Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Science Technology News

Creating Hydrogen With (Very) Hot Water 542

carbonman writes "NYTimes is reporting that a public-private research team will announce on Monday that they have discovered a new technique to produce pure hydrogen that is far more efficient than conventional methods. The advance could be a significant development in attempts to realize the dream of the hydrogen economy in taking gasoline-powered vehicles off the road, and without releasing carbon dioxide emissions that are linked to climate change. It does, however, require the use of advanced high-temperature nuclear reactors, none of which have been built on a production scale before." swiftstream adds a link to the same story at the no-reg Indianapolis Star, and summarizes the method as "electrolysis of very, very hot water."
This discussion has been archived. No new comments can be posted.

Creating Hydrogen With (Very) Hot Water

Comments Filter:
  • by Anonymous Coward on Sunday November 28, 2004 @03:58PM (#10938631)
    Don't they mean steam?
    • Re:Very Very hot? (Score:3, Informative)

      by Anonymous Coward
      no, PVT diagram shows that you have very hot water without steam at high pressures.
  • by FiReaNGeL ( 312636 ) <.moc.liamtoh. .ta. .l3gnaerif.> on Sunday November 28, 2004 @03:59PM (#10938635) Homepage
    Is it just me or water can't be very very hot? At about 100 degrees Celcius, it vaporize... are they doing electrolysis on hot vapor? If so, can their tech be called Vaporware? :)
    • by Stevyn ( 691306 ) on Sunday November 28, 2004 @04:03PM (#10938656)
      A pot of boiling water on your stove will probably not reach a higher temperature. This is because of the surrounding air pressure. If they put this in a closed system like a "pressure cooker", it could get hotter.

      That's why a pressure cooker works faster than an open pot. The increased pressure allows the water to boil at a higher temperature.
    • by kooshvt ( 86122 ) on Sunday November 28, 2004 @04:04PM (#10938659)
      Is it just me or water can't be very very hot? At about 100 degrees Celcius, it vaporize...

      Yes it does at standard temperature and pressure. If you were to increase the pressure it would require a higher temperature to vaporize, just as lower pressures require lower temperatures.
    • by Wm_K ( 761378 )
      It depends on the pressure the water is kept under...that's the reason that you're able to prepare food faster in a Pressure Cooker.
    • by d3m057h3n35 ( 695460 ) on Sunday November 28, 2004 @04:05PM (#10938668)
      Water can be superheated as much as you please, it simply has to be at a high enough pressure. Past water's critical point (about 650 K and 22 MPa), it becomes a supercritical vapor, indistinguishable from liquid or vapor. Additionally, the boundary between liquid and gas dissapears, and the properties of the substance are somewhat different.
      • by Caseyscrib ( 728790 ) on Sunday November 28, 2004 @05:00PM (#10938941)
        The earth's magma leaks into the sea in a few spots near the bottom of the ocean. This water is superheated naturally, and the pressure restricts it from evaporating. The guy that discovered it took his submarine up to it and held a temperature guage to measure the vent, and it melted.

        Is it possible to take this naturally superheated water and use it to create hydrogen more efficently?

        • by Yorrike ( 322502 ) on Sunday November 28, 2004 @08:04PM (#10939783) Journal
          "The earth's magma leaks into the sea in a few spots near the bottom of the ocean"

          These "spots" of super heated water occur around what are called black smokers [amnh.org]. The magma, or more accurately, mantle, is drawn up at mid ocean ridges [agu.org] due to the top-cooled convection of which plate tectonics is a direct result.

          Mid Ocean Ridges rarely heat water beyond 400 degress C, but even so there could be potential there, since it's already heated to a great degree, requiring less energy investment. Plus, there's tens of thousands of kms worth of MORs on Earth.

      • by ozmanjusri ( 601766 ) <.moc.liamtoh. .ta. .bob_eissua.> on Sunday November 28, 2004 @10:54PM (#10940446) Journal
        Additionally, the boundary between liquid and gas dissapears, and the properties of the substance are somewhat different.

        The change in properties is what's important to the separation of hydrogen and oxygen. Past the supercritical point, water becomes non-polar and more acidic.

