12-02-2002, 09:09 PM | #1 |
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Xogen-phoenix or failure ?
Those of you who have followed TIQ discussions for quite some time, may recall that at one point there was some back and forth about 'Hydrogen on Demand' technology. I believe that Lawrence had been the first to bring to our attention a company called 'Xogen'. This company claimed to have developped a technology that could produce hydrogen in such a way that it would be delivered directly to the burner tip of a furnace or engine (hence the name given to this process : "Hydrogen...on demand") For some time now, I've assumed that Xogen, which is funded by Tathacus Resources, was a story with a simple ending - another fly by night company, making grand claims about a secret, energy producing process... with nothing to back up their assertions. In fact, as far as I know, there's nothing solid, to say that this won't be the epitaph that will be written about Xogen. Afterall, they had their research evaluated by the Alberta Research Council, and the main conclusion of the report produced, was that 'modest amounts of hydrogen' could be produced by the process. Nothing was, and ever has been said, about energy efficiencies or cost efficiencies, of the hydrogen conversion. Still, I find it intriguing, that after all this time, Xogen and their finacier Tathacus, are still touting the technology as a viable one...even now. What do you make of this saga...Science or Snake oil ? Click here to go to the Tathacus website, and see their Lastest News release : www.tathacus.ca Seeker |
12-02-2002, 10:20 PM | #2 | |
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I learned in high school chemistry and have believed it in close to 50 years as a professional physicist, including many water dissociation lab experiments while teaching physical science, that a DC current in water liberates pure hydrogen at the negative electrode and pure oxygen at the positive electrode. I don't know what oxy-hydrogen is. Dr. Paul O. Johnson Senior Exhibit Developer The Science Place Dallas, Texas 75210 |
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12-03-2002, 02:01 AM | #3 |
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I began a thread on Millenium Cell several months back on TIQ. They are calling their technology "Hydrogen on Demand". They have tested their product with Daimler Chrysler , one of the more forward-looking auto companies with regard to alternative energy.
http://www.millenniumcell.com/news/hod.html Hydrogen on Demand; Overview: Millennium Cell has invented, patented, and developed a proprietary process called Hydrogen on Demand; that safely generates pure hydrogen from environmentally friendly raw materials. The hydrogen is stored on-board at ambient conditions in a liquid "fuel"; an aqueous (water-based) solution of sodium borohydride, NaBH4. Sodium borohydride is made from borax, a material that is found in substantial natural reserves globally. The process supplies pure hydrogen for energy applications without the need (and associated energy penalties) for compression or liquefaction. Hydrogen produced by this system can be used for numerous applications, addressing a wide range of power requirements. |
12-03-2002, 01:00 PM | #4 | |
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The fact that companies like Daimler Chrysler, and Peugot, have engaged in joint projects with Millennium Cell, gives good reason to believe that they're on to something. The impression I have, is that the Millennium Cell hydrogen on demand system would be both efficient and safe. At this point it would be costly to implement though. However, if the technology was introduced on a large scale, I'm sure the costs would come down. I think the sodium borohydride was the main cost element in this system. Seeker |
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12-03-2002, 01:16 PM | #5 | |
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I agree, the info provided on the Tathacus website about this process , is short on details. I don't exactly know what this ortho & para hydrogen are either. Here's a link you can go to, to check out a patent by Xogen, which uses the terms 'ortho' and 'para' hydrogen, in the body of the patent : http://patft.uspto.gov/netacgi/nph-P...xogen&RS=xogen Have you ever heard of Stanley Meier ? He was an inventor who has sort of ‘cult’ following, who believe that he came up with some sort of amazing electroylsis device a few decades back .I've heard that the Xogen patents are similar to his electrolysis patents. It sounds like this brand of electrolysis is claimed to be superior because it uses a "pulsed current". After reading through some information relating to it, the impression I got was that the pulsed current was supposed to cause the water molecules to be aligned within the electrolysis device in a particular way, so that it would require less energy to break their chemical bonds, or something along those lines. The other impression I had come away with, was that a common problem associated with the production of hydrogen via electrolysis, was that the hydrogen molecules have a tendancy to stick to the electrodes, thus reducing the yield of hydrogen gas. I seem to recall that this method was claiming to liberate hydrogen from the electrodes more easily, so that the hydrogen yield would be greater. My understanding is incomplete, concerning the scientific rationale which this technique is supposed to rely upon. But If there was anything to this whole process...which in all likelihood there isn't... it might be that the process was harnessing electric current in a more productive way than most electrolysis methods do. I’ve wondered if maybe a pulsed current could set up some sort of a ‘resonance frequency’ within a water molecule, which would have the result that you would be using the same amount of electrical energy as most electrolysis methods...but putting that energy to better use. Here's an analogy : Fred & Joe both push against a fridge. Fred pushes against the fridge 5 times with a force of 1000N each time (arbitrary figure) Joe pushes only 1 time with a force of 5000N. Only Joe is able to move the fridge ( do useful work)...though they both use the same amount of force in total. Just wondering if a pulsed current could be something like Joe, in terms of being better able to decompose a water molecule. Another comparison could be to the way in which wind, pushing on a bridge in typical fashion, may have a minimal effect on the integrity of the bridg. But if a resonance frequency is established in the timed force of the wind coming against the bridge, then the bridge may start swaying violently, and eventuallly be destroyed. It's fun to speculate, but I'm sure this theory has some flaws in it ! Seeker |
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12-08-2002, 01:55 AM | #6 |
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Sodium borohydride is a hydrogen storage strategy. It's a safer alternative to transporting hydrogen under pressure in a cylinder. Unlike compressed hydrogen gas, sodium borohydride won't explode on you. The drawbacks are cost and the fact that sodium borohydride is a solid, which makes it harder to handle. For example, you can't pump it from place to place, like gasoline or hydrogen gas. Note that sodium borohydride has nothing to do with the original hydrogen generation. You still have to generate hydrogen somehow so that you can then synthesize sodium borohydride from borax and hydrogen.
