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Topic: Cheaper Hydrogen From Recycling Brine Electrolysis Products?  (Read 6310 times)

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Offline TheLorax

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Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« on: September 11, 2014, 10:37:47 PM »
Shoot this down....

I have the opinion that recycling the products of brine electrolysis Cl2 and NaOH into a well made chemical reactor to make the neutralization reaction to harvest the enthalpy so that the heat can be used in an organic rankine type of engine is the way to make cheaper hydrogen.

The reaction makes a big pile of charged particles so why not use that?

My research is not good but my internet searching gives me 155 kj per Mol of reaction and that is alot of enthalpy.

Purifying NaOH is not difficult, purifying HCl is more difficult but not impossible if you spend enough $ on PE's.  It looks like a 90% return each time which makes for about six cycles which is way over the amount of electricity originally spent.

That half life type of figuring confuses me.

One flaw may be that the amount of zap needed to break NaCl is more than just breaking up distilled H2O.  Changing the second stage might help, its an option.  What I mean is that for the first stage to use NaCl and the second cycle plain H2O.  Instead of making 1/3 H2, you get 100% product.

The battery people are on to this.  They want to charge liquids and have electric car drivers fill up with two liquids at the fuel pump.  After the cations and anions are spent, you go back, disgorge the spent fluids

Am I clear?

KatyPerrysLeftBoob
« Last Edit: October 27, 2014, 04:17:49 PM by Arkcon »

Offline Borek

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #1 on: September 12, 2014, 02:43:39 AM »
I don't see a neutralization reaction here.
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Offline TheLorax

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #2 on: September 12, 2014, 04:59:00 AM »
Introduction and Definitions:

A salt is any compound which can be derived from the neutralization of an acid and a base. The word "neutralization" is used because the acid and base properties of H+ and OH- are destroyed or neutralized. In the reaction, H+ and OH- combine to form HOH or H2O or water molecules. A neutralization is a type of double replacement reaction. A salt is the product of an acid-base reaction and is a much broader term then common table salt as shown in the first reaction.

The following are some examples of neutralization reactions to form salts.

a. HCl + NaOH --> NaCl + HOH

Offline Borek

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #3 on: September 12, 2014, 06:13:52 AM »
And?

Brine electrolysis produces NaOH and Cl2, which of these two is the acid?

Or, in other words - where does HCl in your scheme comes from?
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Offline TheLorax

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #4 on: September 12, 2014, 11:45:09 AM »
HCl comes from here

 2 Cl2 + 2 H2O → 4 HCl + O2

referenced at the bottom of the page



Formation, stability and reactions

Addition of chlorine to water gives both hydrochloric acid (HCl) and hypochlorous acid:[8]

    Cl2 + H2O is in equilibrium with HClO + HCl

When acids are added to aqueous salts of hypochlorous acid (such as sodium hypochlorite in commercial bleach solution), the resultant reaction is driven to the left, and chlorine gas is formed. Thus, the formation of stable hypochlorite bleaches is facilitated by dissolving chlorine gas into basic water solutions, such as sodium hydroxide.

The acid can also be prepared by dissolving dichlorine monoxide in water; under standard aqueous conditions, anhydrous hypochlorous acid is impossible to prepare due to the readily reversible equilibrium between it and its anhydride:[9]

    2 HOCl is in equilibrium with Cl2O + H2O K(0°C) = 3.55×10−3 dm3mol−1

The presence of light or transition metal oxides of copper, nickel, or cobalt accelerates the exothermic decomposition into hydrochloric acid and oxygen:[9]

    2 Cl2 + 2 H2O → 4 HCl + O2

9  Inorganic chemistry, Egon Wiberg, Nils Wiberg, Arnold Frederick Holleman , "Hypochlorous acid" p.442 , section 4.3.1

Offline Borek

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #5 on: September 12, 2014, 12:31:59 PM »
HCl comes from here

 2 Cl2 + 2 H2O → 4 HCl + O2

Far from being obvious. Bleach solutions are reasonably stable, so it can't be really fast.

Do you have anything on kinetics? Transition metals accelerate the reaction, but can it be made fast enough for commercial applications?
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Offline TheLorax

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #6 on: September 13, 2014, 11:31:32 AM »
Hi - this doesn't look good.  I thought the neutralization reactor was the hard part, its doesn't look like it now.  A reactor like that looks manly. Its full of muscle heat and force and its likely to grow a beard after a while. 

