Landfill Gas to Energy (LFGTE) projects seem like a very logical one to pursue..take a waste material and turn it into energy, then sell it for money. However, one of the major concerns that is holding back many landfill from rushing to support this idea is capital recovery. Installing a turbine for electricity generation (or pipes for selling methane directly) is not a small investment. If a project is not sized properly, there’s the risk that there won’t be sufficient methane and hence revenue to support the LFGTE project. A popular tool is the LandGEM model which uses a first-order decomposition rate to estimate annual emissions. It is extremely important to pick the two input parameters, methane yield and decay rate, very carefully. The methane yield is dependent on the waste composition. Decay rate is based primarily on environmental factors. Traditionally, these factors were derived based on laboratory experiments. However, it’s difficult for this kind of research to take into consideration environmental factors that could affect methane generation, such as atmosphere pressure, humidity, temperature, and etc.
There are proposals now to collect data in the field and to derive a model of landfill gas generation stochastically. Such model would create a great check and balance with the existing LandGEM model to predict landfill gas generation. Having better resolution of a landfill’s gas production may also help landfill managers better tune the wellheads for methane extraction. We’ll be blogging more about research related to this concept hereon!