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Jor
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constant boiling hydrobromic acid
First of all, I know there about 3 threads about this subject.
But this is more of a question about what I'm doing wrong.
I followed procedure in Vogel, but scaled down 10 times.
So 24 grams of KBr (lab-grade) were dissolved in 40 mL of water (deionised). Slight heating was needed.
Slowly, while cooling, 18mL of 96% sulphuric acid (lab-grade) was added. Some HBr fumes evolved during this process.
The solutionw as decanted, and a glass rod was used to 'free' the trapped crude HBr in the KHSO4 crystal mess.
This was distilled. About 3mL came over at 100-110C. This was discarded, and tested with hydrogen peroxide. No bromine was formed, so this was mostly
water.
then the temperature raised slowly, and after about 1-2 minutes, 125C was reached. About 4mL was collected already. Now the temperature was maintained
at about 127C, but went to 135C once. After distillation, I put my product in a beaker.
There was about 28mL of liquid, nonfuming. It weighed about 38grams.
That is a specific gravity of about 1,36. 48% HBr is said to have a specific gr. of 1,49.
So I'm having a dilute HBr-solution  .
What did I do wrong? Maybe onbtained distillate in the 1-2 minutes when the thermometer raised to 125C should have been discarded as well? I'm not
really sure. Besides, even if I discarded that, 1,49 would still not be obtained...
And if I may ask, can the dilute solution be concentrated by just boiling it, until the temperature at thermometer starts rising above 100-110C ?
And my last question (I know, many questions!  ), does anyone know what
concetration my HBr is, and can it be used for synthesises in organic (e.g. isopropyl bromide). I do not have the apparatus for deteming H3O+
-concentration.
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BromicAcid
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One key component missing to your question is, what kind of setup were you using for the distillation? Specifically, what kind of collumn did you
use? Without a good collumn your azeotropic HBr (aq) is going to be less than perfect.
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Jor
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I just a very basic distillation-setup.
But even if I should have used a good column, the spec. gr. shouldn't be so low, right?
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Klute
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I guess your setup offered a very poor seperation, and that the water content was higher than that of the azeotrope. If all the water present was
distilled with the HBr, your solution would ~28%, ~30% counting the discarded 3mL forerun (assuming it's only water).
maybe you should try using less water at the beggining (although complete dissolution of KBr might be difficult, and the K2SO4 slurry much thicker),
or at least use a decent vigreux column or other means of offering a better seperation.
For reaction such preparation of isopropyl bromide, you can prepare your HBr in situ without prior distillation, just add conc. acid to a hot
saturated solution of KBr and then add your alcohol dropwise while distilling the bromide (or after a initial reflux period, check availble
procedures). But even consideirng you solution is close to 30%, i guess it can be used as such for simialr reactions.
Acido-basic titrations are very easy to perform, you can obtain rough results without burettes or precise volumetric glassware. Indicator such as
phenolphtalein can easily be obtained (in the worst case, but those chemistry boxes for kids, even a gram of phenolphtalein will last a looong
time..), and use a graduated pipette (in worst a large syringe or something). even if you will not have 0.1% precision (which you surely won't need
anyway), you can determine concentrations at a few % close.
Always use dilute solutions (0.01-0.10mol.L), acido-basic standards such as oxalic acid, hydrogenophtalate, bicarbonate, etc can be used as long as
they are dry and pur.
You cna also titrate KMnO4 solutions with ascorbic acid, I2 with thiosulfate (zn indirect iodide titrations, such as reacting a unknown conc. H2O2
with exces iodide, and then titrating the formed I2 with thiosulfate to determine conc. of H2O2, etc). Titrations can be very usefull for determining
conc. of reatgents, yields of reactions, etc and often can be fone with available materials.
I think people who have actually prepared the HBr azeotrope would be more abilitated to answer your questions than me, and how important the
seperation needs to be.
Good luck with your futur reaction, please report your results!
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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BromicAcid
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It all depends on how carefully you distill. With just one distillation it would be difficult with that setup to get a pure product. Even taking
into account the forecut that you discarded you would have to re-distill your product a few times to get it to the constant boiling azeotrope without
the help of a vigurex collum or the like. Azeotropes are strong, but unless you are starting with the exact azeotropic mixture to begin with you can
skew your mixture without repeated distillations. If you read some of the older texts where they are distilling off a given azeotrope, the first
distillation gives a somewhat dillute product, the next more concentrated, and after a few more distillations a constant boiling azeotropic mixture.
