An examination of fugitive methane emissions and combustion of ultra-lean mixtures within gas turbines

Natural gas is an environmentally friendly fuel, yet its emissions have received much attention with growing concerns for its contribution to global warming. The reduction of fugitive methane emissions from industrial installations is included in the ever increasing efforts to attain sustainable atmospheric greenhouse gas concentrations.;Several sources of natural gas emissions from transmission operations have proven difficult to avoid. One such source is pipeline compressor dry gas seal leakage.;The present contribution examines the potential of reducing these emissions by allowing seal leakage to be introduced into the intake air of a typical gas turbine compressor drive. Combustion of the resulting ultra lean methane-air mixture is evaluated analytically and through experimental determination of the survival of the ingested methane.;It is shown that such measures can convert the fugitive gas at a thermal utilization efficiency of around 73% and an avoidance efficiency of around 81%.