Xogen's patent describes a hydrogen production strategy, generating hydrogen gas from water using electricity. Short powerful pulses of electricity should be more efficient than a continuous lower level of power. First, the periods when there is no electricity flowing gives the evolved gases a chance to get away from the electrodes, so you don't waste power by putting it into the hydrogen or oxygen gas bubbles that collect on the electrodes. You want the energy to go into water molecules to generate more hydrogen gas, instead of going towards heating up the hydrogen gas that you generated earlier. Second, a short powerful burst of electricity helps to minimize losses to the bulk water in the vessel. Ideally, you would put all of your energy into one O-H bond at the electrode until it broke, then move on to the next, etc. In reality, however, the energy that you put into the system at the electrodes is constantly bleeding away into the bulk water, heating it up. Eventually, that will give you steam, instead of the hydrogen gas that you want. Short powerful pulses help push the kinetics towards hydrogen gas instead of steam. All that being said, I think that much of the Xogen patent is a load of BS. It talks about "ortho" and "para" hydrogen, which supposedly differ in their chemical properties because their nuclei have different spins. But nuclear spin has next to zero effect on chemical activity, as far as I know. Electron spins can have major effects, but not nuclear spins. My guess is that this ortho and para hydrogen junk is just a smokescreen to help them get around an existing patent. |
12-08-2002, 02:51 AM | #7 | |
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Thanks for these good insights. With the sodium borohydride, as I'm understanding it, this would be dissolved in water, and the solution could be used in much the same way as gasoline.Am I wrong about this ? As far as the ortho and para hydrogen goes, it sounds like these 2 forms have different physical properties, such as stability,boiling point,and thermal conductivity, however, their chemical properties are the same. I seem to recall that the Xogen people were claiming that one form of hydrogen was slow burning ,while the other was explosive... Hmmm? Seeker |
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12-08-2002, 11:38 AM | #8 |
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An aqueous NaBH4 solution is easier to handle than powder, but it has an important drawback: NaBH4 decomposes in water. The reaction is slow, but over time, some of your fuel will just disappear as a puff of invisible gas, unless you make provisions for capturing the hydrogen gas (complicated, expensive, heavy). According to the Merck Index, aqueous NaBH4 solutions "can be kept for several days." The decomposition reaction is temperature sensitive, so don't park your car in the sun.
Regarding the two forms of hydrogen: it sounds like they are talking about different electronic structures. One of the forms of hydrogen they are talking about must be an excited state. This excited state hydrogen will react much more quickly than normal hydrogen due to energy or symmetry considerations. However, excited state hydrogen probably has a halflife of only a fraction of a second before it reverts to the ground state, i.e. until it becomes normal hydrogen. For practical purposes of hydrogen generation, transport, and storage, excited state hydrogen gains you nothing. If anything, it represents an energy loss, since the energy difference between the excited state and the ground state will be lost as heat. |
12-08-2002, 02:10 PM | #9 | ||||||
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The molecule looks like a Mickey Mouse head, with the two H atoms being the ears. So a water molecule's positive end (the H end)is attracted to a negative charge and its negative end (the O end) is attracted to a positive charge. Therefore, polar molecules such as water attract one another and are relatively difficult to separate. H2O has a boiling point of 100 degrees C whereas CO2's boiling point is only minus 79 degrees C. This is a dramatic difference in molecular stability considering that the two molecules differ by only type of atom. So water molecules are, indeed, aligned with the electric field created in an electrolysis device, but that doesn't make their chemical bonds any easier to break. Quote:
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This is far greater than any pulsed current could achieve but is smack dab in the middle of the microwave range. You cook food in a microwave oven by heating the water in the food. The flipping H2O molecules slam into and warm the food molecules from within. Quote:
The most spectacular example of this was the collapse of the Tacoma Narrows bridge in 1940. See http://www.nwrain.net/~newtsuit/reco...ws/narrows.htm The vortex shedding phenomenon was first discovered and understood as a result of the post-collapse analysis done at CalTech. I enjoyed reading your message. Dr. Paul O. Johnson Senior Exhibit Developer The Science Place Dallas, Texas 75210 |
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12-08-2002, 10:21 PM | #10 |
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Hi Dr J, Thanks for shedding some more light on this electrolysis question. What you wrote about using a pulsed current, makes me remember some comments I've come across somewhere, to the effect that the value of a pulsed current would be in preventing heat from building up in the electrolysis solution. The build up of heat, does seem to be a problem with common electrolysis approaches. As far as the hydrogen bubbles sticking to the electrodes, maybe what I had gotten this confused with, was the fact that hydrogen bubbles are near the electrodes. This quote seems to suggest that hydrogen bubbles in an electrolysis solution, present a resistance to the flow of electrical current: "The evolution of gas bubbles at the electrodes is often exploited to drive the electrolyte through the electrolyser. But a large volume fraction of bubbles increases the electrical resistance of the electrolyte, which increases the loss of energy. The consumption of energy is perhaps the most critical problem in the electrochemical process industry." http://www2.mech.kth.se/faxenlab/elekt-en.html So possibly there would be a rationale for an electrolysis approach which could remove the bubbles from the solution as quickly as possible (maybe especially the ones which are near the electrodes) Seeker |
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