        From memory there was some work done a while back on producing peroxides using supercritical water, carbon dioxide and palladium catalysts. Acetylenes were the byproduct, and I wonder now if there might be an energy storage pathway in that reaction.
    • by Anonymous Coward
      Since no one else has pointed it out yet, I'll just mention that it's possible if it's at a different pressure
  • Hydrogen grid? (Score:3, Insightful)

    by upsidedown_duck ( 788782 ) on Sunday November 28, 2004 @04:02PM (#10938648)

    Why not put the nuclear power plant way out in the boonies (i.e., no one's back yard) and run pipelines to where hydrogen is needed?

    I have nothing against nuclear power, until efficient solar power comes along, as long as the nuclear power minefield can be navigated.
    • Re:Hydrogen grid? (Score:5, Insightful)

      by EnronHaliburton2004 ( 815366 ) on Sunday November 28, 2004 @04:06PM (#10938670) Homepage Journal
      Most nuclear plants are located in areas with rural populations. (or at least, areas that were rural when they planned and built the plants).

      You can build the plant in the boonies, but you still need to operate in a region where you can attract enough workers to staff the plant.
    • Re:Hydrogen grid? (Score:5, Insightful)

      by Hamster Of Death ( 413544 ) on Sunday November 28, 2004 @04:06PM (#10938673)
      Simple: Cost.

      You'd have to build something on the same scale as the current oil pipeline system, but with the added hurdle of being able to hold hydrogen.
      The current system won't work since it can't hold hydrogen.

      Also with no immediate profit, people tend not to like investing is something they won't see return on in the short term.
      • Re:Hydrogen grid? (Score:5, Interesting)

        by Guanix ( 16477 ) on Sunday November 28, 2004 @04:15PM (#10938716) Homepage
        When the current Danish natural gas pipeline network (the one that connects cities and houses) was designed, one of the requirements was that the network could carry hydrogen instead of natural gas.
    • Re:Hydrogen grid? (Score:4, Interesting)

      by mikael ( 484 ) on Sunday November 28, 2004 @04:23PM (#10938748)
      If they drilled deep enough into the Earth's crust, they could do away with the nuclear reactor bit altogether, and use the natural heat of the planet.
    • Re:Hydrogen grid? (Score:5, Informative)

      by bigberk ( 547360 ) <bigberk@users.pc9.org> on Sunday November 28, 2004 @04:52PM (#10938897)
      The fellas at Ballard Power Systems [ballard.com] seem to have an interesting vision in this regard. (I'm trying to recall what I heard on a CBC interview with one of the company's founders, so what I describe here may be partly my own fabrication). Anyway, they describe an electrical grid in which individual cars help generate and store electricity for the entire system. Something about micro power plants. You may choose to sell your power to the grid (when your car is unused), benefitting from the current market price of the power. Similarly, you can purchase electricity and store it in your car (in hydrogen form) hopefully taking advantage of a cheap power rate. Buy low, sell high. Anyway it all seems very interesting to me, an idea of millions of micro power plants contributing to the greater power grid. One big distributed storage and generation system, probably better at absorbing peak power demands too -- you see that it's 1 pm on a hot summer day and the grid will pay big $$ for your power, you take advantage of that.
    • Re:Hydrogen grid? (Score:5, Informative)

      by UniverseIsADoughnut ( 170909 ) on Sunday November 28, 2004 @05:44PM (#10939188)
      Nuclear plants are built in places where the conditions are right. Primarily where there is a large source of water for cooling. Usualy big lakes or rivers, sometimes oceans. You need a massive amount of water to keap them going without killing all the fish and such in the water source when the hot water is dumped back in.

      Since the location of plants is defined by water, it tends to put them in the same regions where cities grew up, next to lakes and rivers. They try to put them in isolated spots, but by the nature of things, areas around them grow up.

      You can't put them in the middle of nebraska cause they don't have a place to get anough water for cooling. Also you want your powersource near the place of use to eliminate losses.

      Besides, their is nothing wrong with nuke plants in ones back yard, i would be perfectly happy with such a thing. Far better then any coal plant or similar. It's nuclear, their is nothing to fear, unless you are one with that bizare fear that something that is glassified then incased in indestructable storage containers that are then moved to remote areas has even a remote chance of ever harming you.
    • Re:Hydrogen grid? (Score:3, Informative)

      by Jeremi ( 14640 )
      Why not put the nuclear power plant way out in the boonies (i.e., no one's back yard) and run pipelines to where hydrogen is needed?


      Sounds like a good idea to me, but one thing to keep in mind is that hydrogen tends to leak out of just about any container you try and keep it in, so over a long distance pipeline you might lose a significant portion of your hydrogen to the atmosphere.

