How is Methane Gas good for the system?
Methane, which is the product of anaerobic bacteria consuming the organic materials in the liquid waste, is a gas much like natural gas. It is produced in the environment all the time from any decaying matter. The difference here is that we capture it in a container so that we can use it rather than let it fly off into the atmosphere. The best use for the gas is to burn it to make heat. In a very small system, such as used in developing countries or in remote areas, the gas is used for cooking gas for one or more families. In larger systems it can be burned to heat barns, homes, greenhouses, etc. The next best use for the methane is to make steam or hot water. This is very useful in any situation where cleanliness is important of where steam is a part of the production process, usually in industrial settings.
The most interesting use though is to run a diesel engine to make power or to produce electricity. Very little needs to be done to a standard diesel motor to make it run on methane the same way it could run on natural gas. Methane is tough to compress so you could not run your car on it but you can run a stationary engine. Large methane digesters, such as covered hog lagoons, produce enough gas to make significant amounts of electricity. The entire electrical needs of a hog farm or dairy could be met from this source and surplus be available for sale. All from using the waste form the farms in an enclosed container so that the methane is captured.
So, the short answer to your question is, that the methane can be used to heat the water for your fish or to heat the greenhouse. It can make electricity or it can make other stationary power.
Cornelius A. Van Milligen
Iowa Protein Inc.
2725 Russell Rd
Utica, Kentucky 42376
This from a hydroponics/aquaponics list I receive.
Offered by Stan.