Size-Resolved Particle Number Emission Patterns under Real-World Driving Conditions Using Positive Matrix Factorization

Abstract

A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source apportionment by Positive Matrix Factorization (PMF) was carried out to interpret the real-world driving conditions. Three emission patterns were identified: (F1) cruise conditions, with medium-high speeds, contributing in this circuit with 60% of total particle number and a particle size distribution dominated by particles >52 nm and around 60 nm; (F2) transient conditions, stop-and-go conditions at medium-high speed, contributing with 25% of the particle number and mainly emitting particles in the nucleation mode; and (F3) creep-idle conditions, representing traffic congestion and frequent idling periods, contributing with 14% to the total particle number and with particles in the nucleation mode (<29.4 nm) and around 98 nm. We suggest potential approaches to reduce particle number emissions depending on particle size and driving conditions. Differences between real-world emission patterns and regulatory cycles (NEDC) are also presented, which evidence that detecting particle number emissions <40 nm is only possible under real-world driving conditions.

The characterisation of diesel exhaust particles – composition, size distribution and partitioning

“…[19][20][21] The size distribution of diesel PM has been extensively studied. 9,[21][22][23][24][25][26][27] The majority of the particle mass exists in the 100 -300 nm diameter range (accumulation mode) and is where the carbonaceous agglomerates and associated adsorbed materials are found. Approximately 1 -20% of the particle mass and >90 % of the particle number exists in the 5 -50 nm diameter range (nucleation mode) and is where the volatile organic and sulphur containing compounds that form during exhaust dilution and cooling are assumed to reside.…”

Experimental Investigation on Emissions Characteristics from Urban Bus Fueled with Diesel, Biodiesel and an Oxygenated Additive from Residual Glycerin from Biodiesel Production

“…The control of thermodynamic properties of the sample prevents particle nucleation from the volatile compounds present in the exhaust gas. The dilution system and particle sampling has been widely demonstrated and illustrated by other authors [25][26][27] and in previous publications of the authors [28,29]. An OBS 2200 (HORIBA Inc., Kyoto, Japan) portable emissions measurement system (PEMS) was used to measure the pollutants concentrations (CO, CO 2 , THC and NO x ) in the exhaust gas.…”

Zone of influence for particle number concentrations at signalised traffic intersections

“…Receptor models such as PMF are mostly applied to ambient particle chemical Cite this article as: Goel, A., Kumar, P., 2015 found to be related to known physical sources (Domínguez-Sáez et al, 2012;Gupta et al, 2012;Hopke, 2000). Identified factors were tentatively assigned to the potential sources based on the following information: (i) comparison of factor specific PNDs profile reported in this study with those available in literature (Figure 5a-d ; Table 10),…”

“…Robustness of the results was further confirmed based on similarity in factor specific PND profiles for the whole route as well as at four different types of TIs (Figure 5f-x). After factor identification, the contribution of each factor to total PNCs was calculated using multiple linear regressions (Domínguez-Sáez et al, 2012).…”