On-Board Sensor-Based NOx Emissions from Heavy-Duty Diesel Vehicles

• DOI: 10.1021/acs.est.8b07048
• Publication Date: 2019-04-17T18:54:11Z
• Authors: Yi Tan; Paul Henderick; Seungju Yoon; Jorn Herner; Thomas Montes; Kanok Boriboonsomsin; Kent Johnson; George Scora; Daniel Sandez; Thomas D. Durbin
• Keywords: Heavy duty; Selective catalytic reduction

Real-world nitrogen oxides (NOx) emissions were estimated using on-board sensor readings from 72 heavy-duty diesel vehicles (HDDVs) equipped with a Selective Catalytic Reduction (SCR) system in California. The results showed that there large differences between in-use and certification NOx emissions, 12 HDDVs emitting more than three times the standard during hot-running idling operations real world. overall conversion efficiencies of SCR on many well below 90% threshold is expected for an efficient system, even when was above optimum operating temperature 250 °C. This could potentially be associated catalyst deterioration some engines. Not-to-Exceed (NTE) requirements currently used by compliance program evaluated data. Valid NTE events covered only 4.2–16.4% engine operation 6.6–34.6% emissions. work shows low cost sensors are convenient tool to monitor real-time, evaluate performance, identify vehicle modes high information can inform programs ensure