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Ragnor73
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looking for cheapest routes to acid sythesis
Hello, I am hoping people can shed some light on the most cost effective methods for production of acids including, Nitric, sulfuric and
hydrochloric.
I have several projects mostly based around metallic mineral extractions and carbon/graphite/graphene conversions.
I have found some sources for acids but they are all a bit of a hassle in one way or another and relatively expensive.
If there are any fairly strait forward and cost effective methods for production I would be interested to know them .
Ive watched several nurd rage videos on the subject, but it always seams like those methods are kind of costly for the volumes produced.
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PirateDocBrown
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HCl and H2SO4 are usually OTC. I got a gallon of HCl for under $20, and half gallon of H2SO4 for the same.
HNO3 has a ton of good videos on making it. Sodium nitrate fertilizer is one of the cheapest sources of nitrate, I got 4 pounds for under $10, and
that is far from as cheap as it gets.
Cost is relative, getting a 2.5 L growler of HNO3 delivered to your door is gonna run you well over $100, these days.
[Edited on 5/11/17 by PirateDocBrown]
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clearly_not_atara
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I think you can distill hydrochloric acid from a mixture of sodium bisulfate and calcium chloride:
NaHSO4 (aq) + CaCl2(aq) >> NaCl(aq) + CaSO4(s) + HCl (g)
If this is not successful it is possible to produce ZnSO4 by dissolving zinc in hot concentrated sodium bisulfate solution:
Zn + 2NaHSO4(aq) + heat >> ZnSO4(aq) + H2 + Na2SO4(aq)
ZnSO4(aq) + cold >> ZnSO4(s)
This reacts with CaCl2 to give zinc chloride hydrate, ZnCl2*2H2O, which decomposes when heated releasing HCl gas.
If CaCl2 is unavailable, ammonium chloride can be made from salt, carbon dioxide and ammonia:
NaCl (aq) + NH3(aq) + CO2 (aq) >> NH4Cl(aq) + NaHCO3(s)
the bicarbonate being removed by exploiting its lower solubility. This makes up the Solvay process. The NH4Cl then reacts with quicklime to give
CaCl2:
2NH4Cl + CaO >> CaCl2 + 2NH3 + H2O
It might be possible to make HCl by the direct oxidation of NH4Cl but I'm not exactly clear on how to do this. From 10000 feet it looks like H2O2 over
TiO2 is the way to go. Noxious gases may be produced.
H2SO4 is harder. Easy in principle because sodium pyrosulfate decomposes to give SO3, but you do not wanna fuck with that molecule. The hydrolysis of
sulfuryl chloride is a little nicer:
SO2 + Cl2 + [catalyst] >> SO2Cl2
SO2Cl2 + 2H2O >> H2SO4 + 2HCl (slow)
Once you have a little H2SO4 you can make more by a reciprocating process:
sulfuric acid + SO3 >> oleum
oleum + H2O >> more sulfuric acid
This "slows down" the exothermic hydration of SO3 enough to make it manageable. It's probably the best way to make large amounts of sulfuric acid.
[Edited on 11-5-2017 by clearly_not_atara]
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Melgar
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The cheapest route for massive quantities would be to set up your own contact process system, burning sulfur and oxidizing that further to SO3, etc.
Combine that with a nitrate salt and distill for nitric acid, combine with a chloride salt and distill for hydrochloric acid, etc. You end up with
three times your mass of sulfur in H2SO4, with that mass being extracted from water and the atmosphere. Agricultural-grade sulfur is fine for this,
and is available in 50-pound bags at least.
If you don't want to go that route, it shouldn't be hard to source sulfuric acid for about $20/gallon and 30%+ HCl for $7/gallon. Calcium nitrate is
probably the cheapest easily-obtained nitrate salt, for about $25 for a 50-pound bag, assuming there are agricultural supply stores near you. If you
can set up a business with the right sort of credentials to buy that stuff commercially, that would be even cheaper.
If you're interested in the economics of different methods of obtaining sulfuric acid, one gallon of the stuff weights about twice as much as water,
about 15 pounds per gallon. At least in the US, if you're buying stuff in bulk, it'll usually come in 50-100 pound bags, or five-gallon buckets, as
the largest amounts an individual can purchase, so it's easier to just use pounds and gallons as your units.
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clearly_not_atara
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Actually come to think of it, it should be possible to make zinc sulfate by combining ZnO with SO2 and H2O2 since the pH will not drop too low to stop
the reaction between SO2 and H2O2 (which is normally the problem with this method). SO2 is quite easy to make unlike SO3.
