Using Unmanned Aerial Systems (UAS – Drones) to Measure NOX Emissions from Stationary Sources

Overview:

The testing of emissions from stationary sources generally involves a field crew having to work on an elevated work platform, scaffold or boom-lift. Source testing involves fragile and heavy equipment that has to be raised from the ground to the elevated platform, often in inclement weather. To minimize the hazard to employees involved in source testing, The Dow Chemical Company and Montrose Air Quality Services LLC are evaluating the use of Unmanned Aerial Systems (UAS – Drones) for the measurement of source emissions.

A comparison test using a UAS was conducted at the Dow Chemical Company facility located in St. Charles, Louisiana. The Dow Chemical Company flew their DJI Matrice 600 UAS equipped with EPA’s Kolibri sensor/sampler attached to the undercarriage. Sampling was conducted by flying the UAS downwind into the plume of the stack. The target pollutants were nitrogen oxide (NO) and nitrogen dioxide (NO2). Carbon as carbon dioxide (CO2) and carbon monoxide (CO) were also measured on the UAS to enable emission factor calculations using the carbon balance method. Emission factors were calculated for the nitrogen species emissions (NO and NO2). The results determined by the UAS were compared to EPA Reference Methods conducted at the same time and also compared to the facility’s Continuous Emissions Monitoring System (CEMS) results. This paper will present the findings of the comparison study and make recommendations for further potential development of an Alternative Test Method.