No announcement yet.


  • Filter
  • Time
  • Show
Clear All
new posts

  • hydrogen

    so i was just reading the post about the power going out(whenever it goes out round here the wife thinks i did it,dont blame the operator blame the machine)and the post started getting into propane powered engines alternate energy ect.

    so let me say first of that im not going to build anything crazy or blow myself up,i,ll wait till ive payed the mortgage off in about a 100 years, but wonder would it be feasable in theory to run a small engine say 100 cc on hydrogen

    then would it be possible to produce hydrogen in the back yard using solar cells or 12 volt wind generator ,compress it ect .

  • #2
    Possible in theory but highly impractical. First, the only reasonable way you could produce hydrogen at home would be by electrolysis. That requires electricity and is very inefficient (one third of the output is oxygen). Then you would have to store it. That would require a very expensive storage tank and compressor system. H2 is such a small molecule that it will sneak out through the walls of an ordinary tank and will also cause hydrogen embrittlement. Gaseous H2 has a very low power density so that to store a reasonable amount for household use would require a very large tank. H2 is very explosive so leaks in the system would be a serious safety risk. I don't know what mods would have to be made to an IC engine but they probably would be extensive.

    [This message has been edited by Evan (edited 08-15-2003).]
    Free software for calculating bolt circles and similar: Click Here


    • #3
      There's a good discussion on the production, storage, cost, and use of hydrogen here:

      Hydrogen isn't very user friendly. It'll escape in a heartbeat, and blow up with the least provocation. The one nice thing about it is that once it escapes, it keeps moving up, instead of collecting near the floor.

      It would be more practical to run an engine on propane or natural gas. The technology is already available for handling those fuels and using them in engines.

      Any products mentioned in my posts have been endorsed by their manufacturer.


      • #4
        You would find that producing "Garbage Gas" (Methane) would be more cost effective---if you didn't accidently blow yourself up!


        • #5
          With that said let me tell you why,ic engines of any type will cost you a bare minimum of .28 per wh of electricity,and thats if you generate on a large scale (200kw plus)and sell your excess,industry uses engine driven gensets all the time to avoid peek demand charges especially in small foundrys.

          Windmills,I was involved in the mechanical aspects of a five year cost study of two verticle blade units,cost lots of money(100,000 each)they would produce a total output of [email protected] approx.we found that maintaining them was quite expensive,they also had in place data loggers to record peeks and valleys,at the end of the study we found that factoring in all costs it still cost .56 per wh,in other words gold plated electricity.

          Solar panels,theres a good one,the greenies love solar panels,why I don't know they are expensive,don't work at night and by and large polute more than the save in the form of heavy metals,Don't have a figure of what the exact cost would be but it ain't cheap.

          With all of this being said I just got ast months bill and I paid .12per wh,need I say more?

          As far as generating your own power I would not,but I would look for ways to augment and conserve,Dad used to get on us boys royal if we left a light on,most kids now think nothing of it.As for solar energy use it for things like making hot water and not producing power directly,I am right now designing a system to augment my hot water heater with solar,if it works it will be cheap and efficient and will automatically switch back to grid power at night or in cold weather,we'll see.
          I just need one more tool,just one!


          • #6
            Standby generators are not used to save money. Weirdscience is correct about it costing more that getting it from the power company. It is really a question of do you want power when the power company can't provide it or use candles and whatever else to get light and cook. I like to stay cool, Air conditioning, and have the conveniences I have grown accustomed to. Having power for days after a hurricane or other power outage problem is worth the extra expence it cost me. Maintenance of the generator set goes on even if you don't use it.



            • #7
              Hydrogen is NOT that dangerous, or at least it does not have to be.

              Saw a program years ago on hydrogen powered cars. They debunked the tank problems very well.

              Turns out that if you adsorb H2 onto certain materials it will be held at low pressure, and release easily, but again not at high pressure. I forget which material was found best.

              "Adsorbing" means essentially that it sticks to the surface area. So a high surface area material, like an open-cell foam, if H2 sticks to it, you can store a lot in a reasonably small volume.

              They showed a test, hydrogen vs gasoline. Put a tank out, partly full, and shot a bullet into it.

              The gasoline tank essentially exploded and burned, big fire.

