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Re: Flash Distillation

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  • tgfoitwoods
    Paul, I can agree your example, and because one of the liquids has no appreciable vapor pressure, only the volatile water would evaporate. That also holds true
    Message 1 of 43 , Mar 10, 2013
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      Paul,

      I can agree your example, and because one of the liquids has no appreciable vapor pressure, only the volatile water would evaporate. That also holds true with your example of volatile methanol and the (essentially) non-volatile, or at least very low vapor pressure, diesel. Both should work fine, according to Roualt's law.

      Yes, I will admit to being a "science geek" by education and later an engineer, also by education, but by and large I've found science to explain and predict behavior of the physical world better than, say, intuition or faith.

      Robert, you want a process that completes way faster than a potstill, but if you look the potstill process, the entire process, that of boiling the boiler to dry, the distillate collected will be identical in concentrations of volatile liquids as what you started with, which is of absolutely no use to the beverage distiller. Flash evaporation essentially does a tiny potstill run in a very short time, but the concentrations will still be unchanged. As beverage distillers and potstiller, we stop the process long before it's finished, and at a point where concentration have been changed radically. 

      If I may quote you, "Keeping chamber heat below boiling point of water should maximize evaporation, while not turning all liquids into a vapor." Yet again, that's in direct violation of Roualt's law, which is a very-thoroughly tested physical law, and not simply an opinion. I read very carefully about your fine droplets, which again, in no way change the behavior predicted by Roualt's law. I encourage you to read this:
      http://www.chemguide.co.uk/physical/phaseeqia/nonideal.html

      In the event that I've missed something, and in the further event that you've found information relevant to separation of volatile components of a mixture by flash distillation, please give us that reference or link, and we can put the discussion to rest.

      If you can't produce such a reference, it will still seem to me that you are believing in leprechauns, and I'll remain in apostasy.

      Give us something solid to clear this up, or there's no longer a point to this discussion.

