Thoughts on this scrubber idea... let me know what you think

[mls26cwru]

first off, I hope this is the right area to post this in... as it could probably belong in a number of areas.
second, please offer any thoughts you might have about this idea... I would like to have ideas BEFORE i try it instead of trial by error

bit of back ground info:
i built this prototype fume scrubber from some left over PVC I had laying around... this is intended to to be used as a dry scrubber for AP method only. My objective is to scrub out the Cl2 and acid vapors coming off the solution in the bucket by forcing air through a activated charcoal bed. although it is not built into the lid yet, my thought is to have an air bubbler line feed through the top of the lid leading into the AP solution, thus providing O2 for the solution and the pressure to force the vapors through the charcoal bed on top of the bucket. I also need to build in a safety valve of some sorts (which is one area where i need ideas)

so please, take a look at the pics, and let me know any thoughts, concerns, advice you have. Once again, this is for ONLY acid-peroxide method fume scrubbing... no nitric acid, no sulfuric as those can produce byproducts that wont be scrubbed with the activated charcoal.

Thanks!
Mike

 

[mls26cwru]

oh, for dimensions, the scrubbing chamber is 4 inch diameter by 12 inches deep.

 

[onewally]

Hellos, heres a couple ideas im still new at this but have some ideas i think will help you.

saftey valve, i am assuming you want one to protect from i build up of pressure, use peice of pvc pipe comming up from the black lid on the inside use small round ball or marble in a tapered peice of pvc ( i think you can use a reducer that is tappered) a light duty spring (plastic coated would probly be a good idea) then take a end cap drill out a couple of holes. the end cap will hold the spring in and the spring will hold the ball down untill enough pressure is built up to force past the ball and spring can also be done with out spring but would only work right when sitting up and useing gravity to hold the ball down

 

[mls26cwru]

Hellos, heres a couple ideas im still new at this but have some ideas i think will help you.

saftey valve, i am assuming you want one to protect from i build up of pressure, use peice of pvc pipe comming up from the black lid on the inside use small round ball or marble in a tapered peice of pvc ( i think you can use a reducer that is tappered) a light duty spring (plastic coated would probly be a good idea) then take a end cap drill out a couple of holes. the end cap will hold the spring in and the spring will hold the ball down untill enough pressure is built up to force past the ball and spring can also be done with out spring but would only work right when sitting up and useing gravity to hold the ball down

oh, i like this idea, simplistic yet effective... thank you!

 

[butcher]

Maybe you can put a hose on the output, maybe as a test capture the gas evolved in a jar of distilled water and run for the unit for some time and test the water (chlorides use silver nitrate look for silver chloride to develop), (test pH for HCl bubled into water and also in gases).


I still would not trust running that in my house or in a shed full of tools, these are some very corrosive acids, which will attack metals some base like aluminum and iron would not last long in the fumes, even if you did not see them or smell the gases.

Although if you use the copper chloride leach properly it will not emit to much harmful gases usually mostly oxygen, even small amounts of HCl gas or chlorine can ruin metals in a closed room.

How will you know when the carbon has lost its effectiveness, or have you calculated how much carbon it would take for a certain amount of these gases, and do you know how much of these gases will be evolving in the temperatures you will be using this, or in a worse case scenerio like too much or too strong of H2O2 added to solution?

I just think this stuff ought to be done outdoors or in a fume hood if you can afford to run the fan that long.

Chlorine-removal efficiency of activated carbon. The dechlorination half-value length is the depth of carbon required to reduce the chlorine level of a flowing stream from 5 ppm to 3.5 ppm.
How much activated carbon is needed before you get to no ppm discharge of chlorine gas?

I know my math skill is not good enough to figure this.
So I just figure I will keep my buckets outdoors.


I do like the idea I just would not trust it myself at this point unless I learn something different.

 

[mls26cwru]

Maybe you can put a hose on the output, maybe as a test capture the gas evolved in a jar of distilled water and run for the unit for some time and test the water (chlorides use silver nitrate look for silver chloride to develop), (test pH for HCl bubled into water and also in gases).

