Hi Hendrik,

I agree. A typical home septic tank would not produce enough methane to be feasible I would think.

If one lived next to a landfill you could probably insert a pipe and get great results. Might be a good idea to clear it with the landfill owner in advance though.

What a clever idea. I, of course, have no idea of the practicality of such an effort. Perhaps there are methane boosting microbial additives?

I have heard of enclosed pig sheds that do a similar thing. Collect the washings into a pit and collect the gas into a small gasometer from which it is used to heat the pig shed

There is a fairly simple method but requires some space. But if you septic you may have space?

Dig a hole 15' x 15' x 6' line bottom with straw. Put 1500 gallon water tank with top hatch approx 15" opening in middle of hole.

Fill tank with soft wood chips that have already soaked in water for 70-80 days and add water to fill tank 2/3's. Wrap hi-temp water hose around tank with each end attached to heat exchanger for house. Vent tank for methane capture into inner tubes then pass into compressor.

Layer soft wood chips and various compost materials in hole douse with water intermittently and around tank to approximate dimension 16' H x 28' W x 40' L.

Pump cold water into one end of hose and 130 degree water will come out other end for heat home about 15 months.

Will ferment in tank and produce methane you run in your car or for generator.

Then you have about 40,000 to 50,000 lbs of humus to sell.

Re: Typically each home just vents the methane through the roof....................

NO ! The vents through the roof are there to prevent syphoning water out of the traps in the drain lines. Traps prevent the gases from the septic system from entering the house. These vents breathe in and out with changes in temperature and atmospheric pressure.

The whole septic system is at atmospheric pressure. To capture the methane gas, you would need to gather the gas in the septic tank. One household would not produce enough gas to hardly maintain a pilot light much less fire off a burner. There are treatment plants who utilize the methane gas to run engines to power pumps, etc................

Years ago, I read an article about a small farm that did this with cow manure. They sank a tank into the ground, them put a slightly smaller tank upside down inside it. The manure went into the larger tank. Methane built up, lifting the smaller tank and providing pressure for distribution. I don't recall how many cows they had, but they ran their home and car.

You will need a odor-free decomposition process, though. All vegitable matter for a starter.

Hi Guest, Look here http://www.motherearthnews.com/Green-Homes/1975-03-01/The-Patch-Whitley-Methane-Generator.aspx for an example of "backyard engineering'.

In India many people use methane stoves which are powered by modified inner tubes filled with a slurry of manure and water. It only takes a few hours in the sun for the inner tube to begin to swell with methane. The modification to the inner tube consists of replacing the normal air valve with a larger cap/valve arrangement. The cap allows for easy filling and cleaning. The tire valve installed in the cap allows one to attach a hose to the stove.

Andy Germany may be able to find some photos of German vehicles operating with large methane filled bags on top. One photo I particularly remember from years ago is that of a large bus with a methane bag covering the entire length of the roof. A friend of mine who spent a terrifying childhood in Germany during the second world war said they had a methane generator in the basement of their house. The methane was used to heat the house when coal was unavailable.

I think you've found an interesting topic. Please join CR4. It costs nothing and enrollment is incredibly easy. You'll find like minds and share in the often brilliant repartee which is both entertaining and informative.

And yet other times utterly ridiculous!

cr3

There are quite a few methane producing digester designs in developing countries, needing the raw materials from a few cows. The fermentation process is quite temperature dependent (the more, the higher, the merrier). Just like in beermaking, over a certain mass it sets its own temperature, as the bacteria do not like approaching 100 celsius, and activity drops.

Whatever else you do, make it sure, that the whole production occurs at a slight overpressure, thereby excluding any chance of air intrusion. This story illustrates why: when I was young, we used an artesian well 500+meters deep, where the water came up under its own pressure, steadily fizzing natural gas. Before using the well, a lit match was thrown into it, usually producing a flash and resounding boom. It is undesirable in an enclosed digester. So, no blower, no gas pump, I would not trust them.

Methane is collected, among other gases, at municipal waste water treatment works and this mixture is referred to as "biogas". At a major municipal works the gas is used as fuel. The fuel is used to produce process heat and any surplus is used to generate electricity, some of which would be used on the works and the rest exported to the local grid.

A major works does, of course, have the dual drivers of economy of scale and of odour-nuisance abatement.

Though technically feasible it is unlikely that the investment in such a facility for single-home domestic use would ever achieve a viable payback. Which is sort-of-why examples of such schemes are as rare as the biogas from rocking horse droppings...

Back in the socialist days the Chinese government provided farmers with the hardware to produce methane from pig manure.

Note. South of Lakeland, Florida there is a huge feed lot for cattle. The owner estimated that he could produce enough electricity to power Lakeland. Nothing was ever done about his suggestion.

ok, here is the deal. I run my house with methane (6-8 hours a day). I am not going to tell you how to do it, because it took me 3 years to get it to work... but I will say this.

1. you don't need cow crap to make methane

2. the septic tank is the wrong way to go.

3. the investment needed will pay for itself in 2 years

4. simple home depot material will work.

The use of old knowledge and new technology is the key. I'm sorry I cant state the "what's and how's" but people need to work for what they achieve.

But, just so we are clear... It's not just possible, its a reality. Just not to people that don't want to try. I hate liberal socializm and giving things to people does not fix anything.

Hello,, Im in Hong kong,Im always seeing in the paper, About , Tibet and other outlying places in China, Where more then 10,000 tibetens are useing, Methane pits about the size 1.5 meters by 1.5meter by 1.5 meters deep,A house hold of 4-5 people can produce enough methane from household trash,and probably crap too. to power their lights and the gas for cooking, Average cost is 400 us dollars, for these home pits, and the governmant is acctually helping to pay for the building of these. Im trying to get plans or info on the hows and whats, Any one have some info please let me know.. Would like to help some friends in 3rd world countries to do this,

Richard Cook,

Ok you got my attention. I am trying to find a way to do just this sort of thing so I can use left over vegitation from my home grown food from my aquaculture process. I also would like to avoid totalitarianism, and socialism. I swore an oath to defend the Constitution against all enimies forign and domestic.

I think this would be fine. My cousin made bio-gas in India (his father was a missionary). They used a big oil drum filled with any organic, and then sunk a small drum into the top and right into the organic. over time in warmish weather, the top tank wouldlrise out of the organic (as it filled with gas). When 2/3rds up, they would but a large weight on it (few bricks) to pressure it slightly and then tap the gas for cooking (small propane type stove).

I would guess a septic tank would be at least as good (it is larger so should produce more gas). methane is much more damageing to the environment than CO2 (I think 5 or 10 X) so using it for fuel would help in two ways, one to convert the methane to CO2 and two to use a renewable resource rather than a fossil fuel which adds CO2 to the environment rather than recycling it.

jef