181 Coupled Model and Simulation of Gas Generation and Transport in Landfill under Non-Isothermal Condition

Based on the theory of mechanics of porous seepage and thermodynamics, from the non-isothermal point of view, a coupled heat and mass transfer numerical model describing the generation and migration of contaminant gas within landfill is established. The results of simulation show that due to the imbalance of heat generation in landfill, there is a non-uniform distribution of temperature which causes temperature gradient that has significant impacts on spatial distribution and temporal change of contaminant gas within landfill. This coupling model is getting closer to the reality of landfill site with more veracity on simulation and prediction of pressure variation of contaminant gas and temperature distribution. The model could be utilized for investigating gas generation and transport in landfill, and the analysis on pressure distribution under the non-isothermal condition is also significant to designing of the LFG recovery systems and liner systems.