Biogas use

Bioreactor technology accelerates biogas production and concentrates this production in a shorter period of time: this has a certain advantage when the biogas is to be used. Nevertheless, whether used or simply flared, overproduction due to leachate recirculation must be quantified in order to properly scale LFG recovering networks and energy recovery units. Several predictive models of biogas production exist for conventional landfills but their long-term validity has yet to be established.

In addition, these models must be adapted to be applied to Bioreactors, which require, among other things, a better understanding of waste degradation kinetics.

With Bioreactor technology, conventional landfill structures are generally reinforced and degradation products used. The leachate is reused to provide the microorganisms the environment necessary for optimal waste degradation. The leachate drainage system is a key Bioreactor structure and it must be scaled to respond to the specifics of the process. The gas is used to produce energy. It is thus desirable to collect the maximum amount of gas. The exercise is complicated because the moisture added to the system to encourage degradation contributes to a reduction in the porosity accessible for gas transfer. The system must be reinforced and consideration made for pressure distributions within the waste mass.