Use of an unmanned aircraft system to quantify NO x emissions from a natural gas boiler.

Brian Gullett,Johanna Aurell,Jennifer Richardson,William Mitchell

doi:10.5194/amt-14-975-2021

Abstract

Aerial emission sampling of four natural gas boiler stack plumes was conducted using an unmanned aerial system (UAS) equipped with a lightweight sensor–sampling system (the “Kolibri”) for measurement of nitrogen oxide (NO), and nitrogen dioxide (NO2), carbon dioxide (CO2), and carbon monoxide (CO). Flights (n=22) ranged from 11 to 24min in duration at two different sites. The UAS was maneuvered into the plumes with the aid of real-time CO2 telemetry to the ground operators and, at one location, a second UAS equipped with an infrared–visible camera. Concentrations were collected and recorded at 1Hz. The maximum CO2, CO, NO, and NO2 concentrations in the plume measured were 10000, 7, 27, and 1.5 ppm, respectively. Comparison of the NOx emissions between the stack continuous emission monitoring systems and the UAS–Kolibri for three boiler sets showed an average of 5.6% and 3.5% relative difference for the run-weighted and carbon-weighted average emissions, respectively. To our knowledge, this is the first evidence of the accuracy performance of UAS-based emission factors against a source of known strength.

Highlights

Aerial measurement of plume concentrations is a new field made possible by advances in unmanned aircraft systems (UASs, or “drones”), miniature sensors, computers, and small batteries
unmanned aerial system (UAS)-based emission measurements are suited for area source measurements of fires and can be used to determine emission factors, or the mass amount of a pollutant per unit of source operation, such as the mass of particulate matter (PM) per mass of fuel burned
The UAS–Kolibri team found the stack plumes at both locations using the wind direction and CO2 telemetry data transmitted to the ground operator

Summary

Introduction

Aerial measurement of plume concentrations is a new field made possible by advances in unmanned aircraft systems (UASs, or “drones”), miniature sensors, computers, and small batteries. UAS-based emission measurements are suited for area source measurements of fires and can be used to determine emission factors, or the mass amount of a pollutant per unit of source operation, such as the mass of particulate matter (PM) per mass of fuel (e.g., biomass) burned. These values can be converted into emission rates, such as the mass of pollutant per unit of energy (e.g., g NOx kJ−1). These determinations typically rely on the carbon balance method in which the target pollutant is co-sampled with the major carbon species present, and, with knowledge of the source’s fuel (carbon) composition, the pollutant-to-fuel ratio or an emission rate and/or factor can be calculated

Methods

Results

Conclusion