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Klute
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hehe the compound itself showed up and answered the questions, you won't find better advise 
EDIT: Oh my, I apologies!  Didn't want to "reduce" BromicAcid
[Edited on 2-7-2008 by Klute]
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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12AX7
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Not quite, your compound is lacking three oxygens
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Jor
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Thanks for all the replies.
I still have numerous uses for the dilute acid (well, actually, it's not that dilute, just not concentrated).
I now have about 80mL of the 28-30% acid (little remained in the distilling flask, just a few mL of liquid and a piece of broken glass for smooth
boiling, so I take your 30%, maybe a little more.), so I think i will redistill it tomorrow, to obtain a higher concentration.
Do you think it is possible to obtain the constant boiling acid with a vigreux in one distillation?
Oh, and BromicAcid, after reading almost all threads on sciencemadness, I conclude you are almost always present when the subject is Br2, HBr,
bromates and perbromates. You really like the element do you ? 
I also love Br and I.
Cl a little less.
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woelen
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Jor, you really need a vigreux column. The boiling points of water and the azeotrope are way too close and your separation is not good at all. I even
had trouble distilling bromine from water. Bromine boils at almost 60 C, water at 100 C, but the distilled bromine still contained quite a few
droplets of water, so separation was not perfect. Vigreux columns make distillation slow, but separation is better (still not perfect).
I actually find that you have done quite a good job if you obtained 30% HBr.
Using less water in the initial preparation is not a real option. I tried that a long time ago, but then there is unwanted oxidation of bromide to
bromine and your product is not colorless anymore. I found it particularly difficult to separate traces of bromine from HBr. These solutions contain
the Br3(-) ion, and the bromine sticks to the bromide ions and are not simply boiled off at 60 C.
The best way to prepare concentrated HBr is the use of KBr and 85% phosphoric acid. You could use your distillation setup with careful heating (not
exceeding 80 C or so, otherwise the phosphoric acid attacks the glass). Gaseous HBr escapes from the liquid. In your receiver flask you have to put
water and you need an inverted funnel, just touching the water surface. This method assures that no suck-back is possible, if production of HBr
ceases.
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Jor
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Ok, I guess I will have to buy a vigreux some time then.
Is it really not possible to use less water? You could make a very cold ice bath, and add H2SO4 dropwise. AFterwards, if any bromine has formed, maybe
adding a saturated SO2-solution drop by drop might help?
I don't think I wanna try the H3PO4-method. First phosphoric acid is not really cheap as well. Second, flask are quite expensive. So I don't think I
will try this. Rather buy it then. I will try it someday for HI though. But I also find the H2S method very interesting (and I can get iodine very
cheap, about 18 EUR for 250g, 'very pure grade'. I2 is cheaper for me than KI
), but problem is the extreme toxiciy of H2S. Unless I can build an entirely closed apparatus in a fume hood, I won't attempt this.
If using a vigreux, isn't it more economical (in terms of use of energy) to apply aluminium foil on the vigreux?
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woelen
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You should not isolate the vigreux, if you do that, then you neutralize the effect of this and then you can as well leave out the entire thing. Using
a vigreux is inherently more energy-consuming. In winter-time that is fine, then you need less heating .
Your suggestion with SO2 does not sound good. First you use less water, and then you use extra water to compensate for oxidized bromide. A solution of
SO2 is not that concentrated, so you will use introduce quite some water again. You could try some experimenting to find the maximum concentration of
acid, for which there is no oxidation of bromide. But there also is a chance that under such conditions the material will become partly oxidized while
heating it for your distillation. But there is only one way to know this, and that it trying it.
I have some commercial HBr and it is not completely colorless. It has a faint yellow/brown color, the color of very dilute bromine. There is no
visible bromine vapor above the liquid though.
Commercial HBr is fairly expensive. IIRC I had to pay EUR 18 for 500 ml of this stuff. It was from an old GDR-lab, not from an official source.
Official sources probably ask even more for this chemical.
