HCL tank vent scrubber 3

[richiekpr]

I have a 200 gallon 32% HCL which I need to vent to fill and let air in to empty. Currently there is no scrubbing and all metals surrounding it are turning into rust. Is there any dry scrubbers to which I may pour some caustic into and neutralize the vapors w/o having to go through the trouble of installing and maintaining a wet scrubber system for 200 gallons worth of HCL? Any help is greatly appreciated as I have encountered a void of this type of product in the market.

 

[ash9144]

I've never encountered a truly dry scrubber. Assuming you mean some solid (pellet) form of caustic. You could construct one but I would imagine the trouble maintaining would be worse than a wet scrubber. You would still have corrosion issues. The HCl is more corrosive than the caustic.

Wet scrubbers can be fairly simple. Could be a simple packed tower with a dilute caustic solution circulating or even water circulating with a pH control on the bottoms liquid. You could probably get by with a seal pot using a caustic sealing fluid.

 

[Zoobie]

I remember using a drum scrubber on ion exchange regen system HCl tanks. The tanks were small (100-200 gallons) filled with 35% HCl (which has a vapor pressure almost twice that of 32% HCl if I recall correctly). Anyways, the drums (45 gallons) had inlet and outlet fittings for the vapor lines. I think the media was carbon. They worked quite well but you definitely knew when it was spent (start to stink). The problem is that I can't remember the supplier/manufacturer name. If it comes to me I will post it.

 

[richiekpr]

thanks for the reply zoobie. so the vapor outlet on the carbon tank would vent to atmosphere?

 

[ash9144]

I would definitely talk to a carbon bed supplier before bringing one in. There are also tables in Perry's and others that show absorbtion capacity on a pound/pound of Carbon basis. I've used carbon canisters to remove hydrocarbon successfully but avoid using in acid vapor service due to potential reactions which could cause a fire.

 

[unclesyd]

An easy one to try would be to use a plastic drum/cannister and fill it with Marble Chips and put you gases in at the bottom. Add a vertical vent to get above any equipment. You will have to add a drain as you generate saltwater in the bottom of the cannister.

All components are to be plastic.

 

[Zoobie]

The vent was to atmosphere inside a building...like I said, when it was spent you could tell....or should I say smell.

Take ash9144's advise and talk to a supplier. The Calgon Carbon website has some limited information. The drum size tank vent scrubbers are common, however I would double check the suitability with HCl....I did stumble onto something at one website that indicated acid vapors could be treated this way.

 

[shahyar]

Dry Scrubber: A drum of dry bed, not carbon based.
Wet Scrubber: A packing tower with just water spray. When the water HCl concentration get high(eg more than 5%), water needs to be removed.
I have designed both of them. No need to use caustic, acid in vapours are very low.
Dry one has simpler design and I prefer it.
Hope this help.

 

[richiekpr]

Thanks for the post shahyar,

The dry bed, is it made of caustic pellets?

 

[shahyar]

No, It was Activated Alumina impregnated with something proprietary. We bought it from Unisorb Canada.