Can a septic tank be used for cooking with methane gas?

Question

if yes, how could I make a simple connection?

Answer 1

Not an ordinary septic tank.  There are methane producing digesters that are designed to produce greater quantities of fuel gas from bathroom wastes and other forms of compost.

Try an internet search on "methane digester."

Answer 2

In theory, yes.  Methane is a product of anaerobic digestion.  But you'd need either a way to collect and store it, or a use for a very small continuous supply, perhaps for heating water.  The place to try to capture it on a septic tank what wasn't designed for methane capture would be at the top of the first chamber, near the manhole.  The filler pipe is sometimes below the water's surface, so just accessing the sewer pipe might not work.  It would be tricky to make a hole for gas extraction without causing structural weakness.

Humans produce much less useful manure because they are very efficient at extracting nutrients from food, especially meat.  Cattle and horses need to eat a lot of grass to nourish themselves, and most of what they eat just passes on through.  That's why digesters have found application on farms and stables.

Answer 3

No

You don't get enough methane (either volume or pressure) to run a consistent flame.

Answer 4

ewwwww!

Answer 5

No!  The gas is of unknown concentration and the tank is not calibrated for the pressure required to burn the gas as a fuel.  You could very easily blow up your septic tank if you tried.