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Author Topic: Electric Water Purification  (Read 4025 times)

Offline science_guy

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Electric Water Purification
« on: 01/06/2006 19:25:43 »
Since water will turn into hydrogen and oxygen when you run electricity through it, could you purify water, without using coal, by running electricity through it, collecting all the gases, and igniting it with a spark?  Is there a cheap way of doing this?

Chemistry is not my best field...

E=MC2... m=deg/360 X C... C= PiD

therefore E=deg/360 X 2(PiD)
« Last Edit: 01/06/2006 19:26:16 by science_guy »


 

another_someone

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Re: Electric Water Purification
« Reply #1 on: 01/06/2006 20:25:02 »
In simple terms, it would work.

There are two problems.

Firstly, you would never be able to recover all of the energy you use in electrolysing the water, so there would be massive energy inefficiency in the process.  You could do the same thing by distilling the water and recovering the heat from the distillation, but that too would lead to some unrecovered energy.

Secondly, ultra-pure water is not necessarily desirable from a health perspective (which is why people don't drink distilled water).



George
 

Offline science_guy

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Re: Electric Water Purification
« Reply #2 on: 02/06/2006 19:17:17 »
perhaps on a wheeled vehicle, electricity is generated by the wheels moving, or some other way, stored in a battery, used to seperate the hydrogen and oxygen, ignited as a propulsion for the pistons in the car, therefore making the water go back into the tank, instead of out of the exaust pipe, and generating more electricity to seperate the water.

Is this plausible?

E=MC2... m=deg/360 X C... C= PiD

therefore E=deg/360 X 2(PiD)
 

another_someone

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Re: Electric Water Purification
« Reply #3 on: 02/06/2006 20:18:12 »
The problem is that an internal combustion engine, even at its theoretically most efficient, will only convert 20% of the available energy back to work the rest is lost as heat.  Thus your process is throwing away 80% of the energy available in each cycle.

You could probably do somewhat better by feeding the hydrogen into fuel cells rather than an internal combustion engine; but it will never get to be close to 100% efficient.

The other question is what do you do with the residue (i.e. that which is left after the water is electrolysed)?



George
« Last Edit: 02/06/2006 20:19:54 by another_someone »
 

Offline science_guy

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Re: Electric Water Purification
« Reply #4 on: 03/06/2006 22:25:34 »
for the heat energy, perhaps you could have somthing to recollect it, and for the residue, maybe somthing to collect it as deposits to be changed about everytime you change the oil.  For the lost energy, perhaps you could have a fan that will be turned by the air flowing through the car, turned by the turbines perhaps of water flowing to be used a fuel, and any other ways to make electricity.  You could also put solar panels on the car.

Would that help to solve the problem?

E=MC2... m=deg/360 X C... C= PiD

therefore E=deg/360 X 2(PiD)
 

another_someone

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Re: Electric Water Purification
« Reply #5 on: 03/06/2006 22:51:42 »
quote:
Originally posted by science_guy
for the heat energy, perhaps you could have somthing to recollect it,



The problem is that the 20% limit is the absolute best efficiency that you can get if you recover every last bit of energy you can.

quote:

 and for the residue, maybe somthing to collect it as deposits to be changed about everytime you change the oil.



Quite so, but it is something that will have to be designed in.

quote:

 For the lost energy, perhaps you could have a fan that will be turned by the air flowing through the car, turned by the turbines perhaps of water flowing to be used a fuel, and any other ways to make electricity.



If you get air to turn a turbine then you will increase the drag on the vehicle.  Every way of recovering energy from the motion of the vehicle will cost in terms of having to increasing the amount of energy you will use in moving the vehicle forward.

quote:

You could also put solar panels on the car.



Using solar energy to purify water is not is not new.  Not sure what value the car has in all of this.

It would not be best to use solar electricity to electrolyse water since at present most solar cells are only about 14% efficient.

The better option is simply to use the sun to directly heat the water, boil off the water, and then feed it through a condenser (using a heat exchange unit to try and cool the condenser while pumping the heat back to the evaporator).



George
 

Offline science_guy

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Re: Electric Water Purification
« Reply #6 on: 05/06/2006 03:38:19 »
Thanks for the input.  There goes another one of my theories.  :)

E=MC2... m=deg/360 X C... C= PiD

therefore E=deg/360 X 2(PiD)
 

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Re: Electric Water Purification
« Reply #6 on: 05/06/2006 03:38:19 »

 

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