Home Hydrogen Generator

[crashsite]

A common science experiment is to crack water back into elemental hydrogen and oxygen and, it's pretty easy to do. Of course, the problem is that it takes more energy to separate it than you get back when you re-combine the hydrogen and oxygen back to water again.

But, if you can find a "free" energy source (the sun) that's otherwise just going to waste, can it be practical to do the cracking at home?

Communist China tried the concept with poor success by having families set up small smelters to generate steel for industry. Unfortunately, the quality control was spotty and the steel output sub-standard. Hopefully, technology has advanced some since then.

Lets say that a photovoltaic solar array is used to provide the electrical power and appropriate electronic and electrical devices are used to control and monitor the process. By having the cracking be automatically taking place whenever there's sufficient sunlight, the home setup would generate the hydrogen and drive it into a relatively low-pressure tank (similar to a household type propane tank).

As the tank would approach capacity, it would report its status to the "hydrogen company" (probably a public utility like the electric, gas, water and phone company) that would have a collection truck stop, on its route, and extract the hydrogen while measuring the volume taken. The family that generated the hydrogen would be credited similar to the way a family can now generate electricity and drive it back into the electrical grid for credit. When the family hydrogen fueled car filled up, the credit would automatically be applied.

What I don't know (and hope people out there in cyberspace do) is whether sufficient hydrogen could be produced and harvested in this manner to make it worth the effort. Unlike LPG, the hydrogen would stay gaseous and would not be as efficient as propane, for the same size tank but, with millions of units operating most every day, would it be efficient enough to be practical?

Also, since propane is a hyrocarbon fuel (and I've read that the most common and efficient way to get hydrogen now is to extract it from natural gas), I wonder if the hydrogen could simply be driven into a propane tank to make a hydrogen enriched propane that would be used (by families that use propane) directly? I'm no chemitst and don't know the ramifications of all this.

 

[RLJ]

BIOGAS (Methane) would probably be the most efficient. Most small farms would have cows, pigs or other other livestock which would generate waste (human as well but most human waste is too rich and must be 'watered' down). A small biomass converter would be easy to setup and maintain. The gas concentrator (holding tank) could then be off loaded and the gas scrubbed and prepared for further compression. Another feature would be that a small portion of the collected gas could then be drawn off for the cooking, heating or power production using a generator modified for burning methane for the farm.

As with anything there would need to be some training and safety precautions but this would be easier and produce more methane gas in less time than hydrogen as well as being able to use 3rd world material. Back in the mid 70's Mother Earth News carried a 55 gal drum gas production unit which used a 55gal drum, a tractor innertube and propane gas stove.

Just a thought.....RLJ

 

[Pommie]

This may be of interest, it's an article from 1991 about home (farm) Methane production.

Mike.

 

[ericgibbs]

This may be of interest, it's an article from 1991 about home (farm) Methane production.

Mike.

Interesting article.
At the moment we trade our pig/goat and other slurry with local nursery gardens, just wonder what change in soil enrichment terms occurs after/during digestion to get the methane?

 

[Pommie]

Eric,

You read VERY fast. I have a few more Home Power articles archived on a disk. They don't appear to have any copyright notice on them. Anyone know the legality of posting some here?

Mike.

 

[RLJ]

Everything I have ever read talks about the slurry left after methane productions can be used for soil enrichment. Although in the back of my head I remember something about if human waste was used that there 'might' be some issues with health departments. The product that comes out is really a 'composted' product and any harmful biological bacterial have been either killed off by the lack of habitable atmosphere, heat generated or the lack of 'digestive' material. The decomposition and release of the methane gasses (byproduct of digestion...yep, igniting release of gasses from the bodies orifices) is the active process.

The rule, if I remember right, when the production of gas is stopped the digestible material is used up and the environment has killed off all bacteria (good and bad) and the material which is left can be used for soil enrichment.

Again, fuel source for the farm, easy setup using cheap material, soil enhancement and commercial production of gas...seem like a win win situation
to me.

RLJ

Also, this article recaps what I remember from the old Mother Earth News...even similar designs.

