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Spaced based H2O separation?

  1. Sep 16, 2004 #1
    This no doubt comes under the heading of Sci-Fi fantasy, but so what? Plenty of not so bad ideas have come out of Sci-Fi so...

    According to the CIA World Fact book the U.S. consumes approximately 3.602 trillion kWh of electricity, 71.4% of which is produced from fossil fuels (aka Oil).

    According to the United States Energy Information Agency the U.S. consumes approximately 20,000,000 barrels of oil per day.
    Although it's not, that amount of oil could be delivered to the U.S. by 20 supertankers arriving a day and off loading around 1,000,000 barrels of oil each.
    (Newer tankers are designed to transport approximately 1.3 million barrels of oil)

    Quite a bit of thought has been dedicated to the idea of orbital power generation for use on Earth.
    The most developed ideas envision orbital solar power generating facilities beaming the power they generate to Earth by way of microwaves aimed at very large ground based rectennas.
    But there are problems with that idea. Cheaper to build and maintain facilities in lower orbits can only beam power to a rectenna for minutes to hours a day. Facilities out at G.S.O. don't have that problem, but have to be HUGE, and building anything that far out, let along maintaining it, is VERY costly, even in the long run.

    So, how 'bout this idea...
    Suppose we were to develop fleets of trans-orbital tankers, these would be vehicles around the size of a KC-130, manned or not, and be capable of lifting around a half million gallons of water each into low Earth orbit for delivery to orbital separation facilities.
    The orbital separation facilities would be similar to small refineries, and use solar power to provide the energy needed to separate the water into hydrogen and oxygen by way of electrolysis, and then cool the resulting gasses into liquid form.
    The liquid hydrogen and oxygen would then be loaded back onto (either the same or variant) trans-orbital tankers for delivery to Earth based spaceports with associated storage and distribution facilities.
    From there the hydrogen and oxygen would be distributed to power, well, just about anything you want.

    1) Even a rube like me realizes that a 42 gallon barrel of oil is not the same as a 28 gallon barrel of liquid oxygen and a 14 gallon barrel of liquid hydrogen when it comes to energy consumption. For all I know, it would take ten times the amount of liquid hydrogen and oxygen to produce the same amount of energy as a single barrel of oil, or one tenth as much, or for all I know a direct comparison of a barrel of oil to a barrel of liquid hydrogen and liquid oxygen isn't all that bad a comparison at all.
    Does anyone have ANY idea at all what a more realistic comparison would be? A 42 gallon barrel of oil produces around 4 gallons of jet fuel, 9-1/4 gallons of fuel oil, and 19-1/2 gallons of gasoline. Assuming you allow the liquid hydrogen and oxygen to warm up to room temperature, expand into a gaseous state, and then just burn the hydrogen and oxygen to produce water as a waste product, how would that compare BTU wise to burning a gallon of gas?

    2) It's all fine and good to talk about lifting a half a MILLION gallons of water into orbit with a "KC-130" like tanker, but you don't get THAT job done for free do you? It could VERY well be the case that by the time you've gotten a fat assed tanker like that into low orbit the amount of fuel you used to do it (in the form of liquid O2 and H to fuel the "tanker") makes the whole idea completely ridiculous. It may well take 10 times the amount of liquid H and O2 to boost a half a MILLION gallons of water into low orbit than you could ever expect to get out of the half millions gallons of water once you separate it out in orbit, and no matter HOW the hell you try to juggle the numbers, they're just never EVER going to add up. I.e. this whole idea boils down to yet another proposal for a perpetual motion machine.
    Does anyone have even the slightest clue as to how those numbers would add up?

    3) I can't imagine I'm the first one to come up with this idea. I'd expect that a few people around here are either chuckling to themselves (or groaning), at yet another goofball bringing up this goofy idea, for around the thousandth time. If that's the case rather than waste time blowing a little reality up the backside of yet another guy with his head in the clouds (or possibly stuck in a less comfortable place), could someone please direct me to info that'll help me to understand just how nutty a fantasy world I'm wandering around in with this whole idea?
  2. jcsd
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