Experiment

To test the principle of methane gas as fuel and to collect data on what types of materials or mixes and temperatures give the best results, do the following:

• Use several 2 or 5 gallon plastic paint buckets with lids. They cost about 4$/each at home depot and have a tight fitting press-on lid.
• Fill with human or animal waste and/or mix with leaves or grass cuttings. Put in enough water to be able to mix it up.
• Cut a hole in the center of the lid so a hose (piece of old garden hose will work) will tightly fit into it. Glue it if necessary so it doesn't leak.
• Run this hose into a large bucket with water in it so the open end of the hose is inside a smaller upside down bucket full of water. As gas is generated it displaces the water in this smaller upside down bucket and the bottom of the bucket will rise out of the water. You can gauge your methane gas production by how fast this bucket rises.
• To keep the mix warm, block the bucket up off the ground with about 3 bricks or wood blocks. Then put a light bulb in the center underneath the bottom of the bucket. By measuring temperature of the mix and adjusting the size of the light bulb or the time it is running one can change the temperature of the mix. One could also use a coffee warmer, an old electric blanket or anything that produces heat.
• From time to time one would need to pick up and slosh the bucket around. How often the slurry would need to be mixed for optimum gas production could then be determined. It would take a number of days to start gas production build to a maximum, then taper off with additional time.

All of this could be plotted against the variables of temperature, what is mixed with what and how often it is sloshed around. Your results would be most interesting.

        
     -----------------------
     | ------------------- |  ---------------
     ||                   ||  |  methane    |
------------             |||  |    gas      |   |
|          |             |||  | ----o ------|   |
|          |             |||  |     o       |   |
|          |             |||  |     o       |   |
| sludge   |             |||--|    || water |---|
| mix      |             |||  |    ||       |   |
|          |             |||  |    ||       |   |
|          |             |||       ||           |
|          |             || ------- |           |
------------             |-----------           |
|  | O  |  |             ------------------------
     ^ Light bulb

Offered by Mike.