It might be possible to then add CaCl2 to the solution directly, filter and distill off HCl, but you should ensure the H2O2 is completely consumed if
you're going to do that! You definitely don't want to be surprised by H2O2 in your HCl (H2O2 is stable in hydrochloric acid so it will persist).
edit: ref for the solubilities used in the prep of ZnCl2*nH2O:
https://www.env.nm.gov/wqcc/documents/NMEDExhibit15.pdf
[Edited on 12-5-2017 by clearly_not_atara]
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JJay
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It's possible to make hydrogen chloride by electrolyzing brine and reacting the gases in a combustion tube. You can make nitric acid by ionizing air.
It's low yielding and requires a lot of electricity, but the starting materials are free. Sulfuric acid... probably the cheapest way is by burning
sulfur and reacting the sulfur dioxide with air over a vanadium pentoxide catalyst. Note that while all of these methods are conceptually simple, none
of them are easy in practice.
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Dr.Bob
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If you want cheap, the solution is to buy them from industrial supply houses, you will not be able to make them cheaper than a big factory, the cost
of shipping them is more than the cost to make them. But if the overall cost includes shipping, then you might be able to make some from others,
like HCl from H2SO4, but ultimately, the cheapest way is to buy them from someone who uses them in bulk. OTC drain cleaner, pool chemicals, muriatic
acid for cleaning masonry are all good sources.
Nitric is the hardest to find easily, so that might be the best to make from sulfuric.
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Corrosive Joeseph
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Quote: Originally posted by JJay  | It's possible to make hydrogen chloride by electrolyzing brine and reacting the gases in a combustion tube.
Note that while all of these methods are conceptually simple, none of them are easy in practice. |
Really........?
I found this the other day and thought it might be promising
"In the chlor-alkali industry, brine (mixture of sodium chloride and water) solution is electrolyzed producing chlorine (Cl2), sodium hydroxide, and
hydrogen (H2):
2 NaCl + 2 H2O → Cl2 + 2 NaOH + H2
The pure chlorine gas can be combined with hydrogen to produce hydrogen chloride in the presence of UV light:
Cl2(g) + H2(g) → 2 HCl(g)
As the reaction is exothermic, the installation is called an HCl oven or HCl burner. The resulting hydrogen chloride gas is absorbed in deionized
water, resulting in chemically pure hydrochloric acid. This reaction can give a very pure product, e.g. for use in the food industry."
https://en.wikipedia.org/wiki/Hydrogen_chloride#Production
Hydrochloric acid from salt, water, electricity and daylight........?
Somebody please, shoot this down
/CJ
Being well adjusted to a sick society is no measure of one's mental health
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yobbo II
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So long as you have an anode and suitable membrane, you are on the pigs back (so to speak).
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JJay
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| Quote: Originally posted by Corrosive Joeseph | | Quote: Originally posted by JJay | It's possible to make hydrogen chloride by electrolyzing brine and reacting the gases in a combustion tube.
Note that while all of these methods are conceptually simple, none of them are easy in practice. |
Really........?
I found this the other day and thought it might be promising
"In the chlor-alkali industry, brine (mixture of sodium chloride and water) solution is electrolyzed producing chlorine (Cl2), sodium hydroxide, and
hydrogen (H2):
2 NaCl + 2 H2O → Cl2 + 2 NaOH + H2
The pure chlorine gas can be combined with hydrogen to produce hydrogen chloride in the presence of UV light:
Cl2(g) + H2(g) → 2 HCl(g)
As the reaction is exothermic, the installation is called an HCl oven or HCl burner. The resulting hydrogen chloride gas is absorbed in deionized
water, resulting in chemically pure hydrochloric acid. This reaction can give a very pure product, e.g. for use in the food industry."
https://en.wikipedia.org/wiki/Hydrogen_chloride#Production
Hydrochloric acid from salt, water, electricity and daylight........?
Somebody please, shoot this down
/CJ
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There was a thread on this a while back: http://www.sciencemadness.org/talk/viewthread.php?tid=2154#p...
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Melgar
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Sure, I'd be happy to help!
Hydrochloric acid is basically a waste product in industry, so nobody ever bothers to actually make the stuff. It's really inexpensive to buy, too.
Not to mention, just about any electrode material you'd use to electrolyze brine, is going to have a difficult time staying intact under those
conditions. Oh yeah, and gas-phase reactions tend to output drop by drop. It would take forever to make a significant amount.
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Corrosive Joeseph
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Hmmm, thanks guys.......... Of all the 'essential' materials, acids are proving most elusive here.
Back to the drawing board so...............
/CJ
Being well adjusted to a sick society is no measure of one's mental health
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Sulaiman
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I got my most recent batch of sulphuric acid via Amazon.uk
e.g. https://www.amazon.co.uk/DRAIN-CLEANER-Strength-Instant-Liqu...
CAUTION : Hobby Chemist, not Professional or even Amateur
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JJay
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Acids, bases, and hydrogen peroxide are pretty much all I can get locally....
