http://www.metacafe.com/watch/128967/water_as_fuel/I haven't seen it posted before...
5/19/2006 2:55:10 AM
Yeah he uses electrolysis on water to create HOH right? Something like that.It doesn't use water as fuel, water is split into fuel using electricity, then the fuel is used to power the car.If he could devise a way to use electrolysis that allowed transportation for cheaper than gas, he might have something.Otherwise it's just a cool welding tool.
5/19/2006 3:12:24 AM
Oh, I see... it slipped by me that it uses electrolysis.Still though, if they could fine an efficient way to perform the electrolysis (there's a lot of research in to this area using various nano-materials), that seems like a pretty clean means of transportation.It still wouldn't have the energy density of gasoline, but it would probably be a little cheaper, and a lot cleaner.
5/19/2006 3:26:21 AM
5/19/2006 3:32:54 AM
What I got from his explanation was that he converted the water molecule into a linear molecule with Hydrogen-Hydrogen-Oxygen. Of course that would not be stable for an appreciable amount of time... And if it uses electrolysis, then you will need a source of electricity. And since the engine wont be 100% efficient, you'll use more energy in the long run, and the electricity will have to come from somewhere (most likely a coal or natural gas powerplant which defeates the purpose).
5/19/2006 5:46:03 AM
Electrical grid:12 cents per kw*hour and 1 kWhour = 3600000 joules therefore the rate is 300,000 J/centGasoline = 1.3 x 10^8 J/gallon at $2.69/gallon, therefore the rate is 480,000 J/centTherefore, no matter how efficient you make the storage and transportation of electricity (such as through hydrogen) gasoline will always be cheaper at these prices. All we have to do is make our gasoline engines more efficient to match or, heaven's forbid, the price of gasoline returns to historical norms. http://www.upei.ca/~physics/p261/Formulae_Data/body_formulae_data.htmhttp://hypertextbook.com/facts/2003/ArthurGolnik.shtml[Edited on May 19, 2006 at 8:52 AM. Reason : .,.]
5/19/2006 8:51:47 AM
it's already been talked about, i don't know where the tww link isthat being said, i did a little research and what they are talking about is Brown's Gasand it while it does burn and can be used for welding, it appears to be a typical conman's ploy to get moneyyou're not going to make an engine run on water[Edited on May 19, 2006 at 10:52 AM. Reason : .]
5/19/2006 10:52:21 AM
not efficiently enough to be worthwhile, anyway
5/19/2006 12:42:32 PM
yet
5/19/2006 1:00:32 PM
no, it has nothing to do with efficiencyit has to do with the fact that it's FUCKING WATER
5/19/2006 1:17:10 PM
no, it has to do with efficiency.we can seperate water into hydrogen and oxygen, but it takes a huge amount of energy to do it. with the technology we have now, it's not a useful way to create fuel.
5/19/2006 1:54:52 PM
That's a negative ghostrider, the pattern is full.
5/19/2006 3:05:11 PM
duke, please tell me you are trolling.even if it were 100% efficient, all we could really do would be keep powering the electrolysis process with no net energy output...
5/19/2006 9:14:07 PM
not if you used an catalyst. somy biological organisms (algae) create hydrogen and oxygen gasses at low rates from water, they use enymes and zero electrical energy.another example;http://www.nature.com/nature/journal/v440/n7082/abs/440295a.htmla synethic photocatalyst. here, you use zero electricity, only light, and get hyodrgen and oxygen from water.[Edited on May 19, 2006 at 9:34 PM. Reason : 663]
5/19/2006 9:30:21 PM
^yes, algae can turn co2 and sunlight into H^2 as well as O^2. So what? We can also make hydrogen via steam reformation of methanol, but it doesn't matter because hydrogen is not suitable as a primary fuel for transportation.^^I'm sorry, what?Electrolysis is about 27% efficient.If it were 100% efficient, "hybrid" cars would have water tanks and onboard electrolyzers to create fuel because hydrogen gas has a hell of a lot more energy per mass than a battery does.[Edited on May 19, 2006 at 9:39 PM. Reason : 2]
5/19/2006 9:36:32 PM
Which is why using electricity alone to seperate hydrogen and oxygen from water probably isnt going to be possible. Put other processes dont follow the same mechanism, as mentioned.
5/19/2006 9:39:50 PM
5/19/2006 10:39:06 PM
On a recent Mythbusters, they were able to run a regular engine for a few seconds on regular hydrogen, pumped in through the carburetor (it was maybe 20 seconds or so, until it backfired and flames shot out the air intake).So, it doesn't seem like too bad of an idea to power a car by H2, assuming they're ever able to refine it efficiently enough.