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blogfast25
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| Quote: | Originally posted by Jor
If using a vigreux, isn't it more economical (in terms of use of energy) to apply aluminium foil on the vigreux? |
A vigreux column should never be insulated because by doing so you essentially reduce the distillation to a one stage distillation (this is the type
of separation you're applying right now with your existing set-up). A good distillation set-up is a counter-current flow liquid-gas phase
separation unit and provides as many units of separation as possible. Not so with your set-up or with the insulated vigreux set-up, both of which
only provide a single step.
Instead, mount the column in a draft-free room and try and run it at 100 % reflux (by carefully adjusting the level of heating applied to the still or
by shutting the reflux valve - if the column comes with one), at that point you're not actually producing any distillate. Allow the column to reach
equilibrium (this can take considerable time), in the form of constant temperature of the vapour/liquid mix at the top. With careful
adjustment of reflux level (still heating or top valve adjustment) you should be able to reach the exact BP of the azeotrope at the top of the column.
Now you can start collecting the first droplets of distillate by either opening the top reflux valve a bit or by gently cranking up the heating bit by
bit.
Vigreux columns are great but also very finicky: the temperature of the column greatly affects the number of separation stages that can be achieved
and hence the purity of the distillate. And since as the vigreux cannot be insulated, it's sensitive to drafts, changes in room temperature etc.
To avoid this sensitivity some resort to another type of set-up which basically involves using a condenser (like yours) as a column: the condenser,
mounted vertically on the still (like you would do with the vigreux) is then cooled with cooling water of constant temperature (this does not need to
be cold water, depending on the actual component mix).It can also (but this is not strictly necessary) be packed with surface area increasing material
like rashig rings, glass beads or other. It's run in the same way as a vigreux but is much less sensitive to drafts, air temperature changes etc. And
it's cheaper too! A vigreux is essentially an air-cooled version of the water cooled set-up just described...
[Edited on 2-7-2008 by blogfast25]
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Klute
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I insulate my vigreux with light plumbing insulation. Very easy (perfect diameter), and the insulation is enough to diminish the influence of drafts,
but not enough to let the surface heat up to a point where there is much less condensation, there still is a gradient of temperature along the
column..
I've often seen vacuum-jacketed vigreux columns, so i don't think insulation is that detrimental to the seperation. When distilling high bp
compounds, insulation is nearly mandatory otherwise you only have a very low take-off and more decomposition than seperation taking place. I know
vigreux offer only minimal seperation compared to true rectification columns, with decent packaging etc, but are more than enough for gross seperation
of solvents, or to avoid any take off of organic mater when removing aq. solution.
In this case, I admit it's a poor solution if one want's to obtained a strict 38% azeotrope, but enough to provide a concentrated solution (more so
than the initial mixture). If Jor is really wanting to get as close as possible to the azeotrope compositions, several distn like you suggested seems
a valid way to do so, but it might not be worth the effort (and energy cost) to exceed 3 distn. A reflux head would be very practical for that matter.
Blogfast, if you have such a reflux head, could you post pictures or a description in the "Solvent stills" thread I started in reagents and apparatus
forum (to avoid too much off topic here )? I'm planning on installing a solvent
still and would like to compare different systems. Thanks!
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
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S.C. Wack
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| Quote: | Originally posted by blogfast25
A vigreux column should never be insulated because by doing so you essentially reduce the distillation to a one stage distillation
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Column lagging is not a disputed technique.
Professionals use foil with or without glass wool. I wrap with old cotton shirts or heating tape, depending. Shirts for this. I have maybe a liter of
the azeotrope on hand, and I'm sure that I did not use a column to obtain it, and I would not call it the azeotrope unless I had verified the amount
of HBr in it. Redistillation, maybe. Low pot temperatures/slow distillation, and good boiling stones keep the amount of HBr coming over to a minimum.
[Edited on 2-7-2008 by S.C. Wack]
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not_important
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| Quote: | Originally posted by blogfast25
A vigreux column should never be insulated because by doing so you essentially reduce the distillation to a one stage distillation (this is the type
of separation you're applying right now with your existing set-up). ... |
http://www.sigmaaldrich.com/catalog/search/ProductDetail?Pro...
http://www.sigmaaldrich.com/catalog/search/ProductDetail?Pro...
From http://ocw.mit.edu/NR/rdonlyres/Chemistry/5-301January--IAP-...
| Quote: | 6) Insulate the column. When using a Vigreux column, it should be wrapped with glass
wool and aluminum foil. Without insulation, these set-ups tend to take a very long time. |
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DJF90
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Slightly off topic, but what are the main advantages of isolating hydrobromic acid rather than using it in situ? As fas as organic chemistry goes I
don't think theres much difference, but perhaps this is not strictly true.
