Terawatt Electrolysis

[matrixscarface]

If there was a terawatt of power running into water as in electrolysis, would it split the water instantly? assuming the ammount was say, 1000 gallons? or at what ammount would it be instant? more or less? :D

[HydrogenBond]

To split water you don't need a lot of voltage, from about 2-10 volts. At one terawatt of power that is a 100M amps at 10 volt. That puny voltage would not vaporize the water, but would sure make a lot of hydrogen and oxygen in a hurry. If you crank up the voltage, you will begin to ionize the oxygen and hydrogen causing water to reform in a very explosive way. It would be a waste of terawatts, since no useful product might result.

[Jay-qu]

If you crank up the voltage, you will begin to ionize the oxygen and hydrogen causing water to reform in a very explosive way. It would be a waste of terawatts, since no useful product might result.

 

what if you did this out the back of a space ship? fuel would be water and then you just need a source of this large amount of electricity.. say a nuclear reactor(fission or fusion in the future) Im sure the overall mass of the system would make it not a feasible idea - but thats where ideas start;)

[UncleAl]

How many joules/sec is a terawatt?

How many moles/second of water will that many joules do

 

2H2O --> 2H2 + O2

 

given the free energy of formation of liquid water from the elements at STP?

 

There is your limiting answer. Don't bother the Forum with questions amenable to simple arithmetic. Spring for a $5 calculator or use the calculator built into Windows.

[Jay-qu]

well I did do the calculations.. but i cant find the piece of paper i did it on.. I had an energy output - but I dont know if that can output enough because I dont know what the overall mass of the system would be

[UncleAl]

but I dont know if that can output enough because I dont know what the overall mass of the system would be

Hell yes you do: per mole.

 

If the answer is indeed indeterminate, why did you post the question?

[Jay-qu]

I wouldnt say the answer is indeterminate - just to me. And yeah sure I worked it out by mol, but what I really meant was that if is where used as the propulsion of a spacecraft then I have no idea what the overall mass of the ship would be, so I couldnt really tell if that amount of energy would be able to accelerate some large mass x..

[HydrogenBond]

Back in the 1960's there was a blue sky space miltary thought project that was based on the idea of strapping rockets onto large orbiting space boulders and then crash landing them in the enemy's back yard, harbors, etc.. One of the ideas for propulsion was based on hydrogen. If you take hydrogen gas and heat it to almost a plasma state, when it reformsm maybe with oxygen you get this extra turbo kick out the hydrogen. Thism I believe, is the basis for what are called ion impulse engines.

[Jay-qu]

isnt there also a hydrogen slush engine design? like liquid hydrogen that has started to freeze or something :hihi: I thought we couldnt get close to making hydrogen freeze...

[nkt]

Hydrogen slush is a way to increase the energy density per unit volume of hydrogen as a fuel. The problem with burning hydrogen is that it doesn't have much energy per mole, and so you need a big container full of light fuel to get where you want.

 

Hydrogen is burned within the ramjet and scramjet engines being designed by the USA military and other groups. It is the best clean fuel for this sort of thing, and leaves a hard to follow trail compared to a gas/petrol burning engine. It also sustains combustion over a very wide range of temperatures, pressures and speeds. In fact, the only downsides are the lack of energy density by volume and the cryogenic tempertures required. (The military don't see cost as an issue, generally. It isn't their money they are burning!)

 

As for blowing up water with electric, if you add some sulphuric acid to the water, it makes it more conductive, and it might be possible to lower the hydrogen bonding using additives. Certainly detergents lower the surface tension dramatically, and this might have an effect on efficiency.

[arkain101]

If there was a terawatt of power running into water as in electrolysis, would it split the water instantly? assuming the ammount was say, 1000 gallons? or at what ammount would it be instant? more or less?

Theoretically, you could contain a small amount of water and jolt it with an intense amount of electricity, which could seperate the water and then burn it, and then sperate it, and end up in burning again with a proper setup.

Or... with a fine mist of water you could send a current through that, which would instantly cause the water to seperate and explode, which might be good for a turbine of sorts and possibly return the exhaust.

[matrixscarface]

Theoretically, you could contain a small amount of water and jolt it with an intense amount of electricity, which could seperate the water and then burn it, and then sperate it, and end up in burning again with a proper setup.

Or... with a fine mist of water you could send a current through that, which would instantly cause the water to seperate and explode, which might be good for a turbine of sorts and possibly return the exhaust.

 

would this still work if it was a terawatt of electricity for only about a microsec?

 

And don't you mean sperate the water, burn it, and then bring it back together?

[Kayra]

Hmm

In effect, you would be using all fo the electricity to produce.... heat.

 

Could put the same electricity through a heating element and get 100% conversion to heat. Apply that to the water and get the same result.

 

This would allow you to use water as a propellant I guess, but you would have to expell the mass of recombined water at some point as reaction mass. No more cycle.

 

Are you trying to design a proplusion system using large amounts of power and water?

[arkain101]

No,

The thought just crossed my mind that if done correctly could a water powered turbine be succuessful. If successful, you could set up a series of conversions through the turbine. It would feed off of water, burn it several times in one passage through the turbine and spit out steam.

Other applications of course could be presented.

My main point is if you zap steam with a high current of electricity can you seperate it, and then instaniously burn it. Like exploding steam. Instead of starting with water in pure cold liquid form.

I would be intriged to mess around with this idea if I had the resources. One could recycle the water through each cylender, if you were to develope an injector that was capable of transfering air and steam into hydrogen/oxygen. etc etc..

[Jay-qu]

My main point is if you zap steam with a high current of electricity can you seperate it, and then instaniously burn it. Like exploding steam. Instead of starting with water in pure cold liquid form.

 

See my 1st post of the thread, I beleive we are talking about a similar idea :hyper:

[Kayra]

Sorry for my confusion :(

 

No,

The thought just crossed my mind that if done correctly could a water powered turbine be succuessful. If successful, you could set up a series of conversions through the turbine. It would feed off of water, burn it several times in one passage through the turbine and spit out steam.

Other applications of course could be presented.

 

So you want to use electricity to generate electricity.

 

Is it possible? Yes.

As long as you are willing to use more electricity then you generate. :(

 

My main point is if you zap steam with a high current of electricity can you seperate it, and then instaniously burn it. Like exploding steam. Instead of starting with water in pure cold liquid form.

I would be intriged to mess around with this idea if I had the resources.

 

Converting water to it's components, and then combining the components should net you 100% efficiency of conversion of electricity into various forms of energy (heat, expansion of the gas, expansion of the hydrogen/oxygen when recombined, more heat, Etc). The problem is, when you try to use that energy to create electricity, you will always end up the loser. Since most of the energy is heat, you will always run into that darned second law of thermodynamics.

 

One could recycle the water through each cylender, if you were to develope an injector that was capable of transfering air and steam into hydrogen/oxygen. etc etc..

 

 

Lost me on that one Arkain101, sorry

[arkain101]

Not as a means of creating electricity..

 

As a means of burning water as an alternative fuel, by instantly converting water to explosive H + 0 instead of storing up hi amounts of Hydrogen in a fuel tank.