Methane - Biodigesters?

[grundle]

Anyone pondered, or actually made one of these? I have considered converting my car to run of natural gas/methane/liquid propane and gasoline. In conjunction with a methane digester you could effectively create your own fuel from your own feces.

It is a pretty gross idea, but heck if I don't have to pay for gasoline I'll do anything. Granted the more animals you have the more effictive this will be, but I believe you can also use plant products. The only catch is you would have to clean out the digester more since plants leave more leftovers after digestion is complete. For anyone interested in building one, here is a decent DIY.

http://www.ruralcostarica.com/biodigester.html?gclid=CK-1_Pmtl5MCFREEIwodHhWhSw

I may try this sooner (or later)

[Rick]

Mechanic: "Uh, Mr. Grundle? What is this black sludge stuff in your engine?"
Grundle: "Sh**."
Mechanic: "What? You can't do that. Oh, man. I got it on me. That's it. Your warranty is voided!"

[grundle]

Wait you aren't supposed to pour the poo directly into the gas tank?

[Rick]

The first part of genius is a plan. You've got that down okay. The second part is execution. You need a little bit of work on that one.

[RaymondPeter]

I know I don't post on here much but I thought I might chime in on this topic.

I just snagged a book from my Grandma's house. It's a Reader's Digest book called Back To Basics How to Learn and Enjoy Traditional American Skills. It was printed/copyrighted in 1981 but it's amazing how many things we consider "new" that are talked about in it.

How does this relate to this topic? Page 123 has a drawing and explination of a Methane Digester. The recomend that "To produce usable quantities, a large amount of animal waste is required. (The waste can be partly vegetable matter, but a greater portion of it should be manure; otherwise, a substantial percentage of the gas produced will be cabon dioxide, a product that is useless as a fuel.) For example, to make enough gas to meet ther cooking needs of one family, the manue of one or two horses or cows, or of several hundred chickens, must be in steady supply. For this reason a farm is the best location for a methane digester."

Now I'm not saying you can't do this on your own, but you might not make as much methane as you want/need. Also a menthan digester will produce sludge, so have someplace to put it if you don't already. (It makes an excellent ferilizer.)

One more thing to watch out for... You must keep the methane pure and away from oxygen. Air mixed with methane can be explosive. (Insert fart jokes now.)

[Rick]

It's only explosive between 5-15% when mixed with air. Higher concentrations burn. Another concern above 15% is the possibility of asphyxiation due to lack of oxygen.

[grundle]

Another thing that I was able to learn about this.

Apparently to be useful in a car the gas must first be cleansed from H2S (hydrogen sulfide). It also must be able to be compressed, and do to the chemistry of the gas it takes more energy to compress than regular natural gas. I believe it requires a higher pressure, and also during pressurization heat must be removed from the gas (generated from the pressurization). This of course means more energy needs to be added to the system before you get the end product that you desire.

Still, I am not daunted by this. Even if it means I could only use methane gas for cooking purposes that is okay. Having a ready supply of manure is not so hard when you live on the fringes of the city. Many farmers are happy to give you their excesss poo.

The sludge that you mentioned makes a great fertilizer. For us self-sufficient minded people that will go straight to the garden ;)

[LeaveThisLifeGuy]

so... i'm guessing that if you mess up the stove connection part, you blow yourself up? My carpentry skills are far from getting gas from point A to point B without a leak or worse.

[Rick]

As I see it, you have some options.

1. Get help for a reliable source

http://simplymarvelous.files.wordpress.com/2007/07/horse-fixes-car.jpg

2. Carry the fuel source with you

http://justinsomnia.org/images/horse-in-car.jpg

3. Or modify your plan

http://simplymarvelous.files.wordpress.com/2007/07/horse-drawn-car.jpg

[Omid]

Use Cow Poop.

I think it might be better to use used cooking oil (but the prices of used cooking oil might go up too).

[crashdive123]

Must be getting tired. First read that as use cow poop for cooking oil. Glad I re-read it or I'd have an aversion to eating fried foods.

[grundle]

Use Cow Poop.

I think it might be better to use used cooking oil (but the prices of used cooking oil might go up too).

Cooking oil is an addition to cooking already, not something you use as a fuel for cooking. Ask your mom what she uses cooking oil for and you will realize that you chose the wrong application.

When you have a high gas bill from your gas run stove, the thought of having a free gas-line coming into the house isn't so bad.

[bulrush]

Rick, those pictures are priceless!

[Rick]

Just here to help, my friend.