Most cost effective way to produce H2 gas

[San2006]

I wish to collect H2 gas in a safe and cost effective way.

One way I read was to react Zn metal with acid ( HCl or H2SO4). Where wil I be able to get all the stuff from?

 

What would be the best way to store H2 gas.

 

The reason I want to produce H2 is, I want to see, if I BUBBLE H2 gas thru water, how does its ORP (Oxidantion Reduction Potential) change. I have read that, when H2 gas is bubbled through water, the ORP of water become highly negative as H2 gas is a strong REDUCTANT ( aka anti-oxidant). I want to prove this with my experiment.

Any ideas?

[hermanntrude]

zinc or any fairly reactive metal (google activity series to see which metals react with acids, but be careful not to use a metal which is TOO reactive!) should do just fine.

 

Zinc is fairly common, although i'm not sure how you would identify it by sight... i expect a junkyard would have loads of zinc for free or cheap. The acid you would probably be better off using HCl, just because it's a bit safer and less messy. You can buy HCl at stores for specialised purposes... i expect one of our home-chemists could tell you what they sell it for. i just buy it from my suppliers.

[insane_alien]

you can get HCl from most hardware stores. its sold under the name 'muriatic acid'

[San2006]

Other than looking for a junkyard, where else can I procure Zinc metal?

 

thanks

 

Thanks. I did not know that HCl is also called Muriatic acid . Learnt something new again.

[YT2095]

you don`t need Zinc, you can use Aluminium instead, that will work with HCl or NaOH (both easily available).

[Alexein]

I wish to collect H2 gas in a safe and cost effective way.

One way I read was to react Zn metal with acid ( HCl or H2SO4). Where wil I be able to get all the stuff from?

 

What would be the best way to store H2 gas.

 

The reason I want to produce H2 is, I want to see, if I BUBBLE H2 gas thru water, how does its ORP (Oxidantion Reduction Potential) change. I have read that, when H2 gas is bubbled through water, the ORP of water become highly negative as H2 gas is a strong REDUCTANT ( aka anti-oxidant). I want to prove this with my experiment.

Any ideas?

 

exactly how are you measuring the change in redox potential of the water? Specialized equipment like that (a Cyclic voltametry system) costs several thousand dollars. The platinum electrode alone will be more expensive then buying zinc off ebay.

 

If you really need hydrogen you can just put a few strips of aluminum foil into a solution of hydroxide based drain cleaner. Very easy to obtain both.

 

But unless you're using a very exotic measuring system you won't be able to observe how hydrogen affects the electrochemistry of a solution with just stuff you find around the home.

[San2006]

I actually own a digital ORP meter which can meaure the Oxidation Reduction Potential of water or any other liquid. I am interested in obtaining -ve ORP water.

 

Normal Tap or filtered water has ORP of +300 to +350 mV. Hence this water is "oxidizing". H2 gas should turn the ORP in other direction and make it like -300 or lower. This water is supposedly electron rich and can scavenge free radicals...

Edited December 9, 2008 by San2006

[CaptainPanic]

What do you mean by "Effective (in the 1st post)"?

Do you mean:

• "the most H2 with the least energy"?

Or do you mean:

• "Most practical: the least problems to do, fool proof, and if I use 2 cents worth of electricity more than strictly necessary, I don't care?"

It's quite a different approach.

[San2006]

I meant, most H2 gas with least amount of energy, less complications and easily obtainable ingredients. Also safety is important. Dont want to deal with very corrosive chemicals.

So basically, best of both bullets.

[insane_alien]

what sort of scale? if i was to design a plant to generate H2 for lab scale it would be very different to the process for industrial scale production.

[CaptainPanic]

Well... I could write a long story, but as so often, wikipedia has an article that is already giving all the answers. It lists a lot of methods to make hydrogen, including a number of chemical methods.

 

To learn the most effective way, you must include the production of the chemicals too.

 

I think the most simple way is electrolysis of water.

 

Please note that none of the processes will be 100% efficient.

[Falkon]

Well you really shouldn't have a problem getting zinc. Post 1982 pennies are copper plated zinc. Just scratch off some of the copper with sandpaper to expose the zinc, then put it into HCl

[hermanntrude]

Well you really shouldn't have a problem getting zinc. Post 1982 pennies are copper plated zinc. Just scratch off some of the copper with sandpaper to expose the zinc, then put it into HCl

 

remember this is an international forum. Which country's pennies are you talking about?

[Falkon]

Sorry about that I'm new

US pennies.

[hermanntrude]

welcome to the forum

[gcol]

I have done it using NaOH an aluminium. I was amazes at the volume oh H produced. I collected it gasometer style. Soon ran out of inverted buckets, rainwater barrels, 6 litre platic containers, etc.

 

Using a large area of Al foil in the primary vessel meant that I could use well-diluted caustic such that the skin burning time was amply long enough to allow wiping off and rinsing in a handy bucket of water. Just top up the primary from time to time. A transparent primary allows you to see when the foil is exhausted. By trial and error, I soon determined how much caustic in practical terms gave me the required volume of gas. When changing things around, I always flush out the garage with fresh air before lighting a fag. The occasional singed eyebrow is o.k, but when my beard singes, bad smell.

 

Wary about hydrogen by hydrolysis. Have you ever mixed hydrogen and oxygen 2:1 and ignited it? No soft friendly whoosh like hydrogen in air, but one almighty roof-lifting crak of an explosion. I don't want the complication of keeping O and H safely separated. User beware.

[cpazchem]

Like the previous suggestion Al and NaOH are the cheapest (and i beleive most effective way) of producing large volumes of H2. I used a large (2L) round bottom flask full of Al foil (shredded with sissors) and dripped saturated NaOH (by means of an upside-down bottle) onto it at a rate which provided me with a constant flow of H2.

 

The one thing i learnt however is make sure it is all air tight and free of O2, particularly if there is a risk of the jet igniting!