Separating compounds

[Vending]

well...i suppose that I did fly off the handle a bit. I am sorry. Its just that i get a little upset when people go all nuts on others for asking simple questions. I guess my take on it is as follows. Unless you came out of the womb knowing all about thermodynamics, you must have had to be educated about it yourself. Thus, you are really no different than the person asking the question, you just happen to be a bit farther along. No one is forcing you to reply. So if you think that the question is stupid, then keep your mouth shut. Basically, don't reply to a question unless you intend to either, clarify the question or attempt to answer it.

 

Yeah, so, in conclusion,

Was mike's question quite simple and a display of ignorance? YES

 

Did it still deserve an answer that would help him out? YES

 

Was there any need for Al to give such a terse and uniformative answer? NO

 

Was anyone forcing AL to reply? NO

 

Yeah, so really, if you have nothing to say, then don't say it. I mean, I realize that these type of questions are ask all the time, and they boil down to, "can we violate the laws of physics as we understand them?" ANd they ARE silly, but they are silly becuase the posters to not understand, and need to be educated. I do not think that mike was being beligerent. He was just asking an honest question, doesn't this deserve an honest answer?

 

As per the who picture fiasco, i stand by what I said. getting all up in arms becuase someone has the same image as you is just rediculous and childish. Was it pretty stupid of mike to choose that image, knowing that al had it? Yes. But still, in the end, it just doesnt' matter.

[mike89]

to be perfectly honest i didnt choose the icon because al had it i chose it because it was on alist of things to choose from and i happened to like this one.... and about the question since no one reasoned WHY it was a bad answer except for 1st and 2nd laws of thermodynamics.. and "youre an idiot" which having read them both i dont understand why it would not be possible to do this someone please help me out here.... if an efficient enough process and quick processing speed of electrolysis to separate the oxygen O2 and the hydrogen H from the previously existing water molecule H2O (2H2O) then you could use the hydrogen for a gas... and the oxygen as a fuel... which pure oxygen is a way better power gain than N20 or nitrous oxide... all N2O is, is a "diluted" version of O2 so the combustion temperature doesnt over heat and destroy your engine... but in small amounts i see no problem with it..... now someone please tell me what is wrong with the whole electrolysis thing?

[Jay-qu]

The problem is no matter how efficient it is you cant get more energy out then you put in - you will not even get the same, always less. This is because of friction and other ways of transfering energy to undesirable forms for this context.

[CraigD]

… i always wondered if it would be possible to use electrolysis efficient enough to use water to power a hydrogen powered car... and then use the o2 to inject it into the intake and make a really powerful yet environmentally secure automobile! yay!

Yes, what you describe is possible, and has been prototyped with many kinds of fuel cells. To my knowledge, no automobile-class (50 KW+) closed system fuel cell power supply has yet been created. Yay!s, however, I think are premature.

 

Besides the more commons system with a separate electrolysizer and fuel cell, a promising closed fuel cell system involves “regenerative fuel cells”, in which the fuel cell itself can be “run backwards” to separate H20 into 2H and O. To date, however, the problem of removing the H and O from close to the fuel cell’s proton exchange membrane have been insurmountable, limiting regenerative fuel cells to very small In addition to the environmental advantage – zero emissions – a closed system also can potentially avoid fuel cell life shortening contaminants (eg: CO) although sealing a system completely enough to avoid hydrogen loss or contamination is not a trivial engineering challenge. Also, currently, electrolysis efficiency is usually about 65%, best around 85%, while electricity generating only efficiency of PEM fuel cells rarely exceeds 25% (combined electrical and thermal efficiency of molten carbonate and phosphoric acid fuel cells approach 80%, the electric only part is still only 20% or so), for total system efficiency of less than 17%, much worse than the 75-95% to be had from lead acid and other chemical batteries.

 

So, essentially, a closed H2O fuel cell system is a very inefficient, expensive storage battery, that could potentially have many more (potentially unlimited) charge cycles than a chemical battery. Since current electric power is supplied mostly by burning hydrocarbons, a closed H2O fuel cell system would be more polluting than an ordinary, hydrocarbon-burning engine.

 

Such systems may find applications is places where hot steam exhausts are unacceptable (eg: embedded in electronics), but are unlikely, IMHO, to be very useful in powerful vehicle applications.

[mike89]

thanks for the info very helpful! unlike others on here...

[Vending]

The problem is no matter how efficient it is you cant get more energy out then you put in - you will not even get the same, always less. This is because of friction and other ways of transfering energy to undesirable forms for this context.

 

 

I think that, in this case, it is not so much friction that is the problem as it is heat. Of course, friction can give rise to heat, but I don't think this is what is happening in this case. I think for Mike's proposed cell the main sources of inecefiency would be the lost heat due to combustion of the fuel and the head generated by the resistance of the wire in the electrochemical cell.

 

Though I am not sure that I fully understand what you propose, Mike. It seems like you are spiting water and then re-forming it. If this is the case, then it will never work as an energy source. At least not a self-contained one.

 

The reason is that if you split water;

 

H2O --> H2 + O2

 

this requires some amount of energy, delta G. Then when you reform the water;

 

H2 + O2 --> H2O

 

this will release some amount of energy, delta G.

 

Of course, since these reactions are the same, just running in different directions, the energy required and released is the same. Thus, in a 100% efficient cell, you will just break even, energetically. ANd in the real world, you will lose energy every cycle.

 

Of course, I could be misunderstanding your proposed cell.

[mike89]

it wasnt proposing a closed system just one that would run off water instead of gasoline and injecting the o2 to make the car have more power

[madazn89]

:) interesting guys, although I didn't read every reply on here so I only got part of what you guys were talking about, as we all know some have nothing to do with anything important, LOL. anyway my moon research paper is finished and posted, go read it and give me some fead back please.

thanks

madazn:phones:

[Odin]

Hi,

I would like to know some of the processes of separating chemical compounds such as titanium oxide.

madazn B)

 

Not to be offkey but there is a procedure of dissolving an amount of urea in H2O and adding CaO to get 2 H2O + CN2 + Ca.

With this procedure heat is only required but with titanium an electric catalyst may need to be present

[Kayra]

http://en.wikipedia.org/wiki/FFC_Cambridge_Process