I still would not trust running that in my house or in a shed full of tools, these are some very corrosive acids, which will attack metals some base like aluminum and iron would not last long in the fumes, even if you did not see them or smell the gases.

Although if you use the copper chloride leach properly it will not emit to much harmful gases usually mostly oxygen, even small amounts of HCl gas or chlorine can ruin metals in a closed room.

How will you know when the carbon has lost its effectiveness, or have you calculated how much carbon it would take for a certain amount of these gases, and do you know how much of these gases will be evolving in the temperatures you will be using this, or in a worse case scenerio like too much or too strong of H2O2 added to solution?

I just think this stuff ought to be done outdoors or in a fume hood if you can afford to run the fan that long.

Chlorine-removal efficiency of activated carbon. The dechlorination half-value length is the depth of carbon required to reduce the chlorine level of a flowing stream from 5 ppm to 3.5 ppm.
How much activated carbon is needed before you get to no ppm discharge of chlorine gas?

I know my math skill is not good enough to figure this.
So I just figure I will keep my buckets outdoors.

I do like the idea I just would not trust it myself at this point unless I learn something different.

thanks for the ideas butcher! questions about the bed depth and how to test the output stream are things i would like to figure out, so any help pointing me in the right direction is exactly what I was hoping to get from the post.

i also forgot to mention that there is no intent on running this reaction inside, especially since i don't have a fume hood or bonafide lab setup. chemical reactions, in the house, are a recipe for disaster as far as i am concerned. What i was hoping to do is design an easy, cheap, weatherproof system so that i can store a bucket outside. I think it is only prudent to be environmentally conscious of what kind of chemicals i am putting into the air for the sake of everyone around me... and it helps me learn about the waste treatment side of refining.

please keep the feedback coming!

Mike

 

[butcher]

I think your bucket needs a small dog house with a light bulb to help heat your bucket and fume scrubber on those chilly nights.

Since you are not planning on using this indoors, I like the idea much better.

They make test papers for chlorine, I do another test for chlorine gas is a capful of ammonia held close to the exiting pipe of your filter, if chlorine gas is evolving the ammonia fumes and chlorine fumes will mix to form a white visible smoke of ammonium chloride gases.

I like glass containers where I can see what is happening inside, as much of the maintenance of the leach is done by visual clues, maybe you can drill a hole in the lid and cement on a Plexiglas window, so you can check on the solution without removing the lid, also a way to add acids or peroxide when needed without having to take the unit apart would be nice.

 

[freechemist]

mls26cwru,

You write:

"i built this prototype fume scrubber from some left over PVC I had laying around... this is intended to to be used as a dry scrubber for AP method only. My objective is to scrub out the Cl₂ and acid vapors coming off the solution in the bucket by forcing air through a activated charcoal bed."

Based on my experiences use of a scrubber in your envisaged process is simply not necessary. The active oxidant in the AP-process is Cu(II), not elemental chlorine (Cl₂), dissolved in aqueous HCl. Instead of using 3% H₂O₂, together with aqueous HCl, to initiate the process, you can dissolve some Cu(II)-salt in the acid, e.g. copper(II)sulfate, CuSO₄ or copper(II)chloride, CuCl₂. Dissolution of metallic copper will occur according to the following stoichiometry:

Cu(metal) + Cu²⁺ <==> 2 Cu⁺ or
Cu(metal) + CuCl₂ + 2 HCl- <==> 2 [CuCl²]^- + 2 H⁺

Bubbling air through the mixture regenerates Cu(II) by oxydation of Cu(I) with oxygen, contained in the air:

4 [CuCl₂]^- + O₂ + 4 HCl <==> 4 CuCl₂ + 2 H₂O

Gaseous chlorine is never evolved, and as long as the HCl-concentration is held below about 20%, the main component of the escaping vapour-phase on bubbling the mixture is water, not HCl.

freechemist

 

[mls26cwru]

thanks freechemist! I have actually noticed that over the course of the last couple days the chlorine gas has subsided greatly... to start with, it was coming out of solution in a very noticeable amount and had me a bit concerned.