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blogfast25
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If by insulating is understood avoiding all heat loss from the column, then, damn yes! - it has to be avoided because you might as
well cut out the column altogether. Mild insulation with the purpose of maintaining a decent temperature gradient across the column is a different
thing altogether. I believe Jor's question on insulation pertained to the first type: restricting all heat loss from the column.
BTW, I've seen a lot of distillations from large lab stills to pilot plant scale and all were ran without insulation or with a cooling mantle: for
most purposes that is applicable. But I've also see undergrads desperately insulating their vigreux columns only to find it had no separating power
whatsoever: without the downward flow of condensate across the column the distillation is essentially a 1 stage affair.
Klute: I will post some ideas on a refluxer later on. Thanks!
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S.C. Wack
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Yale Professor Emeritus of organic chemistry Ken Wiberg wrote in his younger, no doubt clueless, drug-fuelled, and ill-informed days, a mere 10 years
after obtaining his PhD from Columbia U. of Tards:
"The Vigreux column should be insulated; otherwise, it
will act essentially as a reflux condenser, and there will
be little opportunity to achieve vapor-liquid equilibrium.
For a short column (20 to 30 cm), it is convenient to use
a silvered vacuum jacket, which acts as an excellent in-
sulator if it is properly evacuated and degassed at a very
low pressure (below 1 micron.) before being sealed off. A
layer of glass wool covered with asbestos tape is also useful for in-
insulating Vigreux columns."
The book is hosted in my 4shared account but is of no interest to anyone, in case anyone thinks that I'm making this up.
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not_important
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| Quote: | Originally posted by blogfast25
...But I've also see undergrads desperately insulating their vigreux columns only to find it had no separating power whatsoever: without the downward
flow of condensate across the column the distillation is essentially a 1 stage affair.
... |
Operating without reflux pretty well makes any fractionation column ineffective. Operating with too large a gradient across the column can reduce its
effectivity. With perfect insulation you still could get a gradient as the descending reflux cools the upper portion of the column.
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blogfast25
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S.C. Wack:
The fact that someone is a professor doesn't make everything he says true. Unless the insulation he refers to is used like Klute's to stop temperature
fluctuations caused by drafts, room temperature changes etc he is plain wrong. Even mild insulation, whilst it can improve reliability and lead to a
more constant equilibrium, will in effect also slightly (depending on just how insulated the column actually is) reduce the number of theoretical
stages of distillation the column is capable of delivering.
Imagine a column that's perfectly insulated: the temperature of the outer layer of insulation is at exactly the same temperature as the surrounding
air, at equilibrium (with the boiler providing the upward flow of vapour). This system cannot exchange heat with the environment and the column
effectively acts as a chimney through which the vapour passes without condensation at all. No rectification at all goes on inside the column. Only the
reflux condenser at the top (assuming it's set to reflux at least some condensate) will condense the vapour and create the much needed downward flow
of liquid, providing however only one distillation stage. Not 1.5, not 2: just ONE.
All insulation between perfect and none at all has the effect of reducing the number of stages the column could otherwise potentially effectively
deliver. But practical requirements, such as operating reliability may make a trade-off desirable: shielding from outside temperature fluctuations
will make the column operate in more constant conditions, even though in effect it reduces its effective height somewhat.
Professor Wiberg may be an expert on organic chemistry but that doesn't make him an expert on liquid/gas countercurrent separation techniques.
| Quote: | | Operating with too large a gradient across the column can reduce its effectivity. |
How, pray, tell?
| Quote: | | With perfect insulation you still could get a gradient as the descending reflux cools the upper portion of the column. |
Poppycock, unless the condenser is running far too cold: it's only supposed to deliver condensate that's at the same temperature as the
vapour at the top of the column.
[Edited on 3-7-2008 by blogfast25]
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ProChem
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Humble Greetings,
My first post.