  • by Anonymous Coward on Sunday November 28, 2004 @04:03PM (#10938653)
    ...perfect for espresso machines.
  • Heat pollution (Score:3, Insightful)

    by Hao Wu ( 652581 ) on Sunday November 28, 2004 @04:04PM (#10938658) Homepage
    One would be better to invent mini-nuclear reactors than introduce yet another step in the creation, storage, and use of energy.
    • Re:Heat pollution (Score:5, Informative)

      by pg133 ( 307365 ) on Sunday November 28, 2004 @04:14PM (#10938712)
      Already invented:
      Mini nuclear reactor could power apartment blocks [newscientist.com]
      A nuclear reactor designed to generate power in the basement of an apartment block is being developed in Japan

  • Smartass (Score:5, Funny)

    by Oriumpor ( 446718 ) on Sunday November 28, 2004 @04:04PM (#10938660) Homepage Journal
    If, he thought to himself, such amachine is a virtual impossibility, then it must logically be a finite improbability. So all I have to do in order to make one, is to work out exactly how improbable it is, feed that figure into the finite improbability generator, give it a fresh cup of really hot tea ... and turn it on!
  • by argoff ( 142580 ) on Sunday November 28, 2004 @04:05PM (#10938663)

    I think the reality is that there are so many unecissary regulations in the states, that nuclear power is impossible - and likely will be for a long time. I myself wish I had enough money to buy a ship and put a nuclear reactor on it out in international waters and sell safe and simple hydrogen back to the mainland. It would also be a cool way to reach the next generation of liberty - I mean we haven't really seen any new methods implemented to improve individual freedom and liberty (especially economic) in government in nearly 200 years. I wish I could start a nation at sea.
    • Full-on. In Philadelphia, you can buy an old WWII-era battleship for $20k. I figure, these, or old oil tankers lashed together and anchored to the sea floor would make for a great non-US country, where commerce can flow unhindered, vacations can be taken, and people (like me) can live without fear of fucked-up governments suddenly labeling us as terrorists for no reason.

      Hell, I'd even like to make scrapple from kelp or something. Vote with your tools, skills, and wits.


      • Cool, anyone up to donation a nuclear reactor? :)

        Seriously though, I herd Toshiba was going to donate a nuclear reactor to a small town in Alaska to get a foothold in the industry in the states - I'm curious if they would consider a ship at sea?
    • And how long until a Shell Oil tanker 'accidentally' collides with your ship?

      It would be most .... regrettable

    • by dbIII ( 701233 ) on Sunday November 28, 2004 @09:02PM (#10939997)
      I myself wish I had enough money to buy a ship and put a nuclear reactor on it out in international waters and sell safe and simple hydrogen back to the mainland ... I wish I could start a nation at sea.
      You don't want a ship, you want a yellow submarine.

      Speaking as someone who has used hydrogen as a furnace atmosphere, if I had considered it as both safe and simple I suspect I would not be around to write this. I suppose if nuclear power at sea is safe and simple then everything else on earth must be even more so.

  • by Professor Cool Linux ( 759581 ) on Sunday November 28, 2004 @04:09PM (#10938690) Homepage
  • by IO ERROR ( 128968 ) <error.ioerror@us> on Sunday November 28, 2004 @04:13PM (#10938707) Homepage Journal
    Once you've got the nuclear reactor in your car, why bother with all this hydrogen business? You've got all the energy you need from the reactor itself.
  • by n0tv3ry3lite ( 833715 ) on Sunday November 28, 2004 @04:17PM (#10938722)
    Does that mean they will be showing their privates in public? Are there any females on this public-private team? If so, then I am there for the 'unveiling'!
  • by Anonymous Coward on Sunday November 28, 2004 @04:17PM (#10938726)
    It has been known for some time that blowing hot steam across coke results in hydrogen, which is how most commercial hydrogen is made.

    Here's the reaction [64.233.167.104]
  • So obvious. (Score:5, Insightful)

    by twitter ( 104583 ) on Sunday November 28, 2004 @04:24PM (#10938751) Homepage Journal
    The new method involves running electricity through water that has a high temperature. As the water molecule breaks up, a ceramic sieve separates the oxygen from the hydrogen.

