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Zyklon-A
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I've looked through this thread, and I haven't had this question answered; How high % sulfuric acid can you get, if you ran the reaction multiple
times with exess KNO3 and S, before you boil it?
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DubaiAmateurRocketry
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I find the SO3 process much more convienient/ promising for us amateurs.
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Mesa
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@Zyklonb: Your question was answered on the same page it was posted. It's also on the first 5 links seen when typing "Lead chamber process" into
google and hitting enter.
@else: Would it be possible to selectively adsorb aforementioned chloramines on something akin to molecular sieves? I was looking into the
preparation of surface modified cellulose type membranes which seems quite achievable for home chemists(starting as far back as unrefined wood pulp.
Probably better off buying some cotton though.)
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Zyklon-A
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It doesn't say anything about, % on the fist page, on Wikipedia, it says, ''Later versions of chamber plants included a high temperature Glover tower
to recover the nitrogen oxides from the chamber liquor, while concentrating the chamber acid to as much as 78% H2SO4'', but I just have a 5 gallon
bucket, not a ''Glover tower''.
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DubaiAmateurRocketry
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Quote: Originally posted by Zyklonb  | | It doesn't say anything about, % on the fist page, on Wikipedia, it says, ''Later versions of chamber plants included a high temperature Glover tower
to recover the nitrogen oxides from the chamber liquor, while concentrating the chamber acid to as much as 78% H2SO4'', but I just have a 5 gallon
bucket, not a ''Glover tower''. |
Read this.
http://www.sciencemadness.org/member_publications/SO3_and_ol...
I strongly suggest this method for sulfuric acid. It can problem high concentration oleum or sulfuric acid.
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Zyklon-A
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Thank you, I could not find that, earlier.
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testimento
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I have been thinking few different approaches of manufacturing of sulfuric acid. All of them uses calcium sulfate as a precursor. It is first reduced
with carbon to calcium sulfide, which is heated with some calcium sulfate to yield sulfur dioxide and calcium oxide. Since sulfur dioxide is highly
soluble in very cold water (up to 230g per liter), it could be stored there before use. Another possibility is to liquify it into a good freezer(-30C
minimum) where a common steel BBQ gas bottle is placed with proper quality needle valve. The valve can be closed when the procedure is done and bottle
brought to room temp, where it gains about 5-10 bars of pressure and pressure boiling point equilibrium keeps it stable. Common steel is happy with
SO2, but it must be dried with CaCl2 trap just in case.
From there, SO2 can be used for few methods to cause sulfuric acid. The "easiest" method is to bubble air through the SO2-water and slowly heat it to
cause SO2 vaporization and lead this composition through CaCl2 to dry it. After this it would be lead through, preferably, quartz tube, with either
powdered or impregnated vanadium pentoxide catalyst, where it would turn into SO3. This would be bubbled through 70-90% sulfuric acid which is heated
up to 70-90C, and the SO3 is turned into H2SO4 and eventually oleum. SO3 must not be condensed(note 46C BP), because it can form strange matter
alpha/beta structures that may spontaneously decompose upon heating with such force it can shatter glass. The unreacted SO2 can be vented off, or
preferably directed through another V2O5 tube and bubbled into another pot of sulfuric acid. It could also be bubbled through water storage trap or
freezer cold trap to obtain total yield of 90-100% with no SO2 losses.
Another variation is to do the heating and air bubbling the same way, but lead the SO2 into nitric acid tank, where H2SO4 is formed and NO is
released, which is lead into a middle tank similar to Ostwald process reaction tank(2 NO + O2 = 2 NO2), and the NO2 is partially condensed and lead
into water where nitric acid is formed again. This structure could be made high so the heavier-than-air-NO will remain there and oxidize again to NO2,
condense and form nitric acid. Through this effective yields of 100% from SO2 and 60-80% from HNO3 can be obtained. Downside is the required
equipment, upside is that everything is mostly OTC. In most simple terms, this process requires only basic labware, DIY electric furnace, some SS and
quartz tubing and some V2O5 and can easily fit on a decent tabletop.
[Edited on 11-2-2014 by testimento]
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jock88
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DO be careful with SO3.
Eyes gone if you make ONE mistake.
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testimento
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A chemist who isn't using full face respiratory mask is a candidate for darwin awards.
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Xenon1898
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Just a nit, but this process flowsheet doesn't have an exit path shown for the acid product.
“If we knew what it was we were doing, it would not be called research, would it?”
-Albert Einstein
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macckone
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There are two points for take off.
They are the concentrated acid storage tank and the chamber acid storage tank.
They are not shown on the diagram but that is where they would be removed.
You pick the take off point based on the concentration you need.
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DoctorZET
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Remember the "Bordeaux mixture" ?
Everybody can go to a agricultural-shop (farm-shop) and buy some CuSO4 and Ca(OH)2 , who are the main ingredients of the "Bordeaux mixture"-a really
good fungicide.