 

[Nigel Goodwin]

Everything I have ever read talks about the slurry left after methane productions can be used for soil enrichment. Although in the back of my head I remember something about if human waste was used that there 'might' be some issues with health departments.

As I understand it, certainly in the UK, you're not allowed to use human waste as fertiliser - although I don't see as there's any more biological risk than anything else?.

In a closed environment (such as a long distance space craft) you obviously would have to recycle the human waste products.

 

[ericgibbs]

hi Mike , RLJ,
There is no human waste in the mix, the human waste goes into the French drain that we built about 6 years ago, that drain works just fine.

Im due to fly out to our farm in South Africa in a couple of weeks for two months, I'll discuss the methane idea with my son.

He always has some project or other lined up for me.

 

[RLJ]

U.S.(states) is the same way, from what I recall. From what I have read animal waste and vegetable matter used as material from methane production is more efficient. It does not have to be 'cut' as much and it processes faster through the digester so you can keep 'feeding' it.

RLJ

 

[RLJ]

Check the internet before you head out. While the technology is simple I know that there are some things you can do like keep the temp in a certain range and work with the ph if you decide to try this.

If nothing else it could be something to 'tinker' with...but remember all the safety precautions....things that burn can prove hazardous, especially if under a little pressure. I have memories of exploding glass test tubes from my High School chemistry class of an experiment with a plugged vent tube to prove that!

RLJ

 

[wmmullaney]

This is kind of off-subject from crashsite's post. Can someone give him an answer?

 

[jpanhalt]

Also, since propane is a hyrocarbon fuel (and I've read that the most common and efficient way to get hydrogen now is to extract it from natural gas), I wonder if the hydrogen could simply be driven into a propane tank to make a hydrogen enriched propane that would be used (by families that use propane) directly? I'm no chemitst and don't know the ramifications of all this.

Hydrogen burns at a much higher temperature than propane burns. Hydrogen flames are typically invisible, unless impurities are present, and hydrogen flames are difficult to extinguish, i.e., they are almost impossible to blow out. I don't know how the mixture with propane would behave, but my experience using hydrogen torches is that they have definite uses, one of which is not in the home for cooking. If one produces a surplus of hydrogen, I would suggest just transporting it to a place for proper use, as in fuel cells.

As for methane (natural gas), it is easy to transport as the compressed gas or refrigerated liquid. Moreover, it has the property of forming clathrates with water (effectively forming an ice with a high concentration of methane and much higher boiling point than LNG) that may make it an even more attractive as a easily transported fuel.


John

 

[mneary]

Why do so many people think that hydrogen solves any problems?

If you have excess electricity, it is much more efficient to sell it to your utility using the infrastructure that's already in place. In many areas, PV produces maximum power just when it's wanted: to run air conditioning!

It's really inefficient and dangerous to make H2 and collect it by truck.

 

[jpanhalt]

It's really inefficient and dangerous to make H2 and collect it by truck.

While I agree with the efficiency statement in the context of the discussion, I am not aware of any data showing that hydrogen is more dangerous to transport by truck than other substances, such as water, fertilizer, and fuel oil. I am not referring to the labeling requirements, but rather to actual data with respect to accidents and injuries.

John

 

[mneary]

It's the transfer of the hydrogen that concerns me, not the highway safety.

I have no data.

 

[jpanhalt]

It's the transfer of the hydrogen that concerns me, not the highway safety.

I have no data.

Whoever first penned the statement, "In God we trust, everyone else bring data," had great wisdom. Was it Einstein?

There is far to much fear mongering in our society today that is making us overlook simple solutions, like the fears expressed in another thread of storing solder paste in a home refrigerator. Lead atoms don't jump (in any appreciable quantity for you quantum gurus) from a closed container into your milk. Similarly, hydrogen is about as safe as any fuel when properly used. BTW, I am not a proponent of a hydrogen economy in the near future, but my reasons are not based on safety. John

 

[mneary]

I'm not that risk-averse. I live within 2 miles of a major oil refinery, for the past 30 years. Before that, I lived near a nuclear plant. They've had accidents, and the professionals on site have been able to contain the problem and only a few lives were lost.

