Diesel Engine Exhaust Emission:  Oxidative Behavior and Microstructure of Black Smoke Soot Particulate

Abstract

Soot particulate collected from a Euro III heavy duty diesel engine run under black smoke conditions was investigated using thermogravimetry, transmission electron microscopy, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy. The characterization results are compared with those of commercial carbon black. The onset temperature toward oxidation of the diesel engine soot in 5% O2 is 150 degrees C lower than that for carbon black. The burn out temperature for the diesel engine soot is 60 degrees C lower than that of the carbon black. The soot primary particles exhibit a core-shell structure. The shell of the soot particles consists of homogeneously stacked basic structure units. The commercial carbon lamp black is more graphitized than the diesel engine soot, whereas the diesel engine soot contains more carbon in aromatic nature than the carbon black and is highly surface-functionalized. Our findings reveal that technical carbon black is not a suitable model for the chemistry of the diesel engine soot.

Characterization of Exhaust Particulates from a Dual Fuel Engine by TGA, XPS, and Raman Techniques

“…Similar observations have been noted previously for diesel exhaust particulates or urban aerosols, and for activated carbon (Biniak et al 1997;Albers et al 2000;Hutton and Williams 2000;Collura et al 2005;Müller et al 2006). When comparing between diesel (high) and dual fuel PM samples, the peak is broadened in the latter case (FWHM = 1.0-1.2 compared to 0.78) indicating a less developed graphitic structure in dual fuel PM as suggested by Müller et al (2006). The next dominant peak at BE = 285.47-285.79 eV, is obtained for all PM except the diesel (low) PM sample.…”

“…These elements are mainly observed in diesel engine/vehicle exhaust PM and have been analyzed by various researchers (Albers et al 2000;Hutton and Williams 2000;Collura et al 2005;Müller et al 2006). Curve fits are performed for individual elements for each PM sample using Gaussian/Lorentzian (G/L ratio = 0.5) line shapes as mentioned earlier.…”

“…Spectra collected in the standard format were selected, viewed, and processed using CasaXPS. The peaks were selected basically looking at the general practices that have been observed in the literature for the similar applications as cited here (such as Albers et al 2000;Müller et al 2006). The assignment gave a perfect fit between the original spectrum and the resultant curve.…”

Combustion and emissions characteristics of a dual fuel engine operated on alternative gaseous fuels

“…were described in detail elsewhere in [21]. Compressed NG and CO 2 were mixed in the laboratory to obtain biogas mixtures such as biogas-1 (80% CH 4 & 20% CO 2 ); biogas-2 (67% CH 4 & 33% CO 2 ) and biogas-3 (58% CH 4 & 42% CO 2 ). The total experimental setup can be found in [21].…”

“…In many cases they are preferable due to their high thermal efficiency, and low regulated emissions of unburned hydrocarbons (HC), carbon monoxide (CO) and carbon dioxide (CO 2 ) compared to those of spark ignition engines [1,2]. The other important advantage of diesel engines is that they can operate at higher compression ratios, which permit them to use low energy-content alternative fuels such as biogas.…”