Dr. Stefan Abel (LfU Brandenburg, Germany) presented some technologies and treatments for weak gas degradation.
In order to avoid greenhouse gas emissions by technical gas treatment facilities, a gas capture system has necessarily to be installed on the landfill. The type of the technical gas treatment facility depends on the calorific value (the methane, CH4-content) of the landfill gas. For gas with a CH4 > 35 Vol.% a gas turbine, a gas motor, or a block-type thermal power station can be used. A stirling motor or a Tandem Mixer is capable to convert gas with CH4 > 25 Vol.%. In all cases adjusting the gas quantity and quality from the well by adapting of the valve / blower / compactor is necessary. Temporal storage of gas, e.g. in membrane gas holders, can be an option when CH4 > 40 Vol% and a certain gas flow rate is required to run the motor. All the technologies mentioned above produce energy, which can be further used.
Flares can be applied to burn gas with CH4 > 20 Vol.%, for gas < 20 Vol.% CH4 preheating the air /gas in the flare or the application of additional, calorific gas into the flare is necessary. In this case special C-nox flares (for CH4> 10 Vol.%), fluidized bed combustion (for CH4> 7 Vol.%), flox flameless oxidation methods (for CH4> 3Vol.%), or a regenerative thermal oxidizer (RTO; for CH4> 0.5 Vol.%),) can be used.
In addition to these active treatments of weak gas, also biological methane oxidation can be used.