So, we can get a lot of CuSO4 (wich is not too expensive, just like the battery acid)
Then, I know 2 methods to make SO3 (sulfur trioxide) :
first involves a tin process:
1)if you don't have tin, take some soldering alloy (Pb+Sn) and bubble the molten metals (it melts at about 170-200*C) with Cl2. Meanwhile, distill the
SnCl4 gas resulted.
Pb Sn + 3Cl2 --(200*C)--> PbCl2 + SnCl4^
Now you have a pure quaternary stannium salt : SnCl4 (a fuming liquid at room temperature, wich can be used in many other purposes)
2)take some SnCl4 and some dehydrated CuSO4 and mix them until the mixture become a dense opaque very pale greenish fluid:
SnCl4 (excess)(liquid) + 2CuSO4(solid) --(time)--> Sn(SO4)2(solid) + 2CuCl2(solid)
3)then distill the excess of SnCl4.
4)heat the remaining powder up to 200-250*C and collect the SO3 vapors:
Sn(SO4)2 --(200-250*C)--> SnO2 + 2 SO3^
(the CuCl2 impurities does no effect at all)
5)to re-use the tin in this process, heat the remaining powder (SnO2+CuCl2) with some H2 gas, in a tube, to reduce the tin(vi) oxide to tin metal and
water, copper will be also reduced to Cu and HCl :
SnO2 + 2H2 --(190-210*C)--> Sn + 2 H2O^
CuCl2 + H2 --(150-170*C)--> Cu + 2 HCl^
now you can start again to transform Sn in SnCl4 ... and so on.
Second method is:
1) a boring school reaction:
Fe2(CO3)3(powder) + 3CuSO4(aq) --(some time)--> 3CuCO3(solid) + Fe2(SO4)3(aq)
2) Heat a bit the Fe2(SO4)3:
Fe2(SO4)3 --(480-500*C)--> Fe2O3 + 3 SO3^
3) Now you have to convert Fe2O3 to Fe2(CO3)3:
Fe2O3(powder) + 3[H2CO3](aq) --> Fe2(CO3)3(solid) + 3H2O
now you can start again to make iron(iii)sulfate...
~the problem with first method is that it requires more atention because of the stannic chloride, but the good part is that this method requires low
temperatures...
~the problem with second method is that it requires higher temperatures (than glass can resist) and that's making a problem about collecting the toxic
SO3 fumes...but if you have the materials, the overall process is simple to make.
[Edited on 16-4-2014 by DoctorZET]
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blogfast25
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This post contains so much nonsense it's hard to tell where to start debunking it.
"SnCl4 (excess)(liquid) + 2CuSO4(solid) --(time)--> Sn(SO4)2(solid) + 2CuCl2(solid)"
That doesn't work as you've basically proved yourself.
"Fe2(CO3)3(powder) + 3CuSO4(aq) --(some time)--> 3CuCO3(solid) + Fe2(SO4)3(aq)"
Fe2(CO3) in all likelihood doesn't exist but if it did how this reaction is supposed to proceed remains a mystery. Presumably '(some time)' here means
all of eternity.
"[...] but if you have the materials, the overall process is simple to make."
Yes and pigs will fly!
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macckone
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If you have copper sulfate, just heat the sulfate.
It decomposes just fine.
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DoctorZET
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Yes, I just discover that SnCl4 needs to be in H2SO4 solution at 100*C in order to react ... and Sn(SO4)2*2H20 always decompose to H2SO4 and SnO2 when
heated just to 80*C.
And iron(iii)oxide remain the same, even I add it to a acidulated Na2CO3 solution. (just a few FeCO3 impurities appear along with FeO(OH) )
And "some time" means 1 to 10 minutes...(just if reactants actually exist  )
The first method is stupid, I know (H2SO4 is one of the incoming reagents to make H2SO4 because SnCl4 is decomposed only by warm sulfuric acid).
The second method is good, but only if I work with Fe2O3 as the main cycle product
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aga
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AJKOER ! Wherefore art thou ?
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AJKOER
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Here is an idea for small quantity production of Sulfuric acid I may soon try when I have the sulfur. At this point, I will discuss only the theory
and leave more precise possible ways to implement till later.
Concept: Heat dry (NH4)2SO4 to sublimation along with burning Sulfur in oxygen to form Sulfur dioxide in the presence of water, where the acid gas
will be employed to neutralize the newly released ammonia gas.
Reactions:
(NH4)2SO42 + Heat (to 235 C) → 2 NH3 (g) + H2SO4 (g)
S8 + 8 O2 → 8 SO2
2 NH3 + H2O + SO2 → (NH4)2SO3
Along with the bisulfite, see "SO2 Removal by NH3 Gas Injection: Effects of Temperature and Moisture Content" by Hsunling Bai , Pratim Biswas , Tim C.
Keener, first page available at http://pubs.acs.org/doi/abs/10.1021/ie00029a019?journalCode=iecred
Then collect the liquid containing Sulfuric acid, some unreacted Ammonium sulfate particles and Ammonium sulfite. Then filter, and mildly heat as, per
the above reference, the sulfite impurity sublimes at 60 C.
