onboard methane digester for the cook stove

[eamarquardt]

I did a search on methane digester on the net. Lots of information. If I were "in charge" of this project (which I clearly am not) I think I'd do a lot of research first and determine if a small methane digester can accomplish what you're trying to do. Then I'd have a better idea of the materials required and get an idea about how much gas I could produce. Of course, you could always burn the gas in this string.

[eamarquardt]

Natural gas is mostly methane.

You gotta lotta sorting out to do to see if this will fly. Me? Simply put: I dunno!

Cheers,

Gus

[dh]

Our local natural gas company will convert your car to run on natural gas, and install a filling station in your house (For big $$$). I'v heard it was possible to fill a propane bottle with natural gas frome one of these stations with a proper adapter, and run a grill off of it. Maybe building an aparatus like this would be more economical than propane, and more efficiant than poop.

Just a side note, you would probably be more efficient to let the poo dry and burn it than you would be to collect the methane.

[eamarquardt]

Our local natural gas company will convert your car to run on natural gas, and install a filling station in your house (For big $$$). I'v heard it was possible to fill a propane bottle with natural gas frome one of these stations with a proper adapter, and run a grill off of it. Maybe building an aparatus like this would be more economical than propane, and more efficiant than poop.

Just a side note, you would probably be more efficient to let the poo dry and burn it than you would be to collect the methane.

Propane in a tank is pressurized to the point that it is a liquid. The liquid boils and you draw off the gas. Because it is stored as a liquid you can fit a whole bunch of it in a tank. The pressure in the tank is low (around 100 psi).

Natural gas doesn't liquify as easy. It has to be pretty cold to remain as a liquid. Cars (propusion)and yachts (mostly for cooking as methane is lighter than air and therefore safer than propane on a boat) sometimes use natual gas for fuel. As it is compressed it is referred to as Compressed Natural Gas (in the neighborhood of 2000 psi) and is stored in high pressure cylinders like scuba tanks or oxygen bottles.

I don't think that because of the pressure limitation on a propane tank you can store that much methane/natural gas in it.

Natural gas is transported around cities at pretty low pressures. To fill a car's tank you need a compressor driven by probably an electric motor. The compressor will have to put out 2000 psi (a bunch) and that's where the big bucks come in.

Cheers,

Gus