    I thought of this when someone first told me about fuel cells. To anyone familiar with conventional thermal cycles and the basics of thermodynamics, the approach is obvious. Thermal cycles take advantage of thermal energy gradients. That such a potential could be exploited with fuel cells seems to be an obvious extention. Hot water is easier to separate than cold water, duh! So you heat the water up, separate it and then combine it in a cold fuel cell. The difference is energy you can use but the devil is in the details. It seems easier than using a turbine but you'd want one of those too if you can't extract all of the heat in electrolysis.

    I'm glad someone is finally working on it. People are so slow. I expect the petroleum and coal industries to step in and kill it before anyone can use it.

  • The article doesn't state why it has to be a nuke reactor, only that the thing requires 300 megawatts to produce 2.5KGs of Hydrogen. What if it were 300mW from a hydro dam or some other source, would that work?

    Or is it somemehow tied into the hot water system of a nuke powered steam turbine?

    • by Firethorn ( 177587 ) on Sunday November 28, 2004 @05:15PM (#10939027) Homepage Journal
      Basically, yes.

      This system works on the heat production to heat the water. So hydro or wind wouldn't work efficiently. Other systems that use the steam cycle to power turbines probably would.

      Using a hydrocarbon based power plant would be defeating the purpose, besides, there's more efficient methods of making hydrogen from hydrocarbonds than even hot water electrolysis.

      The mirror type solar power plant might work too, but they cost an order of magnitude more to make per megawatt than a nuclear plant. And they're not manintenance free once built.
  • to provide enough H2 to replace our use of gasoline for personal transportation, according to google (about 1.18B gallons/year). While there are certainly some risks to mitigate with nuclear power, such an H2 infrastructure could be built in the near future. Once done, the nuclear portion could be replaced by whatever better power source comes next (He3 fusion, perhaps), without requiring any changes to the infrastructure. Mark
  • ... as there seems to be a requirement for the FORBIDDEN TECHNOLOGY. So much for that idea. Anyways, there will never be a lack of hydocarbons [cornell.edu] so who needs an alternative? We just have to make hydrocarbon use cleaner and more efficient.
  • http://jlnlabs.online.fr/cfr/index.htm
  • by pg133 ( 307365 ) on Sunday November 28, 2004 @04:47PM (#10938879)


    Generation IV Nuclear Reactors [uic.com.au]

    • An international task force has agreed on six nuclear reactor technologies for deployment between 2010 and 2030.
    • All of these operate at higher temperatures than today's reactors. Hence four are designated for hydrogen production.
    • All six systems represent advances in sustainability, economics, safety, reliability and proliferation-resistance

    Very high-temperature gas reactors. These are graphite-moderated, helium-cooled reactors, based on substantial experience . The core can be built of prismatic blocks such as the Japanese HTTR and the GTMHR under development by General Atomics and others in Russia, or it may be pebble bed such as the Chinese HTR-10 and the PBMR under development in South Africa, with international partners. Outlet temperature of 1000C enables thermochemical hydrogen production via an intermediate heat exchanger, with electricity cogeneration, or direct high-efficiency driving of a gas turbine (Brayton cycle). There is some flexibility in fuels, but no recycle. Modules of 600 MW thermal are envisaged


  • Reactor designs. (Score:5, Informative)

    by acey72 ( 716552 ) on Sunday November 28, 2004 @04:53PM (#10938900)
    "But the plan requires the building of a new kind of nuclear reactor, at a time when the United States is not even building conventional reactors. And the cost estimates are uncertain."

    This isn't really correct - although pretty much all the power reactors in the USA are water cooled (primarily due to the Navy's interest is nuclear propulsion), there are plenty of gas cooled reactors elsewhere. Most of our (Britain's) nuclear generating capacity is from either AGR (Advanced Gas-cooled Reactors) or Magnox (named after the Mg-alloy fuel can) reactors, both of which use carbon dioxide as the coolant.

    So, the technology may be new to the USA, but there's are wealth of knowledge on designing and running these reactors elsewhere in the world.

    Oh yes, they're arguably quite a bit safer than PWRs as well!