              The adsorbed gas hydrogen tank had a flame coming out through the hole in the tank. Yes, it was a couple feet long, and yes it was hot. But, it wasn't a 15 foot diameter roaring fire like the gasoline.


              • #8

                I suggest you read the article that Winchman linked to.
                Free software for calculating bolt circles and similar: Click Here


                • #9
                  im thinking along the lines of what happens if you are washed up on a desert island with a bunch
                  of eco twits who have banned the emissions of co2 with your lathe milland all your tools and lots of other junk and need to get a smalloutboard engine running in order to escape back to the real world and eat some red meat ect.

                  what would Macgyver do ?


                  • #10
                    He would collect all the **** in a pit. Cover it with a layer of wide leaves with sap to join the edges to form a methane proof cover. A hollow bamboo tube would be stuck into the top of the reactor pile. Out of this tube would come combustible fuel gas, kinda like a massive continous biological fart. This would be fed to Gilligan's left over Seagull outboard trolling engine with the prop removed and belt (twisted hemp, a no-no in the US) driven to a 6 watt bicycle generator from the fold up cycle they used for when they were in port using a pulley made of an unused piece of coconut shell turned on a lathe made of a left over pencil and a paper clip that was stuck to the water destroyed map. When the phase of the moon and the impending solar eclipse was just right it would be possible with a spark gap transmitter using the magneto of the Seagull to alert the authorities that an attack on the liberian power grid was pending.

                    PS: The Liberians haven't had power since 1992.

                    [This message has been edited by Evan (edited 08-16-2003).]
                    Free software for calculating bolt circles and similar: Click Here


                    • #11
                      It might be possible to generate your own power for less than what you're paying for it. It all depends if the folks at Idealabs can pull it off. See here:

                      I highly recommend reading Fuel From Water, which is a how-to manual for running things off of hydrogen.

                      Here's a discussion on steam powered cars which got side tracked onto the topic of hydrogen powered cars:


                      • #12
                        Well as for the island if theres food and water I would kill off the ecotwits and stay,Gilligan was slow,he should have wiped out the hard leg and shacked up with Ginger and Mary Ann
                        Ever wonder why the Liberians don't have power?or why most of Africa doesn't have power?Because they are more interested in killing each other than having a/c
                        Like the man said its up to us to save Africa from the Africans

                        I just need one more tool,just one!


                        • #13
                          Evan, I am well aware of the dangers of H2, and the extreme wide flammability range.

                          But you yourself drive around with gasoline enough in your car to completely take out a skyscraper if halfway properly carbureted.

                          Shakin in yer boots yet?

                          Didn't think so.

                          The deal is to manage the problems. Gasoline in a mobile, thin, exposed tank at high speed is the stupidest imaginable design. Almost any hydrogen system would be no worse.

                          Big starter difference is gas vapors go down and collect. H2 goes up and dissipates.......

                          The adsorbing tank works, no amount of articles can disprove what is a proven fact.

                          Having H2 floating around loose is a problem in enclosed areas. A taggant odor would be in order.

                          Did you know though, that if you let it loose, it eventually escapes from the atmosphere? True.


                          • #14

                            Yes, I know. That is why we don't have loose H2 or HE in our atmosphere. I refer you to the Challenger for an example of the hazards of LH2. Yes, a gallon of gasoline is equal to several sticks of dynamite, properly mixed with oxygen and enclosed. It does happen but is not nearly as convienient as a few barrels of ANFO.

                            Storing H2 under pressure is a real problem. It will escape unless the tank is made of special materials and lined with special sealants. The hydride methods of adsorbing H2 are inefficient and expensive. This needs a lot of work. I feel that it is a solvable problem, but it ain't ready for prime time yet.

                            [This message has been edited by Evan (edited 08-16-2003).]
                            Free software for calculating bolt circles and similar: Click Here


                            • #15
                              For other stupid energy systems, besides the common auto gas tank, I refer you to Mexico City.

                              They use LNG, as I recall, and as a result have had sewer explosions that take out several blocks. They have had at least two, with major devastation.

                              Liquids which are not just volatile, but almost explosively volatile are just not smart to use. Liquid hydrogen is no different.

                              At least gaseous material does not have the energy density of the liquid.

                              I agree, the problems will be solved, after a few major explosions.