5/19/2006 11:44:37 PM
^ yea but wasnt that just residual gas[Edited on May 20, 2006 at 12:07 AM. Reason : like they said. i thought they never got it running after the first one.]
5/20/2006 12:07:28 AM
^ They tried the weird gadget first, and that was just residual gas.Then they got one of those big tanks of H2, and pumped it in, and that worked.http://www.cxliv.org/2006/05/17/exploding_pants.phpThat link corroborates my memory.In the same episode, they also ran an unmodified diesel engine directly on used, filtered cooking oil, and it worked perfectly fine.[Edited on May 20, 2006 at 12:22 AM. Reason : ]
5/20/2006 12:21:41 AM
If you can get the mixture right there is no reason for you not to get a regular gasline engine to run off hydrogen. Regretfully, you will at best be getting equivalent engine efficiency. gasoline 130,000,000 J/gallon259 cents/gallon501,931 J/centGasoline Burning Gasoline Engine 130,000,000 J/gallon30 miles/gallon4,333,333 J/mile501,931 J/cent8.63 cent/mileElectricity 3,600,000 J/kilowatt*hour12 cents/kilowatt*hour300,000 J/cent Hydrogen Conversion 100% Efficiency300,000 J/centHydrogen burning Gasoline Engine 4,333,333 J/mile300,000 J/cent14.44 cent/mile
5/20/2006 12:50:58 AM
Even with a 20% premium on cost/gallon of H2 (or any alternative fuel), the benefits of being near 0-emissions may be worth it to some people.
5/20/2006 12:57:22 AM
^ perhaps, but you must notice I used 100% efficiency for the conversion between electricity and hydrogen, which is impossible. Normally it is closer to 20%, thanks to recent developments of Catalysts to help the process we have it up to 40%, some theorize 60% might someday be possible, but we aren't there yet. Efficiency___cent/mile__Relative Cost to Gasoline___20%______72.22_______x8.37___40%______36.11_______x4.18___60%______24.07_______x2.79___80%______18.06_______x2.09Of course, this is still moot, because if you are running your car on hydrogen you're not going to use a gasoline engine but a fuel-cell which is at about double the efficienccy, even though it costs more up-front.
5/20/2006 10:01:26 AM
The problem with hydrogen as a transportation fuel is and always has been hydrogen storage. It simply is not feasable to store it as a liquid, and it's energy density is too low when stored as a gas.Fuel cells are pretty cool and their prices are going down, but they are more suitable for stationary CHP (combined heat and power) applications because of the strong exothermic reactions that take place inside. The most efficient fuel cells on the market, solid oxide fuel cells, operate at around 850 degrees Celsius. As such, that thermal energy is better used to heat up a building than a car. A promising idea that NASA is researching is a fuel cell that can also be used as an electrolyzer. That way, during braking, the fuel cell could reverse it's process and use electricity to create more hydrogen fuel. Nevertheless, if we ever see fuel cells in mass-produced cars, they will probably be fueled by methanol or LNG with an onboard steam reformer, because hydrogen is simply too difficult to store.
5/20/2006 1:08:16 PM
5/21/2006 11:59:20 AM
nothing on earth could burn hotter than the sun.
5/21/2006 2:37:46 PM
H-bombs can for a short period of time
5/21/2006 8:50:10 PM
and of course inside nuclear reactors -- the point is, its not happening in that guys lab[Edited on May 21, 2006 at 8:52 PM. Reason : 5]
5/21/2006 8:52:11 PM
5/21/2006 8:59:11 PM
Somebody mentioned something about performing electrolysis using a catalyst. Before I ask my question, I want to set an example up first.Suppose (for the sake of argument, because I don't actually know the numbers) it takes 1000 J/g to electrolyze water into hydrogen and oxygen (this is the absolute minimum amount of energy needed and ignores the obvious inefficiencies). If it takes this much energy for the reaction to go in this direction, the reverse reaction direction presumably gives off that same amount of energy. So you could get a maximum of 1000 joules of energy out of reacting a combined mass of 1 gram of hydrogen with oxygen.But, now you have this catalyst that allegedly reduces the amount of energy necessary for electrolysis. For the sake of argument, let's say it reduces the necessary energy input to 500J/g. In the unaided reaction, it takes 1000J/g, and the reverse reaction gives off that much. In the catalyzed reaction, it only takes 500J/g.Here's my question. I'm assuming that the reverse 500J/g reaction will happen without the catalyst being added, ie we only use the catalyst to electrolyze the water and not form it. If this is the case, then does the hydrogen and oxygen formed from the electrolysis only give off 500J/g of energy? If that is the case, then while this magic catalyst has made electrolysis cheaper it has also decreased the energy density of the fuel, which (I would imagine) completely offsets the reduced cost of electrolysis. If, however, the hydrogen and oxygen give off the original 1000J/g of energy, then where did the other 500J/g of energy come from? Conservation of energy still applies; we cannot extract more energy from a system than we put into it. So if the catalyst only requires that we put in 500J/g of energy, isn't it only possible to get a maximum of 500J/g of energy back out?