First a reference to making anhydrous HBr: Preparation of Anhydrous Hydrogen Bromide
T0107 1,2,3,4-Tetrahydronaphthalene
Bromine is slowly added dropwise to a round bottom flask containing a suspension of iron and 1,2,3,4-Tetrahydronaphthalene. In the early stage of the
reaction, the flask is cooled with water. The reaction is warmed to 30 to 40ºC allowing gas evolution. The gas is passed through a wash bottle
containing 1,2,3,4-Tetrahydronaphthalene in order to eliminate any bromine in the hydrogen bromide. For optimum yields of hydrogen bromide, dry the
1,2,3,4-Tetrahydronaphthalene over anhydrous sodium sulfate and then distill it under a dry inert atmosphere (such as argon or nitrogen). If any
moisture is introduced into the reaction, the yield of hydrogen bromide becomes remarkably poor.
Page Top
Literature
6)Inorg., Synth., 1939, 1, 149.
Second: For twenty two years I have been doing distillations from micro scale to pilot plant scale and usually insulated the column. If you have an
ideal case where your column is perfectly insulated you still lose heat up the column. Also, if you have a moderate reflux, the condensate will warm
on its way down to the column where some of it will reboil and some of it returns to the pot. I have used vigreaux columns without insulation for low
boiling material at atmospheric pressure but needed to insulate it for higher boiling material under vacuum. I haven't yet found a definative
laboratory type text on distillation techniques or equipment and each one of my co-workers have their own style. Basically do what you have to do to
get separation since you have temperature control, column (theoretical plates) volume, and if you are lucky good control of reflux ratio and pressure.
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S.C. Wack
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| Quote: | Originally posted by blogfast25
S.C. Wack:
The fact that someone is a professor doesn't make everything he says true. |
Wow, thanks! I was such a tool! Now I just believe everything that people post on the internet.
Your idea of fractional distillation is at odds with not just Wiberg...he was a convenient quote...it's everybody. Your brilliance was ahead of its
time.
Please tell us if any part of bullshit artist Wiberg's book is true.
http://www.4shared.com/file/45764521/d9556198/Laboratory_Tec...
This stupidity is widespread. How could so many distinguished instructors of laboratory technique be so wrong?
Americans-
"Probably the most widely used column (and the most overrated by students uninitiated in the art of distillation) is the Vigreux column (Fig. 2-11).
This consists of a tube with frequent indentations throughout its length that serve to increase the effective surface area of the column. For maximum
efficiency, the column should be silvered and vacuum jacketed to minimize external heat losses. If this is not practical, the column can be wrapped in
glass wool and bound with asbestos tape to increase its efficiency."
http://www.4shared.com/file/27116855/6214f3d/Research_Techni...
British-
"The assembly shown in Fig. 2.104 illustrates a set-up for simple fractionation using a Vigreux column which has moderate fractionating efficiency and
is probably one of the most widely used columns. The column consists of a glass tube with a series of indentations such that alternate sets of
indentations point downwards at an angle of 45° in order to promote the redistribution of liquid from the walls to the centre of the column. The
mixture to be fractionated is placed in a flask of convenient size (it should be one-third to one-half full), a few fragments of porous porcelain
added and a water condenser attached to the side-arm. The distillate is collected in small flasks or in test tubes. The bulb of the thermometer should
be just below the level of the side-arm. It is advisable to lag the column to minimise the effect of draughts in producing excessive cooling. Lagging
of the column is essential if the boiling point of any of the components exceeds 100°C."
http://www.4shared.com/file/27117716/48a4fbdb/Vogels_Practic...
Germans-
"Optimale Trennung erreicht man nur dann, wenn das fließende Austausch-Gleichgewicht zwischen Siedekolben und Kühler so wenig wie möglich gestört
wird. Dazu ist erstens nötig, daß die Kolonne weitgehend adiabatisch arbeitet, also nach außen wärmeisoliert ist, und zweitens, daß nur ein
Bruchteil des Dampfs aus dem Gleichgewicht entnommen wird.
Die Wärmeisolierung ist desto sorgfältiger auszuführen, je schwieriger die Trennung, je höher die Siedetemperatur und je dünner und länger die
Kolonne ist. Im einfachsten Fall genügt ein überzogenes mit Korkstopfen gehaltenes Glasrohr; Abbildung 41a-b. Bedeutend effektvoller sind hoch
evakuierte Glasmäntel, sie haben Bälge, die die Temperaturspannungen auffangen; Abbildung 41c. Sehr gute Reflexion der Wärmestrahlung
gewährleistet Aluminiumfolie. Man kann sie in mehreren Lagen direkt um das Rohr wickeln oder in den Glasmantel einlegen. Die evakuierten Mäntel sind
meistens verspiegelt. Asbestschnur hat nur dann Wert, wenn sie mehrere Zentimeter dick aufgewickelt wird. Man vergesse nicht, auch den Oberteil des
Siedekolbens zu isolieren! - Hochwertige Kolonnen besitzen (besonders für höhere Destillationstemperaturen nützliche) elektrische Außenheizungen.
