Synthetic Methane

  • Thread starter MacGyver2
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Main Question or Discussion Point

Does anyone have a quick and dirty method to make methane from pure hydrogen?

Background: I am new here, but a regular at TheBackshed.com, where most of us design and build wind turbines and alternators. When a 'windmill' generates more electricity than its system can handle, the overage is diverted to what is termed a "dump load". A dump load is usually a resistive load (heater) and often times an electric water heater is used. This allows a pathway for over-production of electricity and ultimately stores that energy in the form of usable, HOT potable water.

What we'd like to do is use electricity to produce Brown's Gas (H-O-H), separate (scrub) the oxygen from the mixture (easily done with iron filings or steel wool) and somehow add a carbon atom to the mix to make methane gas (CH4). Sounds easy 'nuf! :smile:

The methane produced will then be stored under a water column and be used for either cooking, heating or low-grade internal combustion.

There is an existing process for this named after the guy who discovered it (Sabatuer?) but the process is WAY too complicated. What I (we) are after is something really simple.

Efficiency is not a part of the equation. After all, the energy in this case is basically "free" meaning "no cost" not to be confused with that over-unity business.

I tried posting this on another thread, but in doing that, thinking I had started my own independent thread, somehow I managed to "hijack" an existing thread and things were pretty much downhill from that point.

Anyone got a brilliant idea?


. . . . . Mac
 

Answers and Replies

  • #2
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Why not just stick with the H2?
 
  • #3
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RocketSci5KN

I like your name. My second son is actually a true "rocket scientist". He's a Ph.D. aeronautical engineer.

Hydrogen is too hard to contain as well as too hard to control when burning with a naturally-aspirated flame like on a stove. The only easy way to contain it is under water or oil and if left as Brown's Gas, it is explosive. At a mere 4% oxidation, hydrogen "burns" as fast or faster than primer cord!

Methane is our first alternate gas of choice, since it has but one carbon atom and it would seem to be an easier build than making something like propane, the next in line.


. . . . . Mac
 
  • #4
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Just a thought but you might be intersted in building a gasification device then add the Fischer-Tropsch process catalyzed with nickel if i recall to produce methane and water.

It requires heat, and biomass, and a bit of metalwork. A rough example of a biomass chamber would be a double wall boiler, where the outer container is burning wood and the exhaust is fed through the center chamber. Through heat alone the wood or any type of biomass is broken into volatiles and char that are combustible. But the outer chamber is also providing steam and carbon dioxide- the result is the volatiles and char become mostly carbon monoxide and hydrogen gas (around 80% of the mass, the rest becomes steam and ash).

Of course carbon monoxide is COMBUSTIBLE AND TOXIC so ventilation should certainly be a important issue, but this mixture often called syngas can be further refined into liquid or gaseous hydrocarbons through the Fischer-Tropsch process, nickel will catalyze the following reaction CO (carbon monoxide) + 3H2 = CH4 (Methane) + H20 (Water)

Also keep in mind iron will catalyze I believe kerosene out of the syngas so the inner chamber and any distillery type exhaust lines of the gasification chamber should be nickel plated to avoid kerosene production.

It might be worth it for you to get a co2 tank and heat water directly into superheated steam mixed with the co2 to heat the innerchamber directly taking care of pyrolysis and gasification quick without wasting any type of fuel in order to start gasification.

Also during WW2 I believe the department of defense released a how-to, to convert gasoline vehicles to run on wood via a 55 gallon drum and some piping to feed syngas directly into the manifold of a running engine (at which point you could shut off the liquid fuel supply and run purely off the fumes) If I did not do a good job describing a gasification chamber that emergency how-to should be able to... if you can find it I know I once did a long time ago :)

Remember to always use proper ventilation methods and I would highly recommend this to be done outdoors and downwind of any nearby residence. And if you get the Co2 please be familiar with what high pressure is and is not (anything over 14 psi is considered high pressure for a reason, IF you do not know why a balloon gets easier to blow up as it increases in size , or why the length of pipe containing a high pressure gas can be any length without compromising overall integrity you are not near ready to tinker with high pressure systems) cause toxic combustible gases are no joke and neither is high pressure.
 
  • #5
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EgadsNo

Using the Fischer-Tropsch process is out! Not interested in the Sabateur process either for the same reason, namely high heat (like 500*F-plus).

Just after a simple way to get 'er done and that may be nothing more than a pipe dream, but I thought I'd toss it out to see if I got any bites. So far, it looks like we're back to using a resistive heating element as a dump load, but then again, that's the way it's been done for a hundred years, so why rock the boat, eh?

