Hydrogen build up in boiler?

Joe_115

A client of mine recently e-mailed me asking me what I was going to do about Hydrogen build up in his boiler. I told him that I'd never heard of it before & could he tell me what brought this question on. He told me that he had read about it on-line. I would think that hydrogen, being lighter than air would vent through normal air venting proceedures. I am still trying to figure out what (if anything) would cause H2O to split & give just straight H2 in the system. Any help would be appreciated.

Aidan (UK)

Hydrogen

Galvanic or bi-metallic corrosion.
Electrolysis splits the water into H2 and O2. The oxygen dissolves and corrodes ferrous components, which results in black magnetite sludge. The hydrogen accumulates in any unvented high-points. You can check that it is hydrogen by venting it into an unturned glass and lighting it. It ignites with a 'pop', and burns upwards.

The usual cure is to check the level of the corrosion inhibitors in the heating system, it usually only happens if the water is acidic.

nicholas bonham-carter

hydrogen

if you put shredded cooking foil into a coke bottle filled with lye and water, it will produce quite a bit of hydrogen gas. if the solution also has soap in it you can do quite a bit of "lighting up" the bubbles of H2, as they float up to the ceiling!

years ago i bought a large lighter-than-air ballon in rome to entertain my children while we had a very late dinner with them and others. in the morning, i noticed the ballon was mostly deflated, and so i thought i would untie the neck and save it for the next time they needed entertaining. i did this next to the stove while boiling water for tea. little did i know the roman ballon-seller had filled it with hydrogen, and so there was a loud explosion, as the ballon emptied towards the open flame of the stove, which rattled the windows, and drove bits of ballon into my skin!

hydrogen could be a high-powered fuel for the future, but we need more work on its handling. in the meantime let's just conserve.--nbc



here is a hydrogen car race:

http://www.shell.com/home/Framework?siteId=eco-marathon-en

scrook_3

classic replacement reaction...

The lye (sodium hydroxide, NaOH) has the hydrogen atom in the hydroxyl (OH) part replaced w/ an aluminum atom, becoming NaOAl -- the hydrogen then rises as a gas.

another interesting reaction is calcium carbide (CaC2) plus water, which yields acetylene gas, C2H2 and calcium hydroxide or hydrated lime, Ca(OH)2. to allow safe handling, the acetylene in your B (or MC) tank is dissolved in acetone soaked into a porous filler.

Isn't chemistry grand?

Jamie Hall

and as for

what to do about it -- if this is a steam system, the answer is... ta da... not to worry. Assuming that the system is vented properly, that is. Any hydrogen produced by the various nifty reactions outlined will be thoroughly mixed with air when the system is off; when the system fires and starts producting steam, any hydrogen in the water will be driven off into the air and steam. Any that is in the air in the system will go along with the air and be vented; any that is in the steam will stay as a gas and be vented when the steam condenses.

That is making two assumptions: one, that you have a moderately normal steam system and, two, that the reactions involved are relatively minor. If you have a reaction which is more enthusiastic, you have other problems...

Joe_115

Much ado about nothing

Jamie,
This is a closed loop Radint/baseboard system. Brand new...The owner just hit me with this complaint out of the blue after ,"Reading about it on-line" Man I HATE the internet... they'll let anyone on here! ;-)

Anyway, after discussing it with guys here in Colorado who have been at this a lot longer then me (almost long enough to qualify for Dan's Dead men series) we've decided he's worrying about nothing. Ther has never been a problem that we can find here anywhere. Bad install maybe, but not hydrogen build up.

Now those guys north of Denver getting natural gags in their well water... That's a whole bigger problem.

Thanks for your help & insight.

JTLP

steve_196

Hydrogen build-up in an unused hot water tank is something that is well known. Are you all saying that this can happen in a closed loop boiler as well?

Jamie Hall

yup

except that in a closed loop boiler, one of two things will happen -- if it's a hot water system, the air eliminator will get rid of it, no problem. If it's steam, the vents will get rid of it, ditto.