I keep solder paste, cyanoacrylate glue and RTV in my refrigerator.

I just don't think my next door neighbor should be manufacturing fuel.

 

[crashsite]

You all raise some good points but, the comment I would make about methane gas is that you have to have the raw materials to make it. The average residential neighborhood would likely be averse to having large numbers of animals milling around or trucking in the poo. On the other hand, water is readily available (and desirable).

Regarding the efficiency issue and just directly piping the energy back into the electric grid...I'm not sure. From a technical point of view, that makes sense. From a political point of view...maybe not. We've all been dismayed at the "idiocy" of budgets in companies we've worked for. You know, throwing away $1000s in unneeded office supplies on one hand while denying you $7 for a whisk broom to dust off your desk because the office budget has money and the janitorial supply budget doesn't. BTW: That's not a real example since I was known for never cleaning off my desk.

If the rules required the home electricity production to be allocated to the commercial cracking of water to produce hydrogen for the fuel cells, the overall efficiency would be greater but, in the real world, the electricity would be used for genreal purpose purpoeses and our dependency of foreign oil and gas would remain uabated.

I believe there would be a strong psychological aaspect to home hydrogen generation that would increase awareness and appreciation of where energy comes from that's largely missing now in our modern world. But, that might just be pie-in-the-sky thinking; especially considering the limited participation in returning power to the grid now (that lack of participation includes me and very likely, you).

My original post addressed only the technical side. But, I am hopeful that the future will provide not just technical feasabiltiy but, also social and political pressures to generate alternate energies and do so with more participation from the "little guy". Okay, Crashsite...enough editorializing!

 

[ericgibbs]

While I agree with the efficiency statement in the context of the discussion, I am not aware of any data showing that hydrogen is more dangerous to transport by truck than other substances, such as water, fertilizer, and fuel oil. I am not referring to the labeling requirements, but rather to actual data with respect to accidents and injuries.

John

hi John,
Slightly off topic.
Can you imagine a world where we didnt have an internal combustion engine propelled vehicles, cars etc.
Then some young inventor comes along and says, I have developed an engine that runs on highly inflammable petrol. To make it run any distance the car needs to carry around 20gallons of petrol in a flimsy tank made from 2mm thick mild steel.
Also the car requires a 12V lead acid battery that can supply upto 100amps on demand.
The car is capable of travelling at speeds upto 70mph and will using the same roads as thousands of other vehicles.

In the event of an impact/crash the petrol tank is liable to rupture and the petrol be ignited by the crushed battery wiring.

BTW all car users would have access to filling stations where they can refill the petrol tank as required.

I would think in todays climate of health and safety, they would lock the inventor in a padded cell!

Yet people are 'worried' about Hydrogen being a problem...

Regards

EDITED:
The inventor adds after a futher study:
BTW the engine will emit carbon monoxide and dioxide.
These oxides will cause thousands of deaths due to cancer and other illness, also change the planets climate to such an extent that
millions of people will suffer severe hardships....

 

[crashsite]

Thank Goodness We Have Aspirin for Headaches Like This

Then some young inventor comes along and says, I have developed an engine that runs on highly inflammable petrol. ....

Many examples could be given. My favorite is whether today's FDA would even consider approving aspirin for over-the-counter sales.

The Hindenberg sort of gave hydrogen its stigma. I believe that hydrogen, properly bottled and vented during a car crash could be much safer than gasoline.

Regarding having one's neighbors generating it. Again, suitable safety measures could be employed. One of the good things about hydrogen is that it is light and so any flames tend to burn upward and don't carry the hazard of floating ash or embers even in windy conditions. I don't think I'd be as concerned about a small hydrogen generator as a poorly placed or maintained burning barrel or the neighbors out burning weeds.

But, the initial question about the technology remains unanswered: Independent of social, safety, political, moral, religious and ethical issues, could a lot of small operations, using "free" energy, as proposed and working in support of a "hydrogen industry", produce hydrogen in economically feasable quantities (ie: Have a shot at reducing our thirst for foreign energy supplies even just a little)?