Different Ways to Produce Methane
There are two ways to produce methane. You can use animal manure, which is most
useful if you live on a farm. You can also use the gas produced by the rotting
waste in a landfill. Both ways require an anaerobic environment (no oxygen),
hence the name anaerobic digester.
When you use manure to make methane, you have several choices of what type of
digester you want to use: a Covered Lagoon, a Complete Mix, or a Plug Flow. Usually
the decision is based on what kind of manure you are dealing with and where you
live, and stuff like that: the amount of solids in the manure, the climate of
the place in which the digester will be, the amount of money you are willing
to invest, and how much time you are willing to commit to the project. The amount
of solids in the manure is usually based upon the animal it came from: cows have
about nine percent solids in their manure, so you would use a complete mix or
a covered lagoon, pig manure is about twelve percent solids, so you would use
a covered lagoon, poultry have about twenty- five percent solids in their manure,
so you would use a plug flow, and horse manure is about twenty percents solids,
so you would use a plug flow. The type of digester also depends on the climate
of the location of the digester. Covered Lagoon digesters are not heated, so
they should be used in warm climates, but Complete Mix and Plug Flow digesters
are heated, so they can be used anywhere. Strangely enough, the cost of the digester
can be another factor in the decision of which digester to use. Covered Lagoons
tend to be the least expensive, but that may be because they are not heated,
making them unsuitable for some colder climates. The Complete Mix and the Plug
Flows are about the same price, because they are both heated. Finally, all of
the digesters need a long time commitment, so you can even out the money spent
on the digester to the money made from it.
When you are using rotting wastes to create methane, you get it from a landfill.
They stick a tube down into the landfill, and then bring it back up and quickly
seal it. The tube now has methane in it that the waste in the landfill produced,
which they can burn and create energy from. In some third-world countries,
small villages have their own landfill that they can recover methane from and
burn
to create energy, and they use the energy generated to help the whole village
cook! It’s a very smart, environmentally friendly way of making energy!
Whether you are using animal manure or compost, they both go to the same place
after production. If there is no need for energy at the time, the gas goes into
storage tanks. If there is no place to keep the gas, it can be burned and released,
and no harm is caused. If there is a need for energy, the methane is burned to
heat water. The steam from the heated water is used to turn the turbines of an
electric generator. That produces electricity, which goes by power lines to our
homes!
Both ways to produce methane- animal manure and compost- are equally efficient and beneficial, but which one to use is up to you.