There is plenty of room for bench type chemistry here and its more exciting because you get to work with gases that are poisonous, explosive and very explosive and I haven't even mentioned acid yet.

"A man hears what he wants to hear and disregards the rest"

1) I have little information about using transition metals  this way although I'm glad to kind of find out that these accelerators  seem to be a catalyst and not a consumptive reactant.  I can't find one paragraph about the matter beyond these two mentions.   That book referred to is $775 on Amazon, Google Books has part of that book with that page missing and I  found it on worldcat so I can get those pages on inter library loan.  I'm glad I found that book, it looks like a some kind of ....bible. I think the book will just say "accelerates".  Having the catalyst in an acidic solution is worrisome.  It looks like testing would be needed.  I don't know if bars, balls, chips or powders work best and I don't know about flow or volume.

2) There is reference to breaking HOCl with sunlight.  Half the pages say it breaks into HCl + O2 and the others say it breaks into something else.  This is magic then.  No info on duration or intensity.  I think this how swimming pools change pH.

3)  Cl2 + H20 <-> HCl + HOCl.  Back and forth reactions are a mess because the have four ish unstable  reactants .  I don't think you can distill something like that easily.  Random web pages say you can shift to one side or the other with temp and pH.  I found a book from Hollerman and the book says HCL + HOCl can be distilled.  I've read about HCl purification but I didn't retain much.  Something about azeotrope. Cl2 dissipates but it leaves plenty of water in the solution.
I think its a good idea to try to keep all of the Cl that can be kept, that is the point of the recycling.


Thanks for the attention!

K
« Last Edit: October 27, 2014, 04:17:19 PM by Arkcon »

Offline billnotgatez

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Offline TheLorax

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #8 on: September 13, 2014, 02:04:32 PM »

Offline Arkcon

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #9 on: September 13, 2014, 03:06:50 PM »
First of all, thanks for changing your username.  Of all the things I've ever wanted to do to KatyPerry'sLeftBoob, having an argument was not one of them.

I think your post is somewhat all over the place, I'd like to contribute, but its hard to know where to begin.  Lets try to take it point by point, and lets see if you can clear it up.

Shoot this down....

Well, I'd like to start with a question, that I can try to answer, on this board.  But OK, if you want a debate, that's fine.  Please remember, you're the one who asked for it.

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I have the opinion that recycling the products of brine electrolysis Cl2 and NaOH

I understand this part so far ...

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into a well made chemical reactor to make the neutralization reaction to harvest the enthalpy so that the heat can be used in an


OK, two different ways of saying you're going to use heat from a reaction to drive something else.

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organic rankine type of engine

I have no idea what this is.  Is it a typo?  Some sort of engine?  A Rankin engine?  But what is an 'organic type' Rankin engine.  Please identify this, if its an important part of the premise.  If this is a metaphor you've come up with, then please exclude it at this stage -- it makes it hard for use to follow.

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is the way to make cheaper hydrogen.

OK, I'm going to assume you're aware of the laws of thermodynamics.  You don't claim to be trying to get all of your energy back from electrolysis, just some to reduce the cost.  Fine.  Just don't be disappointed when it proves minimally useful.

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The reaction makes a big pile of charged particles so why not use that?

Sure.  Why not.  Unless its impractical.

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My research is not good but my internet searching gives me 155 kj per Mol of reaction and that is alot of enthalpy.

Which reaction, in particular?  Perhaps one you mention later?  Why not organize this better so you mention it first.

Quote
Purifying NaOH is not difficult, purifying HCl is more difficult but not impossible if you spend enough $ on PE's.

All purification is at least minimally energy intensive.  So that's some wasted work.  Although why you have to, given the inputs are the same as the outputs, I don't know.  Again, this would be a more useful thesis if you explained every reaction you need from the beginning.

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  It looks like a 90% return each time which makes for about six cycles which is way over the amount of electricity originally spent.

I don't understand the significance of this statement.

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That half life type of figuring confuses me.

Likewise, I can't follow this.

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One flaw may be that the amount of zap

Amount of 'zap'?  Can we stick to defined chemical terms please.