Thanks for the safety warning. To ease your mind, I'm a college grad and a plumbing contractor of over 40 years, a welder and so on, so I'm familiar with using gas under pressure.

Thanks for the reply.


. . . . . Mac
 
  • #6
chemisttree
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  • #7
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Well dont know if this will help either- but if you purely are going for energy storage, have you thought about molten salts or something similar? A household thermos stores a higher energy density for longer periods of time then lith-ion batteries (not saying terribly much but never need replacing). I am actually in the midst of that but using zinc and chunks of copper instead of salts with a piece of 325 Mil-T spec 1/4 tube 0.35W that will run smack through with JIC bulkhead connectors. You did express a concern over high heat but for me that would be because you would be mixing an explosive gas with it lol so heat might be ok here.

Only thing that is setting me back is I am still building a custom single stroke steam engine connected to a planetary gear drive that will connect to a crank shaft otherwise i'd tell you how well it works ;) Oh that and my wife keeps spending my hobby money hehe

By the way as for the warning- you certainly seemed like you had your head screwed on right, but this the internet after all, never know who is gonna read this. So if you do more then think about it here is another one, remember that molten nickel will derate the tensile strength of your steam line tube- so make sure the storage chamber is not completely enclosed but I would suggest gooseneck vents to limit air flow.
 
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  • #8
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All I'm after is a quick-and-dirty method to create methane from Brown's Gas; that's all folks!


. . . . . Mac
 
  • #9
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I would have provided links, but I'm not allowed because I have less than 10 posts. You'll just have to search for the keywords as I did to write this response.

There is no *quick and dirty* method. It doesn't even sound easy enough, either. The Fischer–Tropsch Process doesn't sound complicated to me; passing gasses over a Nickel catalyst at temperatures exceeding 300C is only scary because even potentially present Oxygen makes pure Hydrogen scary. If there really were a *quick and dirty* method already known, then I doubt the world's energy systems would work the way they do currently.

On that note (and because I never criticize without also being constructive) and in respect to your given conditions (excess electricity and available raw materials), I would suggest looking into methanogenesis via Archaea microorganisms (see also Electromethanogenesis). (I assume the Brown's Gas is to obtain pure Hydrogen and its exhaustion is not actually necessary to your goal, so I'm going to ignore it.) These microbes are not hard to find, as one study found them in the feces of Five out of Nine adults. Another study found that passing an electric current through a nutritious/anearobic medium impregnated with Archaeas capable of methanogenesis, produced not only a circuit with lower resistance but huge quantities of methane gas. They were looking to produce Hydrogen, but were pleasantly surprised when they thought about how much better methane would be to use and transport.

Hopefully my assertion that "a lack of occurance is proof of impossibility" is flawed logic based on current observations. Who knows, with this dirty method you might revolutionize the world's energy economy. If I had the facilities and spare time, I certainly would try. I hear that China is.
 
  • #10
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Unless there is a reason that you cannot make separate electrodes and use DC in your electrolysis, you are better off isolating and collecting the hydrogen at the cathode and passing it to an anaerobic bioreactor for methanogenesis. It would be very sensitive to even traces of oxygen, so an iron getter would be useful still. Methanogenesis takes place at the low energy life spectrum and they are consequently slow to populate and establish a good generator. It is well known that the availability of the reduced hydrogen is limiting nutrient, so adding H2 even by incorporating the cathode in the bioreactor makes sense for increasing rates. CO2, bicarbonate, formate and acetate are the typical carbon sources.

Generally biogenic methane will also have CO2, N2, and traces of NH3 and H2S to contend with, so your storage in a water column has to be on the lookout for methanotrophic bacteria which may use iron or sulfate as their oxidant (corrosion is the worst problem here) and consume your hard won methane (or worse destroy your containment vessel).
 
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  • #11
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This is just a thought, when doing sputtering, Ionized gas is used to cause a "rain"
of atoms on whatever is sitting on the cathode. The atoms come from the anode.
Many gasses are used based on the desired coating.
I have never thought much about the flowed vent gasses, but vent gasses from the vacuum pump would have some bonding occurring.
So, if we ionize a flow of hydrogen with a carbon anode, the vent gasses might well
be a grab bag of hydrocarbons (think natural gas).
On the surface, I think the Hydrogen should not have ANY oxygen around
when ionized, and precautions for combustible gasses should be taken.
Can anyone think why ionized hydrogen would not readily stick to excited carbon?
Also what dangers might be involved with ionizing a highly reactive gas?
Chemistry is not my area, I was just wondering if this might be practical.
 

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