Filtering fumes through water

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Romix

Well-known member
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Jul 24, 2014
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132
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Would this technic work? Pour water in 5l beaker place 250ml beaker in water, and cover it with another 800ml beaker. Chuck Al foils in that water to neutralise hcl fumes. Cu foils for NO2.
 
Romix said:
Would this technic work? Pour water in 5l beaker place 250ml beaker in water, and cover it with another 800ml beaker. Chuck Al foils in that water to neutralise the hcl fumes. Cu foils for NO2.

I saw something similar in Hoke's book and there is not reason why it wouldn't work, but I reckon its better if you use acid peroxide. Did you mean Nitric instead of HCl fumes? HCl doesn't generate NOx.
 
MarcoP said:
Romix said:
Would this technic work? Pour water in 5l beaker place 250ml beaker in water, and cover it with another 800ml beaker. Chuck Al foils in that water to neutralise the hcl fumes. Cu foils for NO2.

I saw something similar in Hoke's book and there is not reason why it wouldn't work, but I reckon its better if you use acid peroxide. Did you mean Nitric instead of HCl fumes? HCl doesn't generate NOx.
Practising with hcl will give off H2 but you still will have tiny amount of hcl gas that evaporates. It's soluble in water and will be neutralized by Aluminium foils.
 
Oh, you meant Al foils for HCl fumes and Cu foils for Nitric's. Sorry about that, I'll sit back and follow the thread :roll:
 
MarcoP said:
Oh, you meant Al foils for HCl fumes and Cu foils for Nitric's. Sorry about that, I'll sit back and follow the thread :roll:
Yes that's what I meant. It's only a theory, not tried it yet.
 
MarcoP said:
Oh, you meant Al foils for HCl fumes and Cu foils for Nitric's. Sorry about that, I'll sit back and follow the thread :roll:
Al can also be used for nitrics, and it's cheaper. But I think it's just a waste of nitrate ions. I chosen Copper because of its place in Reactivity Series and I wona go through it.
 
I hope it will work, would using Cu to scrub NOx make dilute copper nitrate?
At the moment I'm really busy in making a frame for my new IT workstation (I'll post a pic when done) but when I'm done with that I'll start making a fume hood with inline scrubbers. At the moment all my acids work is done outside and using dilute nitric with a little peroxide is keeping all NOx down and I'm really happy with that.
If your idea works in the last scrubber I could use pieces of copper to catch any fume that might get through, if memory doesn't fail on me the first two scrubbers are filled with peroxide and marbles while the last is plain water and marbles, using copper instead of marbles (in the last one) would be a great addition.
 
If bubbling NO2 through H2O will turn it back to HNO3. Then yes, you'll get dilute solution of copper (II) nitrate.
 
Romix said:
Would this technic work? Pour water in 5l beaker place 250ml beaker in water, and cover it with another 800ml beaker. Chuck Al foils in that water to neutralise the hcl fumes. Cu foils for NO2.

NO - if you are trying to "scrub" your fumes this is not the way to do it --- al you are doing here is making a "weak" acid which reacts with the metal which in turn produces fumes

NaOH (sodium hydroxide) is used to scrub acidic fumes - do not use NaOH in your beaker for making a scrubber it will "etch" the glass - here is a link to a thread that talks about fume hoods & scrubbers http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=19965

Kurt
 
Romix said:
Will NaOH etch borosilicate?

Yes - if its allowed to sit in the beaker for an extended period of time (even cold) &/or heat is applied --- if you are going to make a scrubber make it out of PVC or CPVC
as shown in the link I provided about fume hood & scrubber construction

Why tie up glassware for a scrubber when you can make one cheap & easy out of PVC/CPVC

I don't know if you can really tell in this pic or not but the beaker on the right has been etched by NaOH & now has a rough cloudy surface on the inside
 

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In a few day I had planned to boil NaOH in a borosilicate glassware! Better if I keep using my old SS pot, thank you kurtak!
 
For NOx do a double filtration, first NO2 goes through water with CU foils, then when it reacts the last few molecules of NO2 can be filltered through NaOH.
Beaker with reactants, covered with bigger beaker standing in a beaker with H2O and Cu foils in it.
And this 3 beakers must be placed in another beaker, and covered with a 5th beaker. Standing in a dish with NaOH solution.
Blow acid in with a syringe with long tube.

Heat needed for alloys like Kovar, so you wona get Pyrex dish, and borosilicate beakers. They handle high temperatures, can tell you that from my experience.
 
No better to filter NO2 straight through alum base in water.
With presence of O2 inside the apparatus.
It decomposes becareful.
 
I'm re-opening the old topic. My thought is to filter my gas through 3 beakers. First H2O, second H20+H2O2, and third a solution of NaHCO3. My intent is to capture and reuse as much NHO3 as possible. Thoughts?
 
NOx Gasses some are soluble in water, some are not. NOx gasses is a group of different nitric oxide gases.

https://en.wikipedia.org/wiki/NOx

NO2 the red cloud, which is water soluble, factors such as retention time needed for the reaction and temperature can determine how much is converted in the scrubber, here good scrubber design is important, to convert NO2 to HNO3. Scrubbing NO2 gas can make dilute nitric that can be concentrated to 68% HNO3 by evaporation.

2 NO2 + H2O → HNO2 + HNO3
4 NO2 + 2 H2O + O2 → 4 HNO3

NO gas is not soluble in water. but will convert to NO2 with oxygen (or air).

NO (g) + O2 (g) --> NO2 (g)

Hydrogen peroxide added to water in the scrubber can convert NO into NO2 which is soluble in the water.


NOX a combination of many different gases of nitrogen and oxygen
NO nitric oxide gas
NO2 nitrogen dioxide gas
H2O water
H2O2 hydrogen peroxide
O2 oxygen
HNO2 nitrous acid
HNO3 nitric acid
(g) gas
--> reaction (=)

some chemical reactions of the gases we are discussing distilling to make the nitric acid.
NO (g) + O2 (g) --> NO2 (g)
3 NO2 + H2O --> 2HNO3 + NO
2 NO2 + H2O → HNO2 + HNO3
HNO2 + H2O2 --> HNO3 + H2O
4 NO + 3 O2 + 2 H2O → 4 HNO3
4 NO2 + 2 H2O + O2 → 4 HNO3
 
butcher said:
here good scrubber design is important, to convert NO2 to HNO3. Scrubbing NO2 gas can make dilute nitric that can be concentrated to 68% HNO3 by evaporation.

Many people without access to nitric acid use this exact method to make nitric. You can find a few good, (and many worthless), u tube videos that show this in action.
 
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