Landfill Gas Resource Assessment - An Adaptation from Oil and Gas Exploration Technique

Abstract

Landfill Gas (LFG) composed of approximately 50% methane and 50% carbon dioxide is known as one of the Greenhouse Gases (GHGs) that could pollute the environment and contribute to the global warming. In the conventional approach, volume of methane is approximated from its emission using the Intergovernmental Panel on Climate Change (IPCC) 2006 First-order Decay (FOD) model. This model has been formalized as a USEPA landfill gas emission model (LandGEM) in 2005 and IPCC Waste Model in 2006. LandGEM is a Microsoft Excel based software application that uses a first-order decay rate equation to calculate methane and LFG generation. It is the most widely used LFG model and is the industry standard. However, the software requires a number of parameters estimates such as organic content, disposal data and rates, site closure dates, expansion schedules or collection efficiencies and knowledge of waste composition. Inaccuracies in the estimates can result in large errors in predicting future recovery, which could affect the production system. This research evaluate the potential of deploying the volumetric estimation technique in oil and gas exploration to locate methane accumulation location and estimate the volume prior to its emission to the atmosphere on the Air Hitam Landfill as the case study. The gross rock volume is an approximation of the total area covered by the landfill, while porosity and water saturation are simulated estimations. The result gives an approximation of 1.65 billion standard cubic feet (BSCF) of LFG in-place that could generate 25,948 tonnes of methane worth RM6 to RM8 millions of carbon credit and RM55 millions of revenues from electricity sale.