Decomposing garbage produces methane, which can be used to produce heat or electricity. Landfills, which are filled with rotting garbage, are reliable sources of methane.
Despite the fact that methane can be used as an energy source, landfills typically flare off the methane they produce. The amount of methane produced is too small to make energy production worthwhile.
However, a new process innovated by Russell Chianelli, Ph.D., a chemistry professor at The University of Texas at El Paso, may help landfills to profit from their methane production.
Methane is produced when microorganisms feed on the rotting waste. In order to increase methane production, those microorganisms need to be provided with more food. This does not mean increasing the amount of garbage placed in landfills. Instead, Chianelli proposes capturing and recycling the exhaust gas that is produced from generating electricity with landfill methane.
“The gas can be used to heat the landfill and to provide additional moisture — conditions that can boost the landfill’s overall methane production,” explains Science Daily. “Carbon dioxide found within the captured exhaust gas will also release additional methane once recycled within the landfill.”
Exhaust gas can be used to cultivate an algae. A portion of this algae can be inserted into the landfill to increase the methane output. The remainder of the algae can be used to produce biodiesel fuels.
Chianelli’s processes is a cycle which feeds itself. As more methane is converted to electricity, more exhaust gas is produced. As more exhaust gas is produced, the landfill can be made more warm and moist. As the landfill environment becomes more humid, the microorganisms are able to produce more methane. As more methane is produced, landfills are able to produce more electricity.
“What’s great about this is that it’s a clean process,” Chianelli said. “Nothing goes to waste; it’s a zero-discharge system.”