered cars. Electricity could be as cheap as 2 cents per kilowatt-hour and hydrogen for our cars, 40 cents per “gallon”. It is the only solution to the problem that has any economic, political, or engineering viability.
In the meantime, burn all the cheap Arab oil you can get and keep supporting the development our own fossil fuel sources for the day when we decide to shut the Arabs off!
We could all lower our wages and go back to work on the farm. I'm not ready. Give me a cheaper, better solution. Japan and France already generate just about all their electricity with nuclear power. You can't win by going backwards.
Hydrogen is, at present, a pipe dream. Separating it from chemical combination (be it H20, water, or in hydrocarbon form - methane is the main constituent of natural gas) will always use more energy than the burning will produce (this is the first and second laws of thermodynamics). It will eventually be a good, clean secondary source of power - after we find an even cheaper way to generate large amounts of electricity. (Oops, we've know one, it's called nuclear.)
Just in case you didn't know, the Three Laws of Thermodynamics, Simplified:
1.) You can't get ahead. Or, you can't get more energy out of a system than you originally put in. This is called "the conservation of energy". Or, no system can ever be more than 100% efficient.
2.) You can't break even. Or, some energy will always be lost in process. This is called "entropy". Or, no system can ever be as much as 100% efficient.
3.) You can't get out of the game. Or, you can't create negative energy, which is the same as saying you can't go below absolute zero temperature. If you could, you'd be able to violate the first two laws whenever you wanted to.
I didn't say it before, but yeah!...nukes are clean in so many ways...no greenhouse gases (as if it matters), no acid rain precursors, no large scale mining operations like coal, a good bit less noisy, too. As for safe, when they're not operated by morons, they're great.
I look forward to seeing our Saudi friends(?) living in tents and humping camels...just like they used to.
EBUCK
I'm no engineer, but the problem I have with those who say fuel cell cars won't work is that I see them working. Daimler and Toyota have been at this for years, producing many prototypes, long before the US government and Detroit got involved. I just don't believe the biggest auto companies in the world would be pursuing something that can't work. The switch in a big way is unlikely, however, unless and until oil prices rise enough to make fuel cell prices more attractive and production increases to make economies of scale possible.
In the meantime, I agree we suck the mideast dry.
Nuclear for baseloads makes complete sense. Fuel cells for topping or local applications can also make sense.
Hydrogen makes sense if you're a politician looking to bullshit your way into people's pocketbooks.
W, I know you're pretty busy, but if you could work it in, please start think about the long term future of this country.
Actually, I don't believe that is quite true. As stated, the process would require 100 percent efficiency, and I don't believe that to be obtainable.
However, I do think it would be possible to create large scale sun-to-electricity or wind-to-electricity facilities in non-populated areas and pipe or ditch water to them. The water could then be converted to hydrogen and oxygen by electrolysis without the loss of too much power through long distance voltage drops. The two elements could then be shipped to wherever they are needed.
Fuel cells, internal combustion - and other types of engines might be feasible.
Now, if we could just get a source of electricity to destinations without too much voltage drop due to the distance, it might just be feasible to create a car that never needs re-fueling. Just fill up a permanently sealed, heavy gauge fuel system with water; conver the water to hydrogen and oxygen during the night; convert the hydrogen and oxygen back to water as the car is used, and recycle that water again at night. The only thing needed to be added is the electricity at night. Wouldn't that be a "gas"!
Just ask the guys at Morton Thiokol.
It appears so. The PR is lacking so far, but the hydrogen hype will blow over. It's methane.
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