LAMBDA-OCHC (Biological Filter)
Biological methane oxidation represents one solution to treating landfill gas with methane contents below 20 %. In this process, the methane available is converted into CO2 and H2O by methanotrophic bacteria under the presence of oxygen. The reaction results in a gain in energy which is used by the bacteria for metabolic activities and to form new cells. The landfill gas is introduced into the lower section of the filter undiluted and the amount of air required is distributed over three air supply levels with different flow rates in this innovative OCHC biofilter system. Thus every point in the filter has only the amount of oxygen required for the biological methane oxidation. The retention time is therefore optimised and the flow rate of inert gases (particularly nitrogen) is minimised.
The amount of air introduced is primarily adjusted to the biological requirement which, including a safety margin, leads to a ratio of approx. 2.5:1 of O2 to CH4. The methane content decreases while the lean gas passes through the filter due to the biological decomposition and due to dilution with the air introduced into the air supply levels. The distribution of the air at the levels is thus adjusted to the upwardly decreasing methane concentration. Thus the conditions at every point in the filter are adjusted to the optimum for the bacteria and the filter material is utilised to the maximum.
- Low air requirement
- Optimum utilisation of filter volume
- Low energy consumption
- Easy adaption to varying methane concentrations
- Modular filter system for adaption to varying gas flows
- No production of nitrous oxide and carbon monoxide
- Filter change possible when full, with multilift truck