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needed to break NaCl is more than just breaking up distilled H2O.  Changing the second stage might help, its an option.  What I mean is that for the first stage to use NaCl and the second cycle plain H2O.  Instead of making 1/3 H2, you get 100% product.

I'm unaware of stages at this point.

Quote
The battery people are on to this.  They want to charge liquids and have electric car drivers fill up with two liquids at the fuel pump.  After the cations and anions are spent, you go back, disgorge the spent fluids

Am I clear?

No, you're not.  And your later posts aren't much better

Quote
KatyPerrysLeftBoob
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline TheLorax

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #10 on: September 13, 2014, 07:38:06 PM »
Hi Arkcon,

Thanks for your reply.  I'm sorry I offended you with my name.  I thought my judgment was good since I saw something immature like images from South Park being used and I got a little too relaxed.  That show is where young children are depicted as taking LSD and then they are shown  taking their clothes off.  I read rules about discussing drugs use but really, I don't run this place.  I think people in San Francisco complain alot.  I don 't know, I'm not from there but that's what I hear.

I don't expect much here, you get what you pay for.  Who knows who you'll meet at the bus stop.

You did a really great job discussing earwax.  I guess chemicalforums.com is place to learn about cleaning out you body orifices and its a good idea to have clean orifices like after you defecate or when you pick your nose.

Offline Arkcon

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #11 on: September 13, 2014, 09:12:40 PM »
Not a fan of Tweek?  I always liked him, seems like the odds are always stacked against him.  That's a cute little image from that 'Raiders of the Lost Ark' spoof they did.  At any rate, maybe you can envision him pointing a bazooka, like Indiana Jones, just to get someone to pay attention.

Yeah, we're here for all aspects of science here.  We even play along with science fiction, from time to time.  Works well if people play along, or just leave themselves open to a joke.  But hey, thanks for browsing my older posts.  I'm innocently wrong from time to time, and sometimes embarrassingly wrong.  I'm not mortified by any of my posts, 'tho, so you could say, on balance, I'm proud of them.

Are you working on a cogent summary of your point in this thread?  I'd like to read it.  If you really care about the topic, a complete summary might be something you can be proud of.  Even if a detail or two turns out to be incorrect.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Zyklonb

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Re: Cheaper Hydrogen From Recycling Brine Electrolysis Products?
« Reply #12 on: September 18, 2014, 11:02:50 AM »
Ahh...
I'll start with this:
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Purifying NaOH is not difficult, purifying HCl is more difficult but not impossible if you spend enough $ on PE's.

Purifying NaOH is quite a bit more difficult then that of HCl(aq) NaOH is very hard to get out of solution, due to it solubility and hygroscopicity. Dilute HCl can easily be distill so long as the setup is airtight to prevent fumes from escaping.
Quote
One flaw may be that the amount of zap needed to break NaCl is more than just breaking up distilled H2O.  Changing the second stage might help, its an option.  What I mean is that for the first stage to use NaCl and the second cycle plain H2O.  Instead of making 1/3 H2, you get 100% product.
By "zap" I assume you mean energy, in the form of electricity. In which case, yes, see this:
 
Cathode:  Na+ + e- → Na(l)   E° = –2.71 v
Anode:  Cl- → ½ Cl2(g) + e–-   E° = –1.36 v
Net:  Na+ + Cl- → Na(l) + ½ Cl2(g)   E° = –4.1 v

Cathode: H2O + 2 e- → H2(g) + 2 OH-   E =+0.41 v ([OH–] = 10-7 M)
Anode:  Cl- → ½ Cl2(g) + e-   E° = –1.36 v
Net:  Cl- + H2O → 2 H2(g) + ½ Cl2(g) + 2 OH-   E = –0.95 v
Didn't that simple equation make everything more understandable?
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Cl2 + H2O is in equilibrium with HClO + HCl
True, that reaction does work. And you're right about how it can be shifted so the HOCl (much better  way of writing HClO) does decompose quickly (with the aid of uv light and/or certain catalysts.) However, the HCl is very difficult to concentrate, as it reacts with HOCl: HCl + HOCl → H2O + Cl2. Effectively destroying any HCl as it's produced. This happens when the morality of the HCl get's over two - which is quite dilute.
I see no reason to pursue this topic further as a major premise is wrong. Even though there is plenty of other misconceptions which I would like to debunk, if I had the time.

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