DIY Hydrogen Fuels

[kontiki99]

I've been thinging about the whole hydrogen fuel thing and I think hydrogen gas is not going to be a practical fuel.

So, I thought that maybe using solar cells to produce hydrogen from hydrolysis might be a good first step, but instead of just using the gas as a fuel, combine the hydrogen with something that's stable.

Perhaps the hydrogen could enhance the energy of an existing fuel, even if it's a solid that you'd burn in a wood (like) burning stove.

Anybody have any ideas how to combine hydrogen to make a fuel in your backyard?

 

[MikeHalloran]

How big a crater can you make in your backyard before the neighbors get upset about it?



Mike Halloran
Pembroke Pines, FL, USA

 

[kontiki99]

My error in posting, that should have been using solar electrical panels to power electrolysis to make hydrogen.

 

[moltenmetal]

We agree that hydrogen's a poor fuel. Indeed it's not really a fuel at all- it's just an energy carrier or storage medium, and a poor one at that.

First, if you're going to electrolyze water, don't just throw away the oxygen- that's half the energy right there.

In "combining the hydrogen with something that's stable", you similarly throw away a significant portion of the energy that was in the hydrogen in the first place. The same goes for compressing it or liquifying it or chemisorbing it for storage- significant energy waste is involved in all of those processes due to the properties of hydrogen. Without significant cost and complexity, you get none of this energy back when you use the fuel.

You'd be far better to just use the solar photovoltaics to replace electricity generated by other means and forget about the hydrogen entirely. If you produce too much electricity, storing it in batteries for off-peak use is far more efficient than bothering with hydrogen as a storage medium.

 

[TheBlacksmith]

I think the whole big deal on hydrogen is that it can be obtained by electrolyzing water and with perfect combustion it makes water, theoretically providing and endless source of portable fuel for vehicles, etc. (Yes, I know, you need solar, nuclear or combustion source to make the hydrogen) Mixing the hydrogen with a carbon based fuel, besides the potential danger pointed out by Mike, would appear to dilute or negate the hydrogen cycle advantage. I guess you'd be making manmade hydrocarbon fuel.

 

[SomptingGuy]

I've just been reading an interesting article in "Engine Technology International" about Bath University's work on hydrogen storage methods. They've come up with some "organo-metallic compound that contains 6 rhodium atoms and 12 hydrogen atoms". The point being that it can absorb and release two hydrogen molecules on demand ... at room temperature. Sounds interesting.

 

[rb1957]

sounds like a fuel cell

 

[SomptingGuy]

Except that the released fuel is burned in a regular IC engine. It's just a low temperature storage system. I found a link on the Bath web site:

http://www.bath.ac.uk/news/articles/archive/hydrogen041206.html

 

[moltenmetal]

Isn't the freaking platinum and palladium in the PEM fuelcells enough? Now they've got to mess with $6,000 USD/troy oz rhodium?

Rhodium is 102 g/mol. Molecular hydrogen is 2 g/mol. They claim two moles of hydrogen storage per mole of rhodium if I read things correctly- or perhaps it's worse than that, if this thing is merely shifting from Rh(6)H(12) to Rh(6)H(14). No matter- even the former would mean you'd need 102 g (~$19,000 USD as a raw material) of rhodium to store 4 g of hydrogen- and you'd need to lug around all that expensive mass with you too!

NO hydrogen storage medium involving significant quantities of rhodium will ever be economically feasible!

 

[Comcokid]

Hydrogen is a failure as a global fuel/energy source from the start. That's why the US automakers are pushing it - they can appear to be 'green' and proactive and at the same time not risk their current business foundation.

Hydrogen will never find more than specialty applications. There are too many problems with storage and transportation. Energy density is low.

Newer technologies have even moved fuel cells away from their dependence on hydrogen, and into a whole array of light hydrocarbons.

Newer technology has improved the efficiency of solar cells to where direct power generation is more feasible.

 

[zdas04]

Hydrogen is a very good fuel source - in a Fusion Reactor. Other than that I agree that it is doomed to be a very noisy sideshow.

David

 

[KENAT]

I saw something somewhere on the net where they'd 'diluted' natural gas with hydrogen. I can't remember the details, like if it chemically combined with the gas or just mixed with it, but it seems people are looking at it.

Certainly using pure hydrogen in vehicles doesn't seem that practical on a large scale in anything like the near or medium term.

Perhaps if they can find a way to use it to enrich some other 'bio fuel' with it that creates a more easily used product it could be useful. Assuming of course that the promise of 'excess electricity' (compared to existing usage) from renewable resources, so that the hydrogen can be made cleanly in the first place, ever happens.

Even then it would probably be better to find ways to use the electricity directly, be it improved batteries for electric/plug-in-hybrid cars or some other technology.

One thing that hydrogen has some possible application is as a storage device for excess electricity generated by all the renewable resources that we’re waiting to magically appear. Many of these sources are intermittent and even unpredictable so being able to handle this is an issue and energy storage of some kind may be part of the solution, although there may be better ways than using electrolysis to generate hydrogen.

Out of interest they’ve decided that hydrogenated bio-oil is bad for us to eat but how does it compare to regular bio-oil as an energy source? Is this a situation where hydrogen enrichment of another fuel source might work?

 

[TheTick]

Ask the folks on the Hindenburg how they feel about hydrogen.

Honesty may be the best policy, but insanity is a better defense.

http://www.EsoxRepublic.com

-SolidWorks API VB programming help

 

[KENAT]

We all know that was because of the Thermite reaction of the doped skin right nothing to do with the hydrogen...

So long as the vehicles aren't made of thermite doped fabric we'll be OK!



Seriously though would the effects of a similar volume of propane, petroleum vapour, or other hydrocarbon gas we currently use routinely & relatively safely, combusting have been any better?

 

[ScottyUK]

Well, the Hindenburg wouldn't fly too well if it was full of propane...

Even assuming a method to produce hydrogen economically can be found, one of the big problems with hydrogen is that it is such a searching gas which will find the tiniest path out of its containment. Makes for some challenging design problems if we are ever to use it as a vehicle fuel: how to transfer it safely between the bulk storage and the vehicle tank?


----------------------------------

Sometimes I only open my mouth to swap feet...

 

[Comcokid]

I seem to recall that a major issue of using any existing infrastructure (pipelines, pipes, storage tanks) for distribution of natural gas mixed with hydrogen was accelerated hydrogen embrittlement of the metals used.