      Zymurgy Bob, a simple potstiller Making Fine Spirits


      --- In Distillers@yahoogroups.com, self.adhesive@... wrote:
      >
      > Here's another use for flash evaporation :  removal of dissolved and suspended water from oils, particularly waste vege oil for use as fuel. In these instances the oil has no appreciable vapour pressure. FE can be used to remove excess methanol from newly-formed biodiesel, which is an ester - the condensation of an organic (fatty in this case) acid and an alkali hydroxide say NaOH.
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      > To me the key factors affecting Robert's proposal are - pressure in the receiving vessel, discharge pressure, temperature of the fluid being evaporated, rate of heat input, and latent heat of vaporization. Azeotrope at this point plays no part.
      >
      > What Robert is suggesting is that these factors be arranged in such a way that only a portion of the sprayed wash evaporates, and he believes that in accordance with Bob's graph the portion that will be most likely to evaporate is the ethanol thus a purifying process occurs.
      >
      > I'm not backing Robert in this, but it sounds technically possible. I was just trying to get back to sleep and had these ideas bouncing around in my skull and had to get them out :D.
      >
      > Paul
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      > --- On Sun, 10/3/13, tgfoitwoods zymurgybob@... wrote:
      >
      > From: tgfoitwoods zymurgybob@...
      > Subject: [Distillers] Re: Flash Distillation
      > To: Distillers@yahoogroups.com
      > Date: Sunday, 10, March, 2013, 9:02 PM
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      > Ok, I had to read up on flash distillation to be certain that I understood it, but mostly what I found was flash evaporation of a mixture of a volatile liquid and a non-volatile solid, as in a water desalinization plant. In that case all of the volatile liquid is vaporized and re-condensed as product, while the non-volatile dissolved solids remain in the flash chamber.
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      > As beverage distillers, we are trying to change the relative concentration of a mixture of volatile liquids, especially to increase the concentration of ethanol, and only incidentally leaving the solids behind.
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      > Unless I'm terribly mistaken, when you "flash" a quantity of a mixture of volatile liquids, you vaporize all of that quantity, and aside from some loss of solids, the concentrations of the volatile liquids going out to be condensed should be identical to the concentrations going in, which would be useless to us as beverage
      > distiller.
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      > Robert, it sounds like you are saying that so long as you hold the flash temperature below the boiling point of water at that pressure, the ethanol will vaporize and the water won't, and that puts us back in the realm of believing that a mixture of volatile liquids has multiple boiling points, that by controlling temperature we can control which volatile liquids vaporize, and which don't. That's just not true and never has been, although it's often cherished by new distillers.
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      > The simple immutable truth is that such a mixture has one single boiling point at a specific pressure. If you hold the temperature below that, you'll get relatively slow evaporation of ALL volatile compounds, in a ratio determined by Roualt's law of partial vapor presures. If you get the temperature to that single boiling point, and keep inputting the latent heat of evaporation, you'll get relatively quick evaporationf all
      > volatile compounds, again in that same ratio determined by Roualt's law of partial vapor pressures.
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      > I don't see any method utilizing flash evaporation that lets us increase the the ethanol concentration, even though it's great for de-salinization of sea water. Am I missing something?
      >
      > Zymurgy Bob, a simple potstiller Making Fine Spirits
      >
      >
      > --- In Distillers@yahoogroups.com, Jan Ooms jkooms@ wrote:
      > >
      > > Hi Robert,
      > > As a small hobby distiller I certainly am interested in your flash distillation. It certainly would not make me change my distilling habits at the moment.
      > > I always have an open mind to people that experiment to improve anything and everything. If your experiment doesn't work out, you have learned something, kept your brain active and lost sweet buggar all. The
      > small amount of money you mentioned is of no importance at all.
      > > I just hope that you will let us know how it all worked out, good or bad.
      > >  
      > > Good Luck My friend.
      > > Jan.
      > > Brisbane. OZ
      > >
      > >
      > > ________________________________
      > > From: RLB last2blast@
      > > To: "Distillers@yahoogroups.com" Distillers@yahoogroups.com
      > > Sent: Sunday, 10 March 2013 2:36 PM
      > > Subject: Re: [Distillers] Flash Distillation
      > >
      > >
      > >  
      > >
      > > Actually, there are many forms of flash distillation and ways of doing flash distillation (pot still like or reflex)  First and foremost is that it can be used to strip wash very quickly as in 1 gal per min.  All you need is a Stainless Steel barrel with drain, outlet pipe (for vapor), heat source, compressor, pipe to hold nozzle in center of drum , and a spray nozzle.  Heat drum to 204 F (In my
      > area my area boiling is 206 F)  As long as I keep interior of drum 204 F and drained of water, Ethanol will turn to gas before the water hits the bottom of the barrel.  Yes, some water will turn into gas too but this is a stripping run.  Compressed air should help to force vapor out  the top and water out of the bottom of barrel, and compressed air should also provide an inversion layer that keeps lighter ethanol vapor going up and heavier water droplets fall to the bottom to drain.    If you are just after high proof ethanol then set it up like a reflex
      > > flash still.  From what I have read so far, the process is simple even for someone with my experience.  If I were to set up several barrels in series (with different temperatures), there is a good chance that cuts can be made without too much of a problem.  Temperature setting will be the most difficult to determine.As for your
      > engineer friend, my bet is that he set it up as a pot flash still, but expected reflux results.  65% abv is almost what I (55% to 65% abv) achieve from my pot still during a stripping runs.  The science for alcohol flash distillation is well established, but I have not heard of anyone actually using it for ethanol.  This is totally amazing to me.Robert
      > >
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      > > ________________________________
      > > From: "self.adhesive@" self.adhesive@
      > > To: Distillers@yahoogroups.com
      > > Sent: Saturday, March 9, 2013 8:10 PM
      > > Subject: Re: [Distillers] Flash Distillation
      > >
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      > > A guy I know here, who has been stilling for 10 years and is an engineer, built a continuous fermenter and distiller as one unit. It produced so much 65% alcohol - 6.5 litres a day he said - that he had to turn it off and he went back to the old ways.
      > >
      > > Flash evaporation is
      > nothing new, but if you read up on refluxing at homedistiller.org you will find putting it into practise with ethanol will be pretty tricky. In refluxing the ethanol is evaporated and condensed over and over as it rises up the column, each time evaporating off in a purer and purer form. Flash evaporators as far as I am aware do it just the once. The graph that ZB refers to often pertains here. Of course you could feed the distillate through again and again, but that's what  happens in refluxing anyway. It would probably work satisfactorily with pot stilling..
      > >
      > > To be quite
      > > honest Robert, I think at your level of expertise, experience and understanding making a miracle breakthrough will be pure serendipity. Kind of like winning a lottery...simply luck and it doesn't happen very often at all.
      > >
      > > Paul
      > >
      > > --- On Sun, 10/3/13, last2blast last2blast@ wrote:
      > >
      > >
      > > >From:
      > last2blast last2blast@
      > > >Subject: [Distillers] Flash Distillation
      > > >To: Distillers@yahoogroups.com
      > > >Date: Sunday, 10, March, 2013, 10:45 AM
      > > >
      > > >
      > > > 
      > > >If I had known about Flash Distillation months ago, I would have my still built for me rather than wasting these many months on current stone age home distilling technology and techniques. Flash Distillation has been around for more than 100 years, and no one mentioned it in my reading, homedistiller.org, Artisans, new distillers, or distillers. It does raise a few interesting questions as to why the experts are still using this old technology. I guess it was a good that my idea was researched even further..
      > >
      >
    • RLB
      I just wanted to tell someone since I dropped the flash distillation subject on Distillers. I figured out how to use it for stripping, and how to use it for
      Message 43 of 43 , Mar 14, 2013
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        I just wanted to tell someone since I dropped the flash distillation subject on Distillers.

        I figured out how to use it for stripping, and how to use it for making cuts.  It will cost around $1,000 to build though.  Now the subject is officially dead for me.

        Robert  



        From: "Distillers-owner@yahoogroups.com" <Distillers-owner@yahoogroups.com>
        To: Distillers@yahoogroups.com
        Sent: Monday, March 11, 2013 9:40 PM
        Subject: [Distillers] Re: Flash Distillation

         
        Message from Management to "last2blast"

        Your posting privileges have been demoted to "moderated".
        Reason:
          Due to excessive badgering by you of both the Y!D forums, re your "new distilling idea".
        Whether it works or not, isn't the issue.
        Harassment is the issue.  Harping on unfounded and untested notions is the issue.
        You've had more than a fair hearing in BOTH groups.  Now it's time for you to "put up, or shut up".  When you are ready with the results, post 'em. Mods will see if you're contributing to the distilling topic, or just continuing to blow steam.  Your post will be dealt with on that score.
        Footnote:
        Part of The Charter for this group states...
        "It is a 'given' that you are familiar with basic distilling."
        I strongly urge you to get educated re Distillation before you continue.  Else you're gonna do yourself a mischief.
         

        The Management
         
        PS for other posters.
          Kindly trim out all the unnecessary previous posts when sending messages to these Distilling groups.  Help us to help you.


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