Diese müssen den gleichen Temperaturgradienten haben wie das Kolonneninnere."
http://www.4shared.com/file/27257707/55ac2e62/Gattermann_Wie...
"Die optimale Leistung einer Kolonne wird bei adiabatischer Arbeitsweise erreicht, d. h. die Wärmeverluste durch Konvektion, Wärmeleitung und
Wärmestrahlung müssen auf ein Mindestmaß herabgesetzt werden. Bei Destillation von Stoffen mit einem Siedepunkt bis zu etwa 80°C genügt oft das
Einbetten der Kolonne in Glas- oder Schlackenwolle oder Isolieren mit geeigneten Schaumstoffschalen bzw. mit einem einfachen Luftmantel (vgl. Abb.
A.73). Einen besseren Schutz gegen Wärmeverluste bieten versilberte Vakuummäntel oder elektrische Heizmäntel. Diese sollen die Wärmeverluste
kompensieren, nicht jedoch die Kolonne aufheizen. Man hält deshalb die Temperatur des Heizmantels etwas unter der Kolonneninnentemperatur."
http://www.4shared.com/file/27258599/38317c14/Organikum_2001...
[Edited on 3-7-2008 by S.C. Wack]
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blogfast25
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| Quote: | Originally posted by S.C. Wack
blogfast25:
Your idea of fractional distillation is at odds with not just Wiberg...he was a convenient quote...it's everybody. Read any book that discusses
fractional distillation.
Please tell us if any part of bullshit artist Wiberg's book is true. |
No, it isn't "everybody". What I say here about how fractional distillation works is entirely true and borne out of the (professional) study of
both the theory and the practice of two phase countercurrent separation techniques, as well as application of it in pilot plant conditions.
Nowhere did I say Wiberg was a "bullshit artist", just that it's entirely possible for even the greatest of minds to be entirely wrong on
something. You clearly lack either the experience or imagination to envisage that.
You however strike me as someone toiling under a belief system and multiple misinterpretations of both theory and practice. As a result you feel the
need to resort to the lamest of arguments, i.e. that Wiberg wasn't a drug-fuelled, ill-informed person or a bullshit artist, something you don't even
know with any degree of certainty and is completely immaterial in any case:
| Quote: | | Ken Wiberg wrote in his younger, no doubt clueless, drug-fuelled, and ill-informed days, a mere 10 years after obtaining his PhD from Columbia U. of
Tards: |
Despite all your hollering you haven't presented a single argument against what I'm saying, instead you resort to puerile (and fairly ad
hominem) quotes by people who allegedly aren't drug-fuelled felons.
Since as you're in the enviable position of having access to a column, why don't you put you're money where your mouth is and conduct a study: cut
down a lot on the old shirts and determine the number of theoretical stages of separation obtained with various degrees of insulation, huh?
Please don't say: "I get good results anyway" because it's perfectly possible to obtain these in sub-optimal conditions. The truth is that you don't
really know what you're doing...
/////////
I see you've now quickly added a shedload of vague quotes, none of which address the crucial point: how the separating power (number of theoretical
stages) is negatively affected by elimination (or reducing) heat flow from the column, thereby flattening its temperature gradient.
By all means, wrap your column in the thickest wads of the finest insulating materials and see where it gets you...
[Edited on 3-7-2008 by blogfast25]
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S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
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| Quote: | Originally posted by blogfast25
The truth is that you don't really know what you're doing...
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Thank God that now we have you to show us the light. Please do not hesitate to bring to our attention and correct more "multiple misinterpretations of
both theory and practice" standard in the undergraduate laboratory and related laboratory technique literature.
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blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
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S.C. Wack:
Not only don't you understand the theory of two phase countercurrent separation techniques very well (not even the fundametals), you're also a bad,
underhand and childish debater: straw man arguments, quote mining, avoiding the actual points on the table, deflection, it's all there. All but
substance. Thank G-d I didn't meet you on a political forum...
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