5/22/2006 6:37:38 AM
5/22/2006 6:48:29 AM
Yes and no. You are correct in that it does state that energy cannot be created or destroyed. However, this must necessarily mean that you cannot get more energy out of a system than you put into it. You're confusing activation energy input with total energy input.Take gasoline, for example. In order to get the exothermic release that we call combustion, there has to be a small, initial energy input called the activation energy. In this sense, you are right; it is possible to get more energy out of a reaction than is required to begin said reaction. However, where did all the chemical energy that is stored up within the gasoline come from? Over millions of years of intense heat and pressure. You and I may not have relocated energy from the sun and into the gasoline, but it did get there nevertheless. Gasoline does not magically appear out of nowhere, that energy has to first come from somewhere. Whether it gets there through natural means or human intervention, it still has to get there period. All the activation energy does is allow for the release of all that pent-up energy.And you still didn't answer my question.[Edited on May 22, 2006 at 7:49 AM. Reason : blah]
5/22/2006 7:46:57 AM
5/22/2006 8:38:42 AM
umbrellaman, I will try to answer your question Ok, I will follow your example. Let us presume that 1 gram of hydrogen can react with oxygen to produce 1000 joules of energy. Given "Conservation of energy," we can also say that the minimum amount of energy required to produce 1 gram of hydrogen is 1000 joules, this assumes perfect efficiency, which doesn't exist in the real world. More likely, without the catalyst required the application of 4000 joules of energy to produce 1 gram of hydrogen, an efficiency of 25%, and with the catalyst we can produce the hydrogen for 2000 joules of energy, an efficiency of 50%. What this means is that 1 gram of hydrogen has a constant energy density, regardless of how it was produced. What different production technologies change is the percentage of your input energy that was wasted.[Edited on May 22, 2006 at 8:53 AM. Reason : umb]
5/22/2006 8:53:25 AM
So the catalyst doesn't reduce the energy density of the fuel, it only reduces the inefficiency associated with producing that fuel? Okay, that makes much more sense to me.thxu LoneSnark
5/22/2006 9:25:51 AM
5/22/2006 2:25:18 PM
5/22/2006 3:02:21 PM
5/22/2006 3:31:56 PM
5/22/2006 5:20:20 PM
You're wrong on this one, mr Burro. If electrolysis were 100% efficient, then water would have replaced batteries in cars a long time ago. because hydrogen gas can be used to efficiently produce large quantities of electricity with a fuel cell, electrolysis of water would be an ideal method of storing onboard energy if the process was more efficient. You could even trap the exaust from the fuel cell and condense it so that you would never have to refill. And it's not like electrolysis is rocket science. Stick an anode and a cathode in some water and gas bubbles up. Storing electrical energy is very difficult. Batteries are really heavy, and they take a damn long time to charge up. Thats why hybrid cars are not a good deal for the average consumer. They sacrifice more from the added cost and weight of the battery than they save in gas money. Onboard electrolysis would be a much more efficient way to store electrical energy if not for the huge energy losses in the electrolytic process.
5/22/2006 6:21:20 PM
5/22/2006 6:36:24 PM
5/22/2006 6:48:18 PM
5/22/2006 8:05:50 PM
5/22/2006 8:08:38 PM
5/22/2006 8:12:16 PM
5/22/2006 8:18:44 PM
5/22/2006 8:21:21 PM
5/22/2006 8:23:56 PM
Let me be more specific.Let us suppose that the free energy of room temperature water is -40J. The free energy of unbonded hydrogen and oxygen is, oh I dunno, -2J. So we're talking about a +38J difference between bonded and unbonded. This is admittedly a simplistic example and these numbers are incorrect, but I think it demonstrates my point. Regardless of what the actual energy states of water and free hydrogen/oxygen are, the difference in their free energies is such that it takes energy to seperate water into its constituent elements, and energy is released when they combine.Now do you understand?
5/22/2006 8:28:59 PM
5/22/2006 9:07:22 PM