One potential advantage of this method over say reacting H2SO3 with Cl2 or concentrated H2O2 or just conc HOCl (from aqueous NaOCl, CO2 gas and CaCl2
forming aqueous HOCl which can be further concentrated by repeated distillation of half of the starting very volatile Hypochlorous acid) is, while the
quantity potentially produced is small, it could be fairly concentrated.
----------------------------------------
One can appropriately extend the sublimation method to use other neutralizing gases like Cl2, Cl2O, O3, possibly Singlet oxygen, ...
[Edited on 26-3-2015 by AJKOER]
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AJKOER
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No success here.
Further research indicates that the above reaction is incorrect in this instance. While gases created are many, the thermal decomposition of Ammonium
sulfate is not a significant source of either SO3 or H2SO4 vapors mixed with NH3.
See, for example, http://pubs.acs.org/doi/abs/10.1021/i260036a001?journalCode=... and http://onlinelibrary.wiley.com/doi/10.1002/jctb.5010200408/a... .
[Edited on 5-7-2015 by AJKOER]
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Assured Fish
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H2SO4 using cation exchange membrane
Ok this is may be a completely bogus idea but would it be possible to use a cation exchange membrane to separate 2 chambers and then put HCL solution
in one chamber and a solution of NaHSO4 in the other chamber and then because the cation exchange membrane will only allow cations to pass through it
i.e. H+ and Na+ then theoretically both the HCL and Bisulfate would disassociate and you would generate sulfuric acid in the bisulfate solution and
sodium chloride in the HCL solution in an equilibrium reaction.
HCL + Na+ <----> NaCl + H+
NaHSO4 + H+ <----> H2SO4 + Na+
After a certain period of time you would remove the liquids and separate the sodium bisulphate from sulfuric acid (fractional distillation 315*C to
337*C), unfortunately i don't know a hell of a lot about cation exchange membranes but in theory it should work provided its energetically feasible,
but i have no idea where the equilibrium constant will sit and i am waaay to tired to bother sitting there for an hour trying to find the entropy of
NaCl, NaHSO4, HCL and H2SO4 and then calculate it, but has anyone got a cation exchange membrane to see if this would work.
Cheers Fish
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hissingnoise
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| Quote: | | Ok this is may be a completely bogus idea . . . |
Indeed, Na+ replaces H+ ─ not the other way round!
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macckone
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Sodium sulfate is commercially electrolyzed in a three chamber cell with cation and anion membranes forming sodium hydroxide and sulfuric acid.
Similar should be possible with diaphragms to produce sodium hydroxide and sodium bisulfate. The bisulfate can then be heated to produce sulfur
trioxide.
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Tin man
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Acording to a few chemistry textbooks I have read, Nitrogen dioxide oxidizes sulphur dioxide according to the following eqaution,
NO2+SO2>NO+SO3.
Then the NO can react with oxygen according to the following reaction
2NO+O2>2NO2.
My proposed rout would be as follows:
A two necked round bottem flask is filled with nitrogen dioxide, then a gas adaptor is placed in each neck. One gas adaptor is led to a source of
oxygen and the other is led to a source of sulphur dioxide. The gas flow ratio is adjusted so that the gas in the round bottem flask remains a light
brown colour, and SO3 can be seen condensing on the sides of the flask. Once you have collected enough SO3 to sufficiently scare yourself shitless,
you can open the flask and pippet out the SO3( under a fume hood, with a dry glass pippet) and ampule it.
Please note that I just thought of this setup, and it is surely very dangerous. My excuse for not trying it yet is that I am not in possession of a
fume hood or a two neck round bottem flask. If anyone should try this, best of regards, but please do be safe.
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yakoot
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Really it is a great work. Sulfuric acid now is produced by Contact Process. The first step for contact process is to melt the sulfur and then burn it
in a furnace to form SO2 .
more information
http://sulfuricacidworld.blogspot.com.eg/
[Edited on 17-4-2017 by yakoot]
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clearly_not_atara
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Mmyes conc H2SO4 is by all reports an absolute bastard to make. Producing sulfur trioxide is nearly trivial by heating pyrosulfate but doing anything
with the gas or simply remaining alive in its presence requires a great deal of care.
Amides form zwitterionic adducts with SO3 yes? Perhaps a lipophilic amide can be chosen such as N-benzoylpiperidine (logP = 2.2) or oleamide, which
can be used to absorb a stream of SO3, forming the amide adduct R(=N+R'R")OSO3-, and then this is hydrolysed with just enough water to separate the
amide. If the hydrolysis is kept cold you should mostly avoid hydrolysis of the amide. Presumably the amide can then be extracted with octanol or
toluene or something.
Another possibility or possibly what can be used together with the amide process is heating dilute sulfuric acid to about 300 C or so to concentrate
it to around 80-85% and then dissolving SO3 into this until it is truly concentrated. I don't know if this is comparably exothermic to adding SO3 to
water; hopefully not.
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Tin man
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I can't think of any scenario in which sulfer trioxide could come in contact with an amide and not turn it into black goo. Are you thinking of sulfur
dioxide?
[Edited on 19-5-2017 by Tin man]
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