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clearly_not_atara
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| Quote: | Hmmm, thanks guys.......... Of all the 'essential' materials, acids are proving most elusive here.
Back to the drawing board so............... |
I have no Earthly idea why anyone thinks the chloralkali process can be carried out at home, is easy (H2 + Cl2 will explode in 99% of rxn conditions
and must be carefully controlled) or really makes any sense at all.
No, seriously: describe how to design a homebuilt reactor to combine H2 and Cl2 in quantity, without catching fire, exploding, or releasing huge
amounts of toxic gas. Don't worry, I'll wait
ZnCl2 hydrolysis by contrast is OTC and could be carried out by a well-trained circus monkey.
[Edited on 13-5-2017 by clearly_not_atara]
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ave369
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If you have concentrated sulfuric acid, all other acids can be easily made from it and the corresponding salts. Sulfuric acid is the "mother" of all
acids.
If you don't have concentrated sulfuric acid, you'll have to boil down battery acid. It isn't practical to synthesize sulfuric acid at small scale.
Smells like ammonia....
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Eyeborg
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Drain cleaner sulfuric acid is probably your cheapest OTC source. It doesn't matter if it has some gunk in it, it should all be gone after a
distillation. If you want bulk, it is probably cheaper to purchase from an industrial supply store.
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clearly_not_atara
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Oh! Ammonium phosphate, found in nearly every fire extinguisher, converts to phosphoric acid upon simple heating. So phosphoric acid is always OTC.
This additionally can be used to make hydrochloric and hydrobromic acids from the corresponding halides.
I think you can also use a modified Solvay process to convert sodium phosphate back to ammonium phosphate so that HCl production is catalytic in
H3PO4.
Ammonium sulfate under the same conditions gives ammonium pyrosulfate. I think this will react with additional anhydrous ammonia to give ammonium
sulfamate, but additional heating will eventually result in complete decomposition to nitrogen, water, and sulfur (among other things).
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j_sum1
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I believe that fire extinguishers contain a mixture of ammonium phosphate and ammonium sulfate. https://en.wikipedia.org/wiki/ABC_dry_chemical
So, given a mixture of reagents, what would be a suitable procedure for obtaining H3PO4? I am seeing possibilities for all kinds of side products.
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clearly_not_atara
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Ammonium dihydrogen phosphate is apparently soluble in ethanol (ty Wikipedia) whereas ammonium sulfate is not. I believe the same is true of methanol.
[Edited on 15-5-2017 by clearly_not_atara]
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Corrosive Joeseph
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"pH down" from hydroponic gardening outlets is 85% food grade phosphoric acid.
I have found H2SO4 drain cleaner my local farm/feed store but it is not always available.
Nitric from CAN fertillizer and H2SO4 - https://www.youtube.com/watch?v=7akk5ppJjEw&feature=yout...
/CJ
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physics inclination
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Would there be any (reasonably simple) way of making sulfuric acid from calcium sulfate, chemically or electrolytically? Because I can get 40 pound
bags of that for $10 from home improvement stores.
Alternatively, and this is kinda more farfetched, but is there any easy way to harvest sulfur from organic matter e.g. fallen leaves or grass
cuttings? If so, that would be a convenient way to get sulfuric acid from that sulfur.
I am just personally curious about ways to get reagents that don't require any shopping at all; I'm also making and testing designs for
higher-efficiency and maybe higher-output nitric acid electric-arc reactors.
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unionised
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| Quote: Originally posted by physics inclination | Would there be any (reasonably simple) way of making sulfuric acid from calcium sulfate, chemically or electrolytically? Because I can get 40 pound
bags of that for $10 from home improvement stores.
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Theoretically.
But, by the time you have roasted the sulphate with charcoal at 1000 degrees for a while to reduce it to sulphide, then slurried it in water and
passed CO2 through it to liberate H2S then burned that to SO2 and then oxidised that over V2O5 to get SO3 and then hydrated that to get H2SO4, it's
probably cheaper (and certainly easier) to just buy the acid.
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clearly_not_atara
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Probably not without reducing the sulfate. If you can selectively reduce to sulfite it's probably better than going all the way to the sulfide, but
I'm not sure how to do that. I think concentrated hydrobromic acid could work but for this application that's wasteful and bromine is a side product.
Maybe try heating CaSO4 with oxalic acid? Beware of carbon monoxide.
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physics inclination
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| Quote: |
Maybe try heating CaSO4 with oxalic acid? Beware of carbon monoxide. |
Yes thanks, I found some similar technique that got sulfuric acid by reacting epsom salt i.e. MgSO4 with oxalic acid, and since magnesium and calcium
are very similar I imagine it would work well.
here's the video I'm referring to if anyone is curious: https://www.youtube.com/watch?v=ePmbRCiLagE
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