Assessment of Methane Emissions from Gas Distribution Networks in Kogi State

Methane emissions from natural gas distribution networks constitute a significant greenhouse gas concern, given methane's global warming potential of approximately 80 times that of carbon dioxide over a 20-year horizon. This study assesses methane emission levels from the gas distribution network operated in Kogi State, covering pipeline sections, pressure regulation stations, and metering points within the Lokoja and Kabba distribution areas. The research employs a measurement-based emissions assessment methodology, utilising a vehicle-mounted laser methane detection system to survey emission hotspots along the network, complemented by direct measurement of emission rates at identified leak sites using flux enclosure chambers. Survey data are cross-referenced with network maintenance records and historical leak repair logs. The study estimates total annual methane emissions from the studied network segment and calculates their carbon dioxide equivalent impact for inclusion in the state's greenhouse gas inventory. Findings reveal that the highest emission concentrations are associated with poorly sealing above-ground valve packings and aging mechanical meter joints, rather than pipeline body leaks, suggesting that targeted valve and meter maintenance could yield disproportionate emission reductions at low cost. Recommendations include annual mobile methane surveys of the entire network, a priority valve repacking programme for identified high-emitting valves, and adoption of the EPA Natural Gas STAR programme methodology for continuous emission improvement tracking. Keywords: methane emissions, gas distribution, Kogi State, greenhouse gas, leak detection.