Wow, that is a facinating material. Could be a game changer if it gets produced in commercial quantities. I don't understand how it can hold helium in, but let water pass through. That's weird. 

Indeed!    Earth shattering game changer .  One to keep  an eye on  and  buy Stock IN!   

Looked again at the Michael Raines, expertvillage video. He is making HHO, hydrogen and oxygen for fuel. Quite combustible, not what we want.
For our needs, the anode and cathode need to be in separate places, separated so the oxygen goes up one way, and the hydrogen goes up another, not to ever mix.
Like he says, the electrodes need to be very noble, platinum is best. His trick of covering the electric lead in plasti-dip is a good idea, will protect the lead from electrolysis.

[url]  Graphene stops helium from escaping from enclosure.

-michaelcweir

Yeah, the trick of course is fabricating it, applying it, and getting it to stick to your envelope.  One of things that there is a "race" on is to make a "graphene paint".  A formulation that has the graphite in solution and as the solvent evaporates, the carbon knits together into a flat(ish) layer of graphine.

HHO is for when you want to burn it right away. In a torch or motor. You can't separate it or even store it, because besides the explosion risk, it will slowly re-associate back into water even if it doesn't burn.

* DO NOT USE NaCl as electrolyte that would make chlorine gas, hydrogen, and bleach. Dangerous unless you are making Bleach or Sodium Perchlorate in that case proceed with caution. Use baking soda.

-cksantos85

Why are you worried about O2 production?  Just vent it to the air. Stay away from candles.

-jamesg

cksantos85: This cell that I have made and operated does not produce chlorine. You're confusing this with the 

Chloralkali process.

jamesg: In the standard electrolysis , Oxygen absorbs in the electrolyte and can come out in small quantities on the Hydrogen side by a diffusion process. In my process, the O2 is chemically bonded as it is formed and winds up as Fe2O3 ( Iron II Oxide ) sludge in the bottom of the reactor.

1. Looked again at the Michael Raines, expertvillage video. He is making HHO, hydrogen and oxygen for fuel. Quite combustible, not what we want. 2. Like he says, the electrodes need to be very noble, platinum is best. His trick of covering the electric lead in plasti-dip is a good idea, will protect the lead from electrolysis.

-mikek

1. You're exactly right on this point.

2. Platinum $1619/Oz. ( as of today). Much cheaper to burn off Iron. 

You only need a thin foil of it. It doesn't erode and the water cools it.

The benefit of electrolysis is that it can be operated "steady-state", just keep the water topped off, whereas any sacrificial catalysis mode is finite. Which means you are going to have to stop production, dismantle your apparatus and reload it. That will get old fast at the quantities needed for a LTA craft.  

I am hoping that electrodes with platinum plating would be available. That would give maximum surface area and a good solid place to attach the wire. Like light bulbs and such, I'm also hoping that the wire connection could be outside the wet area, with a bulkhead fitting.

Sort of on the subject, but I came across this paper while looking for something else.  Its an experiment in direct thermal solar hydrogen production.  Basically using a solar concentrator to "cook" water into H2 and O2.  The published results weren't spectacular, but its an interesting read and food for thought.

http://www.hionsolar.com/n-hion96.htm

You only need a thin foil of it. It doesn't erode and the water cools it. The benefit of electrolysis is that it can be operated "steady-state"

-jamesg

Even thin foil is expensive. Additionally, platinum is very easily poisoned. Additionally ( to the additionally) normal electrodes use platinum black, which is finely distributed on the electrode surface. A procedure best done by a chemist as it involves dangerous chemicals to accomplish.

Iron is cheap. I've been through the procedure to de-poison platinum, and it ain't cheap.

 If you can afford all of the platinum electrodes you're going to go through, you might as well buy your hydrogen.

P.S. Have you done the calculations for determining the area of platinum and the amperage to produce the amount of H2 you plan to use in the planned inflation time? 

We ain't talking demonstration chemistry lab beaker sizes.

Also, water is a sorry electrolyte. That's why they add sulfuric acid or sodium hydroxide to the water so the whole deal happens with a reasonable current flow.

Sort of on the subject, but I came across this paper while looking for something else.  Its an experiment in direct thermal solar hydrogen production.  Basically using a solar concentrator to "cook" water into H2 and O2.  The published results weren't spectacular, but its an interesting read and food for thought.[url]

-jamesg

That is a good paper. But the H2 and O2 are produced at the same time requiring another separation step and BIG equipment.