  • by rdean400 ( 322321 ) on Sunday November 28, 2004 @04:53PM (#10938901)
    The product of hydrogen combustion is water. If this is released into the environment, then we're dealing with another greenhouse gas (water vapor).
  • by xenocide2 ( 231786 ) on Sunday November 28, 2004 @05:00PM (#10938946) Homepage
    What would be far more influential in building the hydrogen economy is solar powered electralysis made cheap. I've heard about some prototypes, but I think they're currently far more than your average gas station can afford. Local production would have to be the intermediate solution that bridges between a concept and widespread adoption.
  • Why Nuclear? (Score:3, Insightful)

    by dmiller ( 581 ) <djm@mindro[ ]rg ['t.o' in gap]> on Sunday November 28, 2004 @05:19PM (#10939060) Homepage
    I don't understand why this hydrogen production method requires the unobtainium of a high-temperature nuclear reactor - it sounds like the breakthrough is in the electrolysis method. Couldn't this be applied to (say) a solar furnace?
  • by PickyH3D ( 680158 ) on Sunday November 28, 2004 @05:36PM (#10939151)
    This probably seems like a trolling post, but it actually is not. Most of you are just listing things that you learn in a standard Physics course and act like you know everything.

    Nuclear companies have nuclear power reactors to put out hydrogen (as a byproduct) ready and good to go, and have had them ready for quite some time. The hold up, in America, is that people are afraid of Nuclear Power, but in a few years as coal rises in cost (it will this winter for example--the cost of the coal has tripled on the East Coast of the U.S., but not the West Coast), there will be a demand for new reactors. However, the reactors that are desired are high energy steam generators, which are NOT the hydrogen power byproduct generators.

    The reason being is because they are still fine tuning these hydrogen byproduct generators to not waste so much energy actually creating the hydrogen (costs energy to split from the other molecules, such as H2O), which is a big concern for the power companies, as they want to maximize profit and that means not wasting energy. Sure, you have the hydrogen eventually, but a lot of the energy is just lost in the conversion process.

  • Suspicious numbers (Score:4, Informative)

    by Yartrebo ( 690383 ) on Sunday November 28, 2004 @05:43PM (#10939184)
    Hydrogen has about 120MJ/kg of energy (lower heat value). They're saying that it either makes 300 MW of electricity or 2.5 kg/sec of hydrogen, which would imply 100% efficiency for electricty->hydrogen (2.5 kg/sec is the same as 300MW).

    I wonder if they're just making up numbers, as 100% efficiency seems unreasonable good.
    • by Anonymous Coward on Sunday November 28, 2004 @07:29PM (#10939637)
      The 300MW is the net amount of electricity that the reactor produces, not the amount of fuel that was put in. So, a fuel input rate of 600MW and a 50% efficient reactor would produce either 300MW of net electricity or 2.5 kg/s of H2. Basically, they're saying that the efficiency of producing H2 is the same as the efficiency of producing electricity. They are NOT simply using the electricity coming out of the reactor to directly produce H2. The efficiency gains come from using the waste heat of the reactor.
  • why bother? (Score:3, Informative)

    by alizard ( 107678 ) <alizard.ecis@com> on Monday November 29, 2004 @02:22AM (#10941048) Homepage
    Hydrogen just isn't good enough for transportation purposes.

    From the biodiesel page at the University of New Hampshire [unh.edu]:

    Diesel fuel has an energy density of 1,058 kBtu/cu.ft. Biodiesel has an energy density of 950 kBtu/cu.ft, and hydrogen stored at 3,626 psi (250 times atmospheric pressure) only has an energy density of 68 kBtu/cu.ft.4 So, highly pressurized to 250 atmospheres, hydrogen's volumetric energy density is only 7.2% of that of biodiesel. The result being that with similar efficiencies of converting that stored chemical energy into motion (as diesel engines and fuel cells have), a hydrogen vehicle would need a fuel tank roughly 14 times as large to yield the same driving range as a biodiesel powered vehicle. To get a 1,000 mile range, a tractor trailer running on diesel needs to store 168 gallons of diesel fuel. When biodiesel's slightly lower energy density and the greater efficiency of the engine running on biodiesel are taken into account, it would need roughly 175 gallons of biodiesel for the same range. But, to run on hydrogen stored at 250 atmospheres, to get the same range would require 2,360 gallons of hydrogen. Dedicating that much space to fuel storage would drastically reduce how much cargo trucks could carry. Additionally, the cost of the high pressure, corrosion resistant storage tanks to carry that much fuel is astronomical.

    For information on better energy alternatives, check the above URL or the one in my sig.

As the trials of life continue to take their toll, remember that there is always a future in Computer Maintenance. -- National Lampoon, "Deteriorata"

Working...