Portable laser gas detector systems for landfill CH4 and CO2 monitoring

There has recently been a marked increase in interest in detecting and quantifying emissions of the greenhouse gases (GHG) carbon dioxide (CO2) and methane (CH4) from landfills in North America and Europe. The primary drivers for this increased interest are: new and pending legislation requires demonstrated reductions in GHG emissions; permits to expand existing facilities require more accurate estimates of emissions; financial incentives in the form of emissions trading credits; increased corporate responsibility enabling development of technologies to improve landfill gas capture and minimise GHG emissions.

A major barrier to effective implementation of emissions reduction and trading plans in general is the absence of real emissions measurements with which to establish baselines and confirm reductions. This is especially true for fugitive emissions from area sources such as landfills. Traditional point monitoring technologies are either too laborious, too expensive or provide insufficient coverage to enable cost effective area monitoring. Engineering estimates are very conservative by design and tend to significantly over-estimate emissions. Two new measurement systems based on laser gas detection have been developed in conjunction with industry and government partners to meet these monitoring needs. The operation of these systems is described and field data are presented.