Also the bio-reactors that produce H2 by enzyme action would require a large lake to make production near our rate needs. 

Naw, the bulk of the experiment was devising the jet skimmer to separate the products shortly after dissociation based on their mass.  I noticed a few flaws in the configuration (everything was inlined with the beam and the actual reaction site was minimal), but its interesting for the potential it holds. Its all solid state. Just keep it pointed at the sun and the water turned on (or you'll vaporize the injector!).

Well, how about sea water? My plan is to spend a lot of time over ocean. One design was to have a torpedo like device connected to the airship. This device would have a prop driven generator, a hydrogen generator feeding gas up a tube to the ship, and rudders to have the torpedo bear off the wind to allow the airship to also bear off the wind.
Having enough lift to carry the torpedo over land is challenging. Maybe the prototype would be confined to sea travel only. That would be ok for starters. There is a lot of the world available from the sea, and no powerlines to run into.
Getting stuck in a harbor with onshore breezes is something the square riggers had to deal with, they seemed to work it out somehow.

aka "a water keel". 

Keep in mind that the prop (screw in marine parlance)  and anything being turned by it creates drag that has to be paid for with your propulsion, even if that is a wind sail.  The only time you get it for "free" is when you are being pushed downwind and dragging it thru the water.

Sea water is a better conductor, but its also contaminated with all sorts of stuff that will quickly gum up an electrolysis reactor. From dissolved minerals to organic chemicals including live microscopic critters.  You're better off just having the electrical generator down in the water and your gas generator above using fresh water from rain or condensate.

How about using a vacuum for lift. there are actually patents that have been filed on this approach.

Good point, Jamesg. Maybe the rain will pick up some salt off the hull as it goes to the collector. Once in the collector, the salt won't leave, and serve as the conductor until it gets stuck somewhere. This takes me back to solar panels and the chein de mer.  It's light, and can be carried over land. Simpler solution.

Putting current through seawater causes the production of chlorine gas and bleach..

rain would be scary.

Not really. The concentration of it would be low and can be easily filtered out of the product gases. Plus it will prevent biological growth in your reaction tank. :D

How about using a vacuum for lift. there are actually patents that have been filed on this approach.

-michaelcweir

Its been around for as long as LTA craft, problem is materials haven't been up to it.  Its still a much harder way of going about it than using a lifting gas.  The curve of the weight of the structure required to hold a good enough of a vacuum requires a huge volume for even an "ultralight" vacuum craft. 

Hi guys, good to see you are all still hashing out ideas.   I noticed that graphene was in the news and is supposedly impermiable to helium and other gasses, and I thought of you guys.   It may be a few years away and cost prohibitive but it may come before helium is so diminished we can no longer afford it.   It is slowly renewed through radioactive decay but not very fast.
.    Water also seems to be impermiable to helium.  THey don't like each other.   Gasses like amonia and chlorine will saturate water like a sponge is filled with...eh water.  But helium is the least water permiable gas, and it seems to be almost completely blocked by it.   It made me wonder how to put a thin layer of water between layers of polyethylene....such as saturating a mesh of ripstop nylong or some other strong porious material.   Keeping the outer and inner layers glued together to the core of reinforcement fiber is the difficult thing, I suspect.  If we could use graphene as the inner layer of reinforcment, that would solve bothe the strength issue and permiability issue for water could easily absorb through the fabric after assembly.
    Just something to think about.
.    It is too bad that there exists no sufficient structures to withstand a total vacuum.   However, it may be possible to layer a ship, like an onion, with each layer having more vacuum than the outer one, so each thin membrane only had to withstand a few pounds of pressure.   The shape inside would be spiked, but subsequent outer layers of hydrogen and finally helium would fill out the outer shape desired.  
.  
.    One last thing, carbon soot as an electrolyte, would it clog things up?  Would it produce methane on one side and Co2 on the other or would it stay out of the hydrolyzation process?   Any clues?   Good to see you guys again.  Wade. / inventive47

Those would be worthy experiments. 

You could thermally bond a fine nylon fabric between two thin plastic films and create effectively a composite envelope material. The nylon would wick up water let in by a perforated bleeder line. It wouldn't add much weight if it proved effective at keeping the H/He from going astray.