A Numerical Model for Methane Production in Managed Sanitary Landfills

Abstract

A mathematical model for the production and transport of biogenic gases in a landfill is developed based on earlier work on the Mountain View Landfill Project in California. The present model incorporates biokinetic model equations for the microbial landfill ecosystems dynamics in a multi-layer, time-dependent gas flow and production model. It is based on first principles of the physics, chemistry, and microbiological processes controlling the production and transport of biogenic gases in a porous media context such as a landfill. The model includes chemical/biokinetic feedback loops for chemical parameter influence on microbiological rate processes. The resulting integrated biokinetic/gas transport model is based on the first principles governing the biokinetics of municipal landfill environment, and the physics of gas-migration. The model was calibrated and verified using approximately 4 years of methane production data from the Mountain View Controlled Landfill Project. Hydrolysis rate appears to be the most sensitive parameter controlling gas generation production. The model can be used to predict the rate and total production of methane in a landfill.