Electron Microscopy Investigation of Particulate Matter from a Dual Fuel Engine

Abstract

The particulate matter (PM) of a dual fuel engine was characterized in size, morphology and fractal geometry by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Particulate samples were collected from the diluted exhaust of the engine operated on diesel fuel, natural gas (NG) and synthetic biogas. The engine operating condition was kept the same to compare the results between diesel and dual fuel PM. SEM images yielded agglomerate number, size distributions and a shape descriptor. TEM was used to investigate the primary particle size distribution in agglomerates and the fractal dimensions of the sampled PM. Long chainlike PM agglomerates appeared for the diesel high load condition, whereas PM agglomerates for dual fueling were found to be smaller in size and with more spherical shapes. All of the measured PM appeared to have a bi-modal number size distribution irrespective of engine fueling condition. The average primary particle diameter increased for dual fuel PM (ranging from 26.9 to 29.5 nm) compared to diesel PM (26.4 nm). The average diameter tended to increase with the introduction of CO 2 in the gaseous fuel. PM fractal dimensions were in the range from 1.69 to 1.88 for different PM samples. Higher fractal dimensions (from 1.73 to 1.88) were obtained for dual fuel PM compared to diesel (high load) PM (1.69). This finding also implies that diesel PM are more chainlike and elongated compared to the PM measured for dual fueling conditions. The very different engine fueling conditions used here give valuable understanding of the formation processes of PM.

Emissions from a Diesel Engine using Fe-based Fuel Additives and a Sintered Metal Filtration System

“…5a). This is in general agreement with results previously reported in the literature for aerosols emitted by diesel engines (Park et al , 2004; Mathis et al , 2005; Lapuerta et al , 2007; Mustafi and Raine, 2009). The general morphology of the EOut aerosols was not discernibly affected by the additives and engine operating conditions.…”

“…(2006) [25 nm], Neer and Koylu (2006) [28–34 nm], Lapuerta et al (2007) [18–30 nm], and Mustafi and Raine (2009) [25–30 nm]. In all cases, the mean size and number of primary particles were equal or greater for I100 than for I50 conditions.…”

A Potential Soot Mass Determination Method from Resistivity Measurement of Thermophoretically Deposited Soot

“…The fact that both effective density (at each mobility size) and primary particles size is similar for the three cases suggests also that the morphology at a given mobility diameter is similar between the three cases. Lee et al (2002), Mustafi andRaine (2009), andPark et al (2004) investigated the structural properties of diesel soot and mentioned that the mean primary particle diameter ranged from (2007) and Burtscher (2005) showed that the engine design, operating conditions, and lube oil influence the properties of PM emissions. In general, a somewhat larger primary particle size range was found from different diesel engines, compared to diffusion flame generators.…”

Petrodiesel and waste grease biodiesel (B20) emission particles at a rural recycling center: characterization and effects on lung epithelial cells and macrophages

“…The number of primary particles per agglomerate, N, was calculated using Equation 2, where K a represents an empirical constant and α represents an empirical coefficient (Oh and Sorensen 1997; Mustafi and Raine 2009). $$N=K_{\alpha }{\left(\frac{A_c}{A_p}\right)}^{\alpha }$$…”

“…For this study, values of 1.35 and 1.1 were selected for K a and α, respectively, based on literature values for diesel engine operation at conditions other than high fueling/heavy load and considering the overlap of the primary particle spheres in the typical agglomerate (Oh and Sorensen 1997; Mustafi and Raine 2009). After N was determined per Equation 2, the fractal dimension, D fL , was calculated by solving for the slope of the ln (N) versus ln (L max /d p ) plot (Mustafi and Raine 2009).…”