Measurements of nitrous oxide and ammonia emissions from diesel automobile under the real-world driving conditions using laser absorption spectrometer

Abstract

Nitrous oxide (N2O) is a greenhouse gas and contributes to ozone depletion, and ammonia (NH3) contributes to the formation of secondary particulate matter. To reduce global warming and particulate matter, the real-world levels of N2O and NH3 emitted from automobiles is required to be examined. However, there are a few studies on the measurements of N2O and NH3 in automobile exhaust under the real-world conditions. In this study, we have measured the real-world emissions of N2O and NH3 from the latest diesel vehicle equipped with an urea-SCR system. N2O was measured by an on-board system using mid-IR laser spectroscopy and NH3 was measured using a sensor-based measurement technique. As a result, NH3 was not emitted, while N